Library

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 101
    ISSN: 1432-1106
    Keywords: Hippocampal mossy fibers ; GABAergicneurons ; GABAergic inhibition ; EM immunocytochemistry ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Mossy fibers are known to form excitatory synapses on pyramidal neurons in regio inferior of the hippocampus. This study demonstrates that the mossy fibers also establish synaptic contacts with glutamate decarboxylase-immunoreactive, supposedly GABAergic inhibitory neurons in the CA3 region. The observed connection provides a morphological basis for feed-forward inhibition of the pyramidal cells.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 102
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 77 (1989), S. 295-301 
    ISSN: 1432-1106
    Keywords: Preoptic area ; Intrinsic neuron ; GABA ; Local neuron ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Neurons intrinsic to the preoptic area might participate in the control of neuroendocrine or behavioral events. To determine their existence and features, we deafferented the preoptic area of female rats, using completely circumscribing cuts with a Halasz knife. Despite obvious signs of degeneration of synapses originating from nerve cell bodies outside the preoptic island, some synapses survived complete deafferentation. We saw synaptic contacts not only on the neuronal cell body, but also on the dendritic shaft and spine. There were no peculiar morphological features, as might suggest unique physiologic functions of these intrinsic synapses. The prominence of intrinsic synapses in the preoptic area suggests that, in addition to hormone effects on preoptic neurons, and long ascending afferents, intrinsic synapses might play significant roles in neuroendocrine controls.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 103
    ISSN: 1432-1106
    Keywords: Met- and leu-enkephalin ; Morphine ; Cortex ; Intracellular recordings ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The action of enkephalin-analogues (D-ala2-D-leu5-enkephalin and D-ala2-D-metenkephalin) and morphine, iontophoretically applied, was tested on rat cortical neurons intracellularly recorded “in vivo”. Inhibition of cellular excitability of 60% of the tested cells followed the iontophoretic administration of opioid peptides. 50% of the inhibited cells were also hyperpolarized. The amplitude of membrane hyperpolarization was related to the value of the membrane potential. In 13 out of the 30 inhibited cells the change in membrane input resistance was measured; the input resistance was decreased by 30%. In 8 cells, hyperpolarized by the opioid peptides, the depolarizing postsynaptic potentials, evoked by cortical stimulation, were also reduced in amplitude. Naloxone, iontophoretically applied, reversed and/or prevented the peptide responses. On the same neurons, morphine induced a bursting pattern of spiking activity and increased the membrane input resistance: this action was naloxone-insensitive. The reported results suggest that opioid peptides and morphine activate, respectively, naloxone-sensitive and naloxone-insensitive mechanisms on the same cortical neurons, leading to different and, in some respect, opposite effects on the neuronal activity.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 104
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 77 (1989), S. 374-380 
    ISSN: 1432-1106
    Keywords: GABAA and GABAB receptors ; Rhythmic activity ; G-protein ; Pertussis toxin ; Septo-hippocampal pathway ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The possible involvement of GABA in the control of the rhythmical bursting activity (RBA) of septo-hippocampal neurons (SHNs) has been studied in the rat in vivo. The discharge frequency of SHNs was modified by the iontophoretic application of a GABA agonist and antagonist as well as by the application of the GABA uptake blocker, nipecotic acid. The GABAB agonist baclofen inhibited the SHNs' activity, this effect being antagonized by the GABAB antagonist phaclofen. However, these different pharmacological manipulations did not modify the RBA frequency. Pretreatment of the rats with pertussis toxin, a substance which is known to block the events mediated by G-proteins (Gi or Go), decreased the RBA frequency. Neither agonists nor antagonists of GABAA or GABAB types had significant effects on the rhythmical bursting activity of SHNs. The effect of pertussis toxin suggests that other neurotransmitters or intrinsic mechanisms involving a G-protein influence this rhythm.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 105
    ISSN: 1432-1106
    Keywords: Somatosensory cortex ; Differential development ; Lectin binding ; Vibrissae ; Forepaw ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Physiological studies have demonstrated a highly organized somatotopic representation of the body surface in SI cortex of rat. This representation is correlated morphologically with the presence of barrel-shaped structures in layer IV. Conventional staining techniques reveal barrels in the latter part of the first postnatal week. Recently, the peroxidase conjugates of lectins, which recognize glycosylated molecules, have been used to study barrel field formation. Con A, for example, has been shown to bind primarily to prospective barrel sides and septa as early as postnatal day 3 (PND-3) in mouse. To date, investigations of SI cortex using the lectin (Arachis hypogaea) peanut agglutinin (PNA) have been confined to the study of the barrel field representation of the face and mystacial vibrissae in the mouse. In the present study we extend these findings to the development of the representation of the entire body surface called the rattunculus. Rats ranging from PND-1 (first 24 h after birth) to PND-12 were anesthetized with Nembutal and perfused with 4% paraformaldehyde and 2% glutaraldehyde in 0.2 M sodium cacodylate buffer. Brains were removed, flattened tangentially, and sectioned on a vibratome at 30–120 microns. Sections were blocked in TRIS-buffered saline (TBS) plus 2% bovine serum albumin and incubated in peanut lectin at 4° C. Following incubation, sections were washed with TBS and processed using peroxidase histochemistry. Lectin binding in the prospective forelimb representation was apparent by PND-5 whereas lectin binding to the prospective face-mystacial vibrissae representation occurred before PND-4. These results suggest that body part representations show individual variations during early pattern formation. In rat, the representation of the limbs may lag behind the representation of the face-mystacial vibrissae during early postnatal development. This developmental gradient within the cortex may reflect a differential expression of lectin receptors.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 106
    ISSN: 1433-8580
    Keywords: Rat ; Liver cirrhosis ; Hypoxia ; Redox state ; Mitochondrial oxidative phosphorylative activity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The influence of hypoxia on hepatic mitochondrial function and energy status was studied in normal and carbon tetrachloride (CCl4)-induced cirrhotic rats. Under hypoxemia of 50 mm Hg-PaO2, hepatic energy status was suppressed both in normal and cirrhotic rats. After the reversal of hypoxia, it was completely restored in normal rats concomitant with a rapid elevation of hepatic mitochondrial redox state (overshoot phenomenon) and increase in the mitochondrial oxidative phosphorylative activity. By contrast, in cirrhotic rats, such an enhancement of mitochondrial function was not observed. It was clarified that cirrhotic liver mitochondria have little capacity to respond to the hypoxic stress. A lower resistance to hypoxic episode in cirrhotics might be attributable to the absence of mitochondrial enhancement which is a compensatory mechanism for the deranged energy metabolism of the liver.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 107
    Electronic Resource
    Electronic Resource
    Springer
    Research in experimental medicine 189 (1989), S. 281-287 
    ISSN: 1433-8580
    Keywords: Serotonin ; Tryptophan ; Small intestine ; Rat ; Pargyline
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary To investigate the release of serotonin from intestinal enterochromaffin cells, we used an in vitro technique which allows studies excluding overlapping influences from outside the gut. The entire small intestine of rats fed a standard or tryptophan-enriched (3% of total) diet was totally isolated by ligatures with the exception of the superior mesentric artery and portal vein that supply and drain the intestine. Simultaneously to the vascular perfusion (Krebs-Ringer bicarbonate buffer, 0,4% human albumin, 5 mM glucose, 0.6 mM glutamine) the gut lumen was infused (buffer or 0.1 N HCL). Acidification of the gut lumen resulted in an increment of venously released tryptophan and serotonin. After feeding tryptophan-enriched food the release of tryptophan was increased. However, the total amount of released serotonin after tryptophan diet did not differ as compared to that after standard diet. Addition of a monoamino-oxidase inhibitor (pargyline) to the arterial perfusate enhanced the released amount of serotonin 3-fold in the portal venous effluent (at a concentration of 1 mM but not 0.1 mM). Recovery studies done by arterial infusions of serotonin (1 µM, 10µM) and evaluation of the amounts venously released revealed a high loss of infused serotonin (40%–70%). Our data suggest gut-born serotonin to more likely play a paracrine role than a role as a classical hormone.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 108
    Electronic Resource
    Electronic Resource
    Springer
    Research in experimental medicine 189 (1989), S. 321-329 
    ISSN: 1433-8580
    Keywords: Fibronectin ; Nerve fibrosis ; Fibrin adhesives ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Although the fibrin adhesion enjoys increasing success in many areas of surgery, it has not, however, become fully established in nerve anastomosis. It was in this area particularly that significant advantages were expected, especially by the avoidance of suture granulomas. As the fibrin clot dissolved prematurely, however, and dehiscences ensued, antifibrinolytic substances had to be added to the adhesive. Fibroses occurred frequently as a result, which to date encumber nerve adhesive. We examined fibronectin for its fibrosis-inducing effect, comparing both presently available fibrin adhesive systems, because one contained up to 5 times more fibronectin per milliliter than the other. On the basis of a test grouping using 100 and 1000 KIU aprotinin/ml, we were able to establish that fibronectin in fibrin adhesives possesses a fibrosis-promoting effect.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 109
    ISSN: 1435-2451
    Keywords: Portocaval shunt ; Liver cirrhosis ; Rat ; Lethality
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Im Lebercirrhose-Modell der Ratte hat die portocavale Anastomose eine sehr hohe Letalitet (87%). Durch eine präoperative Vorbereitung mittels einer Therapie, die einen eta blierten Stellenwert in der Behandlung der portosy stemischen Encephalopathie hat, wird erstmals experimentell eine Senkung der Operationsletalität dokumentiert, was den konsequenten klinischen Einsatz nahelegt.
    Notes: Summarry Following portocaval anastomosis a high lethality (87%) can be observed in a standardized micronodular liver cirrhosis model. By a special preoperative regimen this lethality can be reduced to 10%.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 110
    ISSN: 1435-604X
    Keywords: Brain tumour ; Rat ; Detection ; Fluorescence ; Laser ; Haematoporphyrin derivative
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Physics , Technology
    Notes: Abstract Laser-induced fluorescence has been used for the identification of brain tumours in rats, which have been previously given tumour-seeking haematoporphyrin derivative. A pulsed nitrogen laser (λ=337 nm) was used in conjunction with an optical multichannel analyzer. For both inoculated RG-2 and TCVC rat-brain-tumour models, the blue autofluorescence was strongly reduced in the tumour compared with normal brain tissue, and at the same time the characteristic red-drug signal increased. The contrast between tumour and normal tissue was strongly enhanced by forming the ratio between the two signals. Implications for possible improvement of tumour delineation in brain tumour surgery are discussed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 111
    Electronic Resource
    Electronic Resource
    Springer
    European journal of applied physiology 58 (1989), S. 446-451 
    ISSN: 1439-6327
    Keywords: Rectal temperature ; Tail vasomotor response ; Exercise ; Estrus cycle ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In female rats, rectal temperature (T re), tail vasomotor response, oxygen uptake $$\left( {\dot V_{{\text{O}}_{\text{2}} } } \right)$$ , and carbon dioxide production $$\left( {\dot V_{{\text{CO}}_{\text{2}} } } \right)$$ were measured in proestrus and estrus stages during treadmill running at two different speeds at an ambient temperature (T a) of 24° C. Experiments were performed at 2.00–6.00 a.m., when the difference inT re was greatest between the two stages;T re at rest in the estrus stage was 0.54° C higher than in the proestrus stage. In a mild warm environment, thresholdT re for a rise in tail skin temperature (T tail) was also higher in the estrus stage than in the proestrus stage. In contrast, no difference was seen in the thresholdT re and steady stateT re at the end of exercise between proestrus and estrus stages. These values were higher at the higher work intensity. $$\dot V_{{\text{O}}_{\text{2}} } $$ was also similar between the two stages, except in the second 5 min after the beginning of exercise, when $$\dot V_{{\text{O}}_{\text{2}} } $$ was greater andT re rose more steeply in the proestrus stage. These data indicate that deep body temperature during exercise is regulated at a certain level depending on the work intensity and is not influenced by the estrus cycle.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 112
    Electronic Resource
    Electronic Resource
    Springer
    Journal of comparative physiology 159 (1989), S. 237-242 
    ISSN: 1432-136X
    Keywords: Amylase ; Mosquitofish ; Rat ; Drosophila ; Structure ; Function
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Amylases from the mosquitofish (Gambusia affinis holbrooki, Pisces: Poeciliidae) and rat were purified and compared withDrosophila amylases in terms of structure and function. At the structural level, amino acid compositions of the three amylases were compared. At the functional level, amylase activities were compared on various substrates and in the presence of inhibitors. While the amylases from all three organisms had properties typical of alpha-amylases, both structural and functional differences were observed. Using resemblance coefficients of distance and similarity from numerical taxonomy, it was determined that the amylases from the rat andDrosophila were more similar to each other than either was to amylase from the mosquitofish, and that structural differences between the amylases did not reflect functional differences, i.e. there was no correlation between amylase structural and functional distances.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 113
    ISSN: 1432-0878
    Keywords: SEM ; TEM ; Interstitial cell ; Myenteric plexus ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary An extensive cellular network becomes visible over the myenteric plexus of the rat after removal of the overlying tissues under the scanning electron microscope. The cells are mainly stellate and have many slender processes via which they interconnect. They form a three-dimensional network and are closely associated with the ganglia and nerve bundles, and also extend over the smooth muscle cells. They are considered to correspond to the interstitial cells of Cajal because of their peculiar arrangement and their topography. Transmission electron-microscopic evidence demonstrates that the majority of those cells have features of fibroblasts. Gap junctions and intermediate junctions are observed between these fibroblast-like cells, and also between them and smooth muscle cells. Examination of serial thin sections reveals that single fibroblast-like interstitial cells connect to both circular and longitudinal muscle cells via gap junctions. It is suggested that the network of interstitial cells conducts electrical signals.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 114
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 256 (1989), S. 553-558 
    ISSN: 1432-0878
    Keywords: Transforming growth factor (TGF)-β ; Myocardium ; mRNA ; Fibroblast ; Cardiomyocyte ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Transforming growth factor-β (TGF-β) is a biologically active polypeptide present in normal tissues as well as transformed cells. Two structurally related forms of this peptide are TGF-β 1 and TGF-β 2. Using freshly isolated cardiomyocytes and non-myocyte heart cells, and a [32P]-labelled cDNA probe to human TGF-β 1, we demonstrated that mRNA for TGF-β 1 could be detected only in the nonmyocyte fraction of heart cells. In the present study, the distribution of TGF-β 1 in the heart was determined by immunofluorescence staining by use of a polyclonal antibody to porcine TGF-β 1 in cryostat sections of rat heart. Immunofluorescence staining was intense around the blood vessels and radially diffuse in the surrounding myocardium.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 115
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 256 (1989), S. 303-307 
    ISSN: 1432-0878
    Keywords: Arachnoid cells ; Tight and gap junctions ; Cold injury ; Ultrastructure ; Freeze-fracture technique ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The junctional complexes of cells in the outer arachnoid layer overlying the cerebral cortex of 2-week-old rats were examined with freeze-fracture electron microscopy up to 60 min after transcranial cold injury to the dorsal surface of the brain. Within 30 min after injury, areas of gap and tight junctions with morphological features characteristic of junction formation and/or junction disruption were found scattered among normal junctional complexes in some arachnoid cells. Within 60 min after injury, tight junctions with features typical of less leaky zonulae occludentes were present in all arachnoid cells examined. These morphological features include increases in the number of tight junctional strands and the number of strand-to-strand anatomoses. Gap junctions were interspersed among the tight junctional strands, and many were completely encircled by the strands. The increase in the number and complexity of the tight junctional strands in response to brain injury may be the morphological basis for the maintenance of the cerebrospinal fluid-blood dural barrier.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 116
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 257 (1989), S. 263-268 
    ISSN: 1432-0878
    Keywords: Retinol ; Vacuoles ; Immunohistochemistry ; Plasma proteins ; Hepatocytes ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The vacuoles occurring in rat hepatocytes after intraportal injection of retinol (33 or 67 μg) were examined immunohistochemically using respective antibodies against rat albumin, human retinol-binding protein, human ceruloplasmin, human α 1-antitrypsin, human transferrin, and human prealbumin as representative plasma proteins. The occurrence of the vacuoles reached a numerical maximum 30 min after injection of 67 μg retinol, followed by a temporal decrease. Hepatocytes from control rats, which had been intraportally injected with either blood plasma diluted to 2/3 concentration or with retinol palmitate solvent (castor oil) dissolved in blood plasma, showed immunoreactive fine granules without the occurrence of vacuoles in the cytoplasm. Identical vacuoles in serial sections appeared immunohistochemically either immunoreactive or non-immunoreactive for all the antibodies used, with rare exceptions. The occurrence of several rare exceptions suggested that 2 kinds of vacuoles might be formed in different cytoplasmic compartments. A zonal distribution of vacuoles was apparent in the hepatic laminae (or acini) within the liver lobules. The vacuoles were predominantly distributed in zone 2, and to a lesser extent in zone 3 and zone 1 in that order.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 117
    ISSN: 1432-0878
    Keywords: Adrenal medullary endothelial cells ; Pheochromocytoma (PC12) cells ; Co-culture ; Cell surface extracts ; Adhesion ; Cell-cell interactions ; Bovine ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Chromaffin cells in the adrenal medulla are found in close proximity to capillary endothelial cells, thereby forming the classical endocrine complex. To examine the possible chemical basis of their interaction in more detail, we have grown bovine adrenal medullary endothelial (BAME) cells in monolayer cultures and added to them pheochromocytoma (PC12) cells, a chromaffin tumor cell line of rats. The PC12 cells were chosen because of the similarities they share with adrenal medullary chromaffin cells. PC12 cells rapidly attached to BAME cells cultures, their rate of adhesion being significantly enhanced over binding of PC12 cells to either uncoated plates or to monolayers of unrelated cell cultures. Consistent with this observation, we noted that the extracellular matrix (ECM) derived from the BAME cells did not enhance PC12 cell adhesion and did not promote neurite sprouting as previously described for ECM derived from corneal endothelial cells. The specific adhesion between PC12 and BAME cells could be abolished by cell surface extracts derived from these two cells but not by extracts derived from unrelated cell types. This activity was heat-labile, sensitive to trypsin and, to a lesser extent, to neuraminidase. We therefore conclude that PC12 cells may interact with BAME cells by specific proteinaceous adhesive factors associated with their plasma membranes. These interactions might represent the formative role of cell-cell contacts in the organization of the developing adrenal gland.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 118
    ISSN: 1432-0878
    Keywords: Gastrin ; Gastrin-releasing peptide ; Bombesin ; Stomach ; Autonomic innervation ; Immunohistochemistry ; Guinea pig ; Rat ; Dog ; Man
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The relationship between bombesin-like immunoreactive (bombesin-LI) nerve fibres and gastrin-LI G-cells was examined in gastric antral mucosa from guineapig, rat, dog and man using a double-labelling fluorescence immunohistochemical technique. The greatest density of bombesin-LI nerve fibres was found within the basal mucosa in all species and the density of innervation decreased towards the luminal surface. Most G-cells were in a band occupying approximately the middle third of the mucosa. The proportion of G-cells found within a distance of 2 μm from bombesin-LI nerve fibres was low in all species (6% in the guinea-pig, 22% in the rat, 14% in the dog, and 9% in the human). It is proposed that the neuropeptide released from bombesin-LI antral mucosal nerve fibres traverses distances of greater than several μm to reach the target G-cells. This may be achieved by passage through the mucosal microcirculation.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 119
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 256 (1989), S. 559-565 
    ISSN: 1432-0878
    Keywords: Retrograde tracing ; Immunocytochemistry ; Vascular innervation ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The origin of nerve fibers to the superficial temporal artery of the rat was studied by retrograde tracing with the fluorescent dye True Blue (TB). Application of TB to the rat superficial temporal artery labeled perikarya in the superior cervical ganglion, the otic ganglion, the sphenopalatine ganglion, the jugular-nodose ganglionic complex, and the trigeminal ganglion. The labeled perikarya were located in ipsilateral ganglia; a few neuronal somata were, in addition, seen in contralateral ganglia. Judging from the number of labeled nerve cell bodies the majority of fibers contributing to the perivascular innervation originate from the superior cervical, sphenopalatine and trigeminal ganglia. A moderate labeling was seen in the otic ganglion, whereas only few perikarya were labeled in the jugular-nodose ganglionic complex. Furthermore, TB-labeled perikarya were examined for the presence of neuropeptides. In the superior cervical ganglion, all TB-labeled nerve cell bodies contained neuropeptide Y. In the sphenopalatine and otic ganglia, the majority of the labeled perikarya were endowed with vasoactive intestinal polypeptide. In the trigeminal ganglion, the majority of the TB-labeled nerve cell bodies displayed calcitonin gene-related peptide, while a small population of the TB-labeled neuronal elements contained, in addition, substance P. In conclusion, these findings indicate that the majority of peptide-containing nerve fibers to the superficial temporal artery originate in ipsilateral cranial ganglia; a few fibers, however, may originate in contralateral ganglia.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 120
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 256 (1989), S. 447-456 
    ISSN: 1432-0878
    Keywords: MAP2 ; Actin ; Dendritic spines ; Spine apparatus ; Spine synapses ; Postsynaptic density ; Synaptic plasticity ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The distribution of MAP2 and actin in dendritic spines of the visual and cerebellar cortices, dentate fascia, and hippocampus was determined by using immunogold electron microscopy. By this approach, we have confirmed the presence of MAP2 in dendritic spines and identified substructures within the spine compartment showing MAP2 immunoreactivity. MAP2 immunolabeling was mainly associated with filaments which reacted with a monoclonal anti-actin antibody. Also, by immunogold double-labeling we colocalized MAP2 with actin on the endomembranes of the spine apparatus, smooth endoplasmic reticulum, and in the postsynaptic density. Labeling was nearly absent in axons and axonal terminals. These results indicate that MAP2 is an actin-associated protein in dendritic spines. Thus, MAP2 may organize actin filaments in the spine and endow the actin network of the spine with dynamic properties that are necessary for synaptic plasticity.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 121
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 177 (1988), S. 349-352 
    ISSN: 1432-0568
    Keywords: Pineal body ; Mongolian gerbil (Meriones unguiculatus) ; Rat ; Calbindin D-28K (vitamin D-dependent calcium binding protein) ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Immunocytochemical reaction for demonstration of calbindin D-28K has been performed in superficial pineal bodies of the Mongolian gerbil (Meriones unguiculatus) and the rat. Whereas in the Mongolian gerbil there were no clearly expressed calbindin immunoreactive cells, these were numerous in the rat pineal body. Here the calbindin-positive cells — probably pinealocytes — were disposed along capillaries. In view of the role of calbindin in binding and transporting calcium and regulating its intracellular levels, the absence of this protein in the gerbil pineal body has been interpreted as signifying the inability of pinealocytes to eliminate intracellular calcium with possible consequent formation of acervuli.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 122
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 178 (1988), S. 119-127 
    ISSN: 1432-0568
    Keywords: Neuronal differentiation ; Fascia dentata ; Granule cells ; GABAergic neurons ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Golgi impregnation was used to study the dendritic differentiation of granule cells in the rat fascia dentata. The impregnated granule cells were gold-toned allowing for a fine structural study of the same identified neurons and of the input synapses onto their cell bodies and dendrites. Due to the long postnatal formation of these cells it was possible to describe a sequence of maturational stages coexisting on the same postnatal day (P5). Characteristic features of the dendritic development of granule cells were i) occurrence of varicose swellings along the dendrites, ii) growth cones on dendritic tips, iii) transient formation of basal dendrites, and iv) progressive development of dendritic spines. Incoming synapses on the differentiating granule cells were mainly found on dendritic shafts. Their membrane specializations were symmetric. At least some of these symmetric synapses were GABAergic because immunostaining of Vibratome sections from the same postnatal stage (P5) demonstrated a well-developed GABAergic axon plexus in the fascia dentata (antibodies against glutamate decarboxylase (GAD), the GABA synthesizing enzyme). Electron microscopy of the immunostained axon plexus revealed numerous GABAergic terminals that formed symmetric synaptic contacts, mainly on shafts of differentiating dendrites but also on cell bodies of granule cells. Our results thus indicate that the plexus of inhibitory GABAergic axons is already well developed at a stage when the target neurons, the granule cells, are still being formed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 123
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 178 (1988), S. 155-159 
    ISSN: 1432-0568
    Keywords: Interhemispheric pathway ; Congenital anophthalmia ; Visual cortex ; Development ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In an effort to assess the innate capacity of the central visual system to specify corticocortical connectivity in the absence of retinal afferents, we examined the tangential distribution of callosal cells and terminations in posterior neocortex of congenitally anophthalmic rats. Although our results indicate that the callosal pattern is clearly anomalous in these rats, all features of the normal visual callosal pattern are recognizable in mutant rats, indicating that central visual pathways can generate many aspects of normal interhemispheric connectivity in the absence of input from the periphery. On the other hand, the presence of anomalies in the pattern indicates that the eyes are necessary to finetune the distribution of callosal connections at some developemental stage. Moreover, the fact that abnormalities in the callosal pattern of mutant rats are the same as those previusly described in rats enucleated at birth suggests that the eyes begin to exert their influence on callosal development after birth.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 124
    ISSN: 1432-0568
    Keywords: Atrial specific granule ; Atrial natriuretic polypeptide ; Impulse conducting system ; Immunohistochemistry ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The present study was performed to clarify the distribution of ANP-containing cells in the adult rat heart by immunostaining for ANP using antiserum against α-human ANP. ANP-immunoreactive cells were generally present in the atrial walls except for the sinoatrial node. In the ventricular walls, they were distributed in the impulse conducting system, particularly the left bundle branch, Purkinje fibers on the left side of the interventricular septum, and those in the false tendons in the left ventricle, while they were sporadically seen in the atrioventricular node and bundle of His. The immunoreactive cells contained specific granules that were positive for ANP. These findings demonstrate that ANP-containing cells are present in the atrial and ventricular walls.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 125
    ISSN: 1432-0568
    Keywords: Visual cortex ; VIP ; Synapse ; Spatial distribution ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In the rat visual cortex vasoactive intestinal polypeptide (VIP)-containing structures were studied by means of light and electron microscopy and image analysis. VIP-immunoreactive axon terminals were found to form symmetric synapses with small dendritic shafts, dendritic spines and somata of pyramidal cells and interneurons. VIP-terminals often occured in pairs with VIP-negative, asymmetric synapses on the same postsynaptic structure. VIP-immunostained dendrites and perikarya were contacted by a purely asymmetric and a mixed population of VIP-negative terminals, respectively. Synaptic connections between two VIP-neurons are seldom as compared to the other types of VIP-synapses. Quantitative studies obtained by the image analysis of VIP-stained boutons and dendritic particles in light microscopic preparations suggest a distinct laminar distribution. Dendritic particles are most frequent in layers I–II, whereas axonal boutons have three laminar accumulations: at the border of layers I–II, in layer IV and layer VI. Together with previous results, the present findings argue for a non-random spatial distribution of VIP-boutons.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 126
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 178 (1988), S. 381-388 
    ISSN: 1432-0568
    Keywords: Ciliary necklaces ; Olfactory ; Vomeronasal ; Respiratory ; Development ; Freeze-fracturing ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Many cilium types have at their proximal base a particulated membrane structure, the so-called ciliary necklace. Necklaces of primary and secondary cilia of olfactory receptor cells and ciliated respiratory cells, and of primary cilia of olfactory supporting cells were studied as a function of embryonic age. Strand numbers in necklaces of primary cilia of these cell types do not differ, but they differ significantly from those of necklaces of secondary cilia. Primary cilia have 2 to 4, but most commonly 3, necklace strands. This is true for necklaces of primary cilia of 8 different nasal cell types: olfactory epithelial basal and glandular cells, vomeronasal receptor and supporting cells, and microvillous respiratory epithelial cells, in addition to the 3 cell types mentioned above. Comparison with other systems suggests that primary cilia resemble flagella of eukaryotic flagellates and spermatozoa of some invertebrates with respect to their number of necklace strands. Average numbers of necklace strands in secondary olfactory cilia increase from 3–4 at the 16th and 17th gestational days to 6–7 in adults. Those in secondary respiratory cilia increase from 2–3 at the 18th and 19th gestational days to 5–6 in adults. Longer cilia have more strands than shorter ones. Necklaces often have free strand endings, also in primary cilia, suggesting that they spiral. Comparing the present data with those in the literature suggests that necklace features occurring during reciliation differ from those of de novo ciliogenesis. Primary and secondary cilia share the following qualities: 1) Membrane regions above necklace strands can differ quite drastically from those below the strands. 2) Necklace particles are firmly associated with cytoskeletal elements underneath the ciliary membrane. Hence, necklaces in primary cilia and in developing and mature secondary cilia may, together with the cytoskeleton underneath the membrane, provide a barrier for lateral diffusion and a region of membrane attachment. The latter may help to determine the shape of cilia.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 127
    ISSN: 1432-0568
    Keywords: Primary afferents ; Muscle ; Anterograde tracing ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The sternomastoid muscle of the rat is divided into a white (dominated by fast-glycolytic twitch fibers) and a red (dominated by fast oxidative-glycolytic twitch fibers, but also containing slow-oxidative twitch fibers) compartent. Previous reports on exclusive location of muscle spindles in the red portion were confirmed. On the basis of anterograde labeling with horseradish peroxidase-wheat germ agglutinine conjugate (WGA-HRP) it was shown in this study that, in addition to muscle spindle compartmentalisation, there was also an exclusive occurrence of tendon organs in the red part of the muscle; moreover, fine afferents (III- and IV-afferents) were mainly distributed to this portion as well. Radioimmunassay studies revealed that this part of the muscle contained twice as much substance P as the white part. It could be shown by acetylcholinesterase (AChE) histochemistry that the myelinated fibers of the white branch to the muscle exclusively displayed high enzyme activity which is characteristic for motor fibers; on the other hand, in the branch to the red portion two classes of AChE-positive fibers were found: a large one with a peak in the alpha-range, and a small one with a peak in the gammarange. In addition, there was also a group of enzyme-negative (sensory) fibers. These results also indicate the red portion of the sternomastoid muscle to be its “sensory compartment”.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 128
    ISSN: 1432-0568
    Keywords: Rat ; Development ; Diencephalon ; Neuromeres ; Sulcus limitans
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The morphogenesis of the ventricular surface of the diencephalon of the rat was studied using scanning electron microscopy, cryostat serial sections and direct observations under a dissection microscope. Based on these observations a description is given of the neuromeres present within the prosencephalon and of the termination of the sulcus limitans. Two conclusions are reached. First, three neuromeres are present in the prosencephalon. Neuromere I consists of the telencephalon, the hypothalamic regions and the parencephalon anterius. Neuromere II is the parencephalon posterius, neuromere III the synencephalon. Second, the sulcus limitans terminates ventrally in the parencephalon posterius and does not continue towards the preoptic recess. No exact termination point of the sulcus limitans could be delineated.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 129
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 179 (1988), S. 89-96 
    ISSN: 1432-0568
    Keywords: Tendon ; Myotendinous junction ; Fibroblast ; Muscle overloading ; Hypertrophy ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Overloading of rat plantaris muscles was produced by aseptic ablation of the synergists. The morphological changes occurring after 1 or 2 weeks were investigated at the light and electron microscopical level in the distal tendon of the plantaris and at the myotendinous junction. Sham-operated rats were prepared as controls. In the tendon, quiescent fibrocytes were replaced by activated fibroblasts displaying a vesicular nucleus with prominent nucleoli and an outstanding increase in cytomembranes, particularly the rough endoplasmic reticulum and the Golgi complex. The plasmalemma of the fibroblasts was modified by the presence of caveolae and the surbsurface cytoplasm contained many membrane-bound vacuoles. In the tendon, the collagen bundles were disrupted, resulting in the formation of empty longitudinally oriented spaces; in these spaces, as in the pericapillary areas, no inflammatory cells were observed. At the myotendinous junction, fibroblast activation was consistently observed in both control and overloaded specimens. At this level, the sarcolemma of the finger-like projections of muscle fibres presented many caveolae close to clusters of large subsurface vacuoles. These observations indicate that, at the beginning of the compensatory hypertrophy, the adaptative changes to overloading include a non-inflammatory reaction of the tendon characterized by enhanced collagen synthesis and intensive membrane renewal and recycling. From the mechanical point of view this reaction can impair the tendon resistance to stretch. At the myotendinous junction the increased membrane turnover of the sarcolemma and the fibroblast activation can be considered permanent phenomena consequent to the increased stress exerted upon the interface connecting the contractile apparatus to the stroma.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 130
    ISSN: 1432-0568
    Keywords: LHRH ; Rat ; Maturation ; Sex-difference
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Luteinizing hormone-releasing hormone (LHRH) neurons were immunohistochemically studied in rats of both sexes at peripubertal ages. The number of immunoreactive LHRH neurons (irLHRH neurons) was counted in the brain region from the level of the septumpreoptic area to the level of the rostral part of the infundibulum in colchicine-treated male and female rats at 30 and 60 days of age. At 30 days, irLHRH neurons were more numerous in male rats than females. At 60 days, the number of irLHRH neurons in female rats increased to the level of male rats of the same age. In non-colchicine-treated rats, the count of irLHRH neuron was quite low. The difference in the number of irLHRH neurons between colchicine-treated and non-treated rats may be regarded as the activity of LHRH system. The difference in the number of irLHRH neurons was larger in male rats than in female rats at 30 days of age. On the contrary, at 60 days of age, the difference was larger in females than in males. LHRH contents were measured in the preoptic-anterior hypothalamic area (POA-AH), where LHRH neuronal perikarya are mainly located, and in the mid-hypothalamic area. LHRH content of the POA-AH in male rats at 60 days of age was not significantly different from that at 30 days of age. While, LHRH content in the POA-AH was greater in 60-day-old female rats at proestrous morning than that in 30-day-old females. At 30 days of age, male rats tended to contain more LHRH in the POA-AH than female rats. However, either at 30 days or at 60 days, no statistically significant differences were detected between male and female rats. In mid-hypothalamic area, LHRH content in 60-day-old male rats was greater than that in 30-day-old male rats. On the other hand, there was no difference in LHRH content between 30-day-old and 60-day-old female rats. At 60 days of age, LHRH content in male rats was greater than that in female rats. The present morphological findings and LHRH measurements suggest that the functional maturation of LHRH system occurred earlier in male rats than in female rats.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 131
    ISSN: 1432-0568
    Keywords: Immunohistochemistry ; Choline acetyltransferase ; Olfactory bulb ; Modified glomerular complex ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The main and accessory olfactory bulbs (MOB and AOB) of the rat were immunohistochemically stained with a monoclonal antibody against choline acetyltransferase (ChAT) in order to know the difference in the distribution patterns of cholinergic fibers between these two structures. A few ChAT-immunoreactive cell bodies were found in the superficial and middle parts of the external plexiform layer (EPL) of the MOB, in the granule cell layer (GCL) of the MOB, and in the GCL of the AOB. The frequency in appearance of these cells was 0.9 cells/section in the MOB and 0.3 cells/section in the AOB. While the glomerular layer (GL) and the superficial part of the EPL were most densely innervated in the MOB, the internal plexiform layer received the richest innervation in the AOB. There were no immunoreactive structures in the olfactory nerve layer of the MOB and in the vomeronasal nerve layer and glomerular layer of the AOB. In addition to a relatively homogenous distribution of cholinergic fibers in the MOB and AOB, there were several foci of very dense network of immunoreactive fibers at the posterior level of the OB. These foci formed a part of the modified glomerular complex that was recently identified using 2-deoxyglucose method and was presumed to be related to suckling behaviour in the neonatal rat.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 132
    ISSN: 1432-0568
    Keywords: Pancreatic islet ; Insulin ; Glucagon ; Ontogeny ; Immunohistochemistry ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Ontogenetic appearances of glucagon, insulin and tyrosine hydroxylase (TH) were immunohistochemically investigated on developing pancreatic islets of rats. Glucagon immunoreactivity appeared first in some epithelial cells (g-cells) of the dorsal anlage of the pancreas on day 11.5 of gestation. On day 12.5, g-cells increased in number manufacturing the primitive islets, in which some cells appeared to be immunoreactive for insulin (i-cells) and about 40% of g-cells indicated also a slight immunoreactivity for insulin (g/i-cells). Afterwards, all the islet cells, especially g-cells, increased in number, and almost half of g-cells were g/i-cells. After day 16.5 of gestation, numerical increase of the cells with insulin immunoreactivity exceeded that of the cells with glucagon immunoreactivity, and about one fifth of g-cells were g/i-cells. After 20.5 days, however, no g/i cells were found. On day 16.5 of gestation, the immunoreactivity for TH appeared in occasional cells of the islets, but the cells did not show immunoreactivity for glucagon or insulin. It is concluded that the progenitor cells of the pancreatic islets appear to synthesize both glucagon and insulin by day 20.5 of gestation, but differentiate giving rise to mature A and B cells of adult isoets afterward.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 133
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 177 (1988), S. 267-275 
    ISSN: 1432-0568
    Keywords: Septal nuclei ; Prenatal development ; Quantitative histology ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Prenatal development of septal cell groups was studied in the rat on samples taken daily from the 14th day of gestation until birth. Coronal serial sections of brains were prepared in which the topography coordinates of septal nuclei were determined, their section profiles measured and their volumes calculated. The rat septum begins to develop on embryonic days 14–15. First the individual neurons start to differentiate, then cell groups characteristic for the adult are formed between days 14 and 17, which is followed by the delineation of nuclei. The only exception is the anterior subdivision of the lateral septal nucleus where the formation of the nucleus precedes the differentiation of its constituent cells. The individual nuclei start to develop at different times defined by a medio-lateral gradient of cell migration. By embryonic day 20 the formation of the nuclei can be considered as complete: all septal nuclei and their subdivisions are to be recognized and distinguished from each other.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 134
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 179 (1988), S. 109-127 
    ISSN: 1432-0568
    Keywords: Rat ; Inferior olive ; GABA ; Glutamate decarboxylase ; Cerebellar circuitry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Boutons presumed to use γ-aminobutyric acid as neurotransmitter (GABAergic boutons) were detected by glutamate decarboxylase (GAD) immunocytochemistry in all regions of the rat inferior olive. The remarkably high concentration of these boutons allowed a clear visualization of olivary subnuclei boundaries. Regional variations in GAD immunostaining intensity were observed within the nuclear complex and were graded both visually and photometrically. The regional staining variations, for the most part, followed subnuclei boundaries and olivary zonal compartments that have been delineated by the topography of climbing fiber projections. Some subnuclei were grouped by similar staining intensities. The beta nucleus and a medial region in the ventral fold of the dorsal accessory olive were most intensely immunostained, followed by the subnucleus c of the medial accessory olive. Lower staining intensities were observed in the dorsomedial cell column, the dorsal fold of the dorsal accessory olive and the dorsal cap. The lowest intensities were observed in the subnuclei a and b of the medial accessory olive, the ventrolateral outgrowth, the rostral lamella of the medial accessory olive, the principal olive, and the lateral part of the ventral fold of the dorsal accessory olive. The factors contributing to the variations in immunostaining intensity (bouton size and frequency of occurrence) were investigated. The largest boutons were observed in the beta nucleus. Intermediate sized boutons were observed in the dorsomedial cell column, dorsal cap and the dorsal fold of the dorsal accessory olive. The smallest boutons were present in the remaining regions of the inferior olive, including the principal olive, the rostral lamella of the medial accessory olive, and the ventral fold of the dorsal accessory olive. The medial region of the dorsal accessory olive ventral fold contained a higher density of GABAergic boutons than other regions. GABAergic bouton size and innervation density therefore largely accounted for the variations in GAD immunostaining intensity. This study provides a map of the rat inferior olive based on the distribution of GABAergic nerve terminals, and may serve as a basis for characterizing different GABAergic afferent systems in the inferior olive.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 135
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 178 (1988), S. 175-181 
    ISSN: 1432-0568
    Keywords: Liver development ; Adrenergic innervation ; Enzymic zonation ; Rat ; Spiny mouse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The development of noradrenergic innervation of rat liver was studied with a polyclonal antiserum against noradrenaline. Nerves are first seen in the larger portal vessels at day 1 after birth and reach their final distribution at 5 days after birth i.e. at the same time as the establishment of the acinar architecture and the heterogeneous distribution of NH3-metabolizing enzymes. The latter distribution of nerves is already seen at birth in the liver of the closely related but precocial spiny mouse. This shows that the onset of extrinsic sympathetic innervation is regulated by the developmental stage of the animal rather than by adaptation to extrauterine life. Chemical sympathectomy at birth with 6-hydroxydopamine did not eliminate the developmental appearance of heterogeneous distributions of NH3-metabolizing enzymes.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 136
    ISSN: 1432-0568
    Keywords: Visual cortex ; VIP ; Neuronal types ; Axonal branching ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Vasoactive intestinal polypeptide (VIP)-immunoreactive cells in the primary visual cortex of the rat were classified on the basis of ramification pattern of cell processes. The distribution of cells over cortical layers, and proportions of cell classes relative to total cell numbers were evaluated by means of quantitative methods. Two main types of VIP-positive neurons, the bipolar and the multipolar were distinguished constituting 76% and 24% of the VIP populations, respectively. The axons of vertically oriented bipolars were observed to ramify within a column around the descending dendrite. By contrast, multipolar cells have a non-oriented ramification pattern. The two overlapping axonal systems form the VIP-innervation of the rat visual cortex.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 137
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 178 (1988), S. 309-326 
    ISSN: 1432-0568
    Keywords: Axons ; Cilia ; Microvilli ; Olfactory ; Respiratory ; Development ; Freeze-fracturing ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Olfactory axons and apical structures of olfactory epithelia and of nasal respiratory epithelia of rat embryos were studied with the freeze-fracture technique; adult tissue samples of the same sources were used for comparison. At the onset of epithelial differentiation (14th gestational day) intramembranous particle densities are the same for all structures in both epithelial types. During further development, particle densities in membranes of primary cilia remain lower than those in membranes of other apical structures. Otherwise, I found the following from the 14th to the 19th day of gestation.a. Olfactory receptor cells of embryos of all age groups have axons wherein the membrane particle densities are about half those of adults. These densities are always lower than those of dendritic ending structures. Dendritic endings with primary cilia have lower densities than endings with secondary cilia; densities mainly increase when the endings sprout secondary cilia. Adult values are reached at the 18th day of gestation.b. Olfactory supporting cells with only globular particles in their apices gradually transform into, or are replaced by, supporting cells which also have dumbbell-shaped particles in their apices. Particle densities are always higher in apical structures of supporting cells than in apical structures of receptor cells. Adult values are reached at the 17th day of gestation.c. Putative ciliated and ciliated respiratory epithelial cells have considerably lower particle densities in membranes of their apical structures than do olfactory epithelial cells. Of special interest is that this is also true for secondary respiratory and olfactory cilia; as soon as genesis of secondary cilia in either epithelial type begins, their membrane features differ. Also, in contrast to apical structures of the olfactory epithelium, particle densities in apical structures of the respiratory epithelium do not systematically change during pre-natal development, and resemble the density values of adults. An exception are the microvilli of the respiratory cells with secondary cilia, membranes of which have considerably higher particle densities in adults than in embryos. In conclusion: Transformations of olfactory receptor cell dendritic endings with primary cilia into endings with secondary cilia, and of olfactory supporting cells with globular particles in their apices into cells with dumbbell-shaped particles in their apices are accompanied by increases in the densities of their intramembranous particles. These developmental changes parallel the electrophysiological onset of olfactory receptor cell specificity.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 138
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 76 (1988), S. 253-264 
    ISSN: 1432-0533
    Keywords: Cerebral ischemia ; Rat ; Hyperglycemia ; Postischemic seizures ; Substantia nigra
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary This study explores how hyperglycemia and enhanced tissue lactic acidosis influence the density and distribution of ischemic brain damage. Ischemia of 10-min duration was produced in glucose-infused rats by bilateral carotid clamping combined with hypotension, and the brains were perfusion-fixed with formaldehyde following recirculation of 3, 6, 12 and 18 h. After about 24 h the hyperglycemic animals developed seizures, and at that time two groups were added, one fixed prior to, and one after the onset of seizures. Similar experiments were made on normoglycemic animals with recirculation times of 1.5 to 96 h. After fixation the brains were embedded in paraffin, subserially sectioned and stained with celestine blue/acid fuchsin. In both normo- and hyperglycemic animals, neurons in the dentate hilus of the hippocampal formation and in the thalamic lateral reticular nucleus showed early and dense neuronal necrosis. In neocortex, hippocampal CA1 sector and caudoputamen, hyperglycemia shortened the delay before damage occurred and markedly enhanced the damage. Specific for the hyperglycemic animals was damage of the substantia nigra, pars reticulata (SNPR), manifest already at the earliest recovery periods studied; this finding is discussed in relationship to the role SNPR is assumed to play in preventing spread of seizure discharge.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 139
    Electronic Resource
    Electronic Resource
    Springer
    Archives of toxicology 61 (1988), S. 489-495 
    ISSN: 1432-0738
    Keywords: Fusarenon-X ; T-2 Toxin ; Jejunal absorption ; Monosaccharide ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In order to delineate the effects of Fusarenon-X (FX) and T-2 toxin (T-2) on intestinal absorption of monosaccharide, jejunal absorption in vivo and uptake in vitro of 3-0-methyl glucose (m-glucose) and l-glucose were studied in rats. Jejunal absorption in vivo was assessed by determining the rate of appearance of the sugars in plasma of the mesenteric vein draining the jejunal segment, which was perfused with the medium containing radiolabelled m-glucose or l-glucose. Jejunal uptake in vitro was assessed by determining the m-glucose or l-glucose uptake by the everted jejunum taken from toxin-treated rats, m-Glucose absorption was reduced 1 or 3 h after either toxin was injected into the jejunal lumen. A reduction of m-glucose absorption was also noted after intravenous injection of the toxins, although the timing and magnitude of the reduction were slightly different from those seen after the luminal injection. These results suggest that both toxins impair the jejunal function relating to monosaccharide absorption in the early stages of intoxication. The reduction in m-glucose absorption was associated with a reduction in l-glucose absorption and unchanged or increased uptake of l-glucose. The active transport component, which was indicated by the difference between absorption or uptake of the two sugars, was also reduced in association with the reduction of m-glucose absorption. These results suggest that the toxins cause specific damage in the active transport system for monosaccharides on the one hand, and impairment of their diffusional movement from the epithelial layer to the mesenteric vein on the other.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 140
    ISSN: 1432-0738
    Keywords: Rat ; Naphthalene ; Peroxidation ; Glutathi one peroxidase ; Superoxide dismutase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Male, weanling Blue-Spruce rats were treated with naphthalene (p.o.) in defined dose increments up to 750 mg/kg body weight over 9 weeks. At necropsy, treated rats showed a 20% decrease in body weight compared to controls. Naphthalene treatment resulted in enhanced peroxidation (p〈0.001) only in the liver. This increased peroxidation was associated with reductions (p〈0.05) in the activity of the selenoenzyme glutathione peroxidase in hepatic cytosolic fractions and an associated increase (p〈0.05) in the selenium-independent glutathione peroxidase. No increase in peroxidation was observed in the lung, eye or heart of these rats and the activities of the selenoenzyme and the selenium-independent glutathione peroxidases were also unaffected by naphthalene in these organs. Naphthalene also did not affect superoxide dismutase activity in any of the organs examined. Thus, in addition to the known effects of naphthalene on tissue glutathione, naphthalene-induced reductions in the selenoenzyme glutathione peroxidase can also contribute to peroxidation in the liver and must be considered as a contributing factor in naphthalene toxicity in vivo.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 141
    ISSN: 1432-0738
    Keywords: Acyclovir ; Embryotoxicity ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Following three s.c. injections of acyclovir (100 mg acyclovir/kg) into rats on day 10 of pregnancy 19 litters were evaluated on day 21 of gestation and the effects were compared to the results obtained from controls (nine litters) which received the vehicle (0.1 N NaOH) only. The following results were obtained (treated group versus control group): 1) Implantations/litter: 11.2±1.3 versus 10.2±1.1; 2) resorptions/implantations: 27.7% versus 2.2%; 3) number of viable fetuses evaluated: 154 versus 90; 4) fetuses with anomalies of the skull: 78% versus 12%; 5) fetuses with anomalies of the vertebral column: 38% versus 13%; 6) gross-structural anomalies predominantly affected the skull and tail. The most frequently registered defects were: os tympanicum (smaller): 23%, os tympanicum (missing): 23%; missing tail: 7%; protruding tongue (15%); none of these defects were seen in the control fetuses. Postnatally we observed a high mortality rate among the offspring. From a total of 85 newborn (nine litters) we obtained 73 viable offspring (9.1±3.4); 81% of them had tail alterations. In the control group of eight litters (9.4±2.3) no tail alterations occurred. On day 21 postnatally 40 viable offspring were alive (mortality rate: 38.8%). Nearly all of these animals had visible alterations at multiple sites of their bodies; most frequently observed were: tail impairment, closed eyes, dragging hind-limbs, and urogenital alterations (e.g. testicular atrophy). These studies show for the first time that prenatal treatment with acyclovir induces gross-structural defects which persist postnatally. With the usually applied precautions during therapeutic use in pregnant women, the teratogenic potency of acyclovir seems to be small; however, acyclovir does have a teratogenic potential.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 142
    ISSN: 1432-0738
    Keywords: (14C)-2-ethylhexyl acrylate ; Rat ; Distribution ; Elimination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The fate of (14C)-2-ethylhexyl acrylate was studied in adult male Wistar rats given an intravenous (i.v.) or intraperitoneal (i.p.) injection of 10 mg/kg (0.054 mmol/kg). The elimination of radioactivity from blood was bi-exponential, irrespective of the route of (14C)-2-EHA administration or the age (weight) of the rats. The first phase half-lives after i.v. and i.p. administration in 4-month-old rats were 30 and 60 min, in 7-month-old rats 115 and 130 min, respectively. The corresponding values for the slow-phase were 5 and 6 h, and 14 and 14h. Elimination of the radioactivity from tissues followed a pattern similar to that seen for blood. More than half of the administered radioactivity was exhaled as carbon dioxide. Exhalation of unchanged (14C)-2-EHA accounted for only 0.05% (i.v.) or 0.3% (i.p.) of the initial dose of radioactivity. The radioactivity excreted in the urine within the first 24 h posttreatment accounted for 7% (i.p.) or 14% (i.v.) of the initial dose, and only 2% was excreted as thioethers.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 143
    ISSN: 1432-0738
    Keywords: Adriamycin ; Heart ; Kidney ; Liver ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The influence of chronic adriamycin treatment on cellular defence mechanisms against free radicals has been determined in rats. To that end, the changes in vitamin E content, activity of superoxide dismutase, catalase and factors of the glutathione system were measured in heart, kidneys and liver after 24 and 52 days of treatment. Moreover, damage was assessed by measuring the activity of NADPH- and NADH-cytochrome c reductase. The results concerning the components of the oxidative defence systems in male rats showed reductions in the activity of superoxide dismutase and catalase in renal tissue and in factors of the glutathione system in liver tissue. In cardiac tissue an increased activity of catalase and elevated content of total glutathione were found. Vitamin E content was increased in liver and to a lesser extent, in kidneys. The activity of Se-dependent glutathione peroxidase sharply decreased only in liver. Major differences between male and female rats were not observed in renal and cardiac tissue, as far as protective factors were concerned. However, a decrease in catalase activity was detectable earlier in male kidneys. The protective factors in liver of female rats were far less susceptible to in vivo treatment with adriamycin, as compared to liver of male rats. Decreased activity of the cytochrome reductases was found in liver of male rats. In male renal tissue only cytochrome c reductase activity was significantly reduced. Male cardiac tissue showed no signs of biochemical damage, although from histological examination in a parallel study [J Natl Cancer Inst 76: 299–307 (1986)] lesions were evident. In female rats no damage was found in liver, kidneys and heart.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 144
    ISSN: 1432-0738
    Keywords: Nephrotoxicity ; Cytostatic drug ; Celiptium ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Celiptium (N2-methyl-9-hydroxy-ellipticinium) is an antitumoral agent used to treat bone metastases from breast carcinomas. This new drug appeared to be of great interest because of the absence of hepato-or myelotoxicity. Three different investigators recently mentioned cases of celiptium-induced renal failure. We therefore undertook a study of renal function and morphology in female Wistar rats. Two single i.v. doses (10 or 20 mg/kg) were administered and animals were sacrificed 4, 8, 15, 28 and 60 days after injection. One group of rats received multiple doses, 5 mg/kg/week for 8 weeks. No mortality was observed. With the 10 mg/kg single dose creatinine clearance (Ccr) and urinary enzymes did not change, and tubular lesions were rare. With the 20 mg/kg single dose CCr decreased on day 4 and returned to normal on day 28. Urinary enzyme excretion (AAP, NAG, γGT) increased. Renal lesions were diffuse with tubular necrosis, luminal dilation and later (day 28) interstitial cellular infiltration. These lesions persisted on day 60 and appeared to be irreversible. Ultrastructural studies showed numerous large fat droplets in proximal tubular cells. Glycerol concentrations in renal cortex homogenates were increased while phospholipids are slightly decreased. With 5 mg/kg every week (multiple doses) Ccr decreased and tubular lesions similar to the observed with the 20 mg/kg single dose were seen. Thus celiptium induced dose-dependent nephrotoxicity in rats with prolonged tubular alterations. Since it has been shown that renal tubular cells metabolized celiptium in vitro into electrophilic intermediates, we suggest that free radicals and quinone derivatives may contribute to peroxidation of unsaturated fatty acids and play a role in the nephrotoxicity of the drug.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 145
    Electronic Resource
    Electronic Resource
    Springer
    Archives of toxicology 62 (1988), S. 452-457 
    ISSN: 1432-0738
    Keywords: Orthophenylphenol ; Metabolites ; Buthionine sulfoximine ; Hepatotoxicity ; Nephrotoxicity ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A single oral administration of orthophenylphenol (OPP, 1400 mg/kg; about half the LD50) to male Fischer 344 rats produced an elevation of serum transaminase activity 24 h later. Pretreatment with l-buthionine-S,R-sulfoximine (BSO, 900 mg/kg) in the OPP-treated rats potentiated the hepatic and renal damage which was accompanied by necrosis. Six hours after the administration of OPP (700 or 1400 mg/kg), hepatic and renal glutathione (GSH) levels decreased with increasing dosage. Hepatic GSH depletion with OPP was enhanced with BSO pretreatment and the recovery of GSH in both organs was slow in the high-dose OPP group. These results suggest that hepatic and renal damage is associated with a serious and prolonged GSH depletion. When either phenyl-p-benzoquinone (PBQ) or phenylhydroquinone (PHQ), which are intermediates of OPP, was administered orally to rats at 700 or 1400 mg/kg, the mortality with the high dose of PBQ was 75% at 24 h. The serum transaminase activity and UN level increased with the low dose of PBQ, accompanied by necrotic hepatocytes. The toxic effects of PHQ on kidney or liver were less than those on PBQ. These observations suggest that the liver and kidney may be target organs for toxic actions of a large dose of OPP and its intermediate, PBQ.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 146
    ISSN: 1432-0738
    Keywords: Methylmercury ; Aminoacyl tRNA synthetase ; Brain ; Protein synthesis ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The activities of six aminoacyl-tRNA synthetase species were determined using enzyme preparations partially purified from the brains of control and methylmercury (MeHg)-treated rats. The activities of Asp-, Leu- and Tyr-tRNA synthetases were significantly reduced in the brains of MeHg-intoxicated rats, whereas those of Lysand Met-tRNA synthetases remained unchanged. In contrast, the activity of His-tRNA synthetase was significantly increased in the symptomatic phase of MeHg intoxication. The activities of these six aminoacyl-tRNA synthetases in the control brains were affected to different extents on the direct addition of MeHg to the assay system in vitro. No positive correlation was observed between the in vivo and in vitro effects of MeHg on the enzyme activities. These results indicate that the aminoacylation of tRNA is one of the actions of MeHg, which leads to inhibition of protein synthesis, and it is suggested that the syntheses of cellular proteins may be modified in different ways by MeHg, depending on their amino acid compositions.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 147
    Electronic Resource
    Electronic Resource
    Springer
    Archives of toxicology 61 (1988), S. 359-365 
    ISSN: 1432-0738
    Keywords: Butylated hydroxytoluene ; Nephrotoxicity ; Phenobarbital ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A single large dose of butylated hydroxytoluene (BHT, 1000 mg/kg) in male Fischer 344 rats produced some renal damage, reduced accumulation of p-aminohippuric acid in renal slices, proteinuria and enzymuria, in addition to hepatic damage. Further, prior administration of phenobarbital (80 mg/kg, i. p., daily for 4 days) in the high-dose BHT-treated male rats produced renal damage accompanied by slight tubular necrosis. The renal damage was confirmed by biochemical and histological changes. These changes were dose dependent, with a maximum at 24 h after BHT administration, but had returned to the normal range by 48 h. Female rats, on the other hand, were less susceptible to BHT-induced renal and hepatic damage than male rats. The results indicate sex differences in BHT-induced renal or hepatic damage.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 148
    Electronic Resource
    Electronic Resource
    Springer
    Archives of toxicology 61 (1988), S. 373-377 
    ISSN: 1432-0738
    Keywords: Dibutyltin dilaurate ; Neurotransmitters ; Brainareas ; Behavior ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Exposure to DBTL (20, 40 or 80 mg/kg body weight) caused a decrease in levels of noradrenaline (NA), dopamine (DA) and serotonin (5-HT) at all treatment levels. Hypothalamus and frontal cortex appeared to be most affected, since levels of all the three amines examined showed changes in these areas. Maximum decrease of DA was found in corpus striatum, NA in pons medulla and of 5-HT in frontal cortex. These animals also showed a decrease in spontaneous locomotor activity and learning at all the doses. The data indicates involvement of hypothalamus and frontal cortical regions of the brain in the neurotoxicity of DBTL.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 149
    ISSN: 1432-0738
    Keywords: Lysozyme ; Renal damage ; Urinalysis ; Radioimmunoassay ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The radioimmunoassay (RIA) as a high sensitive detection method for rat lysozyme (LZM) was established and applied to determine LZM excretion in urine from rats treated with tubulotoxic chemicals in order to establish a sensitive method of detecting minor renal damage. Rat LZM which showed a single protein band on sodium dodecylsulfate polyacrylamide gel electrophoresis was purified by ion-exchange chromatography and gel filtration. The assay sensitivity of the established RIA using the purified rat LZM was 4–256 ng/ml rat LZM and was about 20 times the turbidity method. The concentration of LZM in normal rat urine was 76.2±6.0 ng/ml (mean ± SE, n = 50) using the RIA. In urine containing more than 100 ng/ml LZM, a high correlation between the values determined by the RIA and those by the turbidity method was observed. However, egg white LZM, human urinary LZM and guinea pig urinary LZM were not detectable by the RIA. Using the RIA, it was ascertained that urinary LZM excretion began to increase on day 5 in rats treated with gentamicin (15 or 30 mg/kg/day sc for 17 days), during the 6–9 h period in the rats treated with mercuric chloride (1 mg/kg sc), and during the 0–3 h period in the rats treated with p-aminophenol (1 mmol/kg sc). These significant increases in LZM excretion were not detectable by the turbidity method; therefore, it was concluded that this RIA for rat LZM was very useful for detection of minor renal damage.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 150
    ISSN: 1432-0738
    Keywords: Gentamicin ; Pregnancy ; Rat ; Fetus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract As part of our studies on the prenatal induction of renal dysfunctions in rats by gentamicin we measured maternal plasma levels of the drug. Additionally, the gentamicin concentrations in the plasma of rat fetuses after single s.c. injections of gentamicin were measured. The following results were obtained: 1) Non-pregnant rats excrete the drug faster than pregnant rats; 2) after a single s.c. injection of 110 mg gentamicin/kg body wt to six pregnant rats on day 21 of gestation the following pharmacokinetic variables were calculated: t1/2(inv): 27.0±6.1 min, t1/2(elim): 54.7±3.8 min, Cmax: 166.2±22.7 mg/l, tmax: 53±6.7 min, AUC: 431.7±53.4 mg/l×h; 3) plasma concentrations increase with the duration of pregnancy; 4) fetal plasma concentrations were determined between 45 and 660 min after single injections of 150 mg/kg to the dams. The concentrations showed minimum variation over this time period. Thus, the ratio of maternal to fetal plasma levels decreases drastically during this period; 5) 8 h after s.c. injection of 110 mg/kg to six dams (day 21 of gestation) individual plasma concentrations in the plasma of mother animals and in the plasma of 65 fetuses were determined. All fetal plasma samples showed higher concentrations than the corresponding maternal ones; 6) after multiple injections a significant increase in plasma concentrations can be seen. A considerable individual variance is obvious at all times and with both doses investigated; 7) since maternal plasma concentrations vary considerably in individual animals, especially after multiple injections, fetal exposure must also be variable in different litters. This would also affect the extent of postnatal dysfunction in various litters.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 151
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 71 (1988), S. 291-297 
    ISSN: 1432-1106
    Keywords: ACTH ; Emotional response ; Motor activity ; Vasopressin ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In an attempt to find whether vasopressin (VP) secretion is suppressed by learned emotional stress, we have given rats under a hypertonic condition simultaneously applied light and tone that had been paired previously with footshocks and have quantified immunoreactive VP (ir-VP) in the plasma. In a training session light (60 watt) and tone (2 kz) of 3-s duration which were paired with electric footshocks (50 Hz, 1-s duration) were given to rats 11 times at an interval of 30 s. Various lengths of time after the training, the rats were tested with light and tone, which were unpaired with footshocks and repeatedly applied every 15 s for 3 min in the box used for training. Hypertonic NaCl (0.5 M, 2 ml/ 100 g b. w.) was injected s. c. 30 min before testing to increase the basal level of plasma VP. After testing, plasma ir-VP was significantly less in the experimental group than in the 0-mA control group of rats that were trained without FS. The values for the experimental group were also significantly less than those of untested control rats that had been trained with FS but were not tested. Plasma osmolality and blood haemoglobin concentration were not significantly different between control and experimental groups. Plasma immunoreactive adrenocorticotrophic hormone (ir-ACTH) level was higher and motor activity as expressed by cumulative time period of body movement during testing was lower in the experimental group than in either of the control groups. The difference in plasma ir-VP between experimental and control groups was statistically significant two days but not seven days after training, whereas ACTH and motor activity in experimental groups were still significantly different from those in control groups seven days after training. The suppressive VP and augmentative ACTH responses to testing disappeared in the rats that had received light and tone repeatedly during the intervening period between training and testing. These data support the hypothesis that emotional stimuli suppress VP secretion.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 152
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 70 (1988), S. 155-165 
    ISSN: 1432-1106
    Keywords: Sm1 cortex ; Receptive fields ; Rat ; Bilateral receptive fields ; Hindlimb
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Single cells in the primary somatosensory (Sm1) cortex were investigated for responses to bilateral hindpaw stimulation in Wistar rats anaesthetised by continuous intravenous administration of Althesin. Fifty-one percent of cells sampled (N = 134) responded to equivalent punctate mechanical stimuli delivered to both the contralateral and ipsilateral hindpaws under light anaesthesia. The distribution by cortical depth of cells with receptive fields (RFs) on both hindpaws was not significantly different from cells which had only contralateral RFs. No cell was found with a purely ipsilateral RF. For 86% of cells tested (N=44) the ipsilateral RF was partly or completely homologous with areas within the contralateral RF. The sizes of ipsilateral RFs were smaller on 66% of occasions when tested against their contralateral RFs. Modal latencies to ipsilateral mechanical stimulation were longer than to contralateral stimulation (34.1±9.1 ms (S.D) cf. 26.4±7.2 ms, N=44). Ipsilateral RFs were lost for 77% of cells tested following a 33% increase in anaesthetic infusion rate. Conditioning mechanical stimuli applied to the centre receptive field (CRF) on the ipsilateral hindpaw reduced or abolished a cell's responses to equivalent test stimuli applied to it's contralateral CRF with C-T intervals of 20–200 ms. Conditioning stimuli applied to the CRF contralateral to the cell reduced or abolished responses to test stimuli on the cell's ipsilateral CRF using C-T intervals of 0–900 ms. Responses in one cortex to stimulation of the ipsilateral hindpaw were unaffected by elimination of responses from the same hindpaw in the opposite contralateral Sm1 cortex, where responses had been suppressed by topical Lignocaine administration. Retrograde transport of horseradish peroxidase from hindpaw Sm1 cortex labelled many cells in homolateral thalamus, but failed to label cells in the entire forebrain contralateral to the injection site. It is concluded that direct crossed thalamocortical and callosal Sm1-Sm1 pathways do not contribute to the production of hindpaw ipsilateral receptive fields.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 153
    Electronic Resource
    Electronic Resource
    Springer
    Pediatric surgery international 3 (1988), S. 338-342 
    ISSN: 1437-9813
    Keywords: Spleen ; Autotransplantation ; Protective function ; Malaria ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Autologous splenic fragments regenerate after transplantation. The regenerated mass only attains a small proportion of that of the normal spleen. Some data on the protective function are controversial. Malaria parasites were inoculated to test splenic function in rats. Peak parasitemia, the course of parasitemia, and anemia were comparable in normal and autotransplanted rats. In rats with splenic transplants only the duration of the parasitemia was longer than in normal rats. In contrast, splenectomized rats were unable to clear the parasites from the blood and became progressively anemic. After stimulating regeneration by increasing the work load to the white pulp or the macrophage system, more regenerated tissue was found, but the protective function did not increase. The amount of regenerated splenic tissue does not correlate with its protective function.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 154
    ISSN: 1432-2307
    Keywords: Mammary neoplasms ; DMBA ; Rat ; Carcinoma ; Sarcoma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Mammary tumours were induced by the direct dusting of 1 mg, 7,12-dimethylbenz(a)anthracene (DMBA) powder onto the mammary gland of both 30-day-old female and male Sprague-Dawley rats, and the tumours were examined histologically. Mammary tumours developed in 43/43 (100%) of the females 11 to 20 weeks after DMBA dusting and 16/23 (70%) of the males 18 to 28 weeks after dusting, while non-mammary spindle cell sarcomas occurred in 5/23 (22%) of the males 15 to 24 weeks after dusting. A variety of benign and malignant mammary tumours of epithelial and/or mesenchymal origin were induced, which are comparable to human mammary tumours. Different histological patterns were observed in different areas of the same tumours. Ovariectomy revealed hormone (ovary)-dependency in 10/17 (59%) of the tumours, revealing regressing epithelial and proliferating mesenchymal tumour elements on histological examination.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 155
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 414 (1988), S. 77-81 
    ISSN: 1432-2307
    Keywords: Epithelium ; Intestine ; Desquamation ; Restitution ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In situ loops of large bowel of anaesthetised rats were used to observe epithelial restitution following surface desquamation using solutions of bile salts. The treatment induced complete surface desquamation but no disruption of the basal lamina. There was evidence of, cell migration at 30 min, and a complete surface epithelium two h post treatment. Neither a continuous contact between migrating cells and the basal lamina, nor a complete covering of secreted mucus, appeared necessary for epithelial restitution to occur.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 156
    Electronic Resource
    Electronic Resource
    Springer
    European archives of oto-rhino-laryngology and head & neck 245 (1988), S. 136-141 
    ISSN: 1434-4726
    Keywords: Tympanic membrane structure ; Topical anesthetics ; Emla ; Rat ; Guinea pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A eutectic mixture of two anesthetic solutions is that of lidocaine and prilocaine, which is available commercially as Emla (eutectic mixture of local anesthetics). This solution is commonly used in clinics in superficial skin surgery and when inserting intravenous catheters, and we also wanted to determine its surface effects when applied onto the tympanic membranes (TM) of rats and guinea pigs as animal models. The animals were observed by otomicroscopy for 2 weeks up to 5 months after administrations of the anesthetic solution. Tissue specimens were then obtained for light microscopy and fine structural analysis. The application of Emla caused minor structural changes to the rat TM, but hardly any alterations to that of the guinea pig. The changes displayed were an overall increased thickness, with typical submucosal edema but only slight epithelial reaction. In comparison with previous results with lidocaine, phenol and Bonain's solution, Emla seemed to be harmless to the structure of the TM. However, the efficacy of Emla as a topical TM anesthetic remains to be proved in future clinical trials.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 157
    ISSN: 1432-0738
    Keywords: Acyclovir ; Prenatal toxicity ; Rat ; Viru-statics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Pregnant rats were treated during organogenesis with s.c. injections of acyclovir and the embryos were evaluated on day 11.5 of gestation (crown-rump length, somites, protein content, score, abnormalities, histological examination). After eight injections of 50 mg/kg body wt on days 9, 10, and 11 of pregnancy a reduction of the crownrump length was noticed. After 100 mg/kg this effect was more pronounced. With two or three applications of this dose on day 10 specific embryonic abnormalities were visible: the shape of the head was abnormal, the width of the skull had decreased resembling a beak-like visceral cranium. With a single administration of 200 mg/kg on day 10 we found a similar but slightly more pronounced outcome. A drastic change of all variables was obtained after eight injections of 100 mg/kg on days 9, 10, and 11. Comparatively we measured maternal plasma concentrations of acyclovir 1 h after the administration of 50, 100 or 200 mg/kg body wt. After an injection of 50 mg/kg on days 9, 10, and 11 of gestation (three injections/day) the plasma levels ranged from 19.1 to 40.0 mg/l (1 mg/l = 4.44 μM). No cumulation was observed. In contrast, a cumulative effect was detected following a dose of 100 mg/kg. After the first injection of this dose a mean value (± SD) of 60.3±14.7 mg/l (n = 16) was obtained. In this case a third injection increased the mean plasma level to 124.6±16.6 mg/l (n = 5). Further injections, however, led to decreasing levels. One hour after administration of 200 mg/kg body wt acyclovir levels ranged from 120.0 to 163.9 mg/l. We conclude that acyclovir, at doses leading to plasma concentrations well above the therapeutic level in the dam, interferes with the embryonic development in the rat. Acyclovir induces typical gross structural abnormalities which have been first observed using a whole embryo culture system.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 158
    Electronic Resource
    Electronic Resource
    Springer
    International journal of biometeorology 32 (1988), S. 17-20 
    ISSN: 1432-1254
    Keywords: Epilepsy ; Electromagnetic fields ; Rat ; Audiogenic seizure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geography , Physics
    Notes: Abstract In order to study the possible association between epileptic seizures and natural electromagnetic fields, 32 female audiogenic seizure (AGS)-susceptible rats were exposed to simulated 10 kHz and 28 kHz atmospherics and to a sinusoidally oscillating magnetic field with a frequency of 100 Hz and field strength of 1 A/m. After the electromagnetic exposure, seizures were induced in the rats with a sound stimulus. The severity of the seizure was determined on an ordinal scale, the audiogenic response score (ARS). The time from the beginning of the sound stimulus to the onset of the seizure (seizure latency) and the duration of the convulsion was measured. No differences from the control experiments were found in the experiments with simulated atmospherics, but the 100 Hz magnetic field increased the seizure latency by about 13% (P〈0.02). The results do not support the hypothesis that natural atmospheric electromagnetic signals could affect the onset of epileptic seizures, but they suggest that AGS-susceptible rats may be a useful model for studying the biological effects of electromagnetic fields.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 159
    ISSN: 1432-1254
    Keywords: Atmospherics ; Carrageenan inflammation ; Rat ; Susceptibility ; Correlations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geography , Physics
    Notes: Abstract Between the mean daily density of 28 kHz atmospherics and the onset of epileptic fits there is a highly significant correlation coefficient (r) of 0.30; there is a negative coefficient of −0.20 between the fits and the mean daily density of 10 kHz atmospherics. The onset of heart infarction is correlated with 28 kHz atmospherics (r=0.15). Furthermore, we have discovered that sudden deafness is also correlated with certain configurations of atmospherics. In this paper we report the following correlation coefficients between the inflammatory reaction of rats to a carrageenan injection (rci) into a hind paw and the mean daily pulse rate of atmospherics of the same day:r=0.49 for the 8 kHz atmospherics (P〈0.02) andr=0.44 for the 10 kHz atmospherics (P〈0.04). The correlations between rci reaction and other atmospherics (12 and 28 kHz) are smaller and not significant. By the method of multiple linear regression we found a multipleR=0.54 between rci reaction and the 8 and 10 kHz atmospherics (the regression function for the rci reaction is 0.15+0.004×8 kHz+0.002×10 kHz,P〈0.05).
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 160
    ISSN: 1619-7089
    Keywords: MIBG ; Monoamine uptake ; Blood platelets ; Rat ; 6OH-DA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The uptake of MIBG, a scintigraphic agent widely used in the detection of APUD tumors, was studied with a pharmacological approach on an in vitro and an in vivo models. MIBG as well as norepinephrine (NE) was taken up by human blood platelets, a model for presynaptic nerve endings amine uptake, with a thermodependant mechanism. MIBG and NE uptake was inhibited by desimipramine and reserpine. However, MIBG but not NE uptake was inhibited by fluvoxamine, a serotonin (5HT) uptake inhibitor. This suggests that MIBG is a NE and also a 5HT uptake tracer which involves uptake one and vesicular storage mechanisms. In rats treated with 6-hydroxydopamine to induced a chemical sympathectomy, we observed an inhibition of uptake similar for MIBG and NE in the heart, the salivary glands and the spleen, but no effect was observed in the liver. Some clinical inferences to best investigate specific monoamine uptake are drawn from these results.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 161
    ISSN: 1432-0983
    Keywords: Ribosomal protein ; Immunological homology ; Yeast ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Polyclonal antibodies raised against ribosomal protein (r-protein) L2 of Schizosaccharomyces pombe were used to check for cross-reaktions with total r-proteins of rat liver. Using this procedure, the rat liver r-proteins, L4 and L24, were identified as being immunologically related to yeast L2. In addtional, homologies between rat liver L4 and L24 were detected. The possible implications for the regulation of r-protein synthesis are discussed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 162
    Electronic Resource
    Electronic Resource
    Springer
    Pflügers Archiv 413 (1988), S. 62-66 
    ISSN: 1432-2013
    Keywords: Erythropoiesis ; Erythropoietin ; Renal artery constriction ; Hypoxia ; Kidney ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract It is generally assumed that the O2 supply to the kidneys is the major determinant of the synthesis of erythropoietin (Ep). In the present study, the O2 supply of the kidneys of rats was lowered by the reduction of renal blood flow (rbf). Plasma Ep was determined after about 18 h of bilateral application of Goldblatt clips with graded inner diameters. The results were compared to findings in anemic rats, in which the systemic O2 supply was lowered by exchange transfusion of blood with plasma. We found a linear correlation between Ep levels in plasma and the degree of reduction of rbf. However, there was an exponential relationship between Ep levels and the concentration of hemoglobin in blood. In addition, the elevation of plasma Ep was only moderate, when rbf was reduced (maximum 0.07 IU Ep/ml plasma). The increase in Ep concentration was much more pronounced in anemia (up to about 7 IU Ep/ml plasma). From these results it may be concluded that decreasing oxygen supply to the kidney through reduction in renal blood flow (ischemic hypoxia) is less effective in increasing erythropoictin production than reducing the hemoglobin concentration (anemic hypoxia). The possibility must be considered that the increase in renal production of erythropoietin due to anemic hypoxia is triggered by one or more extrarenal signals.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 163
    ISSN: 1432-2013
    Keywords: Chloride channel ; Rat ; Skeletal muscle ; Stereoisomers ; 2-(p-chloro-phenoxy) isobutyric acid ; Clofibric acid ; Myotonia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The S-(−) isomers of a series of clofibric acid analogs produced only a block of chloride conductance of rat skeletal muscle fibers with increasing concentrations until block was nearly complete. The R-(+) isomers, on the other hand, at low concentrations increased chloride conductance by as much as 9% to 39% and at higher concentrations decreased chloride conductance, but never by more than 27% of the control value. The actions of the enantiomeric pairs to either produce or inhibit myotonic excitability paralleled their ability to block or increase chloride conductance, respectively.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 164
    ISSN: 1432-1335
    Keywords: Prostate ; Rat ; Electron microscope
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The prostate epithelium of rats which received repeated cadmium chloride (CdCl2) injections showed a gradual disruption of structural differentiation. Electron microscopy studies revealed severe changes in the ultrastructure affecting all epithelial cell organelles, particularly the nuclei, rough endoplasmatic reticulum, the golgi apparatus, and mitochondria. The cells infiltrating the stroma contained secretory vacuoles and their nuclear evaginations on the invasion front showed similarities to ultrastructural pathological changes in man. Examination of the ventral prostate following oral CdCl2 administration revealed changes ranging in severity up to dysplasia, but there was no evidence of carcinoma.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 165
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 72 (1988), S. 443-449 
    ISSN: 1432-1106
    Keywords: Protein kinase C subspecies ; Immunocytochemistry ; Visual cortex ; Hippocampus ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Monoclonal antibodies against type II and type III subspecies of protein kinase C PkC(II/III) were used to map the distribution of these isoenzymes in the visual cortex (area 17), hippocampus and dentate gyrus of the rat. PkC(II/III)-immunocytochemistry resulted in a specific staining of neuropil and of neuronal somata with their proximal dendrites. The majority of immunopositive cells exhibited a punctate distribution of reaction product, while only a few neurons were homogeneously labeled. In the visual cortex stained neurons were distributed throughout all laminae and reached a particularly high density in layers II/III. Moreover, PkC(II/III)-positive neurons were found within the strata pyramidale and radiatum of the hippocampus proper and in the stratum granulosum, the subgranular zone and the hilar region of the dentate gyrus. The present results suggest that PkC(II/III)-positive neurons constitute a distinct population of both projection and local circuit neurons that are not exclusively associated with any one neurotransmitter system.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 166
    ISSN: 1432-1106
    Keywords: Extracellular Na+ concentration ; Quisqualate (quis) ; N-methyl-D-aspartate (NMDA) ; Tetrodotoxin (TTX) ; Hippocampal area CA1 ; Rat ; Extracellular Ca2+ concentration ; Extracellular Mg2+ concentration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Decreases in extracellular sodium concentration ([Na+]o) and associated slow negative field potentials (fp's) were monitored with double barreled sodium sensitive/reference microelectrodes in area CA1 of rat hippocampal slices during iontophoretic application of the glutamate receptor agonists N-methyl-D-aspartate (NMDA) and quisqualate (quis). The effects of lowering [Ca2+]o on these signals were compared to those of lowering [Mg2+]o. Both NMDA- and quis-induced decreases in [Na+]o of up to 60 mM and in the fp's of up to 8 mV. Decreasing [Mg2+]o enhanced NMDA-induced signals, whereas quis-induced signals were unaffected. Lowering [Ca2+]o also enhanced NMDA signals, although somewhat less than lowering [Mg2+]o. This effect was still present, even when voltage dependent Na+ currents were blocked by 10-7 tetrodotoxin. Interestingly, quis-induced signals could be enhanced in a low Ca2+ medium as well, but only when high quis concentrations were used. The results suggest that, during the sorts of large decreases of [Ca2+]o observed during seizure activity, activation of NMDA receptors is facilitated.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 167
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 72 (1988), S. 71-82 
    ISSN: 1432-1106
    Keywords: Cholinergic-specific ganglioside ; Cholinergic neurons ; Chol-1 ; Spinal cord ; Brain ; Retina ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Previous work from this laboratory has identified gangliosidic surface markers specific for cholinergic neurons. Antibodies to these markers, collectively designated Chol-1, induce complement-mediated lysis of the cholinergic subpopulation of synaptosomes and provide the basis for a new immunocytochemical method for staining cholinergic neurons in rat, guinea pig and human material. The specification and localization of immunocytochemical staining for Chol-1 was investigated in selected areas of the rat central nervous system. The antigen was typically expressed on all neurons previously identified as being cholinergic using monoclonal antibodies to choline acetyltransferase. At spinal levels Chol-1 was present on large and smaller cell bodies in the ventral horn motoneuron area. The preganglionic sympathetic neurons in the thoracic intermediolateral nucleus were also Chol-1-positive. Nerve terminal-like staining was observed in association with stained large Chol-1 positive and smaller unstained Chol-1 negative neurons, and in lamina I and III of the dorsal horn. In the mesencephalon, motoneurons of the oculomotor and trochlear nucleus, as well as neurons within the pedunculopontine tegmental nucleus and the red nucleus were Chol-1-positive. In addition visceromotoneurons of the Edinger-Westphal nucleus were stained with anti Chol-1 antibodies. In the basal forebrain the antibodies gave a positive reaction on well known cholinergic neurons in the vertical and horizontal limbs of the diagonal bands of Broca and the medial forebrain bundle. In agreement with studies using antibodies to choline acetyltransferase, a small sub-population of neostriatal neurons (1–2%) was Chol-1-positive. In the rat retina, both anti-Chol-1 and anti-choline acetyltransferase antibodies gave rise to a nerve terminal-like staining in the same bands within the inner plexiform layer. The anti-Chol-1 antibodies also stain normal and pathological human material and could have a useful application in human neuropathology.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 168
    ISSN: 1432-1106
    Keywords: Adult hypothyroidism ; Dendritic spines ; Pyramidal cells ; Cerebral cortex ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary We have previously shown (Ruiz-Marcos et al. 1980, 1982) that thyroidectomy (T) performed in rats at 40 days of age, well past the neonatal period of development, results by 80–90 days of age in a decrease of the number of spines along the shaft of pyramidal neurons with the cell body in layer V in the visual area of the cerebral cortex. We have here studied how soon after the operation an effect on spine number and distribution may be observed. We have found that the response of these neurons to T is very rapid: a decrease in the number of spines/shaft between T and age-paired controls (C) rats is statistically significant by the earliest period of observation, namely 5 days after T. These results may be related to those of Dembri et al. (1983) showing that T performed in adult rats decreases the activity of Type I RNA polymerase by 5 days after the operation. It is possible that T impairs the synthesis of some compound(s) necessary for the formation and maintenance of spines. The present results suggest that spine number is not a fixed structure of the apical shaft once brain development is over, but is in a state of continuous formation and degradation. We have further observed that the effect of T performed at 40 days of age is more pronounced in the distal part of the shaft than on the rest, a result similar to that found after neonatal T (Ruiz-Marcos et al. 1982). However, contrary to findings after early hypothyroidism, T at 40 days of age does not distort the distribution of spines along the shaft.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 169
    Electronic Resource
    Electronic Resource
    Springer
    Psychopharmacology 94 (1988), S. 115-118 
    ISSN: 1432-2072
    Keywords: Clozapine cue ; Drug discrimination ; Acetylcholine ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Rats were trained to discriminate clozapine (CLZ; 5.76 mg/kg, IPt-30 min) in a two-lever operant task in which responding on the correct lever was reinforced with water under a fixed ratio 32 schedule. The ED50 of CLZ was 1.1 mg/kg. The CLZ cue was generalised to atropine (ED50=8.7 mg/kg), scopolamine (ED50=0.37 mg/kg) and fluperlapine (ED50=4.0 mg/kg), but not to non-cholinergic compounds, i.e. buspirone, diazepam, ketanserin, prazosin or SCH 23390. The peripherally-acting muscarinic antagonist methylscopolamine did not substitute for CLZ. Furthermore, the CLZ cue was marginally attenuated byd-amphetamine; a high dose of oxotremorine (1 mg/kg) appeared to block the CLZ cue (to 22%). However, this effect could not be evaluated statistically due to an insufficient number of animals responding. These results may indicate that the discriminative stimulus effects of CLZ primarily involve antagonism of central muscarinic acetylcholine receptors.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 170
    Electronic Resource
    Electronic Resource
    Springer
    Psychopharmacology 94 (1988), S. 161-166 
    ISSN: 1432-2072
    Keywords: Hangover ; Thermoregulation ; Tolerance ; Ethanol ; Stress ; Compensatory reactions ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The recent finding of rebound hyperthermia in rats on the day after a single IP injection or oral intubation of ethanol was confirmed. In our studies, body temperature measured by rectal probe was significantly decreased for 8 h after 2.5 g/kg ethanol IP and was then significantly elevated 16–24 h after injection; increased vocalization during handling at 24 h was also found. However, rats isolated in a sound-attenuation chamber with remote temperature measurement showed no hyperthermia even though they were hypothermic during intoxication. The results do not support the hypothesis that rebound hyperthermia was caused by either a disruption of circadian rhythms, or by a mild abstinence syndrome alone. Instead, it appears that external stimuli, perhaps related to stress or associated with ethanol administration, are necessary on the day after a moderate dose of ethanol to produce the hyperthermia. Like hangover in humans, hyperthermia was reduced in rats made tolerant to ethanol: both the hypothermia and the rebound hyperthermia were significantly lower on the day after the 12th alternate-day ethanol injection than after the first injection. The aftereffects in rats of acute intoxication are, by definition, hangover signs, and they resemble hangover in humans in several ways, but their relevance as an animal model of hangover remains to be determined.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 171
    ISSN: 1432-2072
    Keywords: Dopamine ; Self-administration ; (+) Amphetamine ; Amygdala ; Nucleus accumbens ; 6-OHDA ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The effects of 6-OHDA lesions of dopamine terminals within the amygdala were investigated on i) (+) amphetamine-induced locomotor hyperactivity and ii) the acquisition of intravenous self-administration of (+) amphetamine. The lesioned rats exhibited increased locomotor activity in response to (+) amphetamine (0.75 and 1.5 mg/kg), but not at the higher dose (3 mg/kg). Self-administration of (+) amphetamine was also significantly greater than in controls. Biochemical analysis of the 6-OHDA-induced lesions of the amygdala indicated increased turnover of dopamine (DOPAC/DA) in the nucleus accumbens. We hypothesize that the behavioural effects were mediated by amygdala-accumbens interactions.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 172
    Electronic Resource
    Electronic Resource
    Springer
    Psychopharmacology 94 (1988), S. 227-231 
    ISSN: 1432-2072
    Keywords: Adrenaline ; Naloxone ; Passive ; Avoidance ; Retention ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The possible involvement of endogenous opioid peptides in the development of the facilitatory effect of adrenaline on memory has been investigated. For this purpose post-training administration of adrenaline and/or naloxone was carried out in rats tested in an inhibitory avoidance paradigm and subjected or not to pre-training (extensive familiarization with the training situation prior to the acquisition trial). Adrenaline injected subcutaneously in a dose of 500 μg/kg facilitated retention performance in rats both subjected or not to pre-training. Naloxone administered SC (400 μg/rat) did not influence retention behaviour in rats subjected or not to pre-training, nor did ICV (0.80 ng/rat) administration. Interestingly, the opiate antagonist when injected SC (400 μg/rat) prevented the facilitatory effect exerted by adrenaline in pretrained as well as in not pre-trained rats. However, ICV administration of naloxone (0.80 μg/rat) dit not influence the behavioral effects exerted by the bioamine. These data suggested a role of endogenous opioid peptides on the facilitatory effect of adrenaline on memory, possibly independent of novelty factors and thus of the brain β-endorphin system. In addition, our results point to the periphery as the most likely site for such interaction.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 173
    Electronic Resource
    Electronic Resource
    Springer
    Psychopharmacology 94 (1988), S. 254-258 
    ISSN: 1432-2072
    Keywords: Anorexia ; Feeding ; Hyperphagia ; Morphine ; Naltrexone ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The delayed suppression of feeding caused by morphine was investigated in the rat. A single injection of morphine evoked a triphasic influence on feeding: a brief (1 h) severe anorexia was followed by hyperphagia (3 h) and a mild (20%) yet persistent (4–24h) anorexia. This latter anorexic effect was at least partially naltrexone reversible, and the duration of this antagonism (8 h) was longer than that of naltrexone's anorexic effect (4 h). Delayed morphine anorexia cannot be ascribed to morphine's initial stuporific influence, and it was not dependent upon previous feeding or deprivation. It was not due to gastric distension. The specificity and significance of this anorexia is discussed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 174
    Electronic Resource
    Electronic Resource
    Springer
    Psychopharmacology 94 (1988), S. 248-253 
    ISSN: 1432-2072
    Keywords: Bremazocine ; EKC ; Forward locomotion ; Grooming ; Open field ; Rat ; Rearing ; Tifluadom ; U-50,488H
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract An observational analysis of the effects of four kappa-opioid agonists on forward locomotion, rearing and grooming displayed by rats in a novel open field was undertaken. The doses of agonists used corresponded to those previously found to produce changes in food consumption. Ethylketocyclazocine (0.1 and 1 mg/kg), bremazocine (0.01 and 0.1 mg/kg) and tifluadom (0.3 and 3 mg/kg) exerted suppressant effects on all the activities monitored. Grooming behaviour appeared to be particularly sensitive to this action, being virtually abolished by the larger doses of these compounds. In contrast, the selective kappa agonist U-50,488H (0.1–3 mg/kg) only attenuated grooming at the two highest doses tested (1 and 3 mg/kg). None of the agonists tested produced stimulation of open field activity during the 1-h study. Reductions in activity occurred at doses previously found to increase and decrease food intake. It was therefore concluded that the hyperphagia induced by kappa agonists was not part of a more general behavioural activation, whilst reductions in food consumption probably result from a non-specific behavioural depression.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 175
    Electronic Resource
    Electronic Resource
    Springer
    Psychopharmacology 94 (1988), S. 359-364 
    ISSN: 1432-2072
    Keywords: Serotonin synthesis ; Dopamine synthesis ; RU-24969 ; Anxiety ; Antidepressant activity ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The regional brain synthesis of serotonin (5-HT) and dopamine (DA) was studied in rats after various doses of 5-methoxy-3(1,2,3,6-tetrahydro-4-pyridinyl)-1H-indole (RU-24969), a 5-HT1 receptor agonist. The potential anxiolytic and antidepressant properties of the compound were examined as well. RU-24969 0.62 mg/kg significantly reduced 5-HT synthesis in the nucleus accumbens and hypothalamus, while with 1.25 and 2.5 mg/kg the effect was also seen in striatum, hippocampus, brainstem and cortex. RU-24969 2.5 and 5 mg/kg had no effect on DA synthesis in the striatum, while 5.0 mg/kg significantly increased it in the nucleus accumbens. At doses of 2.5 and 5.0 mg/kg the drug increased the motor activity of rats measured during 1 h in activity cages while 0.625 and 1.25 mg/kg had no effect. Doses ranging from 0.62 to 2.5 mg/kg RU-24969 significantly reduced unpunished responding in a test of conditioned suppression of drinking. Doses of 1.25 and 2.5 mg/kg also reduced punished responding. Finally, of various doses only 2.5 mg/kg RU-24969 significantly reduced the duration of immobility of rats in the forced swimming test but the effects were due to running around the cylinder rather than to escape attempts. In conclusion, RU-24969 reduced 5-HT synthesis in all brain areas examined, with a preferential effect for the nucleus accumbens and the hypothalamus. At higher doses, there was also a specific increase in DA synthesis in the nucleus accumbens. The compound raised the level of activity of rats but no clear evidence of any potential anxiolytic or antidepressant properties has been obtained.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 176
    Electronic Resource
    Electronic Resource
    Springer
    Psychopharmacology 95 (1988), S. 151-156 
    ISSN: 1432-2072
    Keywords: Apomorphine ; Amphetamine ; Strychnine ; Yohimbine ; Acoustic startle reflex ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Rats were presented with noise bursts alone or noise bursts 60 ms after presentation of either a 60 dB or an 80 dB prepulse after injection of the dopamine agonists apomorphine (3 mg/kg) or d-amphetamine (4 mg/kg), the glycine antagonist strychnine (1.5 mg/kg) or the α2 antagonist yohimbine (5 mg/kg). Presentation of prepulses inhibited startle, with greater inhibition following an 80 dB versus 60 dB prepulse. Apomorphine, d-amphetamine and strychnine increased overall startle levels but did not attenuate prepulse inhibition, since the absolute change in startle following prepulse presentation was significantly greater after administration of these drugs. A lower dose of apomorphine also increased startle but had no effect on prepulse inhibition using test intervals of 10, 60, 100, 200 or 1000 ms. While these drugs did decrease per cent prepulse inhibition, this seemed wholly attributable to their increasing overall startle levels, rather than a real attenuation of prepulse inhibition. Yohimbine did not alter either startle baseline or prepulse inhibition. The results do not support the conclusion that overactivity of dopamine systems attenuates prepulse inhibition and, in addition, suggest that prepulse inhibition does not result from activation of either glycine or norepinephrine projecting to α2 adrenergic receptors.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 177
    Electronic Resource
    Electronic Resource
    Springer
    Psychopharmacology 95 (1988), S. 231-236 
    ISSN: 1432-2072
    Keywords: Latent inhibition ; Early handling ; Haloperidol ; Amphetamine ; Male ; Female ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Latent inhibition (LI) is a behavioral paradigm in which nonreinforced pre-exposure to a stimulus retards subsequent conditioning to that stimulus. The development of LI is considered to reflect learning not to attend to, or ignore, irrelevant stimuli. In our previous studies investigating the effects of early handling on LI, we have shown that normal LI was obtained in handled males and females, as well as in nonhandled females. In contrast, nonhandled males failed to show LI. This finding pointed to a long-term attentional deficit in nonhandled males. Since there is evidence that the development of LI is mediated by the dopaminergic system, the present experiments tested the possibility that the attentional deficit of nonhandled males may be related to a dopaminergic dysfunction. Experiment 1 tested whether the administration of haloperidol, which was shown to enhance LI in normal animals, would reinstate the LI effect in nonhandled males. Infantile handled (Days 1–22) and nonhandled male and female rats were tested in maturity in the LI paradigm, using a conditioned emotional response procedure. Experiment 2 tested the locomotor response of handled and nonhandled males to 0.3, 1 and 2.5 mg/kg d-amphetamine. Experiment 1 showed that handled males, handled females and nonhandled females showed a normal LI effect, whereas nonhandled males failed to develop LI. Haloperidol enhanced LI in all the groups, but this effect was most dramatic in nonhandled males, in which the drug reinstated LI. Experiment 2 showed that nonhandled males exhibited a reduced locomotor response to d-amphetamine.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 178
    Electronic Resource
    Electronic Resource
    Springer
    Psychopharmacology 95 (1988), S. 413-417 
    ISSN: 1432-2072
    Keywords: DRL-schedule ; Imipramine ; Mianserin ; Idazoxan ; Yohimbine ; Amphetamine ; α2-Adrenoceptors ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Previous studies have reported that antidepressant drugs exert specific effects on responding maintained by DRL schedules of reinforcement, giving rise to increased frequencies of reinforcement. In order to investigate whether the α2-adrenoceptor antagonist idazoxan would produce similar effects, the actions of this compound were compared with those of yohimbine, imipramine, mianserin and d-amphetamine in rats trained to lever press for food reinforcement on a DRL 60-s schedule. Neither imipramine nor mianserin produced any effects on response rate or reinforcement frequency, except at the highest doses. In contrast, both idazoxan and yohimbine gave rise to dose-related increases in rates of responding and consequent decreases in reinforcement frequencies. Amphetamine also increased responding, but higher doses of this drug produced marked hyperactivity and stereotyped movements which were not observed after idazoxan and yohimbine. Although the present behavioural baseline was not sensitive to antidepressants, it demonstrated an unexpected activity of two α2-adrenoceptor antagonists which deserves further investigation.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 179
    ISSN: 1432-2072
    Keywords: Anhedonia ; Drive ; Extinction ; Free feeding ; Neuroleptic ; Pimozide ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Both pimozide pretreatment and free feeding caused within-session and between-session decrements in variable interval operant performance; response decrements generated under pimozide were maintained on transfer to free feeding, and vice versa. On subsequently testing under extinction conditions (after food deprivation and drug free) large initial increases in responding were seen in all groups, and subsequent response decrements in extinction were steeper than in either pimozide or free feeding conditions. The effects of pimozide pretreatment do not resemble those of extinction, but may in some circumstances be functionally equivalent to a decrease in drive level.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 180
    ISSN: 1432-2072
    Keywords: Nucleus accumbens ; d-Amphetamine activity ; Exploration ; Raclopride ; D2-receptors ; Schizophrenia ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The effect of the D2-antagonist raclopride was investigated in two test situations, which are presumed to involve dopamine (DA) transmission within the nucleus accumbens of the rat. Local injection of d-amphetamine sulphate (10 μg/0.5 μl) produced a marked increase in motor activity, measured as motility, locomotion, and rearing, which was dose- and time-dependently antagonised by local injection of raclopride (0.05–5.0 μg/0.5 μl). After an initial decrease, at low doses (0.05–0.25 μg/0.5 μl) an apparent enhancement of the d-amphetamine-induced motor activity appeared, which was most clearly seen with rearing. These lower doses, however, did not induce any clear changes in the exploratory activity in a novel environment (i.e., the second test situation). Only the higher doses used (1.0–5.0 μg/0.5 μl) decreased exploratory activity during the first 5–10 min, also measured as motility, locomotion, and rearing. These data are discussed with respect to the role of D2-receptors within the nucleus accumbens of rats in the motor activity induced by a novel environment and d-amphetamine. Overall, the data underline previous notions that raclopride is a potent antagonist of DA-mediated behaviour.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 181
    ISSN: 1432-2072
    Keywords: Tolerance ; Opioids ; Reinforcement ; Place conditioning ; Morphine ; U-69593 ; d-Amphetamine ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The issue of whether tolerance develops to the motivational effects of opioids was addressed by use of an unbiased place preference conditioning procedure. Administration of the μ-opioid agonists morphine or fentanyl produced dose-related preferences for the drug-associated place in control rats. In contrast, the κ-opioid agonist, U-69593 produced conditioned place aversions. Non-contingent administration of morphine (5.0 mg/kg/12 h) for 4 days prior to conditioning resulted in tolerance to its reinforcing effects, and cross-tolerance to the effects of fentanyl. No cross-tolerance to the motivational effects of the psychostimulantd-amphetamine or the κ-opioid agonist U-69593 was observed. Chronic administration of U-69593 prior to conditioning produced tolerance to its aversive effects. This treatment did not, however, modify the reinforcement produced by morphine. These data demonstrate that tolerance develops to both the reinforcing and aversive properties of opioids and suggest that differential cross-tolerance may provide a useful method for determining the pharmacological basis underlying drug-induced motivational effects.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 182
    ISSN: 1432-2072
    Keywords: Clonidine ; Locus coeruleus ; Intracerebral infusion ; Withdrawal ; Naloxone ; Morphine ; 3-Methoxy-4-hydroxyphenylglycol (MHPG) ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Clonidine, an alpha-2-adrenergic agonist, suppresses signs of opiate withdrawal in animals and in man. Electrical or chemical stimulation of the nucleus locus coeruleus (LC) increases noradrenergic activity and brain concentration of the noradrenergic metabolite MHPG, and produces many signs of opiate withdrawal. Thus, clonidine's ability to attenuate withdrawal might be due to the reduction of noradrenergic neuronal activity originating in the LC, but additional alpha-2-adrenergic receptors throughout the body and other mechanisms may also play a role. The present study explored the neuroanatomical and pharmacological selectivity of alpha-2-adrenergic receptors of the LC in the anti-withdrawal action of clonidine. Experiment 1 tested the hypothesis that behavioral and biochemical measures of naloxone-precipitated withdrawal from morphine would be blocked by infusions of clonidine (0.6 or 2.4 μg/μl) into the LC. Significant reductions were observed in the occurrence of diarrhea, ptosis, weight loss and wet-dog shakes. Clonidine also reversed the naloxone-precipitated increase in hippocampus MHPG concentration. In experiment 2 subjects received an LC infusion or IP injection of a non-lipophilic alpha-2-agonist (ST-91), which does not penetrate the blood-brain barrier, or of clonidine into the dorsal parabrachial nucleus (DPB) to test the selectivity of the effects of clonidine infusions into the LC. ST-91 infusions into the LC reduced several of the observed withdrawal signs and increased others (e.g., jumping). Although peripheral injections of ST-91 attenuated some of the checked signs associated with naloxone-precipitated withdrawal, the frequency of wet-dog shakes was not reduced. ST-91 infusions into the LC, but not systemic ST-91 administration, prevented the withdrawal-induced increase in hippocampus MHPG concentration. Clonidine infused lateral to the LC into the DPB did not significantly attenuate withdrawal or reduce hippocampus MHPG levels. These results provide behavioral and biochemical evidence to support the suggestion that clonidine significantly attenuates naloxone-precipitated withdrawal through an interaction with noradrenergic neurons located in the vicinity of the LC.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 183
    Electronic Resource
    Electronic Resource
    Springer
    Psychopharmacology 96 (1988), S. 135-141 
    ISSN: 1432-2072
    Keywords: Apomorphine ; Sulpiride ; SCH-23390 ; Central drug administration ; Dopamine autoreceptors ; Feeding behaviour ; Microstructural analysis ; Eating rate ; Eating time ; Open field ; Nucleus accumbens ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The inhibition of feeding following the administration of apomorphine, systemically or directly into the nucleus accumbens/ventral striatum, was studied using a microstructural analysis paradigm. On systemic administration, apomorphine reduced food consumption, eating rate and eating time; the effects were blocked by sulpiride but not by SCH-23390. Two doses of apomorphine were administered centrally. Both doses reduced total food intake and eating rate; only the higher dose also reduced eating time; all of these effects were blocked by sulpiride pretreatment. Only the lower dose reduced locomotor activity and rearing in the open field. The results suggest that apomorphine reduces eating rate by an action on dopamine (DA) axon terminal autoreceptors. We have previously demonstrated that apomorphine reduces eating time by an action on DA cell body autoreceptors. Therefore, the two populations of DA autoreceptors appear to be differentially involved in behaviour.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 184
    Electronic Resource
    Electronic Resource
    Springer
    Psychopharmacology 95 (1988), S. 195-199 
    ISSN: 1432-2072
    Keywords: Drug discrimination ; Scopolamine cue ; Muscarinic agonists ; Muscarinic antagonists ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The discriminative stimulus properties of scopolamine, a potent antagonist at muscarinic receptors, were used for testing the discriminative effects of drugs known to act on cholinergic transmission. Rats were trained in a standard two-bar operant conditioning procedure with food as the reinforcer, according to a FR10 schedule. The training dose of scopolamine was progressively reduced from 0.25 mg/kg SC to the low dose of 0.062 mg/kg SC. Scopolarmine yielded an accurate discrimination in all the six rats tested. The generalization gradient resulted in an ED50 of 0.027 mg/kg. The scopolamine cue lasted for 1 h and was of central origin, since it was not mimicked by scopolamine methylbromide. The scopolamine stimulus generalized to atropine and trihexyphenidyl (respective ED50 values 2.20 and 0.21 mg/kg SC). Atropine depressed rate of responding, while trihexyphenidyl did not. Antagonism experiments with both direct agonists at the muscarinic receptor (arecoline and oxotremorine) and indirect agonists, i.e., inhibitors of the acetylcholine esterase [physostigmine and tetrahydroaminoacridine (THA)], led to inconsistent results. Increasing the doses of the agonists in order to block the scopolamine cue may be limited by their rate suppressant effect on responding. Based upon previously published results, it is suggested that the muscarinic agonist cue is more useful than the antagonist cue for investigating muscarinic transmission.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 185
    ISSN: 1432-2072
    Keywords: Drug discrimination ; Cocaine ; Tolerance ; CNS stimulants ; Rat ; Amphetamine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Rats were trained to discriminate cocaine, 10.0 mg/kg, using a two-lever operant procedure. Dose-effect data were determined for the substitution of cocaine, diethylpropion, methylphenidate, phenmetrazine, phentermine, and fenfluramine for the cocaine stimulus. All of these drugs, except fenfluramine, substituted fully for the cocaine stimulus. Subsequently, training was halted and cocaine, 20 mg/kg/8 h, was administered for 9 days, and dose-effect data were redetermined for all of these drugs on days 7–9 of chronic administration. Chronic administration of cocaine produced tolerance to the stimulus properties of cocaine, and cross-tolerance to the stimulus properties of methylphenidate, phenmetrazine, and phentermine, such that doses approximately two-fold higher than those used acutely were necessary to reproduce the original effect; the potency for the substitution of diethylpropion for the cocaine stimulus was decreased greater than four-fold; and fenfluramine still failed to substitute for the cocaine stimulus. These data suggest that 1) a common mechanism may mediate tolerance to the discriminative stimulus properties of cocaine, methylphenidate, phenmetrazine, and phentermine, and 2) tolerance in the drug discrimination procedure may have potential for establishing a comprehensive evaluation of dependence liability of CNS stimulants.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 186
    ISSN: 1432-2072
    Keywords: Tachykinins ; Senktide ; Cholinergic ; Autoreceptor ; 6-Hydroxydopamine ; Yawning ; Mouth movements ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The selective NK-3 tachykinin receptor agonist senktide elicited yawning, chewing mouth movements and sexual arousal following subcutaneous administration (0.1–1.0 mg/kg) in the rat. These responses were not significantly affected by the dopamine antagonist haloperidol (0.03 mg/kg) or by 6-hydroxydopamine lesions of the nigrostriatal projection. In contrast, the behaviours were markedly attenuated by the peripheral and central muscarinic antagonist scopolamine (1 mg/kg), but not by the peripheral muscarinic antagonist N-methylscopolamine (1 mg/kg). These findings suggest that stimulation of NK-3 receptors produces yawning, chewing and sexual arousal by directly activating central cholinergic neurons.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 187
    Electronic Resource
    Electronic Resource
    Springer
    Psychopharmacology 96 (1988), S. 262-266 
    ISSN: 1432-2072
    Keywords: Alpha-melanotropin ; Inulin ; Blood-brain barrier ; Lipid solubility ; Pharmacokinetics ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The permeability of the blood-brain barrier (BBB) to immunoreactive alpha-melanotropin (α-MSH) was quantified in rats pretreated with monosodium l-glutamic acid to deplete their CNS stores of endogenous α-MSH. The methodology, suitable for poorly permeable substances, monitored blood and brain tissue concentrations of α-MSH over 15 min following intravenous injection of 30 nmol synthetic α-MSH. Rate constants for entry of α-MSH into brain tissue were estimated from separate nonlinear least-squares fits of connecting two- and one-compartment open models to plasma and extravascular brain tissue concentration data, respectively. Comparisons were made to rate constants measured similarly for 14C-inulin. The BBB had a low permeability to immunoreactive α-MSH, consistent with peptide penetrating the barrier by passive diffusion dependent upon the lipid solubility of the molecule.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 188
    Electronic Resource
    Electronic Resource
    Springer
    Psychopharmacology 96 (1988), S. 281-284 
    ISSN: 1432-2072
    Keywords: Drug discrimination ; Oral administration ; Transdermal administration ; Nicotine ; Cytisine ; Arecoline ; Mecamylamine ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In a standard two-lever drug discrimination paradigm, rats were trained to discriminate nicotine 0.5 mg/kg PO from saline. Injections occurred 15 min before the session. Subjects reached the training criterion in a mean of 38 sessions. Nicotine PO, SC, and IP generated similar dose-effect curves (ED50=0.073 mg/kg PO, 0.076 mg/kg SC, 0.090 mg/kg IP); the dose-effect curve for transdermal (TD) administration fell approximately 1 log unit to the right (ED50=1.34 mg/kg). The percentage of rats choosing the nicotine-appropriate lever peaked at 15 min and gradually decreased to 50% or less by 180 min for nicotine PO and TD, a time-decay function similar to that previously shown for SC administration. The nicotinic cholinergic agonist cytisine (0.5–8.0 mg/kg) PO and TD produced up to 56% nicotine-appropriate responding, while the muscarinic cholinergic agonist arecoline (1.0–4.0 mg/kg) PO and TD produced only saline-appropriate responding. The nicotine cue did not generalize to the cholinergic antagonist mecamylamine (0.125–0.5 mg/kg) PO or TD; mecamylamine 0.5 mg/kg PO but not TD completely blocked the PO and TD nicotine cues. These results show that an approximately equal cue occurs with PO, IP, and SC administration, and that the TD cue is considerably weaker. The significance of the procedure as an animal analog of human transdermal nicotine intake is discussed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 189
    Electronic Resource
    Electronic Resource
    Springer
    Psychopharmacology 96 (1988), S. 311-316 
    ISSN: 1432-2072
    Keywords: Rat ; Neuroleptics ; Catalepsy ; Dopamine receptors ; Muscarinic receptors ; SCH23390 ; Pilocarpine ; Atropine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In an attempt to understand the nature of the interactions between D1 and D2 dopamine subsystems as well as between dopamine and acetylcholine, catalepsy was assessed in rats following various drug treatments. The D1-specific antagonist SCH23390 (0.1 mg/kg) produced prompt, potent and brief (〈90 min) catalepsy with an ED50 of 0.105 mg (0.3 μmol)/kg. Conversely, fluphenazine (0.1 mg/kg), spiroperidol (0.1 mg/kg), and haloperidol (0.2 mg/kg) all had comparably potent but more slowly rising and prolonged (〉240 min) effects. The action of SCH23390 was synergistic with spiroperidol, inhibited by apomorphine or atropine, unaffected by mecamylamine, and markedly potentiated by pilocarpine. However, pilocarpine was unable to significantly potentiate the action of fluphenazine or spiroperidol. It is inferred that SCH23390 differs from the classical neuroleptics in its mechanism of cataleptogenicity, that there is a cholinergic link with the D1 dopamine system, and further, that there may be a difference in the nature or impact of the cholinergic interaction with the D1 and D2 dopamine systems.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 190
    ISSN: 1432-2072
    Keywords: Nicotine ; Ageing ; Body weight ; Water intake ; Locomotor activity ; Exploratory behavior ; Memory ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract To assess the effects of long-term treatment with nicotine on several behavioral measures (locomotor activity, exploratory efficiency, habituation, short-term and long-term memory) of young (5 months) and old (22 months) rats in a hexagonal tunnel maze, nicotine was added to the drinking water (0, 20 or 50 mg/l) for up to 131 experimental days. With the exception of effects on exploratory efficiency, young and old rats did not differ in their response to the drug. Nicotine decreased body weight throughout the experiment. Nicotine treatment reduced water intake during the first 30 min of the daily 4.5 h access to drinking water. Nicotine increased locomotor activity throughout the experiment. When nicotine treatment was discontinued during a 7-day withdrawal period, locomotor activity immediately dropped to control values. Intertrial habituation was not affected by nicotine. Long-term nicotine treatment had an attenuating effect on exploratory efficiency in young rats; however, the drug did not influence performance in tasks measuring spatial memory. Finally, age increased weight, decreased locomotor activity and impaired exploratory efficiency and short-term memory. Age, however, did not affect the performance of the long-term memory task.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 191
    Electronic Resource
    Electronic Resource
    Springer
    Psychopharmacology 94 (1988), S. 119-125 
    ISSN: 1432-2072
    Keywords: Place conditioning ; Cocaine ; Intraperitoneal and intravenous administration ; Reward ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract It has been shown that pretreatment with dopamine (DA) receptor blockers disrupts the effect of intravenously (IV) and intracerebrally (ICV), but not intraperitoneally (IP) administered cocaine on place preference conditioning (PPC). The present study was undertaken to further evaluate possible differences between IV and IP cocaine PPC. To this end, several factors which may differentially influence IV and IP cocaine PPC were examined. Firstly, dose-response effects were studied. Intravenous cocaine produced PPC within a narrow dose range (0.5–2.5 mg/kg). Animals receiving IV injections of 5 and 10 mg/kg cocaine experienced convulsions and did not show PPC. For IP cocaine a 10-fold increase in dose (10 mg/kg) and twice the number of training trials was required in order to obtain PPC equal in magnitude to that with IV cocaine (0.5 mg/kg; two trials). Cocaine PPC was retained at least 1 month. Following IV cocaine preference developed for the side associated with the drug regardless of whether the conditioning was to the least or most preferred side. After IP cocaine, preference developed for the drug side only when the drug was paired with the least preferred side. Rats trained with IV, but not IP, cocaine significantly preferred the drug familiar side to a novel compartment. Preference for the IV or IP cocaine side developed regardless of whether testing was carried out in the drugged or undrugged state, excluding possible state-dependent effects as an explanation of the cocaine PPC. The results show PPC procedure to be a valid test for evaluating rewarding properties of IV cocaine. However, they fail to show rewarding effects of IP cocaine.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 192
    Electronic Resource
    Electronic Resource
    Springer
    Psychopharmacology 94 (1988), S. 133-137 
    ISSN: 1432-2072
    Keywords: Diazepam ; Haloperidol ; Domperidone ; 6-Hydroxydopamine ; DSP-4 ; Place conditioning ; Dopamine ; Noradrenaline ; Reward ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The conditioned place preference paradigm was used to investigate the neurochemical and neuroanatomical substrates which mediate the rewarding properties of diazepam. The results confirmed that diazepam (1 and 2.5 mg/kg, IP) produced place preference for a distinctive environment that had previously been paired with injections of the drug. Pretreatment with haloperidol (0.1 mg/kg) antagonised the place preference induced by diazepam (1 mg/kg). Pretreatment with domperidone (2 mg/kg) failed to influence this effect of diazepam. Haloperidol (0.1 mg/kg) and domperidone (2 mg/kg) alone did not produce place aversion. In separate experiments the diazepam-induced place preference was examined in rats having 6-hydroxydopamine (6-OHDA) lesions of the nucleus accumbens. These animals did not show preference for the compartment associated with diazepam. Depletion of central noradrenaline produced by systemic injections of DSP4 did not affect diazepam-induced place preference conditioning. These findings suggest that dopamine-containing neurons of the mesolimbic system are a component of the neural circuitry that mediates the reinforcing properties of diazepam.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 193
    ISSN: 1432-2072
    Keywords: Electroconvulsive shock ; 5-HT transporter complex ; β-Adrenoceptor ; [3H]-Paroxetine ; [3H]-Imipramine ; [3H]-Dihydroalprenolol ; Cerebral cortex ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The effects of repeated electroconvulsive shock on the 5-HT uptake site were studied in rat cortex using [3H]-paroxetine binding. This ligand was used because it is thought to directly label the 5-HT uptake site, whereas [3H]-imipramine may bind to a presynaptic recognition site different from the uptake site. No changes were found in the maximum number of [3H]-paroxetine binding sites and equilibrium dissociation constant after repeated electroconvulsive shock, whereas a parallel investigation of β-adrenoceptor binding showed the expected decrease in receptor number.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 194
    ISSN: 1432-2072
    Keywords: Benzodiazepines ; Triazolopyridazines ; Noradrenaline ; Clonidine ; Yohimbine ; Drug discrimination stimulus ; Fixed ratio performance ; Bicuculline ; Ro 15-1788 ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The effects of clonidine on the antianxiety and sedation of benzodiazepines (BZD) were assessed respectively in rats trained in a two-lever diazepam cue discrimination procedure and in single-lever fixed-ratio (FR) water-reinforced performance. Clonidine (10–60 μg/kg) significantly shifted to the left the dose-effect curves of diazepam in the discrimination paradigm. This treatment also shifted generalization dose-effect curves of the diazepam cue to chlordiazepoxide and CL 218872 to the left in the drug discrimination procedure. The diazepam cue was antagonized in a dose-related manner by Ro 15-1788, but not by bicuculline. Clonidine also potentiated the rate-decreasing effects of diazepam on the FR schedule when the dose of diazepam was increased to 0.3 mg/kg, but not the milder rate-decreasing effect of CL 218872 until the dose of CL 218872 was increased to 10 mg/kg. The potentiating effects of clonidine on the stimulus control and depression of diazepam were antagonized by yohimbine. Yohimbine (1.0 mg/kg) also significantly shifted the dose-effect curve of diazepam cue to the right. Bicuculline (3 mg/kg) completely antagonized the rate-decreasing effect of diazepam (1 mg/kg), but significantly potentiated the rate-suppressant effect of clonidine (10 μg/kg). These results suggest that the central noradrenaline (NA) system may be involved not only in the antianxiety, but also the sadative action of BZD. The nature of NA involvement in relation to the different subtypes of BZD receptors requires further exploration.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 195
    ISSN: 1432-2072
    Keywords: LY 171555 ; SKF 38393 ; Combined D1 and D2 stimulation ; SCH 23390 ; D1 supersensitivity ; Locomotor activity ; Grooming ; Stereotyped behaviour ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The selective D1 receptor stimulant SKF 38393 dose-dependently increased grooming time in rats without affecting locomotor activity or eliciting stereotyped behaviour. The selective D2 receptor agonist LY 171555 induced a dose-dependent increase in rat motility, a marked decrease in grooming time and a low occurrence of stereotyped behaviour. Concurrent administration of the two selective agonists induced high-degree stereotyped responses and reductions in locomotor and grooming behaviours. Rats withdrawn from repeated treatment with the selective D1 receptor blocker SCH 23390 (0.05 mg/kg twice daily for 21 days; 7 days of washout) did not exhibit any change of locomotor and grooming responses to threshold doses of LY 171555 and SKF 38393 given alone or in combination. On the contrary, a significantly greater occurrence of high-degree stereotyped responses to the combination of the two selective agonists was observed. The data support the view that D1 and D2 receptors have a cooperative role in the generation of stereotypies and suggest that D1 receptor supersensitivity needs D2 stimulation to be revealed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 196
    ISSN: 1432-2072
    Keywords: Amphetamine ; Circling behavior ; Asymmetry ; Pavlovian conditioning ; Sensitization ; Placebo ; Latent inhibition ; Extinction ; Reverse tolerance ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Amphetamine-induced circling behavior increases over the course of repeated administration of the drug; likewise, after repeated administration of amphetamine, an injection of saline prior to placement of the rat in the test apparatus previously associated with the pharmacologic effects of amphetamine will increase circling behavior. Experiments were designed to determine if either of these effects would respond to manipulation of the temporal contiguity between the test environment and the peak effects of amphetamine. The placebo-like response, in accordance with a Pavlovian conditioned response, was reduced by prior non-reinforced exposure to the test environment and subject to extinction. In contrast, the increase in the amphetamine-induced response was entirely dependent on the test environment but not affected by latent inhibition or extinction. These and previous findings indicate that the development and expression of the placebo-like response is the result of a Pavlovian associative process. Although amphetamine sensitization is environment dependent, it does not resemble a conditioned response in other respects.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 197
    ISSN: 1432-2072
    Keywords: Haloperidol ; Partial reinforcement ; Continuous reinforcement ; Extinction ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The effects of haloperidol 0.1 mg/kg on the partial reinforcement extinction effect (PREE) paradigm at one trial a day, were examined. Two groups of rats were trained to run in a straight alley. The continuously reinforced (CRF) group received food reward on every trial. The partially reinforced (PRF) group was rewarded on a quasirandom 50% schedule. All animals were then tested in extinction. Haloperidol 0.1 mg/kg was administered in a 2 × 2 design, i.e., drug-no drug in acquisition and drug-no drug in extinction. The PREE, i.e., increased resistance to extinction of partially reinforced as compared to continuously reinforced animals, was obtained in all four drug conditions. The administration of haloperidol in acquisition increased markedly resistance to extinction in CRF animals. The administration of the drug in extinction decreased resistance to extinction in both CRF and PRF animals. The results are explained in terms of two independent actions of haloperidol: the well-known effect of reduction in the effectiveness of reinforcement as well as enhancement of the effectiveness of nonreinforcement.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 198
    Electronic Resource
    Electronic Resource
    Springer
    Psychopharmacology 96 (1988), S. 40-44 
    ISSN: 1432-2072
    Keywords: Drug discrimination ; d-Amphetamine ; Nimodipine ; Diazepam ; Morphine ; Haloperidol ; Calcium channel ; Behavior ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The discriminative stimulus (DS) properties ofd-amphetamine (AMP) are thought to be mediated by enhanced release of catecholamines, which may involve neuronal calcium influx through voltage sensitive channels. The present study examined the influence of nimodipine, a calcium channel blocker, on the DS properties of AMP. Rats (N=8) were trained to discriminate AMP (0.5 mg/kg, IP) from saline in a two-lever, food-reinforced, drug discrimination paradigm. Nimodipine alone (2.0–5.6 mg/kg, IP) did not substitute for AMP. When given in combination with AMP, 2.0 mg/kg nimodipine increased by less than 2-fold the AMP dose necessary to induce AMP-appropriate responses. Higher doses of nimodipine combined with AMP did not increase the magnitude of this effect. Nimodipine enhanced the effects of AMP on response rate. Haloperidol (0.125 mg/kg) increased by approximately 4-fold, whereas diazepam (0.5 or 1.0 mg/kg) and morphine (5.0 mg/kg) increased by approximately 2-fold the AMP dose necessary to induce AMP-appropriate responses. The interaction with AMP was associated with enhanced reduction of response rate in the tests with diazepam and morphine but not haloperidol. These results suggest that nimodipine attenuates the DS properties of AMP, probably in a non-specific way, due to the ability of nimodipine itself to induce a discriminable internal state.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 199
    ISSN: 1432-2072
    Keywords: Rat ; Drug discrimination ; NMDA ; Phencyelidine ; ±SKF 10047 ; MK 801 ; CPP ; Ifenprodil
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Rats were trained to discriminate phencyclidine (PCP) from saline at doses of 2 and 4 mg/kg, using a two-lever food reinforced operant technique. ±N-allylnormetazocine (±SKF 10047), +5-methyl-10,11-dihydro-5H-dibenzo[A,D]cyclohepten-5,10-imine (MK 801), 3-(2-carboxypiperazin-4-yl) propyl-1-phosphonic acid (CPP) and ifenprodil, which have been shown to antagonise the effects of N-methyl-d-aspartate (NMDA), were tested for their ability to give rise to PCP-appropriate responding. In rats trained at both doses of PCP, ±SKF 10047 (2–12 mg/kg) and MK 801 (0.0125–0.2 mg/kg) produced dose-related responding on the lever associated with PCP injection. The relative potency of these two compounds was the same in the two groups of animals, but their absolute potencies to produce a PCP-like discriminative stimulus were dependent on the training dose of PCP. In contrast, neither the competitive NMDA antagonist CPP (4–20 mg/kg) nor the non-competitive antagonist ifenprodil (2–12 mg/kg) produced PCP-appropriate responding and ifenprodil (4-mg/kg) neither potentiated nor antagonised PCP. These findings are discussed in the light of the hypothesis that the behavioural effects of PCP are mediated via a reduction of neurotransmission at the NMDA-subtype of glutamate receptors.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 200
    ISSN: 1432-2072
    Keywords: Enkephalin ; Ventral mesencephalon ; Investigatory behaviour ; Motor behaviour ; Dopamine ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The mesolimbic dopamine (DA) system, originating in the ventral tegmental area and projecting to limbic forebrain regions, plays a crucial role in mediating several important aspects of behaviour. Proximal to these DA neurons are enkephalin-containing nerve fibers. In an attempt to characterize the behavioural role of enkephalinergic transmission in the VTA, the present experiment examined in detail the investigatory and motor responses to microinfusion of d-ala-met-enkephalin (DALA), a long lasting analogue of enkephalin, into the ventral tegmental area (VTA). Injections into the substantia nigra (SN) and the hippocampus (HPC) were also performed as controls for site specificity. The behavioural apparatus consisted of an eight-hole box monitored by a video camera. Four doses of DALA were injected in the VTA (0.05, 0.1, 1 and 2.5 μg/μl bilaterally in 1 μl volume) and one dose in the SN and HPC (0.1 μg/μl bilaterally in 1 μl volume). The effect of DALA injections in the VTA was characterized by an inverted U-shape dose-effect curve. The low doses (0.05 and 0.1) induced an increase in the frequency of hole visits accompanied by a decrease in the mean duration of visits, whereas the highest doses induced a decrease in hole visit frequency. Low doses of DALA had no effect on strategy or organization of exploration, whereas the high doses produced decreased switching between holes. After low doses of DALA, locomotor activity at the periphery of the testing box was not significantly affected but locomotor activity in the centre was increased. After high doses of DALA, locomotor activity in the center and at the periphery of the box were decreased. Frequency of rearing was either not affected or decreased by DALA treatment. DALA injected in the SN resulted in a small increase in frequency of hole visits and did not affect rearing and locomotor activity. DALA injection in the HPC had no effect on investigatory and spontaneous motor behaviour. The results are discussed in terms of a modulatory role of endogenous enkephalin on mesolimbic dopamine neurons.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...