Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Electronic Resource  (775)
  • 1990-1994  (775)
  • 1980-1984
  • 1992  (775)
  • Computational Chemistry and Molecular Modeling  (582)
  • Rat  (193)
  • Nuclear reactions
Source
Material
  • Electronic Resource  (775)
Years
  • 1990-1994  (775)
  • 1980-1984
Year
Keywords
  • 101
    Electronic Resource
    Electronic Resource
    Similarities and differences between cholinergic systems in the superior colliculus of guinea pig and rat (1992)
    Springer
    Experimental brain research 90 (1992), S. 291-296 
    Details
    ISSN: 1432-1106
    Keywords: Cholinergic systems ; Acetylcholinesterase ; Choline acetyltransferase ; Superior colliculus ; Guinea pig ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary We studied the distribution of acetylcholinesterase activity and choline acetyltransferase immunoreactivity in the superior colliculus of the guinea pig and the albino rat, using enzyme histochemical and immunohistochemical methods. Choline acetyltransferase-like immunoreactivity was localized in the neuropil throughout the colliculi, but the density of the immunoreactive neuropil varied among layers as well as between species. In the intermediate collicular layers the pattern of choline acetyltransferase immunoreactivity was closely matched by the distribution of acetylcholinesterase activity in guinea pig and rat, confirming our previous findings in the cat. Furthermore, in the guinea pig, but not in the rat, choline acetyltransferase-like immunoreactivity was localized in a prominent population of perikarya of the superficial gray layer.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00227240
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 102
    Electronic Resource
    Electronic Resource
    Coactivation of metabotropic glutamate receptors and of voltage-gated calcium channels induces long-term depression in cerebellar Purkinje cells in vitro (1992)
    Springer
    Experimental brain research 90 (1992), S. 327-331 
    Details
    ISSN: 1432-1106
    Keywords: Synaptic-Plasticity ; Cerebellum ; Metabotropic-glutamate-receptor ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Using an in vitro slice preparation, we studied the effects, on parallel fiber (PF)-mediated EPSPs, of coactivation of metabotropic-glutamate receptors and of voltage-gated calcium (Ca) channels of Purkinje cells (PCs) by bath application of 50 μM trans-1-aminocyclopentyl-1,3-dicarboxylate (trans-ACPD) and by direct depolarization of the cells, respectively. These effects were compared with changes in synaptic efficacy obtained when α-amino-3hydroxy-5-methylisoxalone-4-propionate (AMPA) receptors of PCs were also activated through stimulation of PFs during the pairing protocol, as well as when similar experiments were performed without trans-ACPD in the bath. In a control medium, pairing for 1 min of PF-mediated EPSPs evoked at 1 Hz with Ca spikes evoked by steady depolarization of PCs (n = 13) led to LTD of synaptic transmission in 9 cases whereas for the others EPSPs were not affected. No LTD occurred in 9 out of 10 other cells tested when PF stimulation was omitted during the 1 min period of Ca spike firing of PCs. Bath application of 50 μM trans-ACPD, in conjunction with the same pairing protocol as before (n = 8), led to a significantly larger LTD of PF-mediated EPSPs after washing out of this drug. Moreover, a clearcut LTD of PF-mediated EPSPs was also observed in 5 of the 8 other cells, when PF stimulation was omitted during Ca spike firing in the presence of trans-ACPD. As trans-ACPD alone induced fully reversible depressions of EPSPs, coactivation of metabotropic-glutamate receptors and of voltage-gated Ca channels is therefore likely to be sufficient to induce LTD of PF-mediated EPSPs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00227245
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 103
    Electronic Resource
    Electronic Resource
    Development of parvalbumin immunoreactive neurons in normal and intracranially transplanted retinas in the rat (1992)
    Springer
    Experimental brain research 90 (1992), S. 359-368 
    Details
    ISSN: 1432-1106
    Keywords: Retina ; Transplant ; Parvalbumin ; Immunocytochemistry ; Development ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Retinas from embryonic day 14 Sprague-Dawley rats were transplanted to the midbrain or cerebral cortex of newborn (P0) rats of which the right eye was enucleated at the time of transplantation. Parvalbumin immunoreactive (PV-I) neurons were studied in the developing retinal transplants, and in the remaining retina of the host, as well as in normal retinas. PV-I neurons were identifiable in retinas of normal and host rats from postnatal day 5 (P5) onward, with the PV-I somata primarily in the inner half of the inner nuclear layer and in the ganglion cell layer. An adult-like distribution of PV-I neurons was attained at P35, as judged by cell packing density, intensity of immunostaining, laminar distribution and soma size of subpopulations of PV-I cells. A similar time course of development and distribution of PV-I somata was observed in the retinal transplants, except for some minor differences such as a slight delay in PV-I cells achieving their final distribution. These findings provide evidence that PV-I neurons can survive, differentiate and mature according to pre-determined programmes intrinsic to the retinal tissue following transplantation to a new and foreign environment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00227249
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 104
    Electronic Resource
    Electronic Resource
    Brain cortical tissue levels of noradrenaline and its glycol metabolites: effects of ischemia and postischemic administration of idazoxan (1992)
    Springer
    Experimental brain research 90 (1992), S. 551-556 
    Details
    ISSN: 1432-1106
    Keywords: Brain ischemia ; Idazoxan ; Metabolism ; Noradrenaline ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The brain noradrenaline (NA) system is known to modulate ischemic neuronal damage, and the turnover of NA has been suggested to increase in the early recovery period following cerebral ischemia. Using HPLC and gas chromatography-mass spectrometry we analyzed the tissue levels of NA and its metabolites, 3,4-dihydroxyphenylethyleneglycol (DHPG) and 3-methoxy-4-hydroxyphenylethyleneglycol (MHPG), in rat brain cortex after 10 min of forebrain ischemia followed by 1 h of recirculation. The effect of idazoxan, given in cerebro-pbrotective doses, as a bolus of 0.1 mg·kg-1 immediately after ischemia followed by 10 μg·kg-1·min-1 for 1 h, was also investigated. Ischemia decreased basal NA cortical levels from 384 ng/g tissue in control animals to 214 ng/g, while DHPG increased from 74 to 103 ng/g (+39%) and MHPG from 82 to 154 ng/g (+88%). Conjugated but not free DHPG increased, while both free and conjugated MHPG increased equally. The findings indicate an enhanced postischemic NA turnover with a major proportion of uptake and metabolism occurring extraneuronally, possibly secondary to a saturation of neuronal NA uptake in the postischemic phase. Idazoxan further increased NA turnover, as evidenced by higher postischemic levels of free MHPG and a higher MHPG/NA ratio. A correlation may exist between the protective action of idazoxan and its effect on NA turnover.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00230938
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 105
    Electronic Resource
    Electronic Resource
    Responses of barrel cortex neurons in awake rats and effects of urethane anesthesia (1992)
    Springer
    Experimental brain research 91 (1992), S. 259-272 
    Details
    ISSN: 1432-1106
    Keywords: Vibrissae ; Somatosensory system ; Cortical columns ; Receptive field ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A “barrel” is an interconnected network of layer IV neurons that is an important component of a functional cortical column in the whisker area of the rodent primary somatosensory cortex. The present study was undertaken in order to resolve apparently conflicting findings from single-unit studies of barrel neurons conducted in rats maintained under different anesthetic conditions. Multiunit responses to controlled deflections of mystacial vibrissae were recorded from the whisker/ barrel cortex of awake, undrugged rats, and responses at the same recording site were reexamined after the animal was anesthetized with urethane. In contrast to the awake condition, stimulus-evoked responses under urethane were characterized by a large late component. Such effects were more pronounced for deflections of noncolumnar or “adjacent” whiskers than for the the columnar whisker. Latencies to peak responses were virtually identical for the columnar whisker in awake and urethane states (11.9 vs 11.8 ms) but were considerably longer for adjacent whisker deflections in urethane-anesthetized animals (15.5 vs 29.0 ms). The magnitudes of adjacent whisker responses, relative to the response evoked by the columnar whisker, varied with the laminar location of the recording site in awake but not in urethane-anesthetized animals; in awake rats, receptive fields were clearly smallest in the layer IV barrels. Results in the awake condition confirm those of previous studies conducted in unanesthetized or lightly sedated animals, and data obtained with urethane are comparable to others' results in urethane-anesthetized rats. The former have important implications for how barrel cortex processes information in behaving animals.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00231659
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 106
    Electronic Resource
    Electronic Resource
    Difference in receptive field features of taste neurons in rat granular and dysgranular insular cortices (1992)
    Springer
    Experimental brain research 91 (1992), S. 408-414 
    Details
    ISSN: 1432-1106
    Keywords: Taste ; Cortex ; Receptive fields ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Receptive fields (RFs) of 59 cortical taste neurons (35 in the granular insular area, area GI, 21 in the dysgranular insular area, area DI, and 3 in the agranular insular area, area AI) were identified in the oral cavity of the rat. The fraction of the neurons with RFs in the anterior oral cavity only was significantly larger in area GI (74.3%) than in area DI (42.9%). On the other hand, the fraction of neurons with RFs in both the anterior and posterior oral cavity was larger in area DI (42.9%) than in area GI (11.4%). On the whole, it is suggested that area GI is involved in discrimination of several taste stimuli in the oral cavity, whereas in area DI taste information originating from various regions of the oral cavity is integrated. When neurons were classified according to the best stimulus which most excited the neuron among the four basic tastes, different categories of taste neurons had RFs in different parts of the oral cavity. It is suggested that, in either taste area, different categories of taste neurons are involved in different sorts of taste coding. The majority of neurons in both areas had bilateral RFs. In area GI, neurons with RFs on single subpopulations of taste buds were significantly more numerous at the rostral region of the cortex than at the caudal region. There was no such relation between RF types and cortical localization in area DI. Otherwise, topographic representation of the oral cavity by taste neurons on the cortical surface was not obvious. RF features of taste neurons did not differ across layers in either cortical area.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00227837
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 107
    Electronic Resource
    Electronic Resource
    Differential effects of long-term transplantation on the growth of cortical neurons containing parvalbumin or calbindin (1992)
    Springer
    Experimental brain research 91 (1992), S. 477-483 
    Details
    ISSN: 1432-1106
    Keywords: Transplantation ; Neocortex ; Parvalbumin and calbindin immunocytochemistry ; Numerical density ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Numerical density and morphology of the two main GABAergic neuronal classes, the parvalbumin (PV) and calbindin- (CaBP)-containing nerve cells were investigated in long-term neocortical transplants in rats. It was observed that 4 months after the transplantation both CaBP- and PV-immunoreactive neurons survive and grow in neocortical grafts. However, the numerical density of PV cells decreased to about half of the control value (host cortex), while the density of CaBP-positive cells was 25–60% of that seen in the host cortex, depending on the degree of integration of the graft. The mean diameter of PV neurons rose to double of the control value, while the size of CaBP-positive perikarya did not change. This indicates that GABAergic neurons with hypertrophic perikarya (Bragin et al. 1991a) are identical to PV neurons. On the basis of these qualitative and quantitative morphological data it is concluded that PV- and CaBP-containing GABA cells in the transplant exhibit different sensitivities to transplantation-related structural and functional alterations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00227843
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 108
    Electronic Resource
    Electronic Resource
    Regulatory aspects of nigrostriatal dopaminergic neurons (1992)
    Springer
    Experimental brain research 91 (1992), S. 489-495 
    Details
    ISSN: 1432-1106
    Keywords: Regulation ; Synthesis ; Release ; Dopamine ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In the urethane-anesthetized rat, electrical stimulation (10 Hz, 30 s, 250 μA) of the medial forebrain bundle (MFB), at 20-min intervals over an 8-h period, combined with intracerebral microdialysis in the striatum caused: an undiminished increase in the release of dopamine (DA) with each stimulation episode; a decreased efflux of 3,4-dihydroxyphenylacetic acid (DO-PAC) and 4-hydroxy-3-methoxyphenylacetic acid (HVA) after the first stimulation only; a delayed increased efflux of DOPAC with no change in HVA; and a poststimulation depression of firing of dopaminergic neurons in the substantia nigra (before, 3.1±0.7 Hz; after, 1.9±1.0 Hz; P〈0.05). After the last stimulation episode, the release of DA declined to prestimulation values, while the increased efflux of DOPAC persisted for three more hours. After the infusion of tetrodotoxin (4.0×10-7 M, 1.5 μl, 1.0 μl/min) into the MFB, the basal release of DA was reduced (P〈0.05), while the efflux of DOPAC and HVA was increased (P〈0.05). A model is proposed suggesting that: (1) during increased release of DA in the striatum, the metabolism of DA is decreased; (2) inhibition of nigrostriatal dopaminergic neurons is the usual cause of increased synthesis and metabolism of DA in the striatum; and (3) increased release of DA, and increased synthesis and metabolism of DA in the striatum are not causally linked and are noncoupled processes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00227845
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 109
    Electronic Resource
    Electronic Resource
    Excitation of cutaneous afferent nerve endings in vitro by a combination of inflammatory mediators and conditioning effect of substance P (1992)
    Springer
    Experimental brain research 91 (1992), S. 467-476 
    Details
    ISSN: 1432-1106
    Keywords: Nociceptor ; Bradykinin ; Serotonin ; Substance P ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A broad mixture of inflammatory mediators (“inflammatory soup”) was used to investigate the responsiveness of primary afferents from rat hairy skin in an in vitro skin-saphenous nerve preparation. In addition, a conditioning effect of the tachykinin substance P on chemosensitivity of nociceptors was examined. Inflammatory soup (IS) was made up in synthetic interstitial fluid from bradykinin, serotonin, histamin and prostaglandin E2 (all 10-5 M). In addition, the potassium and the hydrogen ion concentration (7 mM, pH 7.0) and the temperature (39.5°C) were elevated. The latter agents, in a control solution, did not excite nociceptors (n = 5). IS was repeatedly superfused over the receptive fields for 5 min at 10 min intervals; substance P (SP 10-6 and 10-5 M) was applied during the last 5 min of the interval and during the subsequent IS stimulation. IS excited more than 80% of the mechano-heat sensitive (“polymodal”) afferents with slowly conducting nerve fibres (n = 72), but none of the low-threshold mechanoreceptive slow and fast conducting units (n = 17). Slow conducting afferents with high mechanical threshold (n = 35) were weakly, and less frequently (〈20%), driven by IS. A majority, but not all, of the responsive units showed tachyphylaxis upon repeated IS application. None, however, lost its responsiveness completely. Conditioning heat stimulation (32–46.5°C in 20 s) did not enhance the subsequent IS response, which may indicate that sensitizing substances normally released by a noxious heat stimulus were already contained in IS. No sensitization to mechanical (von Frey) or heat stimulation could be established in the period after the IS response had subsided and after the washout was completed, respectively. A short-lived sensitization may have been overlooked under these temporal restrictions. Conditioning SP in 10-5 M but not in 10-6 M concentration significantly increased the IS response of polymodal C fibres, by 58% on average (n = 14). SP did not excite the units. Comparing with previous data, we conclude that there is a significant synergism between inflammatory mediators, acting to induce more intense and more sustained discharge via many nociceptors than single mediators alone could achieve. Conditioning substance P can further enhance this algogenic action. Mechanisms of interaction and relative contributions of single substances remain to be elucidated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00227842
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 110
    Electronic Resource
    Electronic Resource
    Kindling is associated with the formation of novel mossy fibre synapses in the CA3 region (1992)
    Springer
    Experimental brain research 92 (1992), S. 69-78 
    Details
    ISSN: 1432-1106
    Keywords: Kindling ; Reactive sprouting ; Dendritic spines ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A Golgi and electron microscopy study of the hippocampal CA3 region was performed on control and kindled Wistar rats. The observations provide evidence that, in epileptic rats, mossy fibres sprout and establish novel synapses with the basilar dendrites of CA3 pyramidal neurons. These newly-developed synapses showed the typical features of mossy synapses observed in the stratum lucidum, including the appearance of complex giant spines. The morphological changes reported here may represent a histopathological substrate for the epilepsy in the absence of overt signs of a hippocampal lesion.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00230384
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 111
    Electronic Resource
    Electronic Resource
    Projections from fetal neocortical transplants placed in the frontal neocortex of newborn rats. A Phaseolus vulgaris-leucoagglutinin tracing study (1992)
    Springer
    Experimental brain research 92 (1992), S. 299-309 
    Details
    ISSN: 1432-1106
    Keywords: Anterograde axonal tracing ; Brain repair ; Neocortical projections, injury, and transplants ; Phaseolus vulgaris-leucoagglutinin ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Fetal rat neocortex grafted into lesion cavities made in the newborn rat neocortex can exchange multiple axonal connections with the host brain. Most previous studies demonstrating efferent transplant-tohost brain connections have used fluorescent retrograde tracers injected into the host brain (Castro et al. 1985, 1987; Floeter and Jones 1984; O'Leary and Stanfield 1989). Other studies have used anterograde axonal tracing with either tritium-labelled amino acids impregnating the transplant and its efferents (Floeter and Jones 1985) or horseradish peroxidase injected into the transplants (Chang et al. 1984, 1986). In the present study we used the anterograde axonal tracer Phaseolus vulgaris — leucoagglutinin (PHA-L) to examine in detail the course and termination of the efferent neocortical graft fibers. Twenty-six newborn rats had the right frontal cortex forepaw area removed by vacuum aspiration, while anesthetized by hypothermia. A piece of fetal frontal cortex 14–16 embryonic days old (E14–16) was immediately thereafter placed in the lesion, and the recipient rats allowed to survive for 5–7 months. At this time the rats were reoperated under sodium pentobarbital (Nembutal) anesthesia and the transplants iontophoretically injected with PHA-L. Two weeks later the animals were again anesthetized, perfused, and processed for PHA-L immunocytochemistry and routine histology. Analysis of acetylcholinesterase- (AChE) and Nissl-stained sections showed graft survival in 19 of the 26 animals used in this study. When these 19 brains were processed for PHA-L immunocytochemistry, 5 of them were found with certainty to have the PHA-L injection confined to the transplant. Based on these cases PHA-L-reactive fibers arising from labelled transplant neurons were traced into the ipsilateral host neocortex adjacent to the transplant and found to project through the subcortical white matter to the ipsilateral parietal neocortical area 1, and claustrum. Callosal fibers were traced to the contralateral frontal neocortical forelimb and parietal areas. Transplant fibers were also observed to descend through the caudate putamen in the dispersed fiber bundles of the internal capsule to distribute as terminal branches and varicose fibers within the mesencephalic periaqueductal gray, red nucleus, deep mesencephalic nucleus, and intermediate gray of the superior colliculus, as well as in the pontine gray. Similar fibers and terminations were present in the caudate putamen, the reticular, ventrobasal, centrolateral, posterior, and parafascicular thalamic nuclei. On the side contralateral to the transplant, fewer fibers were observed in the caudate putamen, the ventrobasal, centrolateral, and posterior thalamic nuclei, as well as more caudally in the deep mesencephalic nucleus and the intermediate gray of the superior colliculus. Our findings demonstrate that homotopic grafts of fetal rat frontal neocortex can project to the developing host brain in a manner which for most projections corresponds to the normal rat neocortical parietal area 1–2 and forelimb area. The density of these transplant-to-host projections is, however, less than in the normal rat corticofugal pathways.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00227972
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 112
    Electronic Resource
    Electronic Resource
    Pentylenetetrazol-induced seizures in rats: an ontogenetic study (1992)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 346 (1992), S. 588-591 
    Details
    ISSN: 1432-1912
    Keywords: Seizures ; Pentylenetetrazol ; Development ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A quantitative description of motor seizures induced by pentylenetetrazol (PTZ, metrazol) was performed. Seizures were induced by PTZ in doses from 40 to 120 mg/kg s.c. in 477 male albino rats of the Wistar strain 7 to 90 days old. Two patterns of seizures were elicited: minimal, i.e. predominantly clonic seizures of facial and forelimb muscles with preserved righting ability, and major, i.e. generalized tonic-clonic seizures with a loss of righting reflex. Minimal seizures could be reliably elicited since the age of 18 days; the CD50 for these seizures did not significantly differ with age. Major seizures were elicited regularly at all developmental stages studied. Their CD50 did not significantly differ among 7-, 12- and 25-day-old rat pups but the value for 18-day-old rats was smaller and for adult animals larger than for these three age groups.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00169017
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 113
    Electronic Resource
    Electronic Resource
    Convulsive behaviour during alcohol dependence: discrimination between the role of intoxication and withdrawal (1992)
    Springer
    Psychopharmacology 107 (1992), S. 97-102 
    Details
    ISSN: 1432-2072
    Keywords: Alcohol withdrawal ; Intoxication ; Seizures ; Aetiology ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Male Wistar rats were subjected to repeated weekly episodes of 2 days severe alcohol intoxication (intragastric intubation) and 5 days of withdrawal. In half of the animals the withdrawal reaction was attenuated during the first nine weekly episodes by intragastric intubations with phenobarbital. During episodes 10–14 both phenobarbital treated and phenobarbital untreated animals were allowed to develop a withdrawal reaction; all animals were video-recorded during withdrawal and the records were rated blindly for the occurrence of convulsive seizures. The results were analyzed by stepwise logistic analysis of regression including phenobarbital treatment, alcohol dose and intoxication score as explanatory variables for the occurrence of convulsive seizures. The animals that had been in withdrawal during all episodes developed significantly more convulsive seizures compared with animals that had their first nine withdrawal episodes attenuated by phenobarbital. The development of withdrawal seizures depended on repeated episodes of withdrawal, whereas repeated alcohol intoxication per se did not explain the development of seizures. There were no differences between the groups in the severity of the non-convulsive signs of alcohol withdrawal. Thus the development of seizures and the non-convulsive signs of alcohol withdrawal may result from two pathogenetically different mechanisms: 1) seizures from a cumulative kindling-like effect over long time periods and 2) physical signs of alcohol withdrawal may reflect the degree of physical dependence during the most recent drinking bout.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02244972
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 114
    Electronic Resource
    Electronic Resource
    Different neuroleptics show common dose and time dependent effects in quantitative field potential analysis in freely moving rats (1992)
    Springer
    Psychopharmacology 107 (1992), S. 195-202 
    Details
    ISSN: 1432-2072
    Keywords: Neuroleptics ; Rat ; Field potentials ; Telemetry ; Frequency analysis ; Electroencephalogram
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Under the assumption that field potentials recorded from particular brain areas reflect the net balance of neurotransmitter activities, the dose- and time-dependent responses induced by intraperitoneal application of different neuroleptic drugs are quantified by spectral analysis of the electroencephalogram recorded from frontal cortex, hippocampus, striatum and reticular formation. The actions of haloperidol, chlorpromazine, clozapine, prothipendyl and thioridazine in general were characterized by increases of the spectral power in the alpha1 and beta range, at higher dosages also in the theta range. This observed pattern of changes is in line with the neuroleptic induced spectral changes reported in the literature for other animals and man. In the light of the already known effects of other psychoactive drugs on the frequency content of field potentials in the rat, it should now be possible to classify different drugs in terms of their clinical indication. With respect to the type of neurotransmitter control underlying the changes produced by various neuroleptics, it is quite obvious from the comparisons with the respective drug effects that dopamine-D1-receptor controlled transmission is not responsible for this action. On the basis of earlier findings a possible interaction between dopamin-D2 receptor or glutamatergic transmitter control is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02245137
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 115
    Electronic Resource
    Electronic Resource
    Effects of remoxipride, a dopamine D-2 antagonist antipsychotic, on sleep-waking patterns and EEG activity in rats and rabbits (1992)
    Springer
    Psychopharmacology 107 (1992), S. 236-242 
    Details
    ISSN: 1432-2072
    Keywords: Neuroleptics ; Remoxipride ; D-2 antagonists ; Sedation ; EEG activity ; Rat ; Rabbit
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The antipsychotic remoxipride, a selective dopamine D-2 receptor antagonist, was studied for its effects on sleep-waking patterns in the rat and electroencephalographic (EEG) activity in the rabbit. Haloperidol, which has lesser selectivity for D-2 receptors, was used for comparison. In the rat, remoxipride (1–10 mg/kg SC) did not affect either total sleep or non-rapid eye movement (non-REM) sleep. Only REM was slightly reduced by the high dose of 10 mg/kg. Haloperidol (0.1–1 mg/kg PO) enhanced duration of both total sleep and non-REM sleep. In the rabbit, remoxipride (3 and 10 mg/kg IV) induced no significant changes of the EEG power spectrum over 0.1–38.5 Hz or individual frequency bands. In both cortex and hippocampus the drug did not alter the arousal response to acoustic sensory stimuli. Plasma concentration of remoxipride 10 mg/kg IV in rabbits declined biexponentially and was 4 and 2 µmol/1 at 30 min and 1 h, respectively. Haloperidol (0.3 and 1 mg/kg) slowed down the EEG activity, enhanced the power spectrum of the cortical and hippocampal activity, and significantly reduced the duration of arousal induced by sensory stimuli. The results indicate that, unlike haloperidol, remoxipride has weak or no sedative effects. The data also provide support to the notion that D-2 receptors are not involved in the regulation of states of sleep and sedation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02245143
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 116
    Electronic Resource
    Electronic Resource
    Like diazepam, CL 218,872, a selective ligand for the benzodiazepine ω1 receptor subtype, impairs place learning in the Morris water maze (1992)
    Springer
    Psychopharmacology 107 (1992), S. 347-351 
    Details
    ISSN: 1432-2072
    Keywords: CL 218,872 ; Diazepam ; Triazolopyridazine ; Benzodiazepine ; Flumazenil ; Spontaneous locomotion ; Thigmotaxis ; Place learning ; Cue learning ; Morris water maze ; Sedation ; Anxiety ; Amnesia ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The sedative, anxiolytic, and amnesic effects of diazepam were compared to those of CL 218,872, a triazolopyridazine that has a preferential affinity for the benzodiazepine ω1 receptor subtype. Spontaneous locomotion was assessed using a running wheel, anxiety was assessed using an open-field divided into central and peripheral areas (thigmotaxis), and amnesia was assessed using the Morris water maze. It was found that CL 218,872, like diazepam, depressed spontaneous locomotion, reduced anxiety, and impaired place learning in a dose-dependent manner. Flumazenil, a benzodiazepine receptor antagonist with a similar affinity for both ω1 and ω2 subtypes, reversed all of the effects of diazepam and antagonized the anxiolytic and amnesic effects, and some but not all of the sedative effects of CL 218,872. These results suggest that the selective activation of the ω1 receptor subtype by CL 218,872 is sufficient to produce sedation, anxiolysis, and amnesia in a manner similar to that produced by the coactivation of both the ω1 and ω2 receptor subtypes with diazepam.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02245160
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 117
    Electronic Resource
    Electronic Resource
    Impaired acquisition of temporal differentiation performance following lesions of the ascending 5-hydroxytryptaminergic pathways (1992)
    Springer
    Psychopharmacology 107 (1992), S. 373-378 
    Details
    ISSN: 1432-2072
    Keywords: 5-Hydroxytrytamine ; Lesion ; Operant behaviour ; Temporal differentiation ; IRT〉t schedule ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Nineteen rats received injections of 5,7-dihydroxytryptamine into the dorsal and median raphe nuclei; 16 rats received sham injections. The rats underwent 50 daily training sessions under an interresponse-time-greater-than-15-seconds (IRT 〉15 s) schedule of sucrose reinforcement. The lesioned group showed impaired acquisition of temporal differentiation, in that their response rates remained significantly higher and their obtained reinforcement frequencies significantly lower than those of the control (sham-lesioned) group. Comparison of the IRT frequency distributions obtained from the two groups during the last 5 days of training showed that the lesioned group produced a significantly higher proportion of very short IRTs (〈3 s) than the control group; when these short IRTs were disregarded, the lesioned group displayed a significantly lower mean IRT and a significantly higher coefficient of variation than the control group. The levels of 5-hydroxytryptamine (5HT) and 5-hydroxyindoleacetic acid in the parietal cortex, hippocampus, amygdala, nucleus accumbens and hypothalamus were markedly reduced in the lesioned group, but the levels of noradrenaline and dopamine were not significantly affected by the lesion. The results suggest that destruction of the ascending 5HTergic pathways may reduce animals' capacity to inhibit positively reinforced operant behaviour, and may impair temporal discrimination.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02245164
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 118
    Electronic Resource
    Electronic Resource
    Comparison of acute and chronic treatment of various serotonergic agents with those of diazepam and idazoxan in the rat elevated X-maze (1992)
    Springer
    Psychopharmacology 107 (1992), S. 405-414 
    Details
    ISSN: 1432-2072
    Keywords: Diazepam ; Idazoxan ; Ipsapirone ; Ritanserin ; Ondansetron ; Acute ; Chronic ; Withdrawal ; Elevated X-maze ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The aim of this study was to use the elevated X-maze to compare acute and chronic treatments of a 5-HT1A partial agonist, ipsapirone, a 5-HT2 antagonist, ritanserin, and a 5-HT3 antagonist, ondansetron, with those of established anxiolytic (diazepam) and anxiogenic (idazoxan) compounds. Acute diazepam (5 mg/kg IP) produced a significant increase in the percentage open:total entries and time and time spent in the end of the open arms (anxiolytic profile) on the elevated X-maze. Chronic treatment with diazepam (5 mg/kg IP twice daily for 14 days) still produced an anxiolytic profile which was not apparent 24 h after cessation of chronic treatment (withdrawal). In contrast, idazoxan given both acutely (0.25 mg/kg IP) and chronically (0.8 mg/kg/h at a flow rate of 5.5 µl/h for 14 days, via osmotic minipumps) resulted in a significant decrease in the percentage open:total entries and time and time spent in the end of the open arms (anxiogenic profile). Acute administration of ipsapirone had no effect on any of the behavioural parameters at doses of 0.01 and 1 mg/kg IP, while 0.1 mg/kg IP produced a significant anxiogenic profile. Chronic treatment with ipsapirone (0.01, 0.1 and 1 mg/kg IP twice daily for 14 days) had no significant effect on rat behaviour on the X-maze but 24 h after ending treatment, ipsapirone at the highest dose used (1 mg/kg) produced a significant anxiogenic profile which was absent when the animals were tested 7 days after cessation of treatment. Ritanserin (0.05 and 0.25 mg/kg IP) had no effect acutely on any of the parameters measured but chronic treatment (0.25 mg/kg IP, twice daily for 14 days) produced a significant anxiolytic effect which was still present 24 h but not 7 days after cessation of treatment. Acute ondansetron (0.01, 0.1 and 1 mg/kg IP) had no effect while chronic ondansetron (0.01 mg/kg IP, twice daily for 14 days) produced a significant anxiolytic profile which was not a result of handling during the chronic dosing schedule, an effect was not measureable 24 h after treatment ended. The results demonstrate that the X-maze can detect anxiolytic activity in non-benzodiazepine drugs, as ritanserin and ondansetron showed anxiolytic profiles but only after chronic treatment. In contrast, the X-maze failed to detect any anxiolytic activity with the 5-HT1A partial agonist ipsapirone after either acute or chronic treatment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02245168
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 119
    Electronic Resource
    Electronic Resource
    Flesinoxan shows antidepressant activity in a DRL 72-s screen (1992)
    Springer
    Psychopharmacology 107 (1992), S. 474-479 
    Details
    ISSN: 1432-2072
    Keywords: Flesinoxan ; 5HT1A agonist ; Serotonin ; Antidepressants ; Differential-reinforcement-of-low-rate (DRL) 72-s ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Schedules which selectively reinforce low rates of responding (DRL, differential reinforcement of low rate) distinguish between antidepressants and other types of drugs. In a DRL schedule a subject is required to pause for a specified minimum period of time between two consecutive responses in order to obtain a reinforcer. The dependent variables are rate of responding and rate of reinforcement. Response patterns of rats treated with clinically effective antidepressant drugs such as imipramine (2.0–32.0 mg/kg) or fluvoxamine (4.0–32.0 mg/kg) are characterized by a decrease in response rate and an increase in reinforcement rate. Treatment with the 5-HT1A agonist flesinoxan (0.1–3.0 mg/kg) also dose-dependently decreased response rates while at the same time increasing reinforcement rates. Chlordiazepoxide (2.5–20.0 mg/kg) and diazepam (0.25–2.0 mg/kg) had no effects in the present experiment.d-Amphetamine increased response rates at low doses (0.5–2.0 mg/kg), and decreased it at the higher doses (4.0 mg/kg), but reinforcement rates were unaltered. Overall analysis of the effects of haloperidol (0.02–0.32 mg/kg) showed decreased responding and increased reinforcement rates. Post hoc analysis, however, clearly differentiated between haloperidol's profile and that of the antidepressants. As such, the results of the present experiment show that flesinoxan might possess antidepressant activity in humans.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02245258
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 120
    Electronic Resource
    Electronic Resource
    Effects of 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) after repeated administration on a conditioned avoidance response (CAR) in the rat (1992)
    Springer
    Psychopharmacology 109 (1992), S. 134-144 
    Details
    ISSN: 1432-2072
    Keywords: Conditioned avoidance response ; 8-OH-DPAT ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract 8-OH-DPAT, a selective 5-HT1A agonist, has variously been found to impair, have no effect on or enhance the conditioned avoidance response (CAR). Procedural differences may account for the difference in results. In the first experiment in the present study rats were trained in the two-way active avoidance procedure to a criterion of 65% avoidance. Separate groups of rats were treated with 0.01, 0.1 or 1.0 mg/kg 8-OH-DPAT SC once per day for 14 days. The rats were tested in the CAR each day 5 min after treatment, using a 10 s light and tone conditioned stimulus and five 0.2 mA/0.5 s electric shocks. On the first day the doses of 0.1 and 1.0 mg/kg impaired avoidance, but by the end of training these two doses increased avoidance. This change in effect was accompanied by a 15-fold increase in the number of trials in which the subject crossed during a 10 s period of the ITI, which in turn led to a significant impairment in the discrimination ratio. The results of this experiment show that with repeated treatment 8-OH-DPAT changes from being antipsychotic like to being stimulant-like. The latter effect produces an improvement in avoidance, probably due to a non-specific increase in activity. In the second experiment, the rats were divided into groups based upon the undrugged performance. The avoidance-enhancing effect of 8-OH-DPAT was greater in magnitude in a group of poor performers, but was qualitatively similar in good performers. In the second stage of the experiment, gradual withdrawal from the drug was compared with sudden withdrawal. In the gradual withdrawal group, a reduction in the dose from 0.085 mg/kg to 0.01 mg/kg resulted in a gradual disappearance of the enhanced activity. There was an almost linear relationship between performance and the log dose of the drug, suggesting that the increase in activity seen after repeated administration of 8-OH-DPAT is directly related to the acute level of drug administered. This effect was evident in both good and poor performers. On the basis of these results it is suggested that many, but not all, antidepressant-like effects of 8-OH-DPAT may result from changes in activity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02245491
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 121
    Electronic Resource
    Electronic Resource
    Effects of methylphenidate on response rate and measures of motor performance and reinforcement efficacy (1992)
    Springer
    Psychopharmacology 109 (1992), S. 145-152 
    Details
    ISSN: 1432-2072
    Keywords: Methylphenidate ; Response rate ; Reinforcement efficacy ; Motor performance ; Matching law ; Response strength equation ; Rate dependency principle ; Clinical effects ; Variable-interval schedule ; Lever press ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract This experiment evaluated the effects of methylphenidate on reinforced responding in rats. In each session the subjects (rats) earned reinforcement on seven different variable-interval reinforcement schedules. The average intervals varied from 108 to 3 s and provided reinforcement rates ranging from about 30 to 1100/h. Response rate was a negatively accelerated function of reinforcement rate. Low doses of methylphenidate (1.0 and 2.0 mg/kg) increased responding maintained by the four leanest schedules, but had little effect on responding maintained by the three densest schedules. In contrast, an 8.0 mg/kg dose increased responding maintained by the three densest schedules and slightly decreased responding maintained by leaner schedules. A quantitative model of reinforced responding, referred to as the matching law or response strength equation, was fitted to the data. This equation has two parameters. On the basis of previous experiments, one was used to measure changes in reinforcement efficacy and the other was used to measure changes in motor performance. The 1.0 and 2.0 mg/kg doses changed the reinforcement parameter in the same way as did increases in deprivation and reward magnitude. The 8.0 mg/kg dose changed the motor parameter in the same was as did decreases in lever weight. It was concluded that methylphenidate increases reinforcement efficacy, and that the highest dose changed the topography of responding. The results are discussed in terms of the response strength equation, the rate dependency principle, and the question of how to interpret changes in reinforcement efficacy and motor performance.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02245492
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 122
    Electronic Resource
    Electronic Resource
    Corticotropin-releasing factor modulates dietary preference in nutritionally and physically stressed rats (1992)
    Springer
    Psychopharmacology 109 (1992), S. 177-184 
    Details
    ISSN: 1432-2072
    Keywords: Dietary self-selection ; Corticotropin-releasing factor ; α-Helical CRF9–41 ; Chlordiazepoxide ; Neophilia ; Protein ; Rat ; Restraint stress
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In order to evaluate the action of central nervous system Corticotropin-Releasing Factor (CRF) in the control of feeding behavior the present studies employed a dietary self-selection task sensitive both to overall appetite as well as preferential intake of familiar versus unfamiliar foods. Prior to the diet selection test, one group of nutritionally stressed animals was fed a protein deficient diet in order to increase the preference for unfamiliar foods relative to nutritionally replete subjects. Both CRF (0.05 and 0.5 µg ICV) and physical restraint (30 min) attenuated selectively the consumption of a novel food choice by deficient animals without affecting concurrent intake of familiar food. Further, CRF administration did not alter water intake or consumption of either diet by the replete control group suggesting that the peptide produced a stress dependent, enhanced response to novelty without a general effect on appetite. The CRF antagonist,α-helical CRF9–41 (1, 5 and 25 µg ICV), increased familiar diet consumption in nutritionally deficient subjects without affecting the self-selection pattern or replete controls. Chlordiazepoxide (5 mg/kg) also increased selectively the intake of familiar food suggesting that this action is the anxiolytic complement of the effect of stress in this paradigm. The CRF antagonist (5 and 25 µg) reversed the anorexia produced by CRF (0.5 µg) as well as that induced by restraint stress. These results favor a direct role for endogenous CRF systems in coordinating the behavioral responses to dietary stress.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02245497
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 123
    Electronic Resource
    Electronic Resource
    Neonatal administration of a GABA-T inhibitor alters central GABAA receptor mechanisms and alcohol drinking in adult rats (1992)
    Springer
    Psychopharmacology 109 (1992), S. 191-197 
    Details
    ISSN: 1432-2072
    Keywords: Alcohol intake ; Development ; Ethanolamine O-sulphate ; GABAA receptors ; Postnatal ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Long-term effects of chronic treatment with a GABA-T (GABA-transaminase) inhibitor, ethanolamine O-sulphate (EOS) (200 mg/kg/day for the postnatal days 3–21) on the binding parameters of GABAA receptors, hypothalamic monoamines and subsequent behavior were studied in Wistar rats. At the age of 1 month, EOS-treated rats showed reduced activity in the open-field and, at the age of 4 months, their voluntary alcohol consumption was increased. No changes were seen in Porsolt's swim test or in the plus-maze test. Weight gain was significantly retarded in EOS-treated rats. Maximal stimulation of [3H] flunitrazepam binding by GABA was decreased in the cerebral cortex and the EC50-value for the GABA stimulation increased in the hippocampus in the EOS rats at the age of 4 months. EOS treatment did not alter the cerebellar diazepam sensitive and insensitive binding components of the imidazobenzodiazepine [3H]Ro 15-4513. No changes were observed in the hypothalamic monoamine concentrations. The results are in agreement with the idea that GABA-T inhibitor treatment permanently alters GABAA mechanisms. Moreover, altering the CNS GABA level during development increases adult alcohol intake in rat.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02245499
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 124
    Electronic Resource
    Electronic Resource
    Preliminary evidence for methamphetamine-induced behavioral and ocular effects in rat offspring following exposure during early organogenesis (1992)
    Springer
    Psychopharmacology 109 (1992), S. 255-263 
    Details
    ISSN: 1432-2072
    Keywords: Methamphetamine ; Rat ; Behavior ; Ocular effects ; Organogenesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Gravid Sprague-Dawley CD (VAF) rats received 50 mg/kg (d,l)-methamphetamine (MA) HCl (expressed as free base,N=15) or distilled water (N=6) by SC injection × 2/day in a 3 ml/kg volume on embryonic (E) days 7–12. Control rats were pair-fed to MA-exposed dams on days E7–18. No control dams failed to deliver; however, of 15 MA-exposed dams 4 did not deliver (2 died and 2 had completely resorbed litters). One additional MA litter had all the offspring die shortly after birth. There was no difference between groups on offspring postnatal (P) body weight. The offspring exposed prenatally to MA had significantly lower olfactory orientation scores (P9, 11, 13) to their home cage scent. In a test of early activity (P10, 12, 14) the MA-exposed progeny were marginally less active than controls. MA-exposed offspring exhibited hyperreactivity and marginally shortened response latency on a test of acoustic startle (P27). Motor activity showed no differential response in MA treated or control offspring to MA (P63) or fluoxetine challenge (P70). However, the MA offspring were more active than controls with respect to central and side activity during the second week of testing. No group differences were found for performance in a straight swimming channel or on the number of errors committed or latency to escape in a complex (Cincinnati) water maze (P84). Prenatal exposure to MA also induced eye defects (i.e., anophthalmia, microphthalmia and folded retina) in 16.7% of the progeny. However, MA did not effect hippocampal or neostriatal monoamine levels when measured on P28. These data support the hypothesis that MA is behaviorally and ocularly teratogenic to the developing rat and results in functional deficits when compared to offspring of pair-fed controls.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02245871
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 125
    Electronic Resource
    Electronic Resource
    Antidepressant-like effect of neurotensin administered in the ventral tegmental area in the forced swimming test (1992)
    Springer
    Psychopharmacology 109 (1992), S. 369-372 
    Details
    ISSN: 1432-2072
    Keywords: Neurotensin ; Dopamine ; Mesolimbic system ; Antidepressant activity ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Locomotor activity and behaviour in the forced swimming test were examined in rats which had received neurotensin (0.5–5.0 µg) in the ventral tegmental area. Doses of 5 µg neurotensin but not lower increased the locomotor activity for at least 2 h. At 0.5 and 1.0 µg neurotensin significantly increased the time the animals spent in struggling with no changes in general motor activity (swimming). The effect of 1.0 µg neurotensin on struggling was completely antagonized by 0.5 µg (−)-sulpiride administered in the posterior nucleus accumbens. The results suggest that activation of the mesolimbic dopamine system through administration of neurotensin in the ventral tegmental area produces antidepressant-like effects. The significance of these findings for a role of endogenous neurotensin in depression remains to be clarified.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02245885
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 126
    Electronic Resource
    Electronic Resource
    Effects of intra-hippocampal scopolamine injections in a repeated spatial acquisition task in the rat (1992)
    Springer
    Psychopharmacology 109 (1992), S. 373-376 
    Details
    ISSN: 1432-2072
    Keywords: Cholinergic system ; Scopolamine ; Hippocampus ; Spatial discrimination ; Learning ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The involvement of hippocampal cholinergic synapses in spatial discrimination learning was evaluated by locally administering scopolamine into the hippocampus. Sixteen 16-month-old male Lewis rats received bilaterally implanted cannulae aimed at the dorsal part of the hippocampus. The rats were trained on a repeated acquisition test in the Morris water-escape task. In this procedure the invisible platform is randomly moved from day to day to one of four possible locations. Thus, the rat has to learn to localize the platform from day to day. On each day the rats received four pairs of trials. Scopolamine injections (35 µg in 1 μl per hippocampus) were given to one group (n=8) on days 5 and 7. On days 6 and 8 all rats received saline injections. Place learning was retarded in the scopolamine-treated rats during the first swims of pairs of trials. During second swims the scopolamine-treated rats showed a general performance deficit, indicating that first and second swims were differentially affected. The data support the hypothesis that cholinergic neurotransmission in the dorsal hippocampus is involved in spatial learning processes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02245886
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 127
    Electronic Resource
    Electronic Resource
    Effects of anxiolytic and antidepressant drugs on long-lasting behavioural deficits resulting from one short stress experience in male rats (1992)
    Springer
    Psychopharmacology 109 (1992), S. 395-402 
    Details
    ISSN: 1432-2072
    Keywords: Footshock ; Stress ; Behaviour ; Diazepam ; Flesinoxan ; Fluvoxamine ; Desmethylimipramine ; Anxiety ; Depression ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Exposure of male Wistar rats to one single session of ten inescapable footshocks induces changes in the behavioural responses to environmental stimuli as measured in the “noise test” 14 days later. Shocked (S) rats showed decreased locomotion and rearing during the first 3 min of exposure to a novel environment compared to control (C) rats. When the 85 dB background noise was switched off a marked immobility response emerged in S rats, concomitant with a further decrease in locomotion and rearing. In response to noise off, C rats showed hardly any immobility and a much smaller reduction in locomotion and rearing compared to S rats. These long-lasting changes in behaviour were not reversed by acute treatment with the antidepressants fluvoxamine (3.0–30.0 mg/kg) and desmethylimipramine (DMI, 2.5–10.0 mg/kg) injected IP 30 min before the noise test on day 14 following the shock session. Chronic treatment (day 1 to day 14) with flvoxamine or DMI did not reverse the behavioural deficits induced by shock exposure. Diazepam (0.6–5.0 mg/kg) administered acutely only reversed the effects of shock on locomotion during the first 3 min of the noise test. Chronic treatment with diazepam normalized the shock-induced decrease in locomotion and attenuated the rearing decrease during the first 3 min of the test, and partially restored shock-induced changes in behavioural response to switching off the noise. The most potent drug in this study was the 5-HT1A receptor agonist flesinoxan (0.3–3.0 mg/kg). Both acute and chronic drug treatment were equally effective in reversing the shock-induced locomotion deficits as well as the marked immobility response in S rats, although rearing was not reversed. However, flesinoxan also increased locomotion and reduced rearing in C rats, suggesting some nonspecific stimulating effects of flesinoxan. In conclusion, the footshock-induced long-lasting behavioural changes are sensitive to treatment with (putative) anxiolytic agents, whereas no beneficial effect of the antidepressant drugs was found.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02247714
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 128
    Electronic Resource
    Electronic Resource
    Differential antagonism of the effects of dopamine D1-receptor agonists on feeding behavior in the rat (1992)
    Springer
    Psychopharmacology 109 (1992), S. 403-409 
    Details
    ISSN: 1432-2072
    Keywords: Dopamine ; D1 ; D2 ; SKF 38393 ; SKF 77434 ; SKF 82958 ; SCH 23390 ; Spiperone ; Feeding ; Behavior ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A series of experiments was conducted to examine the effects of dopamine D1 receptor agonists on food intake in rats. In the first experiment, the D1 agonist SKF 38393 (3.0–30.0 mg/kg) dose-dependently suppressed feeding during a 40 min food-access period, both in food-deprived rats and in non-deprived rats fed a highly palatable diet. Non-deprived rats were more sensitive to these effects of SKF 38393. Using the limited-access, food-deprivation procedure, a comparison was made between the anorectic effects of three D1 agonists with differing intrinsic efficacies and receptor selectivities. Rank order of potencies for reducing food intake was SKF 82958 〉 SKF 77434 〉 SKF 38393 (ED50 values: 0.7, 3.6 and 15.7 mg/kg, respectively). Dose-related, surmountable antagonism by the D1 antagonist SCH 23390 (0.01 and 0.03 mg/kg) was only obtained with SKF 82958 (0.1–10.0 mg/kg). In contrast to the other compounds, the effects of SKF 38393 were not appreciably altered by the D1 antagonist. The effects of SKF 82958 were also antagonized by the D2 receptor antagonist spiperone (0.05 and 0.1 mg/kg), although not in a dose-dependent manner. The present results support a role for D1 receptors in central feeding mechanisms. They also suggest that the effects of SKF 38393 on feeding may not be mediated exclusively by the D1 receptor and, further, that SKF 38393 may not serve well in behavioral studies as a prototypical D1 agonist. The results also demonstrate the need for comparisons among several compounds in studies of D1 mediated behavioral effects.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02247715
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 129
    Electronic Resource
    Electronic Resource
    Quantification of SCH 39166, a novel selective D1 dopamine receptor antagonist, in rat brain and blood (1992)
    Springer
    Psychopharmacology 106 (1992), S. 455-458 
    Details
    ISSN: 1432-2072
    Keywords: SCH 23390 ; SCH 39166 ; D1 dopamine receptor ; Antagonist ; Pharmacokinetics ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A gas chromatographic method for measuring concentrations of a novel D1 antagonist SCH 39166 [(−)-trans-6,7,7a,8,9,13b-hexahydro-3-chloro-2-hydroxy-N-methyl-5-H-benzo[d]naphto(2,1–6)azepine] in rat brain and plasma was developed. The method was applied to descriptive pharmacokinetics of two subcutaneous doses of SCH 39166 (0.25 mg/kg and 2.5 mg/kg). For comparison, concentrations of the “prototype” D1 antagonist SCH 23390 (0.25 mg/kg, SC) [R-(+)-chloro-2,3,4,5-tetrahydro-3-methyl-5-phenyl-1-H-3-benzazepine] were also measured in plasma and brain. SCH 23390 (0.25 mg/kg, SC) had a very short elimination half-life of about 30 min in plasma, and disappeared in a slightly slower manner from striatum and cortex. SCH 39166 (0.25 and 2.5 mg/kg, SC), however, had a longer elimination half-life of about 1.5–2.5 h in plasma and brain. Interestingly, the 2.5 mg/kg dose of SCH 39166 produced only two-to five-fold increases in maximum concentrations in plasma and brain compared to the 0.25 mg/kg dose. The reason for this is not clear. The ability of these two doses of SCH 39166 to induce catalepsy in the bar test was also evaluated. It was found that SCH 39166 in these two doses, unlike SCH 23390, was not cataleptic. In conclusion, these pharmacokinetic features of SCH 39166 in the rat should be useful when designing experiments with this novel selective D1 antagonist. Furthermore, the longer elimination half-life of SCH 39166 makes it a more useful probe in pharmacodynamic comparisons of D1 receptor antagonists and classical as well as atypical neuroleptics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02244814
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 130
    Electronic Resource
    Electronic Resource
    Opposite effects of pentylenetetrazol on self-defensive and submissive postures in the rat (1992)
    Springer
    Psychopharmacology 107 (1992), S. 457-460 
    Details
    ISSN: 1432-2072
    Keywords: Defense ; Submission ; Flight ; Ethopharmacology ; Pentylenetetrazol ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In a previous work, using the resident-intruder situation, we have shown that a benzodiazepine inverse agonist could exert a “fear-promoting” effect, in decreasing self-defensive behaviours while increasing submissive postures. To further test this hypothesis, the effects of pentylenetetrazol on different forms of defensive behaviour were examined in male intruder rats confronted with offensive residents. Administration of pentylenetetrazol (10 and 20 mg/kg, IP) increased submissive postures such as immobility and on-the-back, but reduced self-defensive postures. Other active behaviours were not reduced, thus excluding a non-specific behavioural suppression. These results suggest that self-defensive and submissive behaviours can be dissociated and that anxiogenic compounds are more likely to increase submissive behaviours than self-defensive ones.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02245176
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 131
    Electronic Resource
    Electronic Resource
    The acoustic startle response as a measure of behavioral dependence in rats (1992)
    Springer
    Psychopharmacology 108 (1992), S. 40-46 
    Details
    ISSN: 1432-2072
    Keywords: Physical dependence ; Acoustic startle response ; Withdrawal ; Morphine ; Naloxone ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A series of experiments was conducted to assess the sensitivity of the acoustic startle response to chronic morphine administration and naloxone-precipitated withdrawal. Rats were implanted with two subcutaneous pellets containing either 75 mg each of morphine or containing only placebo. In experiment 1, withdrawal induced by 0.05–0.2 mg/kg naloxone dose-dependently decreased the magnitude of the startle response. Physical dependence was confirmed by a naloxone-induced acute weight loss seen in morphine-implanted rats, but naloxone had no effect on startle or body weight in nondependent animals. In experiment 2, a modified procedure with fewer trials per session and fewer test days was employed. Naloxone (0.2 mg/kg) given 4–5 days after implantation induced large startle-response decreases in morphine-dependent rats while having no effect in placebo-implanted rats. Post-naloxone saline tests revealed no significant differences in startle between morphine and placebo groups. Startle scores were significantly higher in morphine-implanted rats than in placebo rats during a saline test given 3 days following pellet implantation. In a separate group of animals, however, acute IP injections of morphine from 0.3–10 mg/kg had no significant effect on startle amplitude. The effect of repeated pairings of withdrawal with the startle environment was assessed in experiment 3. Morphine-dependent rats startled significantly less if naloxone injections were given before the startle session than if they were administered 4 h later. Conditioned withdrawal effects, expressed during a final test session when all rats received saline, were observed for the body-weight measure but not for the startle response. These results suggest that the acoustic startle response may be a useful objective measure in evaluating physical dependence produced by substances of abuse.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02245283
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 132
    Electronic Resource
    Electronic Resource
    5-HT1A receptor agonists prevent in rats the yawning and penile erections induced by direct dopamine agonists (1992)
    Springer
    Psychopharmacology 108 (1992), S. 47-50 
    Details
    ISSN: 1432-2072
    Keywords: Yawning ; Penile erections ; (+) S-20499 ; 5-HT1A agonists ; D2 receptors ; Apomorphine ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The new compound (+) S-20499, an amino chromane derivative (8[-4[N-(5-methoxychromane-3yl)N-propyl]aminobutyl] azaspiro[4–5] décane-7,9 dione), is a high affinity full 5-HT1A agonist. We have investigated its effects on dopaminergic transmission. (+) S-20499 displayed a 10−8 M affinity for D2 dopamine (DA) receptors, 100 fold lower than for 5-HT1A receptors. The hypothermic effect of the drug was reversed by haloperidol in mice, suggesting that it behaves as a direct dopamine agonist. However, increasing doses of (+) S-20499 induced neither yawning nor penile erections, which constitute characteristic responses of direct DA agonists administered at low doses. In addition, (+) S-20499 prevented the apomorphine (100 µg/kg SC) induced yawning and penile erections. This inhibition appears to result from the stimulation of 5-HT1A receptors since it is an effect shared by both buspirone (from 5 mg/kg) and 8-OH-DPAT (from 0.10 mg/kg). In addition, when rats are treated with the 5-HT1A receptor antagonist tertatolol (2–5 mg/kg; SC), increasing doses of (+) S-20499 elicit the expected yawns and penile erections. It is concluded that the 5-HT1A agonist property opposes to that of D2 dopamine receptor stimulation with regard to yawning and penile erections.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02245284
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 133
    Electronic Resource
    Electronic Resource
    Pharmacological dissociation between the spatial learning deficits produced by morphine and diazepam (1992)
    Springer
    Psychopharmacology 108 (1992), S. 147-152 
    Details
    ISSN: 1432-2072
    Keywords: Diazepam ; Morphine ; Naloxone ; Flumazenil ; Place learning ; Cue learning ; Morris water maze ; Benzodiazepines ; Opioids ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract This study sought to determine whether the place learning deficits produced by diazepam are a secondary result of opioid release. Rats pretreated with diazepam (3 mg/kg) or morphine (15 mg/kg) were trained in the Morris water maze. Diazepam impaired place learning-slowing acquisition and preventing the formation of a quadrant preference. Morphine also slowed acquisition, but did not prevent place learning, and impaired escape to a visible platform. Flumazenil blocked the deficits produced by diazepam, but not morphine. Naloxone (2 mg/kg) blocked the deficits produced by morphine, but not diazepam. A high dose of naloxone (10 mg/kg) slowed acquisition, and exacerbated the deficit produced by diazepam. These results demonstrate that diazepam interferes with mnemonic processes through endogenous benzodiazepine receptors, independently of opioidergic systems. Further, they suggest that morphine interferes with motivational processes through opioidergic systems, independently of endogenous benzodiazepine systems.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02245300
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 134
    Electronic Resource
    Electronic Resource
    FG 7142 selectively decreases nonpunished responding, but has no anxiogenic effects on time allocation in a conflict schedule (1992)
    Springer
    Psychopharmacology 108 (1992), S. 185-188 
    Details
    ISSN: 1432-2072
    Keywords: Conflict schedule ; FG 7142 ; Inverse agonist ; Punishment ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Previous work (Thomas et al. 1990) showed that an anxiolytic benzodiazepine increased the time allocated to responding in a conflict situation (where responses were both food-reinforced and shock-punished) versus a nonpunishment situation. The present experiment tested whether a benzodiazepine-receptor inverse agonist (FG 7142, 1–30 mg/kg) would have the opposite effect (i.e., decrease time spent responding in a punishment situation). Chain pulls determined whether a rat's lever presses were reinforced on 1) a lean variable-interval schedule, or 2) a richer variable-interval schedule in which responding also produced shock intermittently. FG 7142 dose-dependently decreased nonpunished lever responding, but did not affect punished responding. The drug nonselectively decreased chain pulling (the schedule-switching response). Like chlordiazepoxide, FG 7142 increased the time spent in the punishment component, showing that not all effects of benzodiazepine-receptor agonists and inverse agonists are opposite. These results are inconsistent with expectations that anxiogenic actions of FG 7142 should 1) decrease punished responding; 2) increase the rate of responses that terminate the punishment condition; and 3) decrease time spent in the punishment component. Rather, nonsuppressed responding seems most sensitive to decreases by FG 7142.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02245305
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 135
    Electronic Resource
    Electronic Resource
    Dexmedetomidine synergism with midazolam in the elevated plus-maze test in rats (1992)
    Springer
    Psychopharmacology 108 (1992), S. 229-234 
    Details
    ISSN: 1432-2072
    Keywords: Anxiolysis ; Benzodiazepine agonist, midazolam ; Benzodiazepine antagonist, flumazenil ; α2-Adrenergic agonists, dexmedetomidine ; α-Adrenergic antagonists, atipamezole ; α1-Adrenergic antagonists, prazosin ; Elevated plus-maze ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The anxiolytic profile of dexmedetomidine, a novel, highly-selective α2-adrenergic agonist, was examined in rats in the elevated plus-maze test when administered either alone or in combination with the benzodiazepine agonist midazolam. Dexmedetomidine, 0.1–10 µg/kg, was inactive in modifying the rats' behavioral response in this test. Midazolam, 0.1–10 mg/kg, dose-dependently produced an anxiolytic-like profile characterized by an increased time spent in the open arms of the elevated plus-maze. A combination of dexmedetomidine 0.5 µg/kg and midazolam 0.5 mg/kg produced a synergistic interaction. This heterergic interaction of dexmedetomidine on midazolam's anxiolytic-like profile was dose-dependently blocked by pretreatment with an α2-adrenergic antagonist, atipamezole, 10–50 µg/kg, and a benzodiazepine antagonist flumazenil, 1.0 and 10 mg/kg, but not by the α1-adrenergic antagonist, prazosin, 0.1–10 mg/kg. While the transmembrane signal transduction pathways for benzodiazepine- and α2-agonist responses do not share any molecular component, there does appear to be “crosstalk” between these two systems. These may involve GABA or noradrenergic “downstream” effects of either dexmedetomidine or midazolam, respectively.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02245313
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 136
    Electronic Resource
    Electronic Resource
    Effects of ritanserin and chlordiazepoxide on sleep-wakefulness alterations in rats following chronic cocaine treatment (1992)
    Springer
    Psychopharmacology 108 (1992), S. 263-270 
    Details
    ISSN: 1432-2072
    Keywords: Sleep-wakefulness ; Chronic cocaine treatment ; Cocaine discontinuation ; Ritanserin ; Chlordiazepoxide ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The effects of ritanserin, a 5-hydroxytryptamine-2 (5-HT2) receptor antagonist, and chlordiazepoxide, a benzodiazepine agonist, on sleep-wakefulness disturbances in rats after acute administration of cocaine and after discontinuation of chronic cocaine treatment were examined. Intraperitoneal (IP) injection of chlordiazepoxide (10 mg/kg) but not ritanserin (0.63 mg/kg) prevented the increase of wakefulness (W) and the reduction of light slow wave sleep (SWS1) and deep slow wave sleep (SWS2) induced by an acute injection of cocaine (20 mg/kg IP). Daily injection of cocaine (20 mg/kg for 5 days, then 30 mg/kg for 5 days IP) at the onset of the light phase elicited an increase of W and a concomitant decrease of SWS1, SWS2 and paradoxical sleep (PS) in the light phase, followed by a rebound in SWS2 and PS in the subsequent dark phase. Following cocaine discontinuation, the circadian distribution of sleep-wakefulness states remained disturbed in saline-treated rats for at least 5 days. Both ritanserin (0.63 mg/kg IP/day) and chlordiazepoxide (10 mg/kg IP/day) reduced the alteration in the distribution of W and SWS2 throughout the light-dark cycle from the first day of administration on, but failed to prevent PS alterations. The mechanisms by which both compounds exert their effect are probably quite different. For chlordiazepoxide sedative and sleep-inducing properties probably play a major role. In contrast, for ritanserin SWS2-increasing properties and its ability to reverse preference for drugs of abuse without inducing aversion might be key factors.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02245110
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 137
    Electronic Resource
    Electronic Resource
    Chronic infusion of clonidine does not alleviate spontaneous morphine withdrawal symptoms in rats (1992)
    Springer
    Psychopharmacology 108 (1992), S. 283-288 
    Details
    ISSN: 1432-2072
    Keywords: Clonidine ; UK-14.304 ; Behaviour ; Withdrawal ; Doxazosine ; Morphine ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Opiate withdrawal is associated with behavioural symptoms and a sympathetic hyperactivity, the latter being sensitive to clonidine. The central question is whether behavioural symptoms would be also sensitive to clonidine. A rat model was used in which the locomotor activity was measured 24 h a day during the morphine withdrawal phase. Spontaneous withdrawal of morphine reduced strongly the high nocturnal locomotor activity, concomitently decreasing food intake and body weight. Chronic infusion of clonidine (30–120 µg/kg/day) using osmotic minipumps had no effect on the withdrawal symptoms. Higher dosages (250–1000 µg/kg/day) potentiated rather than alleviated the withdrawal symptoms, suggesting anα 1-adrenergic effect of clonidine rather than anα 2-action. Therefore, we studied the action of a more specificα 2-agonist UK-14.304. UK-14.304 was less potent than clonidine in naive animals. It slightly alleviates the decrease of nocturnal activity during spontaneous morphine withdrawal. Furthermore, we have tested whether the effects of high dosages of clonidine could be altered by a specificα 1-antagonist doxazosine. Doxazosine reduced only slightly the potentiation in the decrease in food intake by clonidine during morphine withdrawal. For the other symptoms no interaction between doxazosine and clonidine was found. The data suggest that the use of clonidine in the detoxification of opiate dependent people is based on the suppression of the sympathetic hyperactivity rather than on symptoms with a more behavioural character.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02245113
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 138
    Electronic Resource
    Electronic Resource
    Comparative effects of alpha-2 receptor agents and THA on the performance of adult and aged rats in the delayed non-matching to position task (1992)
    Springer
    Psychopharmacology 109 (1992), S. 127-133 
    Details
    ISSN: 1432-2072
    Keywords: Short-term memory ; Aging ; Noradrenergic system ; Alpha-2 adrenoceptors ; Cholinergic system ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The present study investigated the effects of dexmedetomidine (an alpha-2 adrenoceptor agonist), atipamezole (an alpha-2 adrenoceptor antagonist) and tacrine (an inhibitor of acetylcholinesterase) on the performance of adult and aged rats in a delayed non-matching to position task assessing spatial short-term memory. Most of the aged rats were impaired in the pretraining phases and in the acquisition of the non-delayed version of the task. After a substantial training period of the delayed version of the task, both adult and aged rats reached their asymptotic level of performance. Both adult and aged rats showed a decline in the percent correct responses at the longest delays in this task, and a delay independent decrease in the percent correct responses across the delays (0–30 s) was found in the group of aged rats (25-month-old) as compared to the adults (10-month-old). Dexmedetomidine (0.3, 1.0 or 3.0 µg/kg), atipamezole (0.03, 0.3 or 3.0 mg/kg) and tacrine (1.0 or 3.0 mg/kg) did not increase the percent correct responses in adult or aged rats. The highest doses of dexmedetomidine and tacrine decreased behavioural activity of rats during this short-term memory testing. Atipamezole (0.03 mg/kg) increased behavioural activity of rats. The results suggest that acute, systemic administrations of alpha-2 drugs or an anticholinesterase do not improve short-term memory in rats.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02245490
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 139
    Electronic Resource
    Electronic Resource
    An analysis of Na+ currents in rat olfactory receptor neurons (1992)
    Springer
    Pflügers Archiv 420 (1992), S. 342-346 
    Details
    ISSN: 1432-2013
    Keywords: Patch-clamp ; Rat ; Olfactory receptor neurons ; Sodium channels
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Na+ currents were observed in acutely-dissociated adult rat olfactory receptor neurons using the whole-cell recording techniques. The threshold for current activation was near −70mV and currents were fully activated by −10 mV (midpoint: −45 mV). Steady-state inactivation was complete at potentials more positive than −70mV and half complete at −110mV (±〈1, n=8). Complete recovery from inactivation required one second at −100 mV (n=7). The addition of 10 μM tetrodotoxin or 1 mM Zn2+ to the external solution was required to completely block the current. The current differs from those in amphibian and cultured neonatal rat olfactory neurons in its unusually negative voltage-dependence and slow recovery. Since mammalian olfactory neurons have very high input resistances, physiological resting potentials cannot usually be measured using whole-cell recording techniques. However, predominantly-capacitatively-coupled spikes activated by depolarisation were frequently observed in cell-attached patches. This indicates that the cells were excitable and implies that they must have had resting potentials more negative than −90 mV in order for this current to underlie the action potential.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00374468
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 140
    Electronic Resource
    Electronic Resource
    An early outward transient K+ current that depends on a preceding Na+ current and is enhanced by insulin (1992)
    Springer
    Pflügers Archiv 422 (1992), S. 267-272 
    Details
    ISSN: 1432-2013
    Keywords: Rat ; Myoball ; Potassium channel ; Potassium current ; Sodium current ; Insulin ; Voltage clamp
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A whole-cell early transient outward current occurs in rat myoballs if and only if there is an immediatly preceding current of large amplitude through the voltage-gated, tetrodotoxin-inhibitable Na+ channel. This early outward transient is a K+ current, designated I K(Na+). Under the conditions in which I K(Na+) appears, simultaneous measurement of voltage and current, under voltage clamp, demonstrates that there is transient voltage escape to depolarized levels, peaking at about the time of peak inward Na+ current arid resembling an action potential. I K(Na+) was never seen in the absence of this breach of the voltage clamp, suggesting that I K(Na+) might be an artefact due to transient depolarization from the clamp. However, when the voltage escape was mimicked by voltage commands under conditions in which the Na+ channel was not activated, there was no I K(Na). Insulin increased or produced I K(Na+) even though insulin had no effect on I Na or on the delayed rectifier K+ current or on the escape from voltage clamp. It is concluded that there is a population of rat myoballs in which there is an early outward K+ current that requires an immediately preceding current through the voltagegated tetrodotoxin-inhibitable Na+ channel and is enhanced by insulin.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00376212
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 141
    Electronic Resource
    Electronic Resource
    Structural changes of a devascularizated colonic graft when its replaces the rat uterine horn (1992)
    Springer
    Archives of gynecology and obstetrics 252 (1992), S. 73-80 
    Details
    ISSN: 1432-0711
    Keywords: Uterine-surgery ; Rat ; Intestinal-surgery ; Fertility-surgery ; Intestinal secretion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A one centimeter length of the left uterine horn in two groups of Wistar rats (n=10) was replaced with normal (VAS group) or with denervated and devascularizated (NVAS group) colonic grafts. All animals maintained pregnancy in the right control horns but not in the grafted horns. At 40, 60 and 90 days after surgery, the light microscopic appearance of the autografts was studied. In the VAS group, and with respect to the last period, the number (5.5±0.7) and height (1.0±0.1 mm,P〈0.05 ANOVA) of the folds, the intestinal glands height (160.2±21.2μ,P〈0.05 ANOVA) and the number of globet cells per gland (26.6±4.2,P〈0.05 ANOVA) had decreased in relation to the colon control (6.0±0.7, 1.4±0.1, 251.7±31.8, 42.6±5.2 respectively). A similar intestinal structure to that described above was observed in the anastomosis areas of the NVAS group, and therefore a decreased mucus production was maintained in this areas. No folds or intestinal glands were observed, but a monoestratified cubic epithelial cells type was observed along 63.7±4.1% of the NVAS colonic graft center. Under this epithelium a connective tissue, like a non-glandular submucosa, was obtained.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02389631
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 142
    Electronic Resource
    Electronic Resource
    Single-dose toxicokinetics of aluminum in the rat (1992)
    Springer
    Archives of toxicology 66 (1992), S. 700-705 
    Details
    ISSN: 1432-0738
    Keywords: Aluminum ; Toxicokinetics ; Rat ; Parenterals
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The toxicokinetics of aluminum (Al) in male Wistar rats was studied after single intragastric (IG) doses of 1000 and 12000 μg Al/kg and intravenous (IV) doses of 10, 100, 1000, and 12000 μg Al/kg. Serial blood samples, daily samples of urine and feces as well as brain, liver, kidney, spleen, quadriceps muscle, and femur samples were collected. Al was measured by atomic absorption spectrometry. Al blood profiles after IV doses were adequately described by a two-compartment open model. Al toxicokinetics was dose dependent and appeared to plateau at 12000 μg/kg. At IV doses between 10 and 1000 μg/kg the terminal half-life of elimination from whole blood (t1/2β) increased from 29.9±7.8 to 209.3±32.6 min, and the total body clearance (CL) decreased from 2.45±0.64 to 0.28±0.03 ml min−1 kg−1. Following an IV bolus of 10 and 100 μg/kg the administered Al was recovered completely from urine (94.4%±9.9% and 98.5%±3.2%). Twenty-nine days after the IV dose of 1000 μg/kg daily renal excretion decreased to baseline values while only 55.1%±8.0% of the dose was excreted. Nineteen days after the single IV dose of 1000 μg/kg Al accumulated in liver (28.1±7.7 versus 1.7±0.5 μg/g of control rats) and spleen (72.5±21.1 versus 〈0.4 μg/g). After the single 1000 μg/kg IG dose no absorption of Al was detectable. The IG dose of 12000 μg/kg resulted in a maximum blood Al level of 47.9±12.4 μg/l after 50 min. The blood concentration time curve fitted a one-compartment open model with a half-life of absorption of 28.2±3.6 min and a t1/2β of 81.2±20.2 min. Cumulative renal Al excretion was 0.18%±0.10% of the dose and oral bioavailability was 0.02%. Seventeen days after the 12000 μg/kg IG dose the Al content in femur samples was increased (2.7±1.3 versus 0.6±0.4 μg/g). In no case was fecal elimination of incorporated Al observed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01972620
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 143
    Electronic Resource
    Electronic Resource
    N-Nitrosodialkylamine dealkylation in reconstituted systems containing cytochrome P-450 purified from phenobarbitaland β-naphthoflavone-treated rats (1992)
    Springer
    Archives of toxicology 66 (1992), S. 137-142 
    Details
    ISSN: 1432-0738
    Keywords: N-Nitrosamine ; Cytochrome P-450 ; Rat ; Phenobarbital ; β-Naphthoflavone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Five cytochrome P-450 forms were purified from livers of rats pretreated with phenobarbital (PB) or β-naphthoflavone (BNF), and the oxidative dealkylation of N-nitrosodialkylamines by the reconstituted cytochrome P-450 systems was measured. PB-II (P450IIB1) showed very high N-nitrosomethybutylamine (NMBA) debutylase activity, high NMBA demethylase activity and high N-nitrosomethyl-benzylamine (NMBeA) debenzylase activity, suggesting that the increase following PB treatment in hepatic microsomal NMBA debutylation and NMBeA debenzylation was due to the induction of PB-II. BNF-H (P450IA2) showed very high NMBA debutylase and high NMBeA debenzylase activities, and BNF-L (P450IA1) showed NMBA debutylase and high NMBeA debenzylase activities. These results suggested that the increase by BNF pretreatment in hepatic microsomal NMBA debutylation was due mainly to the induction of BNF-H and in some part to that of BNF-L. PB-II also showed very high dealkylation activity of lipophilic N-nitrosodialkylamines with long alkyl moieties. On the other hand, BNF-H dealkylated N-nitrosodipropylamine (NDPA), N-nitrosomethylbutylamine (NMBA) and N-nitrosoethylbutylamine (NEBA) at higher rates than N-nitrosodibutylamine (NDBA). BNF-L dealkylated NEBA at higher rates than NMBeA and NDBA. These results reveal that substrate specificity of each cytochrome P-450 form in N-nitrosodialkylamine metabolism is different from each other and several forms of cytochrome P-450 support each N-nitrosamine dealkylase activity in mammalians.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02342508
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 144
    Electronic Resource
    Electronic Resource
    Degree of ethoxyquin-induced nephrotoxicity in rat is dependent on age and sex (1992)
    Springer
    Archives of toxicology 66 (1992), S. 51-56 
    Details
    ISSN: 1432-0738
    Keywords: Ethoxyquin(6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline) ; Nephrotoxicity ; Rat ; Proteinuria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The toxicity of ethoxyquin (EQ) to rat kidney was examined in males which were either weanling or adult at the beginning of the experiment, and also in adult females. Female rats were much less susceptible to the toxic effects of EQ than males of the same age. In males damage to the cortex, mainly as an acceleration of the normal ageing process, was similar in both age groups, but rats exposed to EQ as weanlings also suffered from extensive papillary necrosis. Male rats were more prone than females to proteinuria, which was greatly exacerbated by EQ in both age groups. Thus there is very little evidence of nephrotoxicity in adult female rats on exposure to EQ at 0.5% in the diet for 26 weeks. In males, the initial age of the animal, as well as the length of treatment, influences the extent of damage.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02307270
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 145
    Electronic Resource
    Electronic Resource
    Effects of exogenous factors on the cerebral glutathione in rodents (1992)
    Springer
    Archives of toxicology 66 (1992), S. 279-285 
    Details
    ISSN: 1432-0738
    Keywords: Acetaminophen ; Aminophenazone ; Ammonium metavanadate ; Brain ; Buthionine sulfoximine ; Cobalt ; Diethylmaleate ; Glutathione ; Lomustine ; Morphine ; Mouse ; Nitrofurantoin ; Phenytoin ; Propyphenazone ; Rat ; Starvation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Since glutathione is thought to be involved in cerebral functions, changes in the glutathione level imply modulations of the neurotransmission in addition to all the known effects of GSH. It was investigated whether alterations of the cerebral glutathione can be induced by consumption of GSH, by inhibition or stimulation of the synthesis of GSH, or by an inhibition of the re-reduction of the oxidized glutathione. Aminophenazone, propyphenazone, acetaminophen, phenytoin, morphine and nitrofurantoin, known to deplete hepatic GSH, had no effects on cerebral GSH. Diethyl maleate (0.6 ml/kg) decreased the cerebral content of GSH and GSSG in adult rats as well as in fetuses. The depletion of the cerebral GSH caused by diethyl maleate treatment for 4 days was followed by an increase up to 125% and a subsequent return to the normal level after 1 week. In rats starved up to 71 h deficiency of exogenous amino acids caused only a minimal or no decrease in cerebral GSH. The specific inhibitor of the gamma-glutamylcysteine synthetase BSO only depleted GSH in the brain of young mice following the repeated s. c. administration of a high dose (890 mg/kg). After cobaltous chloride (20 mg/kg; twice a day for 2 or 4 days) the GSH level in the brain was unchanged. In vivo inhibition of the cerebral glutathione reductase was caused by ammonium metavanadate (12.5 mg/kg; three times a week for 6 weeks). Nitrofurantoin (150 mg/kg) had no effect. After lomustine (10 mg/kg) a minimal increase in glutathione reductase was found, but simultaneously also an increase in GSSG and of the ratio GSSG/total glutathione.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02307174
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 146
    Electronic Resource
    Electronic Resource
    Decrease in bone strength of cadmium-treated young and old rats (1992)
    Springer
    Archives of toxicology 66 (1992), S. 315-320 
    Details
    ISSN: 1432-0738
    Keywords: Cadmium ; Rat ; Bone ; Long-term administration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A decrease in mechanical strength of bones was observed both in young and old rats for long periods of administration of cadmium. Young (3-week-old) female rats were given 0 (control), 5 and 10 ppm cadmium in drinking water, respectively, for 20 weeks. Old (18-month old) female rats were given 0 (control) and 40 ppm cadmium in drinking water, respectively, for 7 months. The compression strengths of bones of young rats which were given 10 ppm cadmium, and those of old rats which were given 40 ppm cadmium, significantly decreased at the distal end portion of femur. Cadmium contents in bones in the 10 ppm and 40 ppm groups were about 110 and 210 ng/g dry weight, respectively. The present result confirmed that cadmium has a lesional effect on the mechanical strength of bone at the concentration of 100–200 ng/g in dry weight of bone, for both young and old rats.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01973625
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 147
    Electronic Resource
    Electronic Resource
    Regional brain distribution of toluene in rats and in a human autopsy (1992)
    Springer
    Archives of toxicology 66 (1992), S. 153-156 
    Details
    ISSN: 1432-0738
    Keywords: Toxicology ; Poisoning ; Toluene ; Brain regional distribution ; Rat ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Toluene concentrations in 9 brain regions of acutely exposed rats and that in 11 brain regions of a human case who inhaled toluene prior to death are described. After exposure to toluene by inhalation (2000 or 10000 ppm) for 0.5 h or by oral dosing (400 mg/kg), rats were killed by decapitation 0.5 and 4 h after onset of inhalation and 2 and 10 h after oral ingestion. After each experimental condition the highest range of brain region/blood toluene concentration ratio (BBCR) was in the brain stem regions (2.85–3.22) such as the pons and medulla oblongata, the middle range (1.77–2.12) in the midbrain, thalamus, caudate-putamen, hypothalamus and cerebellum, and the lowest range (1.22–1.64) in the hippocampus and cerebral cortex. These distribution patterns were quite constant. Toluene concentration in various brain regions were unevenly distributed and directly related blood levels. In a human case who had inhaled toluene vapor, the distribution among brain regions was relatively similar to that in rats, the highest concentration ratios being in the corpus callosum (BBCR: 2.66) and the lowest in the hippocampus (BBCR: 1.47)
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02342512
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 148
    Electronic Resource
    Electronic Resource
    Spontaneous neoplasms in aged sprague-dawley rats (1992)
    Springer
    Archives of toxicology 66 (1992), S. 496-502 
    Details
    ISSN: 1432-0738
    Keywords: Spontaneous ; Tumor ; Neoplasm ; Rodent ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Incidence of neoplastic lesions in untreated Sprague-Dawley rats (1340 males and 1329 females) used as controls in 17 carcinogenicity studies are tabulated and evaluated. In male rats, the most common neoplasms were benign pheochromocytomas and keratoacanthomas (4.0% in each case) followed by pancreatic islet cell adenomas (3.7%), thyroid parafollicular cell adenomas (3.6%), fibromas and squamous cell papillomas of the skin and hepatocellular adenomas (2.0% in each), malignant lymphoma lymphocytic (1.9%), histiocytic sarcomas (1.4%), and adrenal cortical adenomas (1.2%). In female rats, the most common neoplasms were of mammary gland origin (31.3%: fibroadenoma 19.0%, adenocarcinomas 8.8%, and adenomas 3.5%) followed by thyroid parafollicular cell adenomas (2.9%), uterine endometrial stromal polyps (2.6%), adrenal cortical adenomas (1.9%), malignant lymphoma lymphocytic (1.6%), fibromas in the skin (1.3%), and pancreatic islet cell adenoma (1.1%). Metastases were observed from pheochromocytomas, hepatocellular carcinomas, nephroblastomas, renal pelvis transitional cell carcinoma, interstitial cell tumor and seminoma of the testes, Zymbal's gland adenocarcinomas, and mammary adenocarcinomas.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01970675
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 149
    Electronic Resource
    Electronic Resource
    Effects of megadoses of pyridoxine on spermatogenesis and male reproductive organs in rats (1992)
    Springer
    Archives of toxicology 66 (1992), S. 198-203 
    Details
    ISSN: 1432-0738
    Keywords: Pyridoxine ; Vitamin B6 ; Testis ; Reproductive system ; Spermatogenesis ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Although it has been indicated that many neurotoxicants also cause reproductive toxicity, the reproductive toxicity of megadoses of pyridoxine, which is a neurotoxicant, has not been studied. In this paper, we studied the effects of megadoses of pyridoxine on male reproductive organs. Pyridoxine hydrochloride, 125 mg/kg, 250 mg/kg, 500 mg/kg or 1000 mg/kg, daily, was intraperitoneally injected into Wistar male rats 5 days a week for 2 or 6 weeks, and its effects on the male reproductive organs were investigated. After 2 weeks of administration, absolute weights of the testis in the 500 and 1000 mg/kg epididymis in all the exposed groups and prostate gland in the 1000 mg/kg group decreased, and mature spermatid counts in the testis decreased in the 1000 mg/kg group. After 6 weeks administration, the absolute and relative weights of the testis, epididymis, prostate gland and seminal vesicle decreased in the 500 mg/kg and 1000 mg/kg groups, and mature spermatid counts in the testis and sperm counts in the epididymis decreased in these groups. Among the marker enzymes of the testicular cells, LDH-X activity decreased, and β-glucuronidase activity, cytochrome P-450 content and cytochrome b5 content increased in the 1000 mg/kg group. Plasma testosterone concentration did not significantly alter in all the exposed groups. From these results, it was concluded that megadoses of pyridoxine affected the spermatogenesis and decreased reproductive organ weights in the rat.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01974015
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 150
    Electronic Resource
    Electronic Resource
    Experimental data from closed chamber gas uptake studies in rodents suggest lower uptake rate of chemical than calculated from literature values on alveolar ventilation (1992)
    Springer
    Archives of toxicology 66 (1992), S. 291-295 
    Details
    ISSN: 1432-0738
    Keywords: Inhalation ; Mouse ; Pharmacokinetic model ; physiologically-based, two-compartment ; Rat ; Acetone ; 1,3-Butadiene ; 2-Butanone ; 1,1-Dichloroethylene ; 1,1-Difluoroethylene ; 1,2-Epoxybutene-3 ; Ethylbenzene ; Ethylene oxide ; n-Hexane ; Isobutene ; Isoprene ; 2-Nitropropane ; Toluene ; 1,1,1-Trichloroethane ; 1,1,2-Trichloroethane ; Styrene ; m-Xylene
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Experimental data obtained in vivo with the closed-chamber gas uptake technique have been reported for a series of volatile chemicals. Pharmacokinetic analyses of these data have been performed either by using a two-compartment model or physiological models. In the former the transfer rate of chemical from ambient air to body is defined by the clearance of uptake. In the latter models the transfer rate depends on alveolar ventilation, cardiac output, and blood: air partition coefficient. In this communication we describe the quantitative relationship between clearance of uptake and alveolar ventilation, cardiac output, and blood: air partition coefficient. Theoretical values of clearance of uptake were calculated for a variety of volatile chemicals using literature data on alveolar ventilation, cardiac output, and blood: air partition coefficient. For most chemicals the experimentally determined values in rats and mice were about 60% of the theoretical values. This suggests that the inhalatory uptake rate of chemical may be overestimated if literature values of alveolar ventilation are used in physiological pharmacokinetic models for rodents.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02307176
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 151
    Electronic Resource
    Electronic Resource
    Differences in the response of Sprague-Dawley and Lewis rats to bezafibrate: The hypolipidemic effect and the induction of peroxisomal enzymes (1992)
    Springer
    Archives of toxicology 66 (1992), S. 327-333 
    Details
    ISSN: 1432-0738
    Keywords: Bezafibrate ; Rat ; Strain differences ; Lipids ; Marker enzymes ; Peroxisomes ; Mitochondria ; Micro-somes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The effects of bezafibrate administered at 10 and 50 mg/kg/day for 7 days to male Sprague-Dawley (SD) and Lewis rats were investigated in order to determine the interrelation between the changes in serum and hepatic lipid contents and activities of selected peroxisomal, microsomal and mitochondrial enzymes in the two rat strains. In both strains, bezafibrate effectively reduced serum and hepatic lipids, increased the liver weight, induced a proliferation of peroxisomes, and selectively elevated the activities of carnitine acetyltransferase and of the enzymes of the peroxisomal Β-oxidation system. Moreover, immunoblotting revealed that the drug specifically enhanced the concentration of only those peroxisomal enzymes involved in fatty acid Β-oxidation. The data obtained demonstrate that although the responses initiated by bezafibrate are qualitatively similar in both strains, they differ in their magnitude in a dose-dependent manner, with the Lewis strain exhibiting a more pronounced response than the SD rats. These results show that dose-dependent strain differences as well as the generally known species differences should be taken into account in pharmacological and toxicological evaluations of fibrates in rodents. Furthermore, generalization and extrapolation from rodent studies should be treated with great caution.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01973627
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 152
    Electronic Resource
    Electronic Resource
    Cell proliferation induced in the kidneys and livers of rats and mice by short term exposure to the carcinogen p-dichlorobenzene (1992)
    Springer
    Archives of toxicology 66 (1992), S. 503-507 
    Details
    ISSN: 1432-0738
    Keywords: Kidney ; Liver ; Cell proliferation ; Rat ; Mouse ; p-Dichlorobenzene
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Cell proliferation in the kidneys and livers of rats and mice exposed short-term to p-dichlorobenzene (p-DCB) was evaluated by immunohistochemical measurement of bromodeoxyuridine (BrdU) incorporation into nuclei of DNA-synthesizing cells. p-DCB was given by gavage at two doses up to 600 mg/kg body weight for 4 days. The cumulative fraction of proliferating cells was increased in the proximal tubule epithelial cells of male rats at the high dose, but not at the low dose nor in females at either dose using gamma-glutamyl transferase reaction to identify tubular cells. Also, no increase in cell proliferation was found in mouse kidneys. The fractions of proliferating cells in the livers of rats and mice of both sexes were also increased. The increased cell proliferation in only male rat kidney and in the livers of mice of both sexes correlates with the reported carcinogenic effects of p-DCB in those tissues. However, the finding that p-DCB also induced cell proliferation in the livers of rats of both sexes, which were not a site of p-DCB-induced tumors in bioassays, and in female mice at the low dose, which was not affected by an increase in tumors, reveals a lack of concordance and indicates that acute induction of cell proliferation is not sufficient to lead to carcinogenesis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01970676
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 153
    Electronic Resource
    Electronic Resource
    Effects of a single haloperidol application to neonatal and early postnatal rats on the neurotransmitter content in the corpus striatum (1992)
    Springer
    Archives of toxicology 66 (1992), S. 573-579 
    Details
    ISSN: 1432-0738
    Keywords: Neurotransmitter ; Haloperidol ; Rat ; Brain -HPLC
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We investigated the influence of the dopamine antagonist haloperidol on the neurotransmitter content in the developing rat brain. Dopamine (DA), serotonin (5-HT) and the corresponding metabolites dopac, HVA and HIAA were determined in the corpus striatum of the rat between day 1 and day 21 pn by HPLC with electrochemical detection. A consistent increase in the content of dopamine was found during postnatal development. The concentrations (ng/g wet tissue; mean ±standard deviation) increased from 793±237 on day 1 pn to 4584±581 on day 21 pn, but remained still lower than in adult animals (9763±494). Similar results were found for the metabolites dopac and HVA. The content of dopac increased from 59±22 (day 1 pn) to 551±59 (day 21 pn) and the content of HVA from 53±18 (day 1 pn) to 419±41 (day 21 pn). Both metabolites were also about two times lower than in adult animals (dopac 1090± 282, HVA 744± 206). In contrast to dopamine and its metabolites we found no age-dependent changes in the content of 5-HT from day 1 pn (99± 11) to day 14 pn(121±21). A remarkable increase in the content of 5-HT was seen from day 14 pn to day 21 pn (438±56), reaching almost adult levels (570±92). The metabolite HIAA was nearly three times higher on day 21 pn (610±123) than on day 14 pn (223±28) and two times higher than in adults (321±58). One hour after application of haloperidol to the pups (1 mg/kg body wt i.p.) a significant increase (i.e. day 21 pn) of dopac (1755±496) and HVA (966±279), but not of 5-HT (382±72) or HIAA (614±130) was detected.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01973388
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 154
    Electronic Resource
    Electronic Resource
    Effect of age on development of tumours in the intrasplenic ovarian grafts in ovariectomized rats (1992)
    Springer
    Journal of cancer research and clinical oncology 119 (1992), S. 111-116 
    Details
    ISSN: 1432-1335
    Keywords: Aging ; Intrasplenic ovarian grafts ; Ovarian tumours ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Female rats at the age of 1, 3, and 14–16 months (“young”, “adult” and “old” groups respectively) were bilaterally ovariectomized and one of the removed ovaries was autoimplanted into the spleen. The total intrasplenic ovarian tumour incidence was equal in the rats subjected to the operation at 3 and 14–16 months (77.4% and 80.6% respectively) and tumours developed more frequently in rats exposed to surgery at the age of 1 month (94.5%),P〈0.05. The incidence of Sertoli and Leydig cell tumours was increased and their latency was decreased in the old group in comparison to the adult one. In rats exposed to the operation at the age of 3 months, granulosotheca cell tumours developed more frequently than other tumour types, and in the young group thecomas were discovered more often than in both older groups. Dysgerminomas and luteomas were discovered only in intrasplenic grafts of rats of the young group. It is supposed that the differences in structure and proliferative activity of various ovarian tissues between young, adult and old rats at the moment of intrasplenic transplantation, as well as the differences in their response to gonadotropic stimulation play a significant role in the development of ovarian tumours of varied histogenesis in the intrasplenic ovarian grafts.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01209666
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 155
    Electronic Resource
    Electronic Resource
    Clonidine and yohimbine modulate the effects of naloxone on novelty-induced hypoalgesia (1992)
    Springer
    Psychopharmacology 107 (1992), S. 575-580 
    Details
    ISSN: 1432-2072
    Keywords: Novelty hypoalgesia ; Noradrenaline ; Naloxone ; Alpha-2 receptor ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Previous research has shown that repeated daily pretreatment with the opiate receptor blocker naloxone retards the development of habituation to novelty-induced hypoalgesia. The present experiments were conducted in order to determine whether noradrenergic substrates mediate this effect. Animals in the NAL condition were administered 10 mg/kg naloxone prior to assessment of pain sensitivity on a 48.5° C hot plate. Control animals (SAL condition) were administered saline prior to pain assessment, and naloxone 2–4 h later. Paw lick latencies declined over repeated tests in SAL animals, suggesting the habituation of novelty hypoalgesia. Naloxone pretreatment attenuated this decline. The longer paw lick latencies observed in NAL condition animals were reduced by administration of 2 µg/kg clonidine, a specific noradrenergic alpha-2 receptor agonist, and enhanced in a dose dependent (0.5–4.0 mg/kg) fashion by the alpha-2 antagonist yohimbine. Clonidine and yohimbine either failed to alter pain reactivity in control animals, or produced less marked effects than those observed in naloxone-exposed animals. These results suggest that noradrenergic substrates mediate naloxone's effects on novelty hypoalgesia.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02245273
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 156
    Electronic Resource
    Electronic Resource
    Effect of chronic treatment with dizocilpine (MK-801) on the behavioral response to dopamine receptor agonists in the rat (1992)
    Springer
    Psychopharmacology 107 (1992), S. 591-594 
    Details
    ISSN: 1432-2072
    Keywords: MK-801 induced hypermotility ; Repeated treatment ; SCH 23390 ; YM 09151 ; 2 ; LY 171555-induced hyperactivity ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The D2 or D1 dopamine receptor blockers (−)-sulpiride or SCH 23390 antagonized, in a dose dependent manner, the hypermotility induced by the N-methyl-d-aspartate (NMDA) receptor antagonist, MK-801 (0.25 mg/kg IP). MK-801 induced hyperactivity was not detected when rats were observed on days 7, 14 or 21 of 21 daily injections of MK-801. This lack of hyperactivity was also noted 5 days after the last administration of the repeated treatment with MK-801. The hypermotility induced by the D2 dopamine receptor agonist LY 171555 (0.3 mg/kg IP) was reduced 5 days following repeated treatment (21 days) with MK-801, while no change in the behavioral responses to the selective D1 agonist, SKF 38393, or the mixed D1/D2 agent apomorphine was detected. The results, although suggesting the involvement of dopaminergic pathways in the behavioral effect of MK-801, are conflicting with regard to the underlying mechanisms and to the adaptive changes of dopaminergic system following repeated NMDA receptor blockade.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02245275
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 157
    Electronic Resource
    Electronic Resource
    Effect of established and putative anxiolytics on extracellular 5-HT and 5-HIAA in the ventral hippocampus of rats during behaviour on the elevated X-maze (1992)
    Springer
    Psychopharmacology 109 (1992), S. 338-346 
    Details
    ISSN: 1432-2072
    Keywords: Microdialysis ; 5-HT ; Ventral hippocampus ; Elevated X-maze ; Diazepam ; Ipsapirone ; F2692 ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract One of the proposed mechanisms of action for the anxiolytic effects of the benzodiazepines is via a decrease in central serotonergic neurotransmission. The aim of this study was to combine in vivo microdialysis in the rat with behaviour on the elevated X-maze to determine changes in 5-HT release in the ventral hippocampus with concomitant measurement of behaviour. Twenty minutes exposure to the elevated X-maze resulted in an increase in extracellular 5-HT in the ventral hippocampus with no change in extracellular 5-HIAA. Restricting the rat to either the open or the closed arms produced an increase in extracellular 5-HT, however the increase in 5-HT when restricted to the open arms was not significantly greater than that on the closed arms. Forty minutes pretreatment with diazepam (2.5 mg kg−1 IP) significantly inhibited the increase in extracellular 5-HT in the ventral hippocampus and had an anxiolytic profile over 5 min and 20 min exposures of the rats to the X-maze. Diazepam had no effect on basal 5-HT levels before exposure to the X-maze but reduced extracellular 5-HT levels when the animal was returned to the holding cage. Forty minutes pretreatment with the 5-HT1A receptor partial agonist ipsapirone (1 mg kg−1 IP) significantly inhibited the increase in extracellular 5-HT in the ventral hippocampus but did not produce behaviour different from vehicle controls after 5 or 20 min periods on the X-maze. Ipsapirone had no effect on basal 5-HT levels before exposure to the X-maze but reduced extracellular 5-HT levels when the animal was returned to the holding cage. Forty minutes pretreatment with the novel anxiolytic F2692 (10 mg kg−1 IP) significantly inhibited the increase in extracellular 5-HT in the ventral hippocampus and had an anxiolytic profile over the 5 min but not the 20 min period when the rat was on the X-maze. F2692 reduced basal extracellular 5-HT levels both 20 min before exposure to the X-maze and when the animal was returned to the holding cage. The results are discussed based on the effects of these compounds on basal and elevated extracellular 5-HT levels and their behavioural profile on the X-maze.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02245882
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 158
    Electronic Resource
    Electronic Resource
    Renal tubular reabsorption of 1,5-anhydro-D-glucitol and D-mannose in vivo in the rat (1992)
    Springer
    Pflügers Archiv 420 (1992), S. 367-375 
    Details
    ISSN: 1432-2013
    Keywords: D-Mannose ; 1,5 Anhydro-D-glucitol ; Renal tubular reabsorption ; In vivo ; Loading test ; Stereospecific requirements ; Anhydrosugars ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract 1,5-Anhydro-D-glucitol (AG) is efficiently reabsorbed in renal tubuli by a mechanism that is saturated at high AG concentrations. To gain insight into the stereospecific requirements of the mechanism, we employed an in vivo loading test technique in which rats were injected with anhydrosugars and aldohexoses in doses that led to excretion of the sugar injected, thus saturating tubular reabsorption. Administration of AG elicited an increase in the excretion of D-mannose (P〈0.0005), while D-mannose caused AG to appear in urine. Administration of 1,5-anhydro-D-mannitol led to increased excretion of D-mannose (P〈0.0005) and the appearance of AG in urine. The effects of 1,5-anhydro-D-mannitol on the excretion of D-mannose and AG, and the effect of D-mannose on AG were dependent on the dose. Myoinositiol, mannitol and C-3–C-6 epimers of AG did not interfere with the reabsorption. The mechanism was highly phlorizin-sensitive. Repeated administration of 1,5-anhydro-D-mannitol rapidly depleted the rat organism from mobilizable AG. The AG space calculated (53% of body weight) suggested the presence of considerable cellular stores of AG. D-Mannose and AG are regular components of the plasma monosaccharide profile. The data suggest that the two sugars are reabsorbed in renal tubuli by a common mechanism, which is distinct from the main D-glucose reabsorption system. The presence of a glucose-type C-3–C-6 and pyranose structure is required for a sugar to be transported by the system. The mechanism accommodates both an axial and an equatorial hydroxyl group at C-2, but a hydroxyl group at C-1 is not required.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00374472
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 159
    Electronic Resource
    Electronic Resource
    Ion conductances of isolated cortical collecting duct cells (1992)
    Springer
    Pflügers Archiv 421 (1992), S. 381-387 
    Details
    ISSN: 1432-2013
    Keywords: Rat ; Cell isolation ; K+ channels ; Na+-conductance ; Patch clamp ; Cell-attached-nystatin technique
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The study of ion conductances in the intact cortical collecting duct (CCD) with the patch-clamp method is rather difficult. An optimized method to isolate CCD cells from rat kidneys using an in vivo followed by an in vitro enzyme digestion is described. Individual CCD segments were collected after this digestion and incubated in EGTA-buffered medium. This procedure resulted in single cells or cell clusters. These freshly isolated CCD cells were studied with different modifications of the patch-clamp method. Membrane voltages measured in the cell-attached-nystatin configuration were −74 ±1mV (n=13) and −68±3 mV (n=22) in cells isolated from normal and mineralocorticoid-treated rats respectively. These values and those measured with the nystatin-perforated slow-whole-cell configuration (−79 ±1mV, n=23) are comparable to those measured in principal cells of isolated CCD segments. The cells hyperpolarized after the addition of amiloride and depolarized with the addition of adiuretin to the bath. The amiloride effect was enhanced when cells were isolated from deoxycorticosterone-acetate-treated rats. The cells were strongly depolarized upon elevation of the extracellular K+-concentration and did not demonstrate a measurable Cl− conductance. A large-conductance K+ channel (174 pS, n=5, cell-attached, 145 mmol/l K+ in the pipette; 140 pS, n=12, cell-free, 3.6 mmol/l K+ in the bath) was seen. It had a very low activity on the cell, but a high open probability when excised into a solution with 1 mmol/l Ca2+ on the cytosolic side. More often a small-conductance K+ channel (36–52 pS, n=19, cell-attached; 30 pS, n=5, cell-free) with a high open probability was found on the cell. These freshly isolated cells seem to be a powerful preparation to study the properties and regulation of ion conductances of rat CCD with several electrophysiological methods. These freshly isolated CCD cells maintain the conductance properties known from principal cells of the intact CCD.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00374227
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 160
    Electronic Resource
    Electronic Resource
    Inhibitory serotonergic effects on rostral ventrolateral medullary neurons (1992)
    Springer
    Pflügers Archiv 422 (1992), S. 93-97 
    Details
    ISSN: 1432-2013
    Keywords: 5-Hydroxytryptamine ; 5-HT1A receptor ; Rostral ventrolateral medulla ; Rat ; Sympathoexcitatory drive
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In rats anaesthetised with urethane, iontophoretic application of 5-hydroxytryptamine (5-HT) and the 5-HT1A agonists buspirone, flesinoxan and 8-hydroxy-2-(di-n-propylamino)-tetralin inhibited ongoing or amino-acid-evoked activity of neurons in the rostral ventrolateral medulla (RVLM) including barosensitive cells with spinally projecting axons. More than 90% of cells tested were inhibited by these agonists. In 5/9 cells the inhibition was reduced after intravenous spiperone (0.6 mg/kg). These results suggest that the sympathoinhibitory effects produced by microinjection of 5-HT1A agonists into the RVLM are due to a direct inhibitory action on neurons that send excitatory projections to the spinal sympathetic outflow.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00370407
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 161
    Electronic Resource
    Electronic Resource
    Changes in ventilatory response to hypoxia in the rat during growth and aging (1992)
    Springer
    Pflügers Archiv 421 (1992), S. 200-203 
    Details
    ISSN: 1432-2013
    Keywords: Growth and aging ; Rat ; Ventilatory response to hypoxia ; Hypoxic ventilatory depression ; Metabolic rate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The influence of aging on the ventilatory response to hypoxia was studied in the halothane-anesthetized male Wistar rats of various ages (1.5–20 months). The magnitude of increase in ventilation (normalized for body weight) during hypoxia in isocapnic conditions was attenuated in parallel with advancing age. However, ventilation in hyperoxia, normoxia or mild hypoxia did not differ among various age groups when the ventilatory volume was normalized for O2 consumption. Furthermore, threshold end-tidal PO 2 for ventilatory depression in deeper hypoxia became progressively lower with advancing age. The results suggest that the age change in ventilatory response to hypoxia depends largely upon the progressive reduction in basal O2 requirement (consumption) with age.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00374827
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 162
    Electronic Resource
    Electronic Resource
    Quinolinate-like neurotoxicity produced by aminooxyacetic acid in rat striatum (1992)
    Springer
    Amino acids 2 (1992), S. 245-253 
    Details
    ISSN: 1438-2199
    Keywords: Amino acids ; Aminooxyacetic acid ; Neostriatum ; Kynurenic acid ; N-Methyl-D-aspartic acid ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The endogenous tryptophan metabolite quinolinic acid elicits in rodent brain a pattern of neuronal degeneration which resembles that caused by L-glutamate. Its qualities as a neurotoxic agent raised the hypothesis that quinolinic acid might be involved in the pathogenesis of human neurodegenerative disorders. Kynurenic acid, another endogenous tryptophan metabolite and preferential N-methyl-D-aspartate (NMDA) antagonist, has been shown to block quinolinic acid neurotoxicity. Here we report that microinjections of aminooxyacetic acid (AOAA), an inhibitor of kynurenine transaminase and of other pyridoxal phosphate-dependent enzymes, into the rat striatum produce neuronal damage resembling that caused by quinolinic acid. AOAA-induced striatal lesions can be prevented by kynurenic acid and the selective NMDA antagonist 2-amino-7-phosphonoheptanoic acid. These results suggest that AOAA produces excitotoxic lesions by depleting brain concentrations of kynurenic acid (inhibition of synthetic enzyme) or due to impairment of intracellular energy metabolism (depletion of cell energy resources). The concept of deficient neuroprotection due to metabolic defects might help to clarify the pathogenesis of human neurodegenerative disorders and to develop strategies that may be useful in their treatment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00805946
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 163
    Electronic Resource
    Electronic Resource
    Analgesic and discriminative stimulus properties of U-62,066E, the selective kappa-opioid receptor agonist, in the rat (1992)
    Springer
    Psychopharmacology 106 (1992), S. 31-38 
    Details
    ISSN: 1432-2072
    Keywords: Kappa-opioid agonist ; U-62,066E ; Morphine ; Analgesia ; Drug discrimination ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The analgesic and discriminative stimulus properties of U-62,066E, a selective kappa-opioid receptor agonist, were investigated in the rat and compared with those of morphine. In the hot-plate test, U-62,066E produced a potent analgesic effect almost comparable to that of morphine. U-62,066E-induced analgesia was far less sensitive to antagonism by naloxone than was morphine-induced analgesia, but was potently reversed by MR-2266, a kappa-receptor antagonist. Although tolerance occurred to both U-62,066E and morphine analgesia, there was no cross-tolerance between these drugs. U-62,066E did show cross-tolerance to U-50,488H, another selective kappa-receptor agonist. Rats were trained to discriminate either 1.0 mg/kg U-62,066E or 3.2 mg/kg morphine from saline in a two-lever food-reinforced procedure. The stimulus effect of U-62,066E was substituted for by U-50,488H and E-2078 a stable dynorphin derivative, but not by morphine. None of the kappa-agonists substituted for the morphine stimulus. Although U-62,066E stimulus by itself was not antagonized by MR-2266 or naloxone up to as high a dose as 10 mg/kg, the U-62,066E-like stimulus effect of U-50,488H was markedly blocked by MR-2266. The dopamine antagonists haloperidol and sulpiride substituted for the U-62,066E stimulus cue that was, however, not attenuated by the dopamine agonist lisuride. Lisuride reversed the U-62,066E-like stimulus induced by U-50,488H. These findings indicate that U-62,066E has a potent analgesic effect that is mediated predominantly by kappa-opioid receptors, and that U-62,066E stimulus is, in contrast to its analgesic effect, based not only on the compound's kappa-agonist action and consequent inhibition of dopaminergic activity but also on the non-opioid mechanisms.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02253585
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 164
    Electronic Resource
    Electronic Resource
    Cocaine enhances retention of avoidance conditioning in rats (1992)
    Springer
    Psychopharmacology 106 (1992), S. 383-387 
    Details
    ISSN: 1432-2072
    Keywords: Cocaine ; Memory ; Active avoidance ; Retention ; Time dependency ; Lidocaine ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The effects of post-training cocaine administration were tested on retention of a one-way active avoidance task in rats. A 5.0 mg/kg IP dose of cocaine enhanced retention of the avoidance task, in three separate experiments, as indicated by an increase in the number of avoidances made when animals were tested 24 h after training, while both a lower (2.5 mg/kg) and a higher (7.5 mg/kg) cocaine dose had no effect. Lidocaine (4–8 mg/kg) administered post-training did not reliably affect retention in the same task. Cocaine's ability to enhance retention depended on the interval between training and drug injection such that only cocaine administered directly after training enhanced retention the following day. The results show that post-training cocaine administration enhances retention of an active avoidance task in rats, and that this effect is probably independent of the anesthetic properties of the drug.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02245422
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 165
    Electronic Resource
    Electronic Resource
    Effects of chronically administered fluoxetine and fenfluramine on food intake, body weight and the behavioural satiety sequence (1992)
    Springer
    Psychopharmacology 106 (1992), S. 401-407 
    Details
    ISSN: 1432-2072
    Keywords: Feeding ; Body weight ; Fluoxetine ; Fenfluramine ; Behavioural satiety sequence ; Chronic drug treatment ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Rats were administered fenfluramine (FF: 3 mg/kg) or fluoxetine (FX: 6 mg/kg) daily for 3 weeks. On acute administration, FF suppressed consumption of 35% sucrose (in a 40 min test) and overnight chow intake. Repeated administration saw the rapid development of extensive tolerance to these effects. FF had no effects on body weight, and no withdrawal effects were apparent. FX reduced chow intake and body weight throughout the treatment period, but there was evidence of some tolerance to the suppression of chow intake and sucrose drinking. Following FX withdrawal, normal body weight was restored in 4 days; food intake was normal during this period. A delayed rebound hyperphagia commenced on day 5 of withdrawal, and persisted for at least 6 days. The behavioural satiety sequence (drinking -activity - grooming - resting) was disrupted by acute FF; on chronic treatment, FF advanced the onset of postprandial resting, but also increased drinking time. FX advanced the behavioural satiety sequence on acute administration, but not after chronic treatment. We consider the implications of these results for the use of resting behaviour as an indicator of postprandial satiety.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02245426
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 166
    Electronic Resource
    Electronic Resource
    Anxiolytic effect of carbamazepine in the elevated plus-maze: possible role of adenosine (1992)
    Springer
    Psychopharmacology 106 (1992), S. 85-89 
    Details
    ISSN: 1432-2072
    Keywords: Carbamazepine ; Papaverine ; Aminophylline ; Elevated plus-maze ; Adenosine ; Anxiety ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In order to extend previously reported observations with other animal models of anxiety, the effect of carbamazepine (CBZ) was presently measured in rats placed on the elevated plus-maze. Intraperitoneal injection of CBZ (5–40 mg/kg) increased the percentage of open arm entries as well as the percentage of time spent on the open arms of the maze, without affecting the total number of arm entries. This effect is characteristic of anxiolytic drugs. The inhibitor of adenosine neuronal uptake papaverine (5–40 mg/kg) caused a similar anxiolytic effect, whereas the adenosine receptor antagonist aminophylline (1–4 mg/kg) selectively decreased the percentage of open arm entries, indicative of an anxiogenic effect. Furthermore, the combination of an anxiogenic dose (4 mg/kg) of aminophylline with an anxiolytic dose (40 mg/kg) of CBZ resulted in cancellation of each other effects. Since reported neurochemical evidence shows that CBZ interacts with adenosine receptors, the present results provide preliminary support for a participation of this neurotransmitter in the anxiolytic action of CBZ.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02253593
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 167
    Electronic Resource
    Electronic Resource
    Effect of peripheral administration of cinnarizine and verapamil on the abstinence syndrome in diazepam-dependent rats (1992)
    Springer
    Psychopharmacology 106 (1992), S. 127-130 
    Details
    ISSN: 1432-2072
    Keywords: Verapamil ; Cinnarizine ; Diazepam ; Withdrawal hyperactivity ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The effects of two calcium channel blockers (verapamil and cinnarizine) were evaluated on diazepam withdrawal symptoms. Rats were made diazepam dependent by chronic treatment with daily injections of the drug, 20 mg/kg IP for 3 weeks. On abrupt termination of the drug, animals showed withdrawal hyperactivity that was assessed by autonomic, behavioural and motor signs. The peak effect was seen 3 days after the withdrawal of diazepam. On IP administration, verapamil and cinnarizine (10, 20 and 40 mg/kg) given on eight occasions at an interval of 12 h reversed the withdrawal-induced increase in spontaneous motor activity. Cinnarizine in higher doses (20 and 40 mg/kg) was found to be effective in suppressing the behavioural signs but verapamil did not show any protective effect against startle response and irritability. These results suggest that modulation of the calcium influx in the CNS might influence withdrawal.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02253599
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 168
    Electronic Resource
    Electronic Resource
    Behavioral analysis of diazepam-induced memory deficits: evidence for sedation-like effects (1992)
    Springer
    Psychopharmacology 106 (1992), S. 297-302 
    Details
    ISSN: 1432-2072
    Keywords: Diazepam ; Benzodiazepine ; Delay-dependent memory ; Behavioral variability ; Sedation ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Rats were trained on a nonmatching-to-sample task with delays of 2, 5, and 10 min. Subsequently, performance was assessed in three groups of rats following treatment with saline or diazepam (2.0 mg/kg) administered acutely or tested chronically in six administrations. Relative to treatment with saline, diazepam produced a deficit in discrimination performance, which was greater in the acutely treated rats than in those treated chronically. The deficit was not dependent on the length of the delays. Diazepam-treated animals differed from controls in erring on trials in which they failed to investigate both test objects, failed to investigate the test object for a long enough period of time, and displaced the test object on the preferred side of the apparatus. The hypothesis that these effects represented a sedation-like reduction in behavioral variability was also supported by evidence of a diazepam-induced decrease in gross bodily activity, increase in inactivity, and increase in latencies to respond to objects. No support was found for the involvement of diazepam-induced changes in habituation, extinction, or reward effects.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02245408
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 169
    Electronic Resource
    Electronic Resource
    Effect of the 5-HT3 receptor antagonists, MDL72222 and ondansetron on morphine place conditioning (1992)
    Springer
    Psychopharmacology 106 (1992), S. 315-320 
    Details
    ISSN: 1432-2072
    Keywords: Morphine ; 5-HT3 receptor ; Ondansetron ; MDL72222 ; Rat ; Place conditioning ; Reward
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The purpose of the present study was to reassess the original findings of Carboni et al. (1988) who suggested that 5-HT3 receptor antagonists may block morphine-induced place conditioning in rats. These workers used a biased protocol with treatments allocated to compartments based on initial preference. In the present study we have adopted an unbiased approach with treatments randomly assigned to conditioning compartment in a counter-balanced fashion. Thus treatments were equally paired between distinct environmental cues. Using this protocol, morphine produced a dose-related place preference (0.3–3 mg/kg SC). Thirty-minute pretreatment with the selective 5-HT3 antagonists, MDL72222 (1 mg/kg SC) and ondansetron (0.01 mg/kg SC) before morphine (1.5 mg/kg SC), significantly antagonized the place conditioning to this treatment. However, with higher doses of ondansetron (0.1–1 mg/kg SC), the antagonism of morphine-induced place preference became variable and dependent on the conditioning compartment. This was probably a reflection of the fact that ondansetron when administered alone also appeared to produce an environmentally dependent place conditioning at these doses. Therefore it is concluded that at certain doses, 5-HT3 receptor antagonists may antagonize morphine place conditioning in a manner consistent with a blockade of the appetitive effects of this drug. However, at higher doses, at least with ondansetron, this antagonism became non-specific and dependent on the training environment. It is suggested that other animal models of opioid reinforcement (e.g., self-administration) are now needed to validate the hypothesis that 5-HT3 receptor antagonists may modify opioid reward.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02245411
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 170
    Electronic Resource
    Electronic Resource
    Conditioned locomotor activity but not conditioned place preference following intra-accumbens infusions of cocaine (1992)
    Springer
    Psychopharmacology 106 (1992), S. 330-336 
    Details
    ISSN: 1432-2072
    Keywords: Conditioned place preference ; Conditioned locomotor activity ; Cocaine ; Amphetamine ; Nucleus accumbens ; Reward ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In the first experiment, the conditioned place preference (CPP) paradigm was used to examine the rewarding properties of bilateral microinfusions of cocaine HCl into the nucleus accumbens (0, 12.5, 25, 50, or 100 µg). No dose of intra-accumbens cocaine induced a significant CPP. However, bilateral intra-accumbens infusions ofd-amphetamine sulfate (10 µg) or intraperitoneal administration of cocaine HCl (5 or 10 mg/kg) both produced a significant preference for the drug-paired compartment. In the second experiment, the ability of bilateral intra-accumbens infusions of cocaine HCl (50 µg) to elicit conditioned locomotor activity (CLA) was examined. During the conditioning trials, intra-accumbens cocaine significantly increased locomotor activity. On the test day, when no drug was administered, the group that had previously received cocaine in the activity chamber showed significantly greater locomotor activity than the vehicle control group. This demonstration of CLA indicates that rats are able to associate the effects of intra-accumbens infusions of cocaine with environmental stimuli; however, these infusions are not rewarding as measured by the CPP paradigm. In addition, these results may indicate important differences between the neural substrates for cocaine and amphetamine reward and reveal a dissociation between CPP and CLA.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02245413
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 171
    Electronic Resource
    Electronic Resource
    The kappa-opioid U-50,488H suppresses the initiation of nocturnal spontaneous drinking in normally hydrated rats (1992)
    Springer
    Psychopharmacology 106 (1992), S. 463-473 
    Details
    ISSN: 1432-2072
    Keywords: U-50,488H ; Kappa-agonists ; Kappa-receptors ; Opioids ; Drinking ; Feeding ; Satiety ; Motivation ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The effect of a systemic (IP) treatment with 1.0, 3.0 and 9.0 mg/kg U-50,488H (U50), a highly selective kappa-agonist, on spontaneous, nocturnal ingestive behavior of the rat was studied using a microcomputer controlled data acquisition system. The latency to initiate drinking was increased and drinking behavior was suppressed in the first hour after injection in a dose-dependent manner. The consummatory indices of drinking were not affected. After this period of adipsia, a phase of polydipsia, that was probably due to the diuretic effect of U50, was evident. The prophagic effect of U50 was evident only at the dose of 3 mg/kg and was accompanied by an increased duration of feeding episodes but not by a reduced latency to feed. These results suggest that kappa-receptors play a pivotal role in modulating spontaneous drinking in the normally hydrated rat and that this control is mainly exerted on the motivational aspect of drinking.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02244816
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 172
    Electronic Resource
    Electronic Resource
    Behavioural tests of the dopamine depletion hypothesis of neuroleptic-induced response decrement (1992)
    Springer
    Psychopharmacology 106 (1992), S. 543-549 
    Details
    ISSN: 1432-2072
    Keywords: Pimozide ; Response decrement ; Random-interval reinforcement schedules ; Motor activation ; Wheel-running ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract This study was carried out to test the hypothesis that neuroleptic-induced within-session response decrements reflect a fatigue process, resulting from dopamine depletion, that is present before the session begins but is masked briefly by activational cues present at the start of the session. Response decrementing effects of pimozide were examined in rats lever pressing on random interval schedules of food reinforcement. An initial experiment was carried out to rule out a pharmacokinetic explanation of the response decrement. In a second experiment, the response decrement was not exacerbated by an immediately preceding period of intense forced motor activity (wheel running). Experiments 3 and 4 tested two further predictions: that the pimozide-induced response decrement should be overcome by removing the animal to its home cage and then replacing it in the apparatus (thereby reinstating the activational cues present at the start of the session); and that response impairments should be present from the outset if the animal is confined in the apparatus prior to the start of the session (thereby allowing activational cues to dissipate). Neither prediction was confirmed. Overall, the results provide no support for the dopamine depletion hypothesis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02244828
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 173
    Electronic Resource
    Electronic Resource
    Effects of the triazole derivative loreclezole (R72063) on stimulus induced ionic and field potential responses and on different patterns of epileptiform activity induced by low magnesium in rat entorhinal cortex-hippocampal slices (1992)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 346 (1992), S. 581-587 
    Details
    ISSN: 1432-1912
    Keywords: Calcium ; Epileptiform activity ; Loreclezole ; Low magnesium ; Rat ; Entorhinal cortex-hippocampus slices
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Effects of loreclezole (R72063), a triazole derivative with anticonvulsant properties, were studied on field potentials in rat hippocampal slices and on different patterns of low Mg2+-induced epileptiform activity in combined entorhinal cortex-hippocampal slices. Lowering extracellular Mg2+ induced recurrent (10–60/min), short (40 – 80 ms) discharges in hippocampal areas CA1 and CA3. In the entorhinal cortex (EC) up to 90 s long ictaform events associated with large negative field potential and changes in the neuronal microenvironment were generated. These seizure like events changed their characteristics after one to two hours to recurrent discharges of 0.8 to 10 s. 20 μM loreclezole blocked the seizure like events in the entorhinal cortex completely 30–80 min after onset of application. The recurrent short discharges in the hippocampus were reliably blocked by 40 μM loreclezole 60 – 90 min after bath application with incomplete recovery after washout of several hours. The recurrent discharges in the entorhinal cortex were reliably blocked by 80 μM loreclezole applied for 80–100 min. Decreases in [Ca2+]0 and associated slow field potentials evoked by repetitive stimulation of the stratum radiatum were depressed in a dose dependent manner, while similar changes induced by alvear stimulation remained almost unaffected. A paired pulse stimulus paradigm used to test for effect of loreclezole on synaptically evoked transient field potentials in normal medium revealed interference with mechanisms involved in frequency potentiation. While responses to alvear stimulation were largely unaffected, the response to a paired pulse stimulus to stratum radiatum was depressed over the whole range of tested stimulus intervals (15 to 150 ms). The findings suggest that loreclezole has effects on different patterns of epileptiform activity induced by extracellular low Mg2+ possibly by interfering with processes leading to frequency potentiation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00169016
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 174
    Electronic Resource
    Electronic Resource
    Effect of dilazep dihydrochloride against ischemia and reperfusion-induced disruption of blood-brain barrier in rats: a quantitative study (1992)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 345 (1992), S. 485-488 
    Details
    ISSN: 1432-1912
    Keywords: Dilazep dihydrochloride ; Blood-brain barrier ; Rat ; Cerebral ischemia ; Evans blue dye
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effect of dilazep dihydrochloride (dilazep) against ischemia and reperfusion-induced disruption of blood-brain barrier (BBB) was quantitatively investigated in Slc:Wistar strain rats using Evans blue dye as a BBB destruction indicator. The forebrain of sham-operated animal had a small amount of the dye. A treatment of 3.5-h ischemia plus 2-h reflow extravasated the dye into the brain and markedly increased the dye content as compared with that of sham group (P 〈 0.01 vs. sham group). Continuous infusion (i.v.) of dilazep during cerebral ischemia dose-dependently reduced the increase of the dye content, and a significant reduction was found at 3 mg/kg/h (P 〈 0.05 vs. control group). Evans blue dye extravasation after ischemia was also greatly reduced in saline-perfused brains by the treatment with dilazep. Dilazep has been reported to inhibit edema formation in cerebral ischemia model of spontaneously hypertensive rats. These results suggest that dilazep prevents the ischemic damage of BBB, which may contribute to reduction of the brain edema.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00176629
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 175
    Electronic Resource
    Electronic Resource
    Involvement of µ-opioid receptors in the antitussive effects of pentazocine (1992)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 345 (1992), S. 203-208 
    Details
    ISSN: 1432-1912
    Keywords: Pentazocine ; Antitussive effect ; Cough reflex ; Analgesia ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effect of pentazocine on the capsaicininduced cough reflex in rats was investigated. Intraperitoneal injection of pentazocine, in doses from 1 to 10 mg/kg, significantly decreased the number of coughs in a dose-dependent manner. The antitussive effect of pentazocine (10 mg/kg, i.p.) was significantly reduced by prior injection of naloxone (0.3 mg/kg, i.p.), but it was unaffected by Mr-2266 BS (5 mg/kg, i.p.), an antagonist of κ-opioid receptors. The antinociceptive potency of pentazocine (30 mg/kg, i.p.), as determined by the formalin test, was significantly reduced by pretreatment with Mr-2266 BS (5 mg/kg, i.p.), whereas naloxane (0.3 mg/ kg, i.p.) had no significant effect on the antinociceptive effect of pentazocine. The antitussive effects of pentazocine (3 mg/kg) and morphine (0.1 mg/kg) were significantly enhanced in rats treated chronically with naloxone (5 mg/kg/day, 5 days), whereas the antitussive effect of U-50,488 H (1 mg/kg, i.p.), a selective κ-opioid agonist, was not enhanced in these rats. By contrast, the antinociceptive effect of morphine (0.01 mg/kg, i.p.) was significantly enhanced in rats that had been pretreated chronically with naloxone. However, the antinociceptive effects induced by pentazocine (3 mg/kg, i.p.) and U-50,488 H (1 mg/kg, i.p.) were unchanged. These results suggest that pentazocine-induced antitussive effects in rats are mediated via stimulation of µ-opioid receptors.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00165737
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 176
    Electronic Resource
    Electronic Resource
    Effects of the local application of 3-PPP and sulpiride enantiomers into the nucleus accumbens or into the ventral tegmental area on rat locomotor activity: evidence for the functional importance of somatodendritic autoreceptors (1992)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 345 (1992), S. 516-522 
    Details
    ISSN: 1432-1912
    Keywords: 3-PPP ; Sulpiride ; Enantiomers ; Dopamine ; Autoreceptors ; Localization ; Locomotor activity ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The present series of experiments was performed in order to determine the relative role of presynaptic and somato-dendritic autoreceptors for the sedative effects produced by systemically administered dopaminergic agonists. Thus, the effects of intracerebral administration of 3-(3-hydroxyphenyl)-N-n-propylpip-eridine (3-PPP), or sulpiride, enantiomers on spontaneous locomotor activity was investigated in rats. It was found that the local application of (−)3-PPP, but not (+)3-PPP, into the nucleus accumbens (1.25–80.0 μg, bilaterally) produced a suppression of the locomotor activity, whereas the local application of the two enantiomers into the ventral tegmental area resulted in a suppression of the locomotor activity in the same dose range. Thus, the full dopamine D2 agonist (+)3-PPP produced suppression of locomotor activity only after local application into the somato-dendritic region, suggesting that in terminal areas postsynaptic receptor stimulation effectively counterbalanced the functional consequences of presynaptic receptor stimulation. The sulpiride enantiomers both produced a suppression of locomotor activity after local application into the accumbens (0.2-5.0 μg, bilaterally). In the ventral tegmental area, however, (−)sulpiride administration (0.25.0 μg, bilaterally) resulted in an increased locomotion, whereas the (+)enantiomer produced no effect or, at the highest dose (5.0 μg), a suppression of the locomotor activity. These observations indicate that for a dopamine D2 antagonist, the postsynaptic receptor blockade in the terminal region, resulting in behavioral suppression, not only counteract compensatory effects produced via the presynaptic receptor in this region, but also to a great extent overshadow the functional consequences of somatodendritic autoreceptor blockade. The results also demonstrate that the dopamine receptor agonist [(+)3PPP], a partial agonist [(−)3-PPP] and an antagonist [(−)sulpiride], each produce distinct functional effects when considering their effects at postsynaptic dopamine receptors in projection areas of the ventral striatum together with their effects at dopamine autoreceptors in the cell body region of the ventral tegmental area. It is concluded that autoreceptor-mediated sedative effects of dopamine receptor agonists, as observed upon systemic administration in the normal animal, primarily are mediated via dopamine autoreceptors in the cell body region.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00168942
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 177
    Electronic Resource
    Electronic Resource
    Receptor-mediated and adsorptive endocytosis by male germ cells of different mammalian species (1992)
    Springer
    Cell & tissue research 268 (1992), S. 471-478 
    Details
    ISSN: 1432-0878
    Keywords: Testis ; Endocytosis ; Spermatogenesis ; Spermatogonia ; Spermatocytes ; Spermatids ; Transferrin ; Ferritin ; Sertoli cells ; Mouse ; Rat ; Monkey, Macaca fascicularis (Primates)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The routes for adsorptive and receptor-mediated endocytosis were studied in vivo after microinjection of tracers into the lumen of the seminiferous tubules, and in vitro in isolated germ cells of different mammals. Cationic ferritin was located on the plasma membrane, in vesicles, in tubules, in multivesicular bodies and in lysosome-like granules of mouse spermatocytes. In these cells the number of multivesicular bodies varied during spermatogenesis. Spermatids and to a lesser extent residual bodies also performed adsorptive endocytosis. In the rat and monkey (Macaca fascicularis) diferric transferrin was specifically taken up by germ cells via receptor-mediated endocytosis. The labelling was observed subsequently in membrane pits, vesicles, endosome-like bodies and pale multivesicular bodies. A progressive decrease in the frequency of the labelling of the germ cells by transferrin-gold particles was observed from spermatogonia to spermatocytes and to early spermatids, which could indicate that iron is particularly required by germ cells during the mitotic and meiotic processes. Adsorptive and receptor-mediated endocytosis therefore occurs in all classes of germ cells. These endocytic processes are most probably required for germ cell division, differentiation and metabolism.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00319154
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 178
    Electronic Resource
    Electronic Resource
    Effects of whole body microwave exposure on the rat brain contents of biogenic amines (1992)
    Springer
    European journal of applied physiology 65 (1992), S. 124-128 
    Details
    ISSN: 1439-6327
    Keywords: Microwave ; Biogenic amines ; Brain ; Rat ; Hyperthermia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effects of whole body microwave exposure on the central nervous system (CNS) of the rat were investigated. Rats weighing from 250 to 320 g were exposed for 1 h to whole body microwave with a frequency of 2450 MHz at power densities of 5 and 10 mW·cm−2 at an ambient temperature of 21–23°C. The rectal temperatures of the rats were measured just before and after microwave exposure and mono-amines and their metabolites in various discrete brain regions were determined after microwave exposure. Microwave exposure at power densities of 5 and 10 mW·cm−2 increased the mean rectal temperature by 2.3°C and 3.4°C, respectively. The noradrenaline content in the hypothalamus was significantly reduced after microwave exposure at a power density of 10 mW·cm−2. There were no differences in the dopamine (DA) content of any region of the brain between microwave exposed rats and control rats. The dihydroxyphenyl acetic acid (DOPAC) content, the main metabolite of DA, was significantly increased in the pons plus medulla oblongata only at a power density of 10 mW·cm−2. The DA turnover rates, the DOPAC:DA ratio, in the striatum and cerebral cortex were significantly increased only at a power density of 10 mW·cm−2 The serotonin (5-hydroxytryptamine, 5-HT) content in all regions of the brain of microwave exposed rats was not different from that of the control rats. The 5-hydroxyindoleacetic acid (5-HIAA) content in the cerebral cortex of microwave exposed rats was significantly increased at power densities of 5 and 10 mW·cm−2. The 5-HT turnover rates and the 5-HIAA:5-HT ratio were significantly increased in the cerebral cortex at a power density of 5 mW·cm−2. Significant increases in the 5-HT turnover rate were observed in the pons plus medulla oblongata and hypopthalamus at a power density of 10 mW·cm−2. These results indicated that whole body microwave exposure with a frequency of 2450 MHz at power densities of 5 and 10 mW·cm−2 affected the function of mono-aminergic neurons in the rat brain. It would seem that the effects of whole body microwave exposure on the CNS can be attributed to the hyperthermia characteristic of microwave exposure, although the direct effects of microwave irradiation on the CNS cannot be completely discarded.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00705068
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 179
    Electronic Resource
    Electronic Resource
    Effect of light history on the rat retina: Timecourse of morphological adaptation and readaptation (1992)
    Springer
    Neurochemical research 17 (1992), S. 91-99 
    Details
    ISSN: 1573-6903
    Keywords: Rat ; light history ; rod outer segment ; morphology ; adaptation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Sprague Dawley rats were born and raised under either 5 or 800 lux cyclic light (12L:12D) and were sacrificed at 1, 2, 3, 6, 12, 16, and 28 weeks of age. At each time point outer nuclear layer (ONL) area and rod outer segment (ROS) length were measured. The former is an estimation of photoreceptor number, and the latter is an estimation of the photon-catching integrity of the retina, both of which are known to be dependent on the light environment. Regression analysis revealed an ONL area reduction with time of 0.003 mm2/wk for 5-lux-reared rats and 0.009 mm2/wk for 800-lux-reared rats. ROS length was relatively constant in the dim light group, but showed a decline in 800 lux rats of 0.5 μm/wk. Rats moved from 800 to 5 lux at 9 and 21 wks of age showed no significant change in ONL area after 3 wks. ROS length in these rats increased at a prodigious rate, and in the 12-wk-olds (9 wks at 800 lux, followed by 3 wks at 5 lux), ROS length exceeded that of age-matched rats raised in 5 lux for life.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00966869
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 180
    Electronic Resource
    Electronic Resource
    Changes in erythrocyte membrane fluidity by endotoxin in rats (1992)
    Springer
    Journal of anesthesia 6 (1992), S. 145-152 
    Details
    ISSN: 1438-8359
    Keywords: Membrane fluidity ; Erythrocytes ; Endotoxin ; Lipoperoxide ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The effect of endotoxin on fluidity and lipid composition of the erythrocyte membrane was studied in rats following the intraperitoneal administration of endotoxin (30 mg·kg−1 body weight). Erythrocyte membrane fluidity measured with 16-stearic acid spin label (16-SAL) was significantly decreased in the endotoxin-treated rats as compared with control. A decrease of lysophosphatidylcholine in the membrane lipid was evident in the endotoxin-treated rats. The cholesterol to phospholipid molar ratios and other phospholipid fractions did not differ significantly in the two groups. The levels of plasma Β-glucuronidase activity and lipoperoxide were significantly increased in the endotoxin-treated rats when compared to controls. There were significant correlations between the parameter of 16-SAL in erythrocytes and plasma Β-glucuronidase activities or lipoperoxide from both endotoxin-treated and control groups, P ≪ 0.005 or P ≪ 0.02 respectively. In conclusion endotoxin decreased rat erythrocyte membrane fluidity in vivo. Since membrane fluidity is closely related to the vital functions of the membranes, the change described could be related to the abnormality of cell membrane functions in endotoxin shock state. (Kadota Y, Kamada T, Yoshimura N, et al.: changes in erythrocyte membrane fluidity by endotoxin in rats. J Anesth 6: 145–152, 1992)
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s0054020060145
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 181
    Electronic Resource
    Electronic Resource
    Modell zur elektromyographischen untersuchung von dünndarmtransplantaten an der ratte (1992)
    Springer
    Langenbeck's archives of surgery 377 (1992), S. 348-351 
    Details
    ISSN: 1435-2451
    Keywords: Small bowel transplantation ; Motility ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Eine entsprechende Motilität eines Dünndarmtransplantats ist für seine resorptive Funktion sowie auch für die Selbstreinigung des Darms von grundlegender Bedeutung. In der Literatur finden sich einige Angaben über Störungen der Motilität nach Denervation oder Transplantation, jedoch keine vergleichende Untersuchung über den Einfluß einer akuten Abstoßung auf die Darmmotilität. Es wurde deshalb ein Modell erarbeitet, das folgende Kriterien erfüllen sollte: eine orthotope Position des Transplantats, ein ausreichender Ernährungszustand des Versuchtstiers auch bei mangelhafter Funktion des Transplantats, dauerhaft implantierte Elektroden sowohl am Transplantat als auch am korrespondierenden Segment des Eigendarms sowie die Möglichkeit der Transplantation in isogener oder allogener Kombination. Von Lewis-Spendertieren wurden 10 cm proximales Jejunum 5 Lewis-Empfängern in orthotoper Position knapp distal der Treitz-Flexur ohne eine Resektion von Eigendarm interponiert. Am Transplantat sowie am anschließenden Eigendarm wurden jeweils 3 bipolare Elektroden fixiert und serienmäßig elektromyographische Untersuchungen bis zum Ende der 3. postoperativen Woche unternommen. Am Transplantat lassen sich unabhängig vom Eigendarm ablaufende Zyklen migratorischer myoelektrischer Komplexe bereits ab dem 5. postoperativen Tag und in der Folge über 3 Wochen beobachten. Die Schrittmacherfrequenz der Transplantate ist gleich der Frequenz des transsezierten Eigendarms. Dieses frühe Wiedereintreten einer quantifizierbaren Darmmotorik macht das gewählte Modell geeignet für eine Reihe von Untersuchungen, insbesondere aber zur Untersuchung des Einflusses der Abstoßung auf die Motilität, da auch in stark allogenen Kombinationen der Darm von Lewis-Ratten nicht vor dem 6. postoperativen Tag histologische Zeichen einer Abstoßung zeigt.
    Notes: Summary Adequate motility of a small bowel transplant is a prerequisite for its resorptive function as well as its self-purging capacity. The literature contains some reports on changes in motility following denervation or transplantation, but none on the impact of acute rejection on motility of small bowel grafts. Therefore an experimental model was established to meet the following criteria: orthotopic position of graft, adequate nutritional status even when graft is functionally impaired, chronically implantable electrodes attached to graft and corresponding segment of native bowel, isogeneic or allogeneic set-up. 10 cm of proximal jejunum were transplanted from Lewis donors to five Lewis recipients in an orthotopic position just distal of the ligament of Treitz without resection of native small bowel. Three bipolar electrodes were sutured to the graft and the same number to the subsequent recipient bowel. Serial myoelectric measurements were taken until the end of week 3. From day 5 on, migratory myoelectric complexes independent of myoelectric activities of native bowel were recorded. Pacemaker frequency of the graft was found to be the same as that of the transsected native small bowel. This early reappearance of myoelectric activities makes this model suitable for comparative studies of small bowel transplant motility and in particular its changes during rejection, since even in strongly allogeneic combinations Lewis small bowel does not show histological signs of rejection before day 6.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00574773
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 182
    Electronic Resource
    Electronic Resource
    Proliferationskinetische untersuchungen im syngenen lebertransplantationsmodell der ratte (1992)
    Springer
    Langenbeck's archives of surgery 377 (1992), S. 360-367 
    Details
    ISSN: 1435-2451
    Keywords: Orthotopic liver transplantation ; Rat ; Rearterialization ; Proliferation kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung In der Ratte kann eine orthotope Lebertransplantation (OLT) ohne arterielle Anastomose des Transplantats durchgeführt werden. In der vorliegenden Studie haben wir die Proliferationskinetik von Leberparenchymzellen nach einer OLT mit und ohne arteriellen Wiederanschluß mittels Bromo-2-deoxyuridin untersucht. Tiere mit einer reinen portokavalen Anastomose zeigten hierbei eine signifikant erhöhte Proliferationsrate von Hepatozyten, Kupffer-Sternzellen und Gallengangsepithelzellen, erkennbar an einer starken Anfärbung mit BrdU am 8. Tag post transplantationem, im Vergleich zu Tieren mit einem arteriellen Wiederanschluß. Dies läßt auf eine ausgeprägte Regeneration und Proliferation von ischämisch geschädigten Leberparenchymzellen nach einer rein portokavalen Anastomose schließen. Die OLT mit arteriellem Wiederanschluß scheint daher auch bei der Ratte das physiologischere Transplantationsmodell zu sein.
    Notes: Abstract Successful orthotopic liver transplantation (OLT) can be achieved in the rat. We used bromo-2-deoxyuridine (BrdU) as a proliferation marker to document morphological differences between OLT with and without rearterialization. Animals with portal anastomosis alone had a significantly increased proliferation rate of hepatocytes, Kupffer cells, and bile duct epithelial cells, as indicated by strong staining with BrdU, 8 days post-transplant compared to animals with rearterialization. Regeneration of ischemically damaged liver parenchymal cells may account for this observation. Thus, OLT with rearterialization appears to be the more physiological transplant model.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00574775
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 183
    Electronic Resource
    Electronic Resource
    Muscarinic and gamma-aminobutyric acid-ergic receptor changes during vestibular compensation (1992)
    Springer
    European archives of oto-rhino-laryngology and head & neck 249 (1992), S. 34-39 
    Details
    ISSN: 1434-4726
    Keywords: Muscarinic receptors ; Gamma-aminobutyric acid-ergic receptors ; Vestibular compensation ; Rat ; Quantitative autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Involvement of the neurotransmitters acetyl choline and gamma-aminobutyric acid (GABA) in vestibular compensation has been suggested by electrophysiological and pharmacological experiments. In this investigation we used quantitative autoradiography to study the modification of muscarinic and benzodiazepine receptors in each nucleus of the rat's vestibular nucleus complex. Tissues were examined 3, 14, 23 h and 3, 12, 37 and 90 days after unilateral surgical labyrinthectomies. The present results demonstrated a muscarinic receptor supersensitivity in the deafferented side in the suprerior vestibular nucleus 90 days after surgery. This increase was not large enough to support the cholinergic receptor supersensitivity hypothesis for vestibular compensation. The changes in the benzodiazepine receptors observed for a short time following surgery were reversed after a few days. These findings support a transient involvement of GABAergic pathways in vestibular compensation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00175668
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 184
    Electronic Resource
    Electronic Resource
    Masthead (1992)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 41 (1992) 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560410101
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 185
    Electronic Resource
    Electronic Resource
    International journal of quantum chemistry - A journal devoted to quantum theory and computations in chemistry, condensed matter physics, and biology. Editorial - Program and Policies (1992)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 41 (1992), S. 1-2 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560410102
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 186
    Electronic Resource
    Electronic Resource
    F. A. Masten (1992)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 41 (1992), S. 3-3 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560410103
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 187
    Electronic Resource
    Electronic Resource
    Introduction (1992)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 41 (1992), S. 5-5 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560410104
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 188
    Electronic Resource
    Electronic Resource
    Scientific reminiscences (1992)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 41 (1992), S. 7-14 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560410105
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 189
    Electronic Resource
    Electronic Resource
    Symmetric-group algebraic variational solutions for Heisenberg models at finite temperature (1992)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 41 (1992), S. 43-52 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The Heisenberg spin Hamiltonian for a collection of N spin-1/2 sites is viewed, as favored by Professor Matsen, to be an element of the group algebra of the symmetric group SN. Several computationally tractable, variational group-algebraic approximations for the finite-temperature density matrix are made so as to minimize the Gibb's free-energy functional. Relations to previous quite differently motivated approximations are identified, though improvements are noted with the present approach.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560410107
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 190
    Electronic Resource
    Electronic Resource
    Algebrants in many-electron quantum mechanics: Applications of generalized determinants or matrix functions (1992)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 41 (1992), S. 15-42 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: We define the algebrant, a mathematical generalization of the determinant, the immanant, the permanent, and the Schur functions. Algebrants are classified as multilinear matrix functions or multicomponent symmetrized tensors. In applications, such as N-electron quantum mechanics, where extensive computation is required, it is vital to reduce computational effort, e.g., the well-known N-factorial problem. We derive certain mathematical properties that can be incorporated in efficient computing algorithms for algebrants. Foremost is our “elimination theorem,” which allows (in important special cases) zeros to be introduced into an algebrant in close analogy with Gaussian elimination for determinants. Savings accruing from such elimination can be substantial. We show examples from Matsen's spin-free quantum chemistry where elimination effectively removes the N-factorial problem that has hitherto stifled possible applications.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560410106
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 191
    Electronic Resource
    Electronic Resource
    The Berry phase in molecular physics (1992)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 41 (1992), S. 53-75 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The geometric phase of quantum mechanics is introduced, and its physical effects are then studied in the context of molecular physics. By performing the most general Born-Oppenheimer procedure, we show how gauge groups appear in the study of molecules. This method is then applied to the doubly degenerate Λ-levels of a diatomic molecule. The resulting dynamics for the slow angular motion of the dumbbell is equivalent to that of a Dirac monopole.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560410108
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 192
    Electronic Resource
    Electronic Resource
    Algebraic methods in molecular structure (1992)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 41 (1992), S. 77-88 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The use of algebraic methods in molecular structure is briefly reviewed. The fundamental algebra, G ≡ U(4), of rotation-vibration spectra is introduced and its implications on spectra of di-, tri-, and polyatomic molecules are discussed.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560410109
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 193
    Electronic Resource
    Electronic Resource
    Eigenvalues of single-cycle class-sums in the symmetric group (1992)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 41 (1992), S. 147-151 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Explicit expressions for the eigenvalues of the class sums [(p)(1)n-p]n, p = 2, 3,…,14, of the symmetric group Sn are presented. Partial results are given for the eigenvalues corresponding to arbitrary p.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560410113
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 194
    Electronic Resource
    Electronic Resource
    Eigenvector and eigenvalues of some special graphs. IV. Multilevel circulants (1992)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 41 (1992), S. 105-116 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A multilevel circulant is defined as a graph whose adjacency matrix has a certain block decomposition into circulant matrices. A general algebraic method for finding the eigenvectors and the eigenvalues of multilevel circulants is given. Several classes of graphs, including regular polyhedra, suns, and cylinders can be analyzed using this scheme.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560410111
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 195
    Electronic Resource
    Electronic Resource
    Graphical unitary group approach to spin-spin interactionThis paper is dedicated to Prof. F. A. Matsen in recognition of and with gratitude for his contributions to quantum chemistry and to the study and applications of unitary groups. (1992)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 41 (1992), S. 89-103 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A detailed exposition of spin-spin operator matrix elements is presented in the context of the graphical unitary group approach (GUGA) to atomic and molecular physics and quantum chemistry. A compendium of subgraph types and formulae is given. Aspects of computer implementation within the structure of the Columbus CI programs is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560410110
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 196
    Electronic Resource
    Electronic Resource
    Valence bond approach exploiting Clifford algebra realization of Rumer-Weyl basis (1992)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 41 (1992), S. 117-146 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A detailed algorithm is described that enables an implementation of a general valence bond (VB) method using the Clifford algebra unitary group approach (CAUGA). In particular, a convenient scheme for the generation and labeling of classical Rumer-Weyl basis (up to a phase) is formulated, and simple rules are given for the evaluation of matrix elements of unitary group generators, and thus of any spin-independent operator, in this basis. The case of both orthogonal and nonrothogonal atomic orbital bases is considered, so that the proposed algorithm can also be exploited in molecular orbital configuration interaction calculations, if desired, enabling a greater flexibility for N-electron basis-set truncation than is possible with the standard Gel'fand-Tsetlin basis. Finally, an exploitation of this formalism for the VB method, based on semiempirical Pariser-Parr-Pople (PPP)-type Hamiltonian and nonorthogonal overlap-enhanced atomic orbital basis, and its computer implementation, enabling us to carry out arbitrarily truncated or full VB calculations, is described in detail.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560410112
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 197
    Electronic Resource
    Electronic Resource
    The measure cone: Irreversibility as a geometrical phenomenon (1992)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 41 (1992), S. 163-185 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The statistical state space is discussed in terms of the geometry of normed real vector spaces with particular reference to the novel concept of direction distance. Specialization to the geometry of the measure cone and the correspondingly specialized concept of mixing distance suggest strong mutual relationship as is shown subsequently in physically required generality. Thereby, the phenomenon of irreversibility attains an interpretation that seems to be the canonical mathematical background for classical and nonclassical statistical physics.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560410115
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 198
    Electronic Resource
    Electronic Resource
    Freeon tensor product states and the unitary group formulation of the many-electron problem (1992)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 41 (1992), S. 187-211 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The freeon tensor product basis provides a rapid method for the evaluation of matrix elements in the unitary group formulation of quantum chemistry. The method employs fast transformations between the Gel'fand and freeon tensor product basis.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560410116
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 199
    Electronic Resource
    Electronic Resource
    On the internally contracted multireference CI method with full contraction (1992)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 41 (1992), S. 153-162 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The configuration interaction (CI) method where the efficiency of the generators of the unitary group is most fully exploited is the internally contracted multireference CI method. In the most recent version of this method the semi-internal configurations were kept uncontracted, which means that the number of configurations can still be quite large. In the present study the necessary formulas are derived for the case where the semi-internal states are also contracted. The highest density matrix that appears in these formulas is of order 5, and the computational treatment of this large matrix is discussed in detail.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560410114
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 200
    Electronic Resource
    Electronic Resource
    On rotations as special cases of unitary transformations with some applications to the theory of spin (1992)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 41 (1992), S. 213-242 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Some problems in elementary geometry are approached from the point of view of linear algebra and generalized to the theory of linear spaces of finite or infinite dimensions having a positive definite binary product. The angle ω between two elements of the linear space is defined from the concept of length by means of the cosine-theorem. A rotation is then defined as a special case of a unitary transformation moving all elements the same angle ω, except that under certain circumstances, some elements may stay invariant. In the former case, one speaks of a rotation around an “external axis,” and in the latter case, of a rotation around an “internal axis” defined by the invariant elements. It is shown that the finite rotations U of both types may be expressed in the simple exponential form U = exp(iωm), where the “generator” m in the former case is an operator satisfying the relation m2 = 1, and in the latter case, m3 = m. The structure of the group of finite rotations in the former case is clarified in some detail. As an illustration of the theory, some applications to the three- and two-dimensional spaces as well as to the theory of spin are given. The coupling between the ordinary three-dimensional rotations and the spinor transformations is considered in somewhat greater detail.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560410117
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...