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  • 1985-1989  (8,506)
  • 1975-1979  (4,073)
  • 1960-1964  (1,637)
  • Cell & Developmental Biology  (11,050)
  • Rat  (1,172)
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  • 101
    Electronic Resource
    Electronic Resource
    Differential tolerance to cataleptic effects of SCH 23390 and haloperidol after repeated administration (1989)
    Springer
    Psychopharmacology 98 (1989), S. 472-475 
    Details
    ISSN: 1432-2072
    Keywords: SCH 23390 ; Catalepsy ; Tolerance ; Neuroleptics ; Rat ; Chronic treatment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The development of tolerance to the cataleptic effect of the selective D-1 antagonist SCH 23390 (0.5 mg/kg/day SC or 0.1 mg/kg/day SC) and haloperidol (1 mg/kg/day SC) during repeated administration was investigated. Catalepsy in rats was measured using the horizontal bar method. SCH 23390 induced a dose-related cataleptic effect of short duration, whereas the cataleptic effect of haloperidol appeared more slowly and lasted longer. Marked tolerance to the cataleptic effect of haloperidol developed already 6 days from the beginning of the treatment. The cataleptic effect of the higher dose regimen of SCH 23390 was also significantly reduced after 6 days' treatment. However, unlike haloperidol, this subacute tolerance was gradually reversed and was no longer significant after 12 and 18 days. The cataleptic response to the lower dose of SCH 23390 (0.1 mg/kg/day) was not significantly altered during the treatment and no initial catalepsy tolerance was observed with this dose regimen. These results suggest that different mechanisms are involved in the expression of cataleptic behaviour during chronic treatment with SCH 23390 and classical antipsychotics, such as haloperidol.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00441944
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  • 102
    Electronic Resource
    Electronic Resource
    Low doses of corticotropin-releasing factor potentiate amphetamine-induced stereotyped behavior (1989)
    Springer
    Psychopharmacology 99 (1989), S. 27-33 
    Details
    ISSN: 1432-2072
    Keywords: Corticotropin-releasing factor (CRF) ; Amphetamine ; Stereotypy ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Corticotropin-releasing factor (CRF) is a 41-amino acid polypeptide that is critically involved in the activation of the hypothalamic-pituitary adrenal axis during stress. In addition, it has been suggested that extrahypothalamic CRF may be important in initiating behavioral responses to stressful events. In the present experiment, we examined the effects of central administration of CRF on amphetamine-induced stereotyped behavior. Amphetamine-induced stereotyped behavior has been considered as a behavioral strategy to cope with excessive arousal. Low doses of CRF (0.02 and 0.1 μg), administered into the lateral ventricle (ICV), were shown to potentiate amphetamine (4.0 mg/kg; SC)-induced stereotyped behavior, as measured by the Creese and Iversen rating scale and behavioral observations. These low doses of CRF specifically enhanced the tendency for rats to sniff with their heads down 20 min after injection, and induced licking behavior later during testing. In contrast, the rats treated with a higher dose of CRF (0.5 μg, ICV) showed more locomotor activity throughout the test, but did not differ from the saline-treated animals in the intensity of amphetamine-induced stereotyped behavior.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00634448
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  • 103
    Electronic Resource
    Electronic Resource
    Infusion of γ2-MSH produce a conditioned taste aversion in morphine-dependent rats (1989)
    Springer
    Psychopharmacology 99 (1989), S. 140-142 
    Details
    ISSN: 1432-2072
    Keywords: γ2-MSH ; Naloxone ; Opiate dependence ; Taste preference conditioning ; Taste aversion ; Withdrawal motivation ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A two flavour, unbiased, taste preference conditioning procedure was used to test for possible motivating effects of γ2-MSH. Three training trials failed to produce any significant effect with doses ranging from 2.4 to 40 μg/ ICV infusion in drug-naive, non-operated or placebo-implanted rats. However, in rats made dependent by SC implantation of a morphine pellet 4 days earlier 15 μg γ2-MSH/infusion produced a taste aversion that was comparable to that produced by infusion of a low dose of the competitive opioid receptor antagonist naloxone (0.32 μg). The findings confirm with a conditioning procedure and with opiate-dependent animals the naloxone-like effects of γ2-MSH. They also suggest that this endogenously-located peptide may acquire an aversive property as a result of chronic morphine treatment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00634469
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  • 104
    Electronic Resource
    Electronic Resource
    Cholinergic mechanisms in a simple test of olfactory learning in the rat (1989)
    Springer
    Psychopharmacology 99 (1989), S. 270-275 
    Details
    ISSN: 1432-2072
    Keywords: Olfactory learning ; Rat ; Scopolamine ; Septal lesions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Male rats were tested in a simple olfactory habituation and discrimination paradigm. Untreated rats habituated their responses over three trials to one odour but were capable of recognising a novel odour presented on the fourth trial. Administration (SC) of either scopolamine or N-methylscopolamine before trials commenced produced a decrease in overall responding. Scopolamine, but not N-methylscopolamine, also blocked habituation to the first odour and recognition to the second, novel odour. Administration of scopolamine after trial 3 did not block the ability of the animals to respond differentially to a novel odour, although again overall levels of responding were decreased. Electrolytic lesions of the medial septal area increased overall levels of responding but lesioned animals still habituated their response over trials and were capable of recognising a novel odour. Therefore although cholinergic mechanisms appear to be involved in this type of learning, these effects are unlikely to be mediated via the septohippocampal system.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00442821
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  • 105
    Electronic Resource
    Electronic Resource
    MDMA produces stimulant-like conditioned locomotor activity (1989)
    Springer
    Psychopharmacology 99 (1989), S. 352-356 
    Details
    ISSN: 1432-2072
    Keywords: Conditioned locomotion ; MDMA ; Aniphetamine ; Cocaine ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Daily administration of a drug in a distinctive environment establishes contingencies that support Pavlovian conditioning. Environmental cues that are paired with the drug injection and that predict the onset of drug action can become conditioned stimuli. Ultimately, the conditioned stimuli come to predict the availability of drug and develop the potential to engender conditioned drug responses. Various psychostimulant drugs can produce conditioned locotnotion when tested in the presence of environmental cues that were repeatedly associated with the drug experience. The ability of amphetamine and cocaine to produce conditioned locomotion was demonstrated in the present study. Stimulant-like properties of methylenedioxymethamphetamine (MDMA) have been reported in locomotor paradigms, drug discrimination procedures, and human subjective questionnaires. MDMA (5 mg/kg), paired for 5 days to a distinct environment signalled by the presence of a distinct odor, produced enhanced locomotion during a test probe with the odor alone indicating that MDMA can also produce conditioned locomotion. The observation that the stimulus properties of MDMA can also become associated with environmental cues supports the hypothesis that some of the behavioral effects of MDMA resemble those of other classical psychostimulants such as amphetamine and cocaine.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00445556
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  • 106
    Electronic Resource
    Electronic Resource
    Roles of intoxicated practice in the development of ethanol tolerance (1989)
    Springer
    Psychopharmacology 99 (1989), S. 366-370 
    Details
    ISSN: 1432-2072
    Keywords: Ethanol tolerance ; Intoxicated practice ; Motor impairment ; Hypothermia ; Narcosis ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The development of tolerance to the motor impairment effect of ethanol was examined in separate groups of rats receiving and not receiving intoxicated practice. Tolerance to the motor impairment effect of ethanol developed whether or not rats received intoxicated practice during chronic ethanol treatment. Depending on the treatment dosage and test dose, intoxicated practice might enhance the level of tolerance attained. Tolerance to other effects of ethanol (hypothermia and narcosis) developed as a function of the treatment dosage. Intoxicated practice on the moving belt did not modify the development of tolerance to these effects of ethanol. Tolerance to the motor impairment effect of ethanol, however, was retained much longer in the intoxicated practice group following the termination of ethanol treatment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00445559
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  • 107
    Electronic Resource
    Electronic Resource
    Potentiation of oxotremorine-induced hypothermia by alaproclate in PCA lesioned and non-lesioned rats (1989)
    Springer
    Psychopharmacology 97 (1989), S. 51-53 
    Details
    ISSN: 1432-2072
    Keywords: Thermoregulation ; Acetylcholine ; Muscarinic ; Serotonin ; Interaction ; Alaproclate ; Oxotremorine ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Stimulation of muscarinic cholinergic receptors with the highly potent and selective receptor agonist oxotremorine produced hypothermia in rats. Alaproclate, a purported selective serotonergic reuptake inhibitor, potentiated this response. Destruction of central presynaptic serotonergic terminals with the potent cytotoxin p-chloroamphetamine (PCA) failed to attenuate the hypothermic response to oxotremorine in alaproclate-pretreated animals. These results could be taken to suggest that alaproclate may act, at least in part, via a non-serotonergic mechanism to potentiate the oxotremorine-induced hypothermic response.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00443412
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  • 108
    Electronic Resource
    Electronic Resource
    Centrally administered neuropeptide Y (NPY) produces anxiolytic-like effects in animal anxiety models (1989)
    Springer
    Psychopharmacology 98 (1989), S. 524-529 
    Details
    ISSN: 1432-2072
    Keywords: Neuropeptide Y ; Anxiolysis ; Conflict model ; Alpha-adrenergic ; Idazoxan ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Effects of intracerebroventircular (ICV), neuropeptide Y (NPY) (0.2–5.0 nmol) and its C-terminal 13–36 amino acid (AA) fragment (0.4–2.0 nmol) have been examined with respect to anxiolytic properties in two rat anxiety models, Montgomery's conflict test (MT), and Vogel's drinking conflict test (VT). In the MT, 1.0 and 5.0 nmol NPY abolished the normal preference for the closed arms of the maze. At 5.0 nmol, the total number of entries made into both closed and open arms was decreased by 50%. In the VT, both 0.2 and 1.0 nmol NPY markedly increased the number of shocks accepted. The effect of 5.0 nmol NPY was less pronounced. In control experiments, NPY (0.2 nmol) did not affect pain sensitivity or thirst. Pretreatment with the selective alpha2-adrenergic receptor antagonist idazoxan, at a dose which by itself did not affect behaviour (2.0 mg/kg), antagonized the effect of 1.0 nmol NPY in the VT. NPY 13-36 was without significant effect in both models. The results suggest that NPY exerts anxiolytic-like effects, and that these effects are mediated through an interaction with noradrenergic systems. Higher doses of NPY produce sedation and ataxia, which decrease overall activity in the MT, and interfere with the ability fully to express behaviourally the anxiolytic-like effect in the VT. The findings are discussed in relation to the noradrenaline hypothesis of anxiety, and to observations indicating involvement of NPY in the pathophysiology of major depression.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00441953
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  • 109
    Electronic Resource
    Electronic Resource
    Discriminative stimulus properties of midazolam: comparison with other benzodiazepines (1989)
    Springer
    Psychopharmacology 97 (1989), S. 466-470 
    Details
    ISSN: 1432-2072
    Keywords: Drug discrimination ; Benzodiazepine ; Midazolam ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Rats (N=12) were trained to discriminate midazolam (1 mg/kg, IP) from vehicle in a food reinforced operant conditioning procedure. Midazolam, flunitrazepam, diazepam, chlordiazepoxide and pentobarbital showed dose-dependent substitution for midazolam. Buspirone and Ro 15-1788 did not substitute for midazolam. The midazolam cue was dose-dependently antagonized by Ro 15-1788. In rats (N=12) trained to discriminate chlordiazepoxide (3 mg/kg, IP) from vehicle midazolam, flunitrazepam, diazepam and chlordiazepoxide substituted completely and dose dependently for chlordiazepoxide. The relative potency of chlordiazepoxide and diazepam was three times less in the midazolam-trained animals than in the chlordiazepoxide-trained animals. Response rate and latency data further support the main finding that the midazolam cue is similar, but not identical to the cue of classical benzodiazepines.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00439549
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  • 110
    Electronic Resource
    Electronic Resource
    Effects of midazolam, DMCM and lindane on potentiated startle in the rat (1989)
    Springer
    Psychopharmacology 99 (1989), S. 362-365 
    Details
    ISSN: 1432-2072
    Keywords: Acoustic startle reflex ; Fear-conditioning ; Midazolam ; DMCM ; Lindane ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Forty-eight male Wistar rats were exposed to contingent light-shock combinations and 48 rats received light and shock stimuli in a random order. One day after fear conditioning the animals were tested for startle potentation after injection of midazolam (0, 0.5, 1.0, 2.0 mg/kg, IP) or DMCM (methyl-6,7-dimethoxy-4-ethyl-beta-carboline-3-carboxylate; 0, 0.1, 0.2, 0.4 mg/kg IP) or lindane (0, 7.5, 15.0, 30.0 mg/kg PO). Midazolam attenuated potentiated startle dose dependently and the inverse benzodiazepine agonist DMCM had the opposite effect. The effects of lindane on startle amplitudes were identical to those of DMCM, indicating that lindane has anxiogenic effects on behavior. It is suggested that the anxiogenic effects of lindane are mediated by an effect at the GABA-ionophore complex.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00445558
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  • 111
    Electronic Resource
    Electronic Resource
    Blockade of 8-OH-DPAT-induced feeding by dopamine antagonists (1989)
    Springer
    Psychopharmacology 99 (1989), S. 402-408 
    Details
    ISSN: 1432-2072
    Keywords: Feeding ; 8-OH-DPAT ; Dopamine ; Antagonists ; Grooming ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Feeding elicited by the 5HT1A agonist 8-OH-DPAT was blocked by pretreatment with the DA antagonists SCH-23390 and sulpiride, in two experiments conducted in non-deprived rats and in three experiments conducted after 4 h food deprivation. In deprived animals, 8-OH-DPAT prolonged the initial period of feeding. However, in non-deprived animals, 8-OH-DPAT delayed the onset of eating, and suppressed post-prandial resting; both SCH-23390 and sulpiride restored the normal pattern of behaviour. All three drugs suppressed grooming. The results suggest that 8-OH-DPAT elicits feeding by a secondary disinhibition of activity postsynaptic to DA neurons. The consequences of this mechanism for the interpretation of 8-OH-DPAT-induced feeding are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00445567
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  • 112
    Electronic Resource
    Electronic Resource
    Evidence that the aversive effects of opioid antagonists and κ-agonists are centrally mediated (1989)
    Springer
    Psychopharmacology 98 (1989), S. 203-206 
    Details
    ISSN: 1432-2072
    Keywords: Place conditioning ; Motivation ; Aversion ; Opioids, μ-, δ- and κ-receptors ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The role of central versus peripheral opioid receptors in mediating the aversive effects of opioids was examined by use of an unbiased place preference conditioning procedure in rats. The non-selective opioid antagonist naloxone (NLX) produced conditioned aversions for the drug-associated place after subcutaneous (SC) as well as intracerebroventricular (ICV) administration. Place aversions were also observed in response to the ICV administration of the selective μ-antagonist CTOP. In contrast, the selective δ-antagonist ICI 174,864 and the selective κ-antagonist norbinaltorphimine (nor-BNI) (ICV) were without effect. Place aversions were also produced by central applications of the selective κ-agonist U50,488H and the dynorphin derivative E-2078. For those opioid ligands tested, the doses required to produce place aversions were substantially lower following ICV as compared to SC administration. These data confirm that κ-agonists and opioid antagonists produce aversive states in the drug-naive animal and demonstrate that this effect is centrally mediated. Furthermore, the ability of NLX and CTOP, in contrast to both ICI 174,864 and nor-BNI, to produce place aversions suggests that the aversive effects of opioid antagonists result from the blockade of μ-receptors.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00444692
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  • 113
    Electronic Resource
    Electronic Resource
    Nucleus accumbens as a substrate for the aversive stimulus effects of opiate withdrawal (1989)
    Springer
    Psychopharmacology 98 (1989), S. 530-534 
    Details
    ISSN: 1432-2072
    Keywords: Morphine ; Opiates ; Dependence ; Nucleus accumbens ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Previous studies from our laboratory using methylnaloxonium, a hydrophilic antagonist, showed that opiate receptors in the region of the nucleus accumbens are important for the acute reinforcing effects of heroin in non-dependent rats. A similar increased sensitivity to the response disruptive effects of intracerebrally injected methylnaloxonium in opiate dependent rats was observed in a fixed-ratio (FR) baseline of operant behaviors. These results suggest that the same opiate receptors in the region of the nucleus accumbens important for the positive reinforcing stimulus properties of opiates may also be responsible for the response disruptive, aversive stimulus properties of opiate withdrawal. These results also suggest that the neural substrates of some aspects of dependence may be partly related to those of the reinforcing effects of opiates. In particular, it is hypothesized that “euphoria” and “dysphoria” induced by opiates may reflect opponent motivational processes operating at a cellular level within the nucleus accumbens.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00441954
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  • 114
    Electronic Resource
    Electronic Resource
    Effects of stimulation and blockade of dopamine receptor subtypes on the discriminative stimulus properties of cocaine (1989)
    Springer
    Psychopharmacology 99 (1989), S. 13-16 
    Details
    ISSN: 1432-2072
    Keywords: Cocaine ; Dopamine ; Dopamine receptors ; Drug discrimination ; Drug stimuli ; Receptors ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The involvement of dopamine (DA) receptor subtypes in the behavioral effects of CNS stimulants was studied in rats trained to discriminate occaine from saline. In substitution tests, the stimulus effects of 10mg/kg of this substance generalized tod-amphetamine (0.25–1.0 mg/kg) and the selective D2 against LY-171555 (0.05–0.25 mg/kg); but not to the D1 agonist SKF-38393 (5.0–15.0 mg/kg); in combination tests, the D1 antagonist Sch-23390 (0.0625–0.5 mg/kg) significantly blocked, and the D2 antagonist spiperone (0.25–0.5 mg/kg) partially blocked the cocaine cue. These data suggest that the involvement of DA systems in the behavioral effects of cocaine is more complex than either D1 or D2 receptor activation; for example, the stimulus properties of this substance might involve both D1 and D2 receptor activation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00634445
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  • 115
    Electronic Resource
    Electronic Resource
    The effect of MK-801 and other antagonists of NMDA-type glutamate receptors on brain-stimulation reward (1989)
    Springer
    Psychopharmacology 99 (1989), S. 87-90 
    Details
    ISSN: 1432-2072
    Keywords: Glutamate ; Kainate ; Ketamine ; Kynurenic acid ; MK-801 ; NMDA ; Phencyclidine ; Rat ; Self-stimulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract MK-801 is a ligand at phencyclidine recognition sites associated with NMDA-coupled cation channels, where it acts as a potent noncompetitive antagonist of central glutamate/aspartate (NMDA-type) receptors. Low doses (10–100 μg/kg IP) produced a dose-related and prolonged (〉1 h) enhancement of variable-interval self-stimulation responding. Higher doses (300 μg/kg) caused flaccid ataxia and disrupted responding. Ketamine HCl (3.0–100 mg/kg IP), a dissociative anaesthetic binding to the phencyclidine site, produced a similar response pattern, but facilitation was less prolonged and occurred over a narrower dose range. Kynurenic acid (3.0–300 mg/kg IP), a nonselective competitive antagonist of glutamate receptors, produced only depression of responding, possibly the result of kynurenate-induced blockade of central kainate and/or quisqualate receptors. The behavioural stimulant effects of MK-801 appear to be an intrinsic and essential feature of selective NMDA antagonists, and these effects of MK-801 differ qualitatively and quantitatively from the well-known facilitatory effects of dopamine-dependent stimulants.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00634458
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  • 116
    Electronic Resource
    Electronic Resource
    Effects of dopamine receptor antagonists on sucrose consumption and preference (1989)
    Springer
    Psychopharmacology 99 (1989), S. 98-102 
    Details
    ISSN: 1432-2072
    Keywords: Sucrose preference ; Two-bottle test ; Dopamine ; Sulpiride ; SCH-23390 ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Effects of the dopamine D2 receptor antagonist sulpiride and the D1 antagonist SCH-23390 were examined, in rats, in two-bottle preference tests (sucrose versus water) and in single-bottle tests, at different sucrose concentrations. Both drugs decreased sucrose intake in single bottle tests, at low sucrose concentrations, but had no effect at high concentrations; reducing drive level had exactly the opposite pattern of effects. In two-bottle tests, both drugs reduced preference for the weakest sucrose concetration (0.7%) but increased preference for the strongest concentration (34%). The effects of antagonizing either subtype of DA receptor appear to be similar to those of reducing the concentration of sucrose.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00634461
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  • 117
    Electronic Resource
    Electronic Resource
    Chronic phosphatidylserine treatment improves spatial memory and passive avoidance in aged rats (1989)
    Springer
    Psychopharmacology 99 (1989), S. 316-321 
    Details
    ISSN: 1432-2072
    Keywords: Aging ; Phosphatidylserine ; Spatial memory ; Passive avoidance ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Learning/memory deficits in senescent animals are widely used as a tool to evaluate the therapeutic potential of agents for treatment of age-associated cognitive dysfunction. As assessed in the Morris water maze test, aged (21–24 months) rats showed a variable loss of spatial memory. Aged non-impaired rats performed as well as young subjects, while aged impaired rats exhibited a severe and persistent place-navigation, deficit. Passive avoidance retention was similarly affected in the two aged subpopulations. Chronic oral administration of phosphatidylserine (50 mg/kg/day for up to 12 weeks), a pharmacologically active phospholipid, was found to improve both the spatial memory and the passive avoidance retention of aged impaired rats. Results are discussed with reference to the phosphatidylserine-induced improvement of age-associated deterioration of brain functions in rats.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00445550
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  • 118
    Electronic Resource
    Electronic Resource
    Intranigral infusion of enkephalins elicits dyskinetic biting in rats (1989)
    Springer
    Psychopharmacology 99 (1989), S. 299-303 
    Details
    ISSN: 1432-2072
    Keywords: Enkephalin analogues ; Intranigral infusions ; Dyskinetic biting ; Tardive dyskinesia ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Leu- and Metenkephalin (Lenk and Menk) and their more stable analogues d-Ala-Leu- and d-Ala-Meten-kephalin (DALenk and DAMenk) as well as d-ala-d-Leu-and d-Ala-d-Metenkephalin (DADLenk and DADMenk) were infused bilaterally into substantia nigra in awake rats and oral movements were recorded for 90 min. DADLenk and DADMenk elicited dose-dependent biting dyskinesias with a chewing rate of about 90 jaw movements/min. DALenk produced a similar but weaker effect, whereas DAMenk, Lenk and Menk were ineffective in the doses given. These findings suggest a possible enkephalinergic mechanism underlying neuroleptic-induced tardive dyskinesias.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00445547
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  • 119
    Electronic Resource
    Electronic Resource
    The in vivo and in vitro effect of calmodulin antagonists on the renal actions of 25(OH) vitamin D3 in the rat (1989)
    Springer
    Pflügers Archiv 415 (1989), S. 372-380 
    Details
    ISSN: 1432-2013
    Keywords: Phosphaturia ; Parathyroid hormone ; 25 Hydroxy-vitamin D3 ; Trifluoperazine ; Adenylate cyclase ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Previous work from this laboratory has demonstrated that 25(OH) vitamin D3 [25(OH)D3] acutely suppresses the phosphaturic action of parathyroid hormone (PTH) and interferes with the PTH-induced activation of adenylate cyclase (AC). Calmodulin inhibitors block vitamin D-induced Ca2+ transport in the gut and phosphorus uptake in renal BBMV's. We have examined whether calmodulin antagonists affect the renal action of 25(OH)D3. Acute clearance experiments were performed in PTH-infused parathyroidectomized rats receiving 25(OH)D3 after pretreatment with trifluoperazine (TFP) or promethazine (P). In vitro PTH-induced activation of renal AC was also studied in membrane preparations from pretreated rats in the presence of 25(OH)D3. 25(OH)D3 reduced the PTH-stimulated increase in fractional excretion of phosphorus (CP/CIn) from 0.292±0.024 to 0.195±0.018 (p〈0.005) and urinary cAMP from 149.3±20.3 to 78.1±10.4 pmol/min (p〈0.01) and also blunted AC activation in vitro. TFP but not P abolished the effects of 25(OH)D3 both in vivo and in vitro. R 24571 also abolished the in vitro effect of 25(OH)D3. Thus, (1) TFP abolishes both the antiphosphaturic and the AC/cAMP-related actions of 25(OH)D3, (2) P does not have these effects, and (3) R 24571 abolishes the in vitro effect of 25(OH)D3. These results suggest that the antiphosphaturic effect of 25(OH)D3 acting via the AC/cAMP system may be calmodulin dependent.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00370890
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  • 120
    Electronic Resource
    Electronic Resource
    Effect of styrene administration on rat testis (1989)
    Springer
    Archives of toxicology 63 (1989), S. 43-46 
    Details
    ISSN: 1432-0738
    Keywords: Styrene ; Testes ; Rat ; Enzymes ; Toxicity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Styrene was administered through gavage to adult male rats for 60 days. At the lower dose of 200 mg/ kg/day no overt signs of testicular toxicity were observed, while at the higher dose of 400 mg/kg/day activities of some marker enzymes for testicular function were found to be altered significantly, along with a decrease in spermatozoa number. Histopathological studies revealed marked degeneration of seminiferous tubules and lumen devoid of sperms, further confirming testicular toxicity of styrene. The present study suggests an overall sensitivity of the male reproductive system towards styrene exposure.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00334633
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    Differential effects of methylmercury on the synthesis of protein species in dorsal root ganglia of the rat (1989)
    Springer
    Archives of toxicology 63 (1989), S. 226-230 
    Details
    ISSN: 1432-0738
    Keywords: Methylmercury ; Protein synthesis ; Dorsal root ganglion ; Two-dimensional electrophoresis ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Dorsal root ganglia from control and methylmercury(MeHg)-treated rats were incubated in vitro with 35S-methionine ant the proteins synthesized were analyzed by two-dimensional electrophoresis. The double labelling method, in which proteins of control dorsal root ganglia labelled in vitro with 3H-leucine were added to each of the two samples as an internal standard, was used to minimize unavoidable errors arising from the resolving procedure itself. The results obtained showed that the effect of MeHg on the synthesis of proteins in dorsal root ganglia was not uniform for individual protein species in the latent period of MeHg intoxication. Among 200 protein species investigated, 157 showed inhibition of synthesis close to that of the total proteins in the tissue (68% of the control). Among the remaining protein species, 20 showed real stimulation of synthesis, whereas 7 were moderately inhibited and 16 were inhibited more strongly than the total proteins in the tissue. These results suggest that the effect of MeHg on the synthetic rates for protein species in dorsal root ganglia differs with the species, and that unusual elevation or reduction of the synthesis of some protein species caused by MeHg may lead to impairment of normal nerve functions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00316373
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    Decrease in the mechanical strength of bones of rats administered cadmium (1989)
    Springer
    Archives of toxicology 63 (1989), S. 320-324 
    Details
    ISSN: 1432-0738
    Keywords: Cadmium ; Rat ; Mechanical strength of bones
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The mechanical properties of the bones of young, adult and old rats administered various concentrations of cadmium were measured to prove the direct effect of cadmium on the bones of young rats. The young rats were divided into three subgroups, which were administered 0 (control), 5 and 10 ppm cadmium, respectively. The adult rats were subdivided into six groups, administered 0, 10, 20, 40, 80 and 160 ppm cadmium, respectively. The old rats were divided into three subgroups, which were administered 0, 80, and 160 ppm cadmium, respectively. The length of the administration was 4 weeks in every group. The decrease in the mechanical strengths of bones of young rats administered with cadmium was observed. On the other hand, no change in mechanical strength of bones was observed in the case of adult and old rats, administered up to 160 ppm cadmium. The correlation between the cadmium in bones and the decrease in the strength of the bone shows that cadmium directly affects the mechanical properties of bones of young rats.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00278646
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    Effects of cadmium exposure during pregnancy on cadmium and zinc concentrations in neonatal liver and consequences for the offspring (1989)
    Springer
    Archives of toxicology 63 (1989), S. 38-42 
    Details
    ISSN: 1432-0738
    Keywords: Cadmium ; Zinc ; Neonate ; Thymus ; Birth weight ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The effects of cadmium exposure during pregnancy (by means of daily subcutaneous injections of 4.4 μmol/kg to the mother) on the neonates were investigated. No effect was observed on fetal or neonatal body weights, nor on neonatal liver weights. These parameters were examined up to 5 weeks after birth. The weight of neonatal thymuses was decreased 7 and 14 days after birth due to cadmium exposure of the mothers as compared with controls. This may be caused by zinc deficiency, because zinc concentrations in fetal and neonatal livers after cadmium exposure were found to be very low 20 days after conception and 5 h after birth. Cadmium concentration in neonatal liver decreased; however, cadmium in malignant liver increased as age increased. In the mother, cadmium was transferred to the milk, as it was demonstrated in the stomach contents of the pups. Simultaneous administration of zinc in amounts equimolar to cadmium did not have any noticeable effect on the amount of cadmium transferred to the fetus or on cadmium concentrations in any of the organs investigated. It could not prevent zinc deficiency in fetal and neonatal liver. In addition, growth retardation of the thymus from exposed pups could not be prevented by zinc administration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00334632
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    Effects of 2,4-dichlorophenoxyacetic acid (2,4-D) on biogenic amines and their acidic metabolites in brain and cerebrospinal fluid of rats (1989)
    Springer
    Archives of toxicology 63 (1989), S. 127-130 
    Details
    ISSN: 1432-0738
    Keywords: 2,4-Dichlorophenoxyacetic acid ; Biogenic amines ; Brain ; Cerebrospinal fluid ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Effects of single subcutaneous doses of sodium 2,4-dichlorophenoxyacetate (2,4-D-Na) on biogenic amines and their acidic metabolites in rat brain and cerebrospinal fluid (CSF) were analyzed by high pressure liquid chromatography. After 200 mg/kg 2,4-D-Na, the cerebral concentration of 5-hydroxytryptamine (5-HT) was increased slightly and that of 5-hydroxyindoleacetic acid (5-HIAA) roughly 3-fold between 1 and 8 h after the administration. There was also a tendency towards slightly lowered dopamine (DA) levels. No statistically significant changes in brain concentrations of noradrenaline (NA), 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA) or tryptophan (TRY) were found. At the same time, however, the maximal increase in DOPAC, HVA and 5-HIAA concentrations in the CSF was 2.3–5.8-fold. The dependency of biogenic amines and metabolites on 2,4-D-Na dose was studied by injecting s.c. 0, 10, 30 and 100 mg/kg and sacrificing the rats at 2 h. In the brain, there was a dose-dependent increase in concentrations of 5-HIAA (at the two highest doses) and HVA (at the highest dose) while in the CSF those of all three acidic metabolites increased at the two highest doses. The 10 mg/kg dose had no effect. The results agree with the hypothesis that 2,4-D inhibits the organic acid transport out of the brain, which should then result in increased cerebral levels of acidic metabolites of biogenic amines, but it may also have effects on the activity of serotoninergic and dopaminergic neurones.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00316434
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    Toxicity study in rats of a tellurium based immunomodulating drug, AS-101: A potential drug for AIDS and cancer patients (1989)
    Springer
    Archives of toxicology 63 (1989), S. 386-393 
    Details
    ISSN: 1432-0738
    Keywords: Tellurium ; Rat ; Toxicology ; Immunomodulator ; Drug
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Male and female Sprague Dawley rats were injected intraperitoneally for 4 weeks with ammonium trichloro (dioxyethylene-0-0′-) tellurate, an immunomodulating drug at closes ranging from 3 to 24 mg/kg/week. Routine laboratory examinations included body weight, food consumption, clinical chemistry and hematological examinations. At termination of the experiment, all rats were sacrificed and subjected to a detailed necropsy. Few mortalities were recorded during the course of the study. Clinical signs included hind limb paresis and paraphimosis. A garlic odor pervaded the room. Body weight and food consumption were adversely affected in a dose-related manner. Effects were elicited on the hematological system; changes being noted in the platelet and leukocyte counts as well. Clinical chemistry evaluation revealed signs of hepatoxicity, especially in the female treated groups. The level of beta-globulin was increased. At necropsy organs were found to have a grayish-blue discoloration. Tellurium related histopathological changes were observed in the eyes, liver, thymus, bone marrow, heart and kidneys. An attempt has been made to compare the toxicity of this drug with other tellurium-containing compounds. A good correlation was found. Novel effects of the drug were retinopathy and replacement of bone marrow by bony or fibrous tissue. The possibility that some of the effects may have been elicited due to selenium-vitamin E deficiency has been considered.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00303128
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    Melatonin accelerates reentrainment of the circadian rhythm of its own production after an 8-h advance of the light-dark cycle (1989)
    Springer
    Journal of comparative physiology 166 (1989), S. 97-102 
    Details
    ISSN: 1432-1351
    Keywords: Rat ; Melatonin ; Circadian rhythm ; 5-hydroxytryptophan
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The rhythm in melatonin production in the rat is driven by a circadian rhythm in the pineal N-acetyltransferase (NAT) activity. Rats adapted to an artificial lighting regime of 12 h of light and 12 h of darkness per day were exposed to an 8-h advance of the light-dark regime accomplished by the shortening of one dark period; the effect of melatonin, triazolam and fluoxetine, together with 5-hydroxytryptophan, on the reentrainment of the NAT rhythm was studied. In control rats, the NAT rhythm was abolished during the first 3 cycles following the advance shift. It reappeared during the 4th cycle; however, the phase relationship between the evening rise in activity and the morning decline was still compressed. Melatonin accelerated the NAT rhythm reentrainment. In rats treated chronically with melatonin at the new dark onset, the rhythm had already reappeared during the 3rd cycle, in the middle of the advanced night, and during the 4th cycle, the phase relationship between the evening onset and the morning decline of the NAT activity was the same as before the advance shift. In rats treated chronically with melatonin at the old dark onset or in those treated with melatonin 8 h, 5 h and 2 h after the new dark onset during the 1st, 2nd and 3rd cycle, respectively, following the advance shift, the NAT rhythm reappeared during the 3rd cycle as well but in the last third of the advanced night only. Neither triazolam nor fluoxetine together with 5-hydroxytryptophan administered around the new dark onset facilitated NAT rhythm reentrainment after the 8-h advance of the light-dark cycle.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00190214
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    Immunogold localization of coenzyme F420-reducing formate dehydrogenase and coenzyme F420-reducing hydrogenase in Methanobacterium formicicum (1989)
    Springer
    Archives of microbiology 151 (1989), S. 307-313 
    Details
    ISSN: 1432-072X
    Keywords: Methanobacterium formicicum ; Formate dehydrogenase ; F420-hydrogenase ; Immunogold ; Ultrastructure ; Methanogen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The ultrastructural locations of the coenzyme F420-reducing formate dehydrogenase and coenzyme F420-reducing hydrogenase of Methanobacterium formicicum were determined using immunogold labeling of thin-sectioned, Lowicryl-embedded cells. Both enzymes were located predominantly at the cell membrane. Whole cells displayed minimal F420-dependent formate dehydrogenase activity or F420-dependent hydrogenase activity, and little activity was released upon osmotic shock treatment, suggesting that these enzymes are not soluble periplasmic proteins. Analysis of the deduced amino acid sequences of the formate dehydrogenase subunits revealed no hydrophobic regions that could qualify as putative membrane-spanning domains.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00406556
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    The ultrastructure of chemolithoautotrophic Gallionella ferruginea and Thiobacillus ferrooxidans as revealed by chemical fixation and freeze-etching (1989)
    Springer
    Archives of microbiology 151 (1989), S. 245-251 
    Details
    ISSN: 1432-072X
    Keywords: Gallionella ferruginea ; Thiobacillus ferrooxidans ; Iron bacteria ; Chemolithoautotrophy ; Ultrastructure ; Freeze-etching ; Cell wall organization ; Intracytoplasmic membranes ; Carboxysomes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract By using sodium thioglycolate to dissolve the high amount of excreted stalk material in axenic cultures of the chemolithoautotrophic iron bacterium Gallionella ferruginea, the ultrastructure of Gallionella cells from pure cell suspensions could be studied without any loss of viability or disturbance by dense ferric stalk fibers, and compared with Thiobacillus ferrooxidans, also grown chemolithoautotrophically with ferrous iron as energy source. Both organisms were chemically fixed or freeze-etched. Particular structural differences between these iron-bacteria could be ascertained. G. ferruginea possesses intracytoplasmic membranes and soluble d-ribulose-1,5-bisphosphate-carboxylase, whereas T. ferrooxidans contains carboxysomes but no intracytoplasmic membranes; Gallionella forms poly-β-hydroxybutyrate and glycogen as storage material; T. ferrooxidans produces only glycogen. Both organisms also differ from each other with respect to the freeze fracture behaviour of the cell envelope layers. Whereas the cells of T. ferrooxidans exhibit a characteristic double cleavage, exposing the plasmic fracture face and exoplasmic fracture face of the outer membrane and cytoplasmic membrane, the exceptionally thin multilayered cell envelope of G. ferruginea revealed a particularly intimate association between the layers, resulting in a visualisation of the supramolecular organisation of only the inner fracture face of the cytoplasmic membrane. The results are discussed predominantly in relation to the extremely distinct environments of both organisms.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00413137
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    Microscopic examination and fatty acid characterization of filamentous bacteria colonizing substrata around subtidal hydrothermal vents (1989)
    Springer
    Archives of microbiology 152 (1989), S. 64-71 
    Details
    ISSN: 1432-072X
    Keywords: Thiothrix sp. ; Beggiatoa sp. ; Sulfideoxidizing ; Polyunsaturated ; Fatty acids ; Inclusions ; Sheath ; Southern California ; Ultrastructure ; Sulfur
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Microscopic examination of the whitish mat that covered the substrata around subtidal hydrothermal vents at White Point in southern California revealed a “Thiothrix-like” bacterium containing sulfur inclusions as the dominant filamentous form in this microbial community. The matlike appearance developed as a result of the closely-packed manner inwhich the basal ends of the filaments were anchored to the substrate. The dominant phospholipid fatty acids of these filaments (16:0, 16:1w7c, 18:0, 18:1w7c) were similar to those recovered from a sample of Beggiatoa isolated from a spring in Florida. Filaments from both sources contained small quantities of C18 and C20 polyunsaturated fatty acids, as well. A larger but less abundant sheathless, filamentous form, which also contained sulfur inclusions and displayed a cell wall structure similar to a previously described Thioploca strain, also colonized the substrata around the subtidal mat. The preservation methods used in the preparation of thin-sections of the subtidal mat material were found to be inadequate for defining some key cellular structures of the large filaments. Nevertheless, the results demonstrate that the filamentous bacteria comprising the microbial mat in the vicinity of the subtidal vents exhibit some of the features of the free-living filamentous microorganisms found in deep-water hydrothermal areas.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00447013
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    The activation of 3H-labeled N-nitrosobis(2-oxopropyl)amine by isolated hamster pancreas cells (1989)
    Springer
    Journal of cancer research and clinical oncology 115 (1989), S. 47-52 
    Details
    ISSN: 1432-1335
    Keywords: Alkylation ; Alkyl guanines ; Pancreas DNA ; Nitrosamines ; Acinar cells ; Duct cells ; Hamster ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The activation of 3H-labeled N-nitrosobis(2-oxopropyl)amine ([3H]BOP) by pancreas acinar and duct tissue from Syrian hamsters and MRC-Wistar rats in vitro was measured as DNA alkylation. Hamster tissue was incubated with [3H]BOP (0.1 mM; 20 μCi/ml) for 2 h. Initial levels of alkylation were similar, 41.7±3.7 (acinar) and 51.5±7.8 (duct) dpm/μg DNA. Alkylation persisted for longer in duct (t/2〉46 h) than in acinar tissue (t/2=6 h). The faster repair of alkylation in acinar tissue was not due to acinar cell death. In rat duct tissue the level of alkylation 2 h after incubation (38.9±4.5 dpm/μg DNA) was similar to that in hamster ducts but declined more rapidly (t/2=27 h). Hamster and rat acinar and duct tissue was incubated with BOP followed by [3H]thymidine to measure DNA synthesis. BOP stimulated DNA synthesis in hamster but not in rat duct tissue or hamster acinar tissue. These data support the hypothesis that the duct tissue is the target tissue for BOP in Syrian hamsters.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00391599
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    Nicotine maintains robust self-administration in rats on a limited-access schedule (1989)
    Springer
    Psychopharmacology 99 (1989), S. 473-478 
    Details
    ISSN: 1432-2072
    Keywords: Nicotine ; Self-administration ; Reinforcement ; Mecamylamine ; Hexamethonium ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Intravenous nicotine maintained substantial responding on the drug-reinforced lever with a limited-access, fixed-ratio 5 schedule of self-administration. Responding demonstrated the expected pharmacological sensitivity; it was dose-dependently reduced by pre-session treatment with either nicotine or mecamylamine but not with hexamethonium. In addition, responding was dependent on the size of the unit dose, with maximum values occurring at 0.01 and 0.03 mg/kg/infusion. Self-administration behavior decreased at doses both above and below these, and extinction followed the substitution of saline for nicotine. Total session drug intake increased with unit dose up to a maximal value of approximately 0.5 mg/kg at 0.03 mg/kg/infusion, but did not increase further at the 0.06 mg/kg/infusion dose. A decrease in the time-out duration at the dose of 0.03 mg/kg/infusion also did not change the total session intake of nicotine. It is suggested that nicotine intake is controlled both by the total amount of drug obtained and by the magnitude of the unit dose. These results demonstrate that intravenous nicotine can maintain substantial self-administration behavior in rodents.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00589894
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    Interaction between accumbens D1 and D2 receptors regulating rat locomotor activity (1989)
    Springer
    Psychopharmacology 99 (1989), S. 558-562 
    Details
    ISSN: 1432-2072
    Keywords: Nucleus accumbens ; Dopaminergic mechanisms ; Selective drugs ; Microinjections ; Locomotor activity ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The effect of intra-accumbens injections of various dopaminergic agonists and antagonists on the rat locomotor activity has been evaluated in automated open fields. Locomotor stimulation has been observed after local administration ofd-amphetamine (10 μg), apomorphine (10 μg), as well as of solution containing the D1 agonist SKF 38 393 and D2 receptor agonist LY 171 555 (quinpirole) in doses (10 and 4 μg, respectively) which were inactive when both drugs were administered separately. On the other hand separate injections of metoclopramide (0.1 μg) and SCH 23 390 (0.5 μg) (D2 and D1 receptor antagonists) very potently inhibited animals' locomotor activity. The data indicate that concomitant stimulation of both accumbens D1- and D2-receptor related mechanisms is a necessary condition to increase rat motility. Moreover, it seems that accumbens D1 receptors may be differently involved in the control of facilitatory versus inhibitory motor processes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00589908
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    Evidence that blockade of post-synaptic 5-HT1 receptors elicits feeding in satiated rats (1989)
    Springer
    Psychopharmacology 97 (1989), S. 54-58 
    Details
    ISSN: 1432-2072
    Keywords: Feeding ; 5-HT antagonists ; 5-HT1 receptors ; 5-HT1C receptors ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The effects of nine central 5-HT antagonists on food intake in free feeding male rats were examined. The 5-HT2 antagonists ritanserin and ketanserin and the selective 5-HT3 antagonists ICS 205-930 and MDL 72222 had no effect on food intake. In contrast, the non-selective 5-HT antagonists metergoline, methiothepin, mesulergine, mianserin and methysergide (all of which have high affinity for various 5-HT1 receptor subtypes), dose-dependently increased food intake during a 4-h daytime test. Furthermore, metergoline dose dependently increased food intake over a 24-h period. Suprisingly, mesulergine decreased food intake over a 24-h period at the same doses that increased daytime food intake. This may indicate that the increase in daytime feeding produced by mesulergine is a non-specific response. Although the antagonists used have varying degrees of selectivity for 5-HT receptor subtypes, the pattern of results suggests that postsynaptic 5-HT1 receptors (possibly of the 5-HT1C type) play an important role in the control of feeding in rats.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00443413
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    Systemic injection of pirenzepine induces a deficit in passive avoidance learning in rats (1989)
    Springer
    Psychopharmacology 98 (1989), S. 286-288 
    Details
    ISSN: 1432-2072
    Keywords: IP pirenzepine ; Passive avoidance ; Brain penetration ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract When injected IP, the M1 muscarinic receptor antagonist pirenzepine dose-dependently induced a deficit in passive avoidance learning in rats. This activity was optimal at 75 mg/kg injected 1 h before the acquisition session. The deficit induced by pirenzepine was antagonized by oxotremorine (0.03–0.3 mg/kg SC) and physostigmine (0.1 mg/kg SC), but not neostigmine. By comparison, under the same experimental conditions, physostigmine and oxotremorine also antagonized the deficit induced by an equipotent dose of scopolamine (0.5 mg/kg IP), although the activity of physostigmine appeared stronger against scopolamine than against pirenzepine. These results suggest that pirenzepine could produce a centrally-mediated behavioural disruption when injected systemically.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00444707
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    β-Adrenoceptor binding correlates with behaviour of rats in the open field (1989)
    Springer
    Psychopharmacology 98 (1989), S. 412-416 
    Details
    ISSN: 1432-2072
    Keywords: Adrenoceptors ; Behaviour ; Noradrenaline ; Open field ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Rats were injected IP once daily for 14 consecutive days with propranolol (5 mg/kg), yohimbine (2.5 mg/kg) or saline vehicle. A fourth group was unhandled during this time. Each rat was then placed in an open field for 4 min and its activity and defaecation recorded. Immediately after this, the animals were killed and cerebral cortices removed for radioligand binding to α2- and β-adrenoceptors and measurement of noradrenaline content. We report two sets of findings. First, β-adrenoceptor density correlated positively, and affinity negatively, with the number of movements towards the centre of the field in the final 3 min of the trial. α2-Adrenoceptor K d, in contrast, correlated both with movements around the field and those directed towards the centre. Secondly, whereas the only specific drug effect was an increase in defaecation after treatment with propranolol, β-adrenoceptor density was increased and affinity decreased in all injected groups, suggesting a non-specific effect of the stress of injection. Movements to and from the centre of the field were also increased in injected groups during the first minute of the trial. In both sets of findings the association of β-adrenoceptor density with greater resistance to stress is hard to reconcile with existing theories of the role of β-adrenoceptors in behavioural responses to stress.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00451697
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    Oxytocin-induced penile erection and yawning in male rats: effect of neonatal monosodium glutamate and hypophysectomy (1989)
    Springer
    Psychopharmacology 97 (1989), S. 383-387 
    Details
    ISSN: 1432-2072
    Keywords: Penile erection ; Yawning ; Hypophysectomy ; Monosodium glutamate ; Oxytocin ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Penile erection and yawning induced by the intracerebroventricular (ICV) injection of oxytocin (10–1000 ng) was studied in hypophysectomized rats and in rats neonatally treated with monosodium glutamate (MSG), a treatment that depletes hypothalamic opiomelanocorticotropinderived peptides without altering their pituitary and circulating concentration. Oxytocin effect was strongly reduced by hypophysectomy, but not by neonatal MSG. Testosterone replacement (50 μ/kg/day for 23 days) partially reversed the effect of hypophysectomy on penile erection, but not on yawning. The present results suggest that oxytocin does not induce penile erection and yawning by releasing an ACTH-derived peptide from hypothalamic opiomelanotropinergic neurons, and that the pituitary gland exerts a permissive role on the expression of the above behavioural responses induced by oxytocin.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00439455
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    Total muscle mitochondrial volume in relation to aerobic capacity of horses and steers (1989)
    Springer
    Pflügers Archiv 413 (1989), S. 343-347 
    Details
    ISSN: 1432-2013
    Keywords: Exercise ; Heart ; Mitochondria ; Oxygen uptake ; Respiration ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The relationship between maximal oxygen consumption rate ( $$\dot V{\text{O}}_{{\text{2max}}}$$ ) and mitochondrial content of skeletal muscles was examined in horses and steers (n=3 each). Samples of the heart left ventricle, diaphragm,m. vastus medialis, m. semitendinosus, m. cutaneous thoracicus andm. masseter, as well as samples of muscles collected in a whole-body sampling procedure, were analyzed by electron microscopy. $$\dot V{\text{O}}_{{\text{2max}}}$$ per kilogram body mass was 2.7× greater in horses than steers. This higher $$\dot V{\text{O}}_{{\text{2max}}}$$ was in proportion to the higher total volume of mitochondria in horse versus steer muscle when analyzed from the whole-body samples and from the locomotor muscle samples. In non-locomotor muscles, total mitochondrial volume was greater in horses than steers, but not in proportion to their differences in $$\dot V{\text{O}}_{{\text{2max}}}$$ . The $$\dot V{\text{O}}_{{\text{2max}}}$$ of the mitochondria was estimated to be close to 4.5 ml O2·ml−1 mitochondria in both species. It is concluded that in a comparison of a highly aerobic to a less aerobic mammalian species of similar body size, a higher oxidative potential may be found in all muscles of the more aerobic species. This greater oxidative potential is achieved by a greater total volume of skeletal muscle mitochondria.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00584481
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    Effect of ruthenium red on responses mediated by activation of capsaicin-sensitive nerves of the rat urinary bladder (1989)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 340 (1989), S. 541-546 
    Details
    ISSN: 1432-1912
    Keywords: Ruthenium Red ; Capsaicin ; Sensory nerves ; Rat ; Urinary bladder
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary (1) Topical administration of Ruthenium Red (10–100 μM in saline) to the serosal surface of the urinary bladder in urethane-anesthetized rats prevented the motor response of the urinary bladder to topical administration of capsaicin and protected the sensory fibers from capsaicin desensitization, but had no effect on the volume-evoked contractions (micturition reflex). At 1 mM increased bladder capacity and decreased amplitude of micturition contraction were observed. (2) At 100 μM, topical Ruthenium Red prevented the blood pressure rise produced by topical administration of capsaicin onto the bladder but did not affect the blood pressure rise produced by sudden bladder distension in spinal rats. (3) After intrathecal administration, Ruthenium Red (80–800 ng/rat) produced a long lasting inhibition of the micturition reflex in urethane-anesthetized rats, this effect being evident in both vehicleor capsaicin- (50 mg/kg s. c. 4 days before) pretreated rats. At 800 ng/rat, intrathecal Ruthenium Red did not affect the blood pressure rise produced by topical administration of capsaicin onto the rat bladder nor that produced by bladder distension. (4) These findings provide further evidence that Ruthenium Red acts quite selectively as a “capsaicin antagonist” preventing both reflex and “efferent” responses activated by peripherally administered capsaicin. By contrast, sensory impulse generation by a natural stimulus such as bladder distension is apparently unaffected by Ruthenium Red. The marked inhibition of the micturition reflex observed after intrathecal administration of Ruthenium Red does probably not involve an interaction with primary afferents in the spinal cord.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00260609
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  • 139
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    Excitatory amino acid receptors in rat locus coeruleus (1989)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 339 (1989), S. 312-314 
    Details
    ISSN: 1432-1912
    Keywords: Locus coeruleus ; Rat ; Excitatory amino acids ; Kynurenic acid ; Mg2+
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The goal of this study was to investigate whether locus coeruleus neurons of the rat are sensitive to agonists of the different excitatory amino acid receptors. All experiments were performed on a midpontine rat slice preparation. Bath-applied l-glutamate, kainate, N-methyl-d-aspartate (NMDA) and quisqualate induced concentration-dependent activations of all neurons which were reflected in an increase of the neurons' mean discharge rate. The rank order of cell activation was kainate ∼ quisqualate 〉 NMDA 〉 l-glutamate. None of the agonists induced a bursting-type of discharge. The NMDA-receptor blocker dl-2-amino-5-phosphonovaleric acid (APV, 30 μM) selectively antagonized the NMDA-induced increase in cell firing. Kynurenic acid (100 μM) non-selectively attenuated the response to NMDA, kainate and quisqualate. Neither APV nor kynurenic acid per se had any effect on the spontaneous firing rate. If the Mg2+ concentration in the superfusion medium was lowered from 2 mM to nominally zero the response to NMDA was selectively increased. In conclusion, locus coeruleus neurons share with other neurons their sensitivity to agonists of all three types of excitatory amino acid receptors. However, in contrast to other neurons, they do not respond with a bursting type of discharge.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00173584
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  • 140
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    Evidence for selective inhibition of limbic forebrain dopamine synthesis by 8-OH-DPAT in the rat (1989)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 339 (1989), S. 551-556 
    Details
    ISSN: 1432-1912
    Keywords: Dopamine ; 5-HT synthesis ; Brain ; 8-OHDPAT ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Regional dopamine synthesis in the rat striatum was estimated by measuring DOPA accumulation following inhibition of cerebral aromatic l-amino acid decarboxylase by means of NSD-1015, 100 mg kg−1 intraperitoneally. In animals treated with reserpine, 5 mg kg−1 subcutaneously −18 h, there was a statistically significant increase in DOPA accumulation in the nucleus accumbens, the ventro-medial neostriatum, the dorso-lateral neostriatum and in the posterior limb of the neostriatum. This increase in DOPA accumulation was antagonized dose-dependently in the nucleus accumbens and ventro-medial neostriatum, but not in the other two regions, by treatment with the 5-HT1A receptor agonist 8-OH-DPAT, 0.15–2.4 μmol kg−1, whereas the partial dopamine D2 receptor agonist (−)3-PPP, 2.5–10.0 μmol kg−1, or the full dopamine D2 receptor agonist quinpirole, 0.05–0.8 μmol kg−, antagonized the reserpine-induced increase in DOPA accumulation uniformly in all four regions of the striatum. The suppression of DOPA accumulation by 8-OH-DPAT in reserpine-treated animals, was completely antagonized by raclopride, 1 μmol kg−1, but not by (−)pindolol, 8 μmol kg−1. The accumulation of 5-HTP in all regions of the striatum as well as in the neocortex following decarboxylase inhibition and reserpine pretreatment, was also inhibited by 8-OH-DPAT, and this inhibition was unaffected by treatment with raclopride or (−)pindolol. It is concluded that 8-OH-DPAT, in addition to general effects on forebrain 5-hydroxytryptamine synthesis, selectively affects limbic forebrain dopamine synthesis. This latter effect is probably due to direct stimulation of dopamine autoreceptors, since it was obtained in reserpine-treated rats, and was completely antagonized by raclopride, but not (−)pindolol.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00167260
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  • 141
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    The putatively antipsychotic agent amperozide produces behavioural stimulation in the rat (1989)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 340 (1989), S. 161-169 
    Details
    ISSN: 1432-1912
    Keywords: Amperozide ; Rat ; Behavioural stimulation ; Monoamines ; Biochemical effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Amperozide (FG 5606; N-ethyl-4-[4′,4′-bis(p-fluorophenyl) butyl]-1-piperazinecarboximide) is a new putatively antipsychotic compound with a postulated 5-HT2 antagonistic profile. Somewhat surprisingly amperozide dose dependently induced a behavioural stimulation in reserpinized and in nonpretreated rats. The behaviour consisted of both forward and backward locomotion as well as forepaw circling and a grooming like behaviour. Since the behavioural pattern clearly differ from that produced by classical dopaminergic or serotonergic agonists (e. g. apomorphine or 8-hydroxy-2-(di-n-propylamino)tetralin, 8-OH-DPAT), and has not been previously reported, we decided to investigate the origin of this effect. In the behavioural paradigms it was not possible to antagonize the amperozide stimulation in reserpinized rats with the dopamine receptor blockers haloperidol, raclopride or R(+)-7-chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1 H-3-benzazepine, SCH 23390. Neither the 5-HT2 receptor blocking agent ritanserin nor the tryptophan and tyrosine hydroxylase inhibitor DL-3,4-dihydroxy-phenyl-α-propylacetamide, H22/54, could block the motoric stimulation or the forepaw circling behaviour produced by amperozide. However, the noradrenaline synthesis inhibitor bis- (4-methyl-1-homopiperazinylthiocarbonyl)-disulfide, FLA 63, as well as the α-adrenoceptor antagonist phenoxy-benzamine, could partly inhibit the locomotor stimulation. Hence, noradrenaline seems to be, at least in part, involved in the behavioural stimulatory effect of amperozide. synthesis rate (DOPA formation) in normal or reserpinized animals in the striatal or the limbic brain regions. In reserpinized animals amperozide also failed to antagonize the decrease in DOPA formation after apomorphine and 3-hydroxy-benzylhydrazine HCl, NSD 1015, in these regions. Thus, amperozide failed to show agonistic or antagonistic action on central dopamine receptors. However, in the noradrenaline rich cortical region amperozide induced an increase in DOPA accumulation. The compound also increased the levels of normetanephrine as well as antagonized the decrease in DOPA accumulation by clonidine in the cortical brain region. Amperozide also increased the disappearence rate of noradrenaline after inhibitor of tyrosine hydroxylase by α-methyl-para-tyrosine. These data suggest that, biochemically, amperozide has got α2 antagonistic properties. However, it is not evident that these biochemical properties are responsible for the behavioural effects of amperozide.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00168964
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  • 142
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    Electronic Resource
    Ultrastructural changes induced by precocene II and 3,4-dihydroprecocene II in the corpora allata of Blattella germanica (1989)
    Springer
    Cell & tissue research 258 (1989), S. 91-99 
    Details
    ISSN: 1432-0878
    Keywords: Corpora allata ; Ultrastructure ; Precocenes ; Juvenile hormone ; Blattella germanica (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Ultrastructural studies on corpora allata (CA) from different stages during the first gonadotropic cycle of the cockroach Blattella germanica have shown well defined changes which have a correspondence with oocyte length, CA volume and juvenile hormone (JH) biosynthesis. The most significant variations concern the mitochondria and the endoplasmic reticulum. Topically applied precocene II (P II) at a dose of 200 ⧎g induced a transient arrest of CA function, although cytotoxic effects were occasionally observed. When CA were maintained in vitro with 10-3 M of P II, a relationship between the time of treatment (3, 6 or 9 h) and the intensity of the effects was apparent. The 9-h treatment led to an irreversible inhibition of JH production which parallels the severe damages observed in the CA (membrane lysis, nuclear pyknosis, vacuolization). Equivalent studies performed with the chroman derivative 3,4-dihydroprecocene II (DHP II) showed that it is less active than P II. Only treatments as severe as 12 h of incubation with a 10-3 M concentration elicited cytotoxic effects which could be due to radical species involved in the in situ oxidative bioactivation of DHP II. Thus, this compound could be regarded as a new type of pro-allatocidin.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00223148
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  • 143
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    Structural features of the epididymis in a dasyurid marsupial (Antechinus stuartii) (1989)
    Springer
    Cell & tissue research 258 (1989), S. 203-210 
    Details
    ISSN: 1432-0878
    Keywords: Epididymis ; Histology ; Ultrastructure ; Antechinus stuartii (Marsupialia)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ductus epididymidis of the marsupial mouse Antechinus stuartii was divided into caput, corpus, and caudal regions using several constant morphological landmarks. Tubule diameter and epithelial height increased gradually from caput to cauda. In contrast, the surface area of the lumen of the ductus epididymidis increased to a maximum in the distal caput region, but decreased markedly in the distal cauda in association with characteristic changes in lumen shape (from circular to slit-shaped) and epithelial height. Epithelial cells of the ductus epididymidis were generally similar in structure to those described in other mammalian species. Principal and basal cells were common throughout the epithelium. Clear and mitochondria-rich cells were also identified, but occurred less frequently. Regional variations in cell ultrastructure were observed only in principal cells. Numerous vesicular inclusions occurred in the apical cytoplasm of cells in caput segments, membrane-bounded, electron-dense bodies were common in distal corpus regions, and a brush border of microvilli characterized the luminal surface of principal cells in caudal segments. Sperm index increased in the proximal caput, declined to basal levels in the distal caput and proximal corpus, and then increased to a maximum in segment 9 of the distal corpus and remained at about this level throughout the cauda epididymidis. Nuclear rotation, loss of cytoplasmic droplets, and other sperm maturational changes were observed along the epididymis. Discarded cytoplasmic droplets collected in large masses interspersed between aggregates of spermatozoa throughout the distal regions of the duct. There was no evidence of phagocytosis by principal cells of cytoplasmic droplets. The epididymis of A. stuartii differs from that of other mammals. The unusual caudal region, which has little storage capacity for sperm, is an unusual adaptation in a species in which the male is known to be polygamous.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00223158
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  • 144
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    Electronic Resource
    System-specific distribution of zinc in the chick brain (1989)
    Springer
    Cell & tissue research 258 (1989), S. 247-257 
    Details
    ISSN: 1432-0878
    Keywords: Zinc ; Timm method ; Ultrastructure ; Synapses ; Avian brain ; Domestic fowl
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The brain of young domestic chicks was investigated using a Timm sulfide silver method. Serial Vibratome sections were analyzed under the light microscope, and the localization of zinc-positive structures in selected areas was determined at the ultrastructural level. Both strong and differential staining was visible in the avian telencephalon whereas most subtelencephalic structures showed a pale reaction. The highest staining intensity was found in the nonprimary sensory regions of the telencephalon such as the hyperstriatum dorsale, hyperstriatum ventrale, hippocampus, palaeostriatum augmentatum, lobus parolfactorius and caudal parts of neostriatum. There was an overall gradient of staining intensity in neostriatal areas from rostral to caudal with the heaviest zinc deposits in the caudal neostriatum. Primary sensory projection areas, such as the ectostriatum (visual), hyperstriatum intercalatum superius (visual), nucleus basalis (beak representation), the input layer L2 of the auditory field L and the somatosensory area rostral to field L were selectively left unstained. Fiber tracts throughout the brain were free of zinc deposits except for glial cells. In electron micrographs of stained regions, silver grains were localized in some presynaptic boutons of asymmetric synapses (Gray type I), within the cytoplasm of neuronal somata and sporadically in the nucleus. The possible involvement of zinc in synaptic transmission and other processes is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00239445
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  • 145
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    Electronic Resource
    Cellular origin and distribution of transforming growth factor-β1 in the normal rat myocardium (1989)
    Springer
    Cell & tissue research 256 (1989), S. 553-558 
    Details
    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
    URL: http://dx.doi.org/10.1007/BF00225603
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  • 146
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    Effects of long-term hypergastrinaemia on the ultrastructure of enterochromaffin-like cells in the stomach of the rat, hamster and guinea pig (1989)
    Springer
    Cell & tissue research 256 (1989), S. 247-257 
    Details
    ISSN: 1432-0878
    Keywords: Enterochromaffin-like cells ; Ultrastructure ; Hypertrophy ; Hypergastrinaemia ; Gastrin infusion ; Omeprazole ; Rat (Sprague Dawley) ; Syrian hamster ; Guinea pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The present report describes the ultrastructure of the enterochromaffin-like (ECL) cells in the stomach of the rat, hamster and guinea pig, and the ultrastructural consequences of long-term hypergastrinaemia evoked either by continuous infusion of synthetic human (Leu15)-gastrin-17 for 4 weeks (rats) or by daily treatment with large doses of the antisecretory agent omeprazole for 2–10 weeks (rats, hamsters and guinea pigs). As a result, the ECL cells increased greatly in size (maximal effect after 2 weeks of omeprazole treatment, no further gain in size after 4 or 10 weeks). Also the endoplasmic reticulum and Golgi area were enlarged. The most conspicuous feature of the ECL cells is the cytoplasmic vesicles, which are of varying size and either devoid of a dense core or with a small, often eccentrically located dense core. The vesicles probably represent the main storage site of the secretory products of the ECL cell. In addition, the cytoplasm contains granules, which differ from the vesicles in that they possess a more or less electron-dense core, surrounded by a narrow halo. The size of the vesicles ranged from small to very large, while the granules were uniformly small. Many vesicles were seen to lie very close together, some displaying an irregular outline (vacuole-like vesicles), at times giving the impression that they were undergoing fusion. The profile size (median value) of the vesicles was unaffected by gastrin infusion for 4 weeks. However, there was a tendency to a relative increase in the number of very small vesicles. In contrast, the vesicles became larger during the omeprazole treatment. Also, the number of vesicles that seemed to be engaged in fusion increased after omeprazole treatment but not after gastrin infusion. The observations support the view that ECL cells are influenced by gastrin. The effects of gastrin infusion and of omeprazole treatment on ECL cell ultrastructure were not completely identical. It cannot be excluded that the omeprazole-evoked achlorhydria evokes effects unrelated to those of hypergastrinaemia on the ECL cells, or that endogenous gastrins may evoke effects that are in some ways distinct from those of synthetic human (Leu15)-gastrin-17. Alternatively, the additional effects seen after long-term omeprazole treatment may reflect simply the duration of the hypergastrinaemic stimulus.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218882
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  • 147
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    Morphological changes in the junctional complex of cells in the arachnoid layer of the rat after cold injury (1989)
    Springer
    Cell & tissue research 256 (1989), S. 303-307 
    Details
    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
    URL: http://dx.doi.org/10.1007/BF00218887
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  • 148
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    Axonal tracing of autonomic nerve fibers to the superficial temporal artery in the rat (1989)
    Springer
    Cell & tissue research 256 (1989), S. 559-565 
    Details
    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
    URL: http://dx.doi.org/10.1007/BF00225604
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  • 149
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    Distribution of MAP 2 in dendritic spines and its colocalization with actin (1989)
    Springer
    Cell & tissue research 256 (1989), S. 447-456 
    Details
    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
    URL: http://dx.doi.org/10.1007/BF00225592
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  • 150
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    The effect of low- and high-density lipoprotein cholesterol on steroid hormone production and ACTH-induced differentiation of rat adrenocortical cells in primary culture (1989)
    Springer
    Cell & tissue research 256 (1989), S. 487-494 
    Details
    ISSN: 1432-0878
    Keywords: Adrenal cortex ; Differentiation ; Tissue culture ; Steroids ; Ultrastructure ; Lipoproteins ; Rat (Sprague-Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary We studied the effects of lipoprotein-derived cholesterol on the ACTH-induced differentiation of cultured fetal rat adrenocortical cells. For this purpose human plasma high-density lipoprotein3 (HDL3) or low-density lipoprotein (LDL) was added to culture media devoid of cholesterol, and thereafter the morphological changes in cells were monitored and the amounts of steroids synthesized were measured. It could be demonstrated that, ultrastructurally, upon ACTH-stimulation the adrenocortical cells differentiated into fasciculata-like cells even in the absence of lipoproteins in the culture medium. The addition of either HDL3 or LDL caused an increase in the number and size of cytoplasmic lipid droplets suggesting uptake and deposition of lipoprotein-derived cholesterol into the differentiating cells. The amount of steroids secreted from cells differentiating in media devoid of cholesterol was only half that observed in cells differentiating in serum-supplemented medium. Addition of either HDL3 or LDL increased the ACTH-stimulated steroid synthesis to the levels observed in serum-supplemented medium. This study demonstrates that both HDL3 and LDL are able to provide cholesterol for steroid synthesis accompanying the ACTH-induced differentiation of fetal rat adrenocortical cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00225596
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  • 151
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    The effect of bromocriptine on the intermediate lobe of the rat pituitary: an electron-microscopic, morphometric study (1989)
    Springer
    Cell & tissue research 255 (1989), S. 405-410 
    Details
    ISSN: 1432-0878
    Keywords: Pituitary gland, pars intermedia ; Bromocriptine ; Secretory granules ; Golgi apparatus ; Ultrastructure ; Rat (Sprague-Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The morphological effect of chronic synthetic and secretory inhibition of the intermediate lobe of the rat pituitary induced by bromocriptine treatment was studied using morphometric techniques in combination with electron microscopy. On the basis of granule diameters, a heterogeneous cell population was shown in the normal intermediate lobe. Bromocriptine treatment did not induce any change in the volume fraction, number or location of electron-dense secretory granules. Instead, there was a shift toward a more homogeneous cell population containing smaller granules, the mean granule volume being reduced by ∼30%. The volume fraction of electron-lucent granules or vacuoles was markedly reduced, indicating a functional significance of these organelles. The volume of the Golgi apparatus was not significantly altered, but the number of condensing granules within the Golgi area was reduced. The volume of the intermediate lobe was decreased, apparently due to a decrease in the mean cell volume.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00224124
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  • 152
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    Distribution of peroxidase and iodination activity in the endostyles of Oikopleura albicans and Oikopleura longicauda (Appendicularia, Chordata) (1989)
    Springer
    Cell & tissue research 255 (1989), S. 505-510 
    Details
    ISSN: 1432-0878
    Keywords: Endostyle ; Peroxidase cytochemistry ; Autora diography ; Ultrastructure ; Oikopleura albicans, Oikopleura longicauda (Appendicularia)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Oikopleura albicans and O. longicauda belong to the two subgenera Vexillaria and Coecaria, respectively. The morphology and ultrastructure of their endostyles were investigated with conventional microscopic procedures as well as with DAB cytochemistry and 125I autoradiography at both light- and electron-microscopic levels. As expected, the general morphology of these endostyles is similar to all hitherto examined endostyles. They possess a ventral portion consisting of alternating glandular and ciliated cell zones, probably serving food capture, and a dorsal region, the corridor. Autoradiographic grains were found mainly in the corridor lumen associated with the apical surface of the two central rows of corridor cells. The same cells also gave strong positive reactions for peroxidase, the iodinating enzyme. Peroxidase activity was found in the apical plasma membrane as well as in the nuclear envelope, rough endoplasmic reticulum, Golgi area and cytoplasmic vesicles. Definitive conclusions concerning an apical uptake and subsequent release into the body fluid of iodinated material could not be made from the present experiments. Our investigations indicate that the two central rows of corridor cells in both subgenera of oikopleurids constitute the protothyroid region, possibly homologous to the vertebrate thyroid gland.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218785
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  • 153
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    Morphogenesis of rat cranial meninges (1989)
    Springer
    Cell & tissue research 257 (1989), S. 207-216 
    Details
    ISSN: 1432-0878
    Keywords: Morphogenesis ; Meninges ; Mesenchyme ; Ultrastructure ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The meninges of albino Wistar rat embryos, aged between the 11th embryonic day (ED) and birth, were sectioned using a specially constructed device. This technique permits optimal microanatomical preservation of all tissues covering the convexity of the brain: skin, muscle, cartilage or bone, and the meninges. At ED11, the zone situated between the epidermis and the brain is occupied by a mesenchymal network. At ED12, part of this delicate network develops as a dense outer cellular layer, while the remainder retains its reticular appearance, thus forming an inner layer (the future meningeal tissue). At ED13, the dura mater starts to differentiate. At ED14, the bony anlage of the skull can be identified, and along with the proceeding maturation of dura mater some fibrillar structures resembling skeletal muscle fibers appear in the developing arachnoid space. At ED15–17, a primitive interface zone — dura mater/ arachnoid — is formed, comprised by an outer electronlucent and an inner electron-dense layer marking the outer aspect of the arachnoidal space. At ED18–19, the innermost cellular row of the inner durai layer transforms into neurothelium, which is separated from the darker arachnoidal cells by an electron-dense band. The arachnoidal trabecular zone with the leptomeningeal cells is formed at ED19. By the end of the prenatal period (ED20–21), its innermost part organizes into an inner arachnoidal layer and an outer and inner pial layer. The results from this study indicate (i) that dura mater and leptomeninges develop from an embryonic network of connective tissue-forming cells, and (ii) that the formation of cerebrospinal fluid (CSF)-containing spaces accompanies the differentiation of the meningeal cellular layers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00221652
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  • 154
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    Terminal processes of serotonin neurons in the caudal spinal cord of the molly, Poecilia latipinna, project to the leptomeninges and urophysis (1989)
    Springer
    Cell & tissue research 255 (1989), S. 619-625 
    Details
    ISSN: 1432-0878
    Keywords: Serotonin-containing cells ; Urophysis ; Spinal Cord ; Ultrastructure ; Leptomeninges ; Poecilia latipinna (Teleostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The caudal neurosecretory complex of poeciliids has previously been shown to be innervated by extranuclear and intrinsic serotonergic projections. In the present study, immunohistochemical techniques were used to characterize fibers originating from serotonin neurons intrinsic to the caudal spinal cord. Bipolar and multipolar neurons were oriented ventromedially, and contained numerous large granular vesicles. Three types of serotonergic fibers were distinguished based on their distribution and morphology. Intrinsic Type-A fibers branched into varicose segments near the ventrolateral surface of the spinal cord and contacted the basal lamina beneath the leptomeninges. Type-B fibers coursed longitudinally to enter the urophysis, where they diverged and terminated around fenestrated capillaries. Labelled vesicles in Type-A and Type-B terminals were the same size as those in labelled cells and in unlabelled neurosecretory terminals in the urophysis. Type-C small varicose fibers branched within the neuropil of the caudal neurosecretory complex. Serotonin may be secreted into the submeningeal cerebrospinal fluid, the urophysis, and the caudal vein by Type-A and Type-B fibers, whereas, Type-C fibers may be processes of serotonergic interneurons in the neuroendocrine nucleus. The possibility that urotensins I and II or arginine vasotocin were colocalized in the processes of the intrinsic serotonin neurons was investigated immunohistochemically. The negative results of these experiments suggest that serotonin-containing neurons may represent a neurochemically distinct subpopulation in the caudal neurosecretory complex.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218799
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  • 155
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    Neural activity pattern is not necessary for the development of adult ultrastructure in katydid (Neoconocephalus robustus) singing muscles (1989)
    Springer
    Cell & tissue research 255 (1989), S. 641-644 
    Details
    ISSN: 1432-0878
    Keywords: Insect muscle ; Denervation ; Ultrastructure ; Development, ontogenetic ; Neoconocephalus robustus (Insecto)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The singing muscles of the katydid Neoconocephalus robustus develop adult ultrastructure late in the last nymphal instar and during the first few days of adult life. The ultrastructural changes during early adulthood were not affected by unilateral axotomy shortly after the adult molt. Both denervated and innervated muscles developed adult proportions of mitochondria, myofibril, and sarcoplasmic reticulum and transverse tubules.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218802
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  • 156
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    Specific adhesion between pheochromocytoma (PC12) cells and adrenal medullary endothelial cells in co-culture (1989)
    Springer
    Cell & tissue research 256 (1989), S. 365-372 
    Details
    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
    URL: http://dx.doi.org/10.1007/BF00218894
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  • 157
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    Three-dimensional observation of the fibroblast-like cells associated with the rat myenteric plexus, with special reference to the interstitial cells of Cajal (1989)
    Springer
    Cell & tissue research 255 (1989), S. 343-351 
    Details
    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
    URL: http://dx.doi.org/10.1007/BF00224117
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  • 158
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    The relationship between gastrin cells and bombesin-like immunoreactive nerve fibres in the gastric antral mucosa of guinea-pig, rat, dog and man (1989)
    Springer
    Cell & tissue research 257 (1989), S. 171-178 
    Details
    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
    URL: http://dx.doi.org/10.1007/BF00221648
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  • 159
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    The three-dimensional structure of the zona pellucida in growing and atretic ovarian follicles of the mouse (1989)
    Springer
    Cell & tissue research 257 (1989), S. 247-253 
    Details
    ISSN: 1432-0878
    Keywords: Zona pellucida ; Ovarian follicles ; Atresia ; Ultrastructure ; Mouse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The present study provides further details on the fine-structural three-dimensional architecture of the zona pellucida (ZP) in growing and atretic follicles of mice by use of ruthenium red in combination with the detergents Triton X100 and saponin. These detergents were used for extraction of the “soluble” fraction of the zonal proteins in an attempt to expose the “structural” zonal glycoproteins, which in turn can be viewed as minute three-dimensional networks upon transmission- and scanning electron-microscopic examination. By use of these methods, the ZP of growing follicles appeared to be formed by interconnected filaments which also bind to globular structures building up a three-dimensional lattice. In contrast, the ZP of stage I as well as other (II and III) stages of atretic follicles showed a structure characterized by the presence of closely packed granules connected with short filaments to form a close-mesh reticulum. This structural change of the ZP, which in the present study is also associated with the disappearance of “gap junctions” within the granulosa and cumulus cell population, might represent one of the early events involved in the onset of atresia. These changes, most probably depending on an altered secretory activity of both oocytes and follicle cells, might lead to a degradation of the ZP network structure and to its subsequent increased density (condensation). All these morphodynamic events eventually contribute to a sequestration of the oocyte in the early stage of atresia.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00261827
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  • 160
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    Immunohistochemistry of vacuoles occurring in rat hepatocytes after retinol administration (1989)
    Springer
    Cell & tissue research 257 (1989), S. 263-268 
    Details
    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
    URL: http://dx.doi.org/10.1007/BF00261829
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  • 161
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    Smooth muscle fiber types and a novel pattern of thick filaments in the wing of the pteropod mollusc Clione limacina (1989)
    Springer
    Cell & tissue research 257 (1989), S. 405-414 
    Details
    ISSN: 1432-0878
    Keywords: Mollusc ; Ultrastructure ; Musculature ; Hydroskeleton ; Retraction reflex ; Clione limacina (Mollusca)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Wing (parapodial) retraction in the pteropod mollusc Clione limacina is a reflex triggered by tactile stimulation. Light and transmission electron microscopy revealed three groups of smooth muscles in the wing hemocoel that participate in retraction movements: transverse, longitudinal, and dorsoventral. Among these, two subtypes of muscle cells were identified. The first (type A) appears in all three groups and forms a well-organized lattice-like structure. The second (type B) is the major component of transverse muscles and runs in one direction only. Quantitative ultrastructural comparisons of dimensions, abundance, and organization of dense bodies, thick and thin filaments, membrane invaginations, sarcoplasmic reticulum, and mitochondria suggest that type A cells are able to contract and relax more quickly with less endurance whereas type B cells are capable of generating stronger contractions with more endurance and slower relaxation speed. Furthermore, type A cells have a unique pattern of thick filament organization, here referred to as pseudosarcomeres. The roles played by the different cell types in wing retraction are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00261843
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  • 162
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    Ultrastructural changes in granule cell somata and mossy fibers of the rat hippocampus during picrotoxin-induced convulsions (1989)
    Springer
    Cell & tissue research 255 (1989), S. 261-267 
    Details
    ISSN: 1432-0878
    Keywords: Hippocampus ; Mossy fibers ; Picrotoxin ; Ultrastructure ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Ultrastructural changes in hippocampal granule cells, mossy fibers and mossy fiber boutons were examined following the administration of picrotoxin in adult rats. Generalized seizures occurred within 5–10 min after the intraperitoneal injection of picrotoxin. The electron-microscopic examination of hippocampal tissues from rats that had been perfused with fixative during the seizure revealed that the large dense-core vesicles increased in number and accumulated on the presynaptic membranes of mossy fiber boutons; some of these vesicles appeared to be fused with the membranes, and omega-shaped exocytotic profiles were frequently seen. Furthermore, greatly increased numbers of coated vesicles (60–90 nm in diameter) were observed on the maturing faces of Golgi fields of granule cells. Thus, our study not only indicates an increased incidence of exocytosis of large dense-core vesicles during picrotoxin-induced seizures, but also suggests that these vesicles are replaced in excess from the perikaryon of the granule cell.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00224107
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  • 163
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    The role of kinetosome-associated organelles in the attachment of encysting secondary zoospores ofSaprolegnia ferax to substrates (1989)
    Springer
    Protoplasma 149 (1989), S. 163-174 
    Details
    ISSN: 1615-6102
    Keywords: Adhesion ; Carbohydrates ; Exocytosis ; K-bodies ; Lectins ; Saprolegnia ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Electron and fluorescence microscopy were used to identify organelles involved in attachment of secondary zoospores ofSaprolegnia ferax as they were transformed into secondary cysts. When secondary zoospores were exposed to 1.0% peptone in the absence or presence of a substrate, they began to encyst. If substrates were present when encystment was induced, the groove surface of the secondary zoospores adhered to them. The first event in attachment was secretion of contents of the kinetosome-associated organelle (K-body), which was typically oriented with the tubule-filled cavity positioned toward the cell surface of the groove region in the zoospore. The tubules which contained carbohydrates became coarsely granular, the matrix became more fibrous, and the shell remained along the membrane concavity that was formed as the K-body fused with the plasma membrane. Five minutes later, a cyst coat appeared, and cysts were not readily dislodged from a substrate. The concavity was no longer found, presumably because it had evaginated; but a layered pad of adhesion material was between the cyst coat and substrate. The layers of the adhesion pad corresponded to the structure of the matrix of K-bodies. As with the tubules of the K-body, the coarsely granular portion at the edge of the pad stained for carbohydrates. Similarly, the lectins WGA and GS-II labeled with fluorescein stained the rim of the adhesion pad on cysts, indicating the presence of glycoconjugates containing N-acetylglucosamines. Because globular areas near the kinetosomes and groove of zoospores (where K-bodies were located) also bound WGA and GS-II, K-bodies contained the same carbohydrates as the adhesion pad. We conclude that K-bodies function in the attachment of encysting zoospores to substrates as the cell differentiates. The tubular portion of the K-body matrix contains carbohydrates which might assist in the adhesion process.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01322988
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  • 164
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    The cytoskeletal involvement in cellularization of theDrosophila melanogaster embryo (1989)
    Springer
    Protoplasma 150 (1989), S. 83-95 
    Details
    ISSN: 1615-6102
    Keywords: Drosophila melanogaster embryo ; Cellularization ; Cleavage furrow ; Ultrastructure ; Cytoskeleton ; Mitosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The distribution and arrangement of cytoskeletal components in the early embryo ofDrosophila melanogaster were examined by thin-section electron microscopy to elucidate their involvement in the formation of the cellular blastoderm, a process called cellularization. During the final nuclear division in the cortex of the syncytial blastoderm bundles of astral microtubules were closely associated with the surface plasma membrane along the midline where a new gutter was initiated. Thus the new gutter together with the pre-formed ones compartmentalized the embryo surface to reflect underlying individual daughter nuclei. Subsequently such gutters became deeper by further invagination of the plasma membrane between adjacent nuclei to form so-called cleavage furrows. Nuclei simultaneously elongated in the direction perpendicular to the embryo surface and numerous microtubules from the centrosomes ran longitudinally between the nucleus and the cleavage furrow. Microtubules often appeared to be in close association with the nuclear envelope and the cleavage furrow membrane. The plasma membrane at the advancing tip of the furrow was always undercoated with an electron-dense layer, which could be shown to be mainly composed of 5–6 nm microfilaments. These microfilaments were decorated with H-meromyosin to be identified as actin filaments. As cleavage proceeded, each nucleus with its perikaryon became demarcated by the furrow membrane, which then extended laterally to constrict the cytoplasmic connection between each newly forming cell and the central yolk region. The cytoplasmic strand thus formed possessed a prominent circular bundle of microfilaments which were also decorated with H-meromyosin and bidirectionally arranged, similar in structure to the contractile ring in cytokinesis. These observations strongly suggest that both microtubules and actin filaments play a crucial role in cellularization ofDrosophila embryos.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01403663
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  • 165
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    Ultrastructure of the nitrogen-fixing, filamentous, nonheterocystous cyanobacterium,Plectonema boryanum (1989)
    Springer
    Protoplasma 152 (1989), S. 130-135 
    Details
    ISSN: 1615-6102
    Keywords: Plectonema boryanum ; Cyanobacteria ; Ultrastructure ; Nitrogen fixation ; Nitrogen starvation ; Immunogold localization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The ultrastructure of fructose-supplemented and unsupplemented nitrogen-fixing (fix +) and nonfixing (fix −)Plectonema boryanum UTEX 581 cells was examined by transmission electron microscopy. The most prominent structural differences included the arrangement and morphology of the thylakoids and alterations in the appearance of the interthylakoidal spaces. These ultrastructural differences, together with other observations such as glycogen content and presence of nitrogenase (using acetylene reduction assay and immunogold localization), readily distinguished nonfixingP. boryanum from nitrogen-fixing cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01323072
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  • 166
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    Ultrastructural changes in maturing pollen grains ofApium nodiflorum L. (Apiaceae), with special reference to the endoplasmic reticulum (1989)
    Springer
    Protoplasma 152 (1989), S. 69-76 
    Details
    ISSN: 1615-6102
    Keywords: Apiaceae ; Apium nodiflorum ; Endoplasmic reticulum ; Pollen grain ; Polysaccharide particles ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The ultrastructural events in 3-cellular pollen grains ofApium nodiflorum L. are investigated during pollen maturation. Three distinct developmental stages are distinguished from the formation of sperm cells up to anthesis, whereby the rough endoplasmic reticulum (RER) is mainly involved. The most conspicious form is the highly dilated RER in the vegetative cytoplasm of the youngest pollen grains, which changes to vesicular RER in the following stage. In mature pollen grains the RER has a narrow cisternal configuration and often forms stacks. Pollen activation is preceded by the accumulation of polysaccharide particles.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01323064
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    The effect of fuel oil on the ultrastructure of the chlorococcal algaScenedesmus armatus (1989)
    Springer
    Protoplasma 151 (1989), S. 47-56 
    Details
    ISSN: 1615-6102
    Keywords: Scenedesmus ; Fuel oil ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Characteristic changes in the ultrastructure of the green algaScenedesmus armatus, grown in batch culture in the presence of aqueous fuel-oil extract (AFOE) have been observed. The changes affected mainly chloroplasts and mitochondria. The regular arrangement of the thylakoid stacks became distorted and the whole chloroplast lobed. Plastoglobules were more numerous in the treated cells than in the controls, especially after long-term exposure to AFOE. The mitochondrial matrix cells exposed to AFOE were more electron-translucent. An increase in the number of small mitochondrial profiles was observed after prolonged treatment with AFOE. The number and size of osmophilic bodies increased markedly in the cytoplasm of the treated cells. The cytochemical reaction of these bodies with Sudan black B indicated their lipid composition. Plasmalemma invagination into the cytoplasm and vacuoles, cytoplasmic “layers”, and an increase in size of the vacuolar compartment were observed in cells exposed to AFOE for a long time. The possibility that detoxification, involving microbody activity, may have occurred inScenedesmus is suggested.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01403300
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    Ultrastructural studies of spermatogenesis inAnthocerotophyta V. Nuclear metamorphosis and the posterior mitochondrion ofNotothylas orbicularis andPhaeoceros laevis (1989)
    Springer
    Protoplasma 151 (1989), S. 137-150 
    Details
    ISSN: 1615-6102
    Keywords: Bryophyte ; Notothylas ; Nuclear metamorphosis ; Phaeoceros ; Posterior mitochondrion ; Spermatogenesis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Ultrastructural observations reveal that the spermatozoids of the hornwortsNotothylas andPhaeoceros contain two mitochondria and not one as described previously. Mitochondrial ontogeny and nuclear metamorphosis during spermiogenesis in these plants differ from all other archegoniates. The discovery that the posterior region of the coiled nucleus (when viewed from the anterior aspect) lies to the left of the anterior, in striking contrast to the dextral coiling of the nucleus of spermatozoids of other embryophytes, underlines the isolated nature of the hornworts among land plants. As the blepharoplast develops, the numerous ovoid mitochondria initially present in the nascent spermatid fuse to form a single elongated organelle which is positioned subjacent to the MLS and extends down between the nucleus and plastid. At the onset of nuclear metamorphosis, the solitary mitochondrion has separated into a larger anterior mitochondrion (AM) associated with the MLS and a much smaller posterior mitochondrion (PM) adjacent to the plastid. The PM retains its association with the plastid and both organelles migrate around the periphery of the cell as the spline MTs elongate. By contrast, in moss spermatids, where mitochondria undergo similar fusion and division, the AM is approximately the same size as the PM and the latter is never associated with the spline. As in other archegoniates, except mosses, spline elongation precedes nuclear metamorphosis in hornworts. Irregular strands of condensed chromatin compact basipetally to produce an elongated cylindrical nucleus which is narrower in its mid-region. During this process excess nucleoplasm moves rearward. It eventually overarches the inner surface of the plastid and entirely covers the PM.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01403451
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    An unusual feature of developing protophloem sieve elements in roots ofTriticum aestivum L. (1989)
    Springer
    Protoplasma 152 (1989), S. 14-21 
    Details
    ISSN: 1615-6102
    Keywords: Differentiation ; Heterochronic lysis ; Polarity ; Root protophloem sieve elements ; Triticum aestivum ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Developing protophloem sieve elements in roots of wheat are arranged in single vertical files. In the last immature differentiating sieve element bearing ribosomes the proximal end of the cytoplasm displays a diluted appearance in contrast to the distal end where the cytoplasm exhibits a considerably increased electron density. Differences can also be observed in ribosome quantity, organelle ultrastructure and the time of initiation of cell component degradation, those at the proximal end disorganizing first, suggesting a nonsimultaneous disorganization of the cell components in the two areas. This phenomenon, termedheterochronic lysis, is presumably an expression of an existing polarity not detectable in younger stages, but it might also be the result of an asynchronous enzymatic activity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01354235
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    Ultrastructural responses of tobacco pollen tubes to heat shock (1989)
    Springer
    Protoplasma 153 (1989), S. 104-110 
    Details
    ISSN: 1615-6102
    Keywords: Nicotiana sylvestris ; Pollen tube growth ; Heat shock ; Ultrastructure ; Endoplasmic reticulum ; Mitochondria ; Golgi apparatus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The effect of elevated temperatures on semivivo growth and ultrastructure of tobacco pollen tubes was investigated. Tube growth was decreased by about 50% at 35 °C, independent of the duration of treatment, and at 40 °C and above there was no growth of tubes. Heat treatment caused ultrastructural changes like accumulation of membranous materials, concentric stacking of rough endoplasmic reticulum, reduction in vesicle production by dictyosomes, increase in the fenestrated regions of the Golgi cisternae, swelling of mitochondrial saccules and increase in the electron density of the mitochondrial matrix. Furthermore, the dictyosomes of the treated tubes showed significant increase in the number of cisternae from 30 to 45 °C. The temperature induced changes were persistant at least for 24 h in 35 °C grown pollen tubes. The possible reasons for the tube growth inhibition are discussed on the basis of the ultrastructural alterations caused by elevated temperatures.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01322470
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    Effects of estrus cycle on thermoregulatory responses during exercise in rats (1989)
    Springer
    European journal of applied physiology 58 (1989), S. 446-451 
    Details
    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
    URL: http://dx.doi.org/10.1007/BF00643523
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  • 172
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    Effect of disuse on the ultrastructure of the achilles tendon in rats (1989)
    Springer
    European journal of applied physiology 59 (1989), S. 239-242 
    Details
    ISSN: 1439-6327
    Keywords: Collagen fibre ; Achilles tendon ; Disuse ; Atrophy ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary We examined the influence exerted, through disuse of the hindlimb, on the collagen fibres of the achilles tendon in rats. With disuse the body mass decreased by 28%, and the mass of soleus muscle decreased by 20%. A decrease in the surface area and diameter was observed in the experimental group when compared to the control group. A histogram of the collagen fibres showed a decrease of the thick fibres in the experimental group. The maximum surface area of collagen fibres in the experimental group was seen to be only 43% of that of the control group. These results showed a decrease in the thickness of the collagen fibres of the achilles tendon through disuse. This seemed to suggest that resistance to tension is decreased by disuse.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02386194
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  • 173
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    Ultrastructure ofCyanoptyche gloeocystis f.dispersa (Glaucocystophyceae) (1989)
    Springer
    Plant systematics and evolution 164 (1989), S. 65-73 
    Details
    ISSN: 1615-6110
    Keywords: Algae ; Glaucocystophyceae ; Cyanoptyche gloeocystis f.dispersa ; Ultrastructure ; endocytobiosis ; cyanelles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Cyanoptyche gloeocystis f.dispersa (Geitler)Starmach is a palmelloid colonial alga that contains prokaryotic blue-green endocytobionts (cyanelles) instead of chloroplasts. The periphery of the host cell shows a peculiar lacunae system with underlying microtubules. Vegetative cells possess two rudimentary flagella. Zoospores are dorsiventrally shaped with two heterokont and heterodynamic flagella which originate from a subapical depression. This depression can also be seen in vegetative cells. Both flagella possess non-tubular mastigonemes. Main reserve product is starch lying freely in the cytoplasm. Cyanelles, enclosed singly in a host vesicle, are provided with a remnant cell wall. Thylakoids are arranged concentrically. The central part of each cyanelle harbours its DNA and one large polyhedral body, probably a carboxysome.Cyanoptyche gloeocystis f.dispersa shares all taxonomically essential characters with the monadoidCyanophora, the palmelloidGloeochaete, and the coccoidGlaucocystis. All of them are members of the cyanelle-bearing small algal classGlaucocystophyceae. Members of this class serve as model organisms for the evolution of chloroplasts from cyanophycean ancestors.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00940430
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  • 174
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    Cell multiplication and ultrastructure ofMicrasterias denticulata (Desmidiaceae) grown under salt stress (1989)
    Springer
    Plant systematics and evolution 164 (1989), S. 197-208 
    Details
    ISSN: 1615-6110
    Keywords: Algae ; Chlorophyta ; Desmidiaceae ; Micrasterias ; Ultrastructure ; electron microscopy ; cell multiplication ; salt stress
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Cells ofMicrasterias denticulata Bréb. were kept in nutrient solution of high osmolality (salt stress) for four weeks. In a special cell multiplication test it was established that cell division is gradually inhibited at increasing salt concentrations and totally arrested at the highest concentration (26 mosm/kg). “Recovery studies” proved that even cells from the highest concentration range start dividing immediately after being placed in aqua bidest. thus indicating the full reversibility of the inhibiting effect. — Cells of the highest concentration range show marked ultrastructural changes. Besides an enormous accumulation of starch and oil bodies and a condensed appearance of the ground plasma, a reduction of mitochondria, ER and the Golgi-system is found. The most striking effect occurs on the vacuolar system which appears extremely reduced and condensed. The cell wall is thickened by the formation of an additional cell wall layer with a “spongy” electron microscopical appearance. Through the cell wall many droplets of a probably fat-like substance are excreted. — In summary, salt stress induces growth-inhibited “akinete” cells in the sense ofFritsch; these can be reactivated by decreasing the salt concentration. The salt-induced “akinete state” seems to be an ecological adaption to unfavourable conditions rather than a degeneration of the cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00940437
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  • 175
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    Comparative ultrastructure of the zoospores of nine species ofNeochloris (Chlorophyta) (1989)
    Springer
    Plant systematics and evolution 168 (1989), S. 195-219 
    Details
    ISSN: 1615-6110
    Keywords: Algae ; Chlorophyta ; Chlorophyceae ; Pleurastrophyceae ; Hydrodictyon ; Neochloris ; Pediastrum ; Sphaeroplea ; Ultrastructure ; flagellar apparatus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Nine species ofNeochloris can be divided into three groups on the basis of comparative ultrastructure of the flagellar apparatus, the cell wall and the pyrenoid of zoospores. In Group I,N. wimmeri andN. minuta, zoospores are thin-walled, pyrenoids are penetrated by stromal channels, and the basal bodies are in the clockwise absolute orientation and connected by the distal and two proximal fibers. In Group II,N. aquatica, N. vigenis, N. terrestris, N. pyenoidosa, andN. pseudostigmatica, zoospores are naked or covered by fuzzy material, pyrenoids are covered by a continuous starch sheath or invaginated by cytoplasmic channels, basal bodies are directly opposed, the distal fiber is differentiated into a ribbed structure at the central region, a striated microtubule-associated component (SMAC) is continuous between opposite two-membered rootlets and connected to the ribbed structure, proximal ends of basal bodies are covered by partial caps, each two-membered rootlet and a basal body are connected by a striated fiber to the X-membered rootlet associated with the opposite basal body, and the basal bodies, when oriented at wide angles, are joined at their proximal ends by core extensions. In Group III,N. pseudoalveolaris andN. cohaerens, zoospores are naked, pyrenoids are traversed by parallel thylakoids, basal bodies are in the counterclockwise absolute orientation and overlapped, and each X-membered rootlet is connected to the end of the opposite basal body by a terminal cap. It is suggested that the genusChlorococcopsis gen. nov. be erected for the Group I species. Group II, which includes the type species,N. aquatica, should be preserved asNeochloris. The group appears to be closely related to the coenobial generaPediastrum, Hydrodictyon, andSorastrum, and to have affinities with the coenocytic generaSphaeroplea andAtractomorpha as well. It is also suggested that the genusParietochloris gen. nov. be erected in thePleurastrophyceae for the species of Group III.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00936099
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  • 176
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    Die portocavale Anastomose um Lebercirrhosemodell bei der Ratte —Bedeutung einer speziellen praoperativen Vorbereitung zur Senkung der Operationsletalität (1989)
    Springer
    Langenbeck's archives of surgery 374 (1989), S. 92-94 
    Details
    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
    URL: http://dx.doi.org/10.1007/BF01261616
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  • 177
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    Ultrastructural localization of carbonic anhydrase in the vestibular end organs of the guinea pig (1989)
    Springer
    European archives of oto-rhino-laryngology and head & neck 246 (1989), S. 56-60 
    Details
    ISSN: 1434-4726
    Keywords: Carbonic anhydrase ; Vestibular organ ; Guinea pig ; Histochemistry ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Carbonic anhydrase activity was demonstrated cytochemically on an ultrastructural level in the vestibular end organs of the guinea pig. Reaction product was found in the dark cells, transitional cells, cells of the planum semilunatum and supporting cells. In the dark cells, reaction product was observed in the cytoplasm as well as in the basal infoldings. Reaction product was also observed in the basal infoldings of the transitional cells and the cells of the planum semilunatum. The globular structures inside the supporting cells, transitional cells and the cells of the planum semilunatum were also surrounded by the reaction product. These findings suggest that carbonic anhydrase may have different functions, such as water and ion transport, respiration, nutrition and calcium carbonate deposition in the vestibular end organs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00454136
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  • 178
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    Encapsulated nerve corpuscles in the human tympanic membrane (1989)
    Springer
    European archives of oto-rhino-laryngology and head & neck 246 (1989), S. 169-172 
    Details
    ISSN: 1434-4726
    Keywords: Tympanic membrane ; Ultrastructure ; Sensory receptors ; Nerve endings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Encapsulated nerve endings were found in both the subepidermal connective tissue and the lamina propria of a human tympanic membrane. The structure of the corpuscles was round or oval and contained a number of axon terminals with mitochondria and Schwann cell processes. Amorphous materials were present in the intercellular space. These features appear to be advantageous in transmitting mechanical forces on the capsule to the axon terminals and are comparable to the function of a mechanoreceptor. Resultant changes in the shape and stiffness of the tympanic membrane as the result of its dislocation indicate similar changes in the pressure on the corpuscle. The arrangement of the sensory corpuscles suggests that they may play a role in detecting pressure changes in the middle ear cavity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00456661
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  • 179
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    Cell mediated calcification in collagen gel cultures of fetal rat calvaria cells. Loss of gap junctions precedes calcification (1989)
    Springer
    Journal of bone and mineral metabolism 7 (1989), S. 6-17 
    Details
    ISSN: 1435-5604
    Keywords: Intercellular communication ; Gap junction ; Calcification ; Collagen gel ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary To analyze the mechanism of initiation of cell-mediated calcification in hard tussue and its relationship to the frequency of gap junctions, enzymatically isolated cells from fetal rat calvaria cultured in collagen gels were observed ultrastructurally over a time course. Calcification was observed at 2–3 weeks after the initiation of culture when the seeding cellularity and the concentration of β-glycerophosphate were sufficiently high. In the collagen gels, round cells (R), spindle or stellate cells (S), and fat cells (F) were characterised morphologically. The ultrastructural features of initial calcification could be classified into 4 subtypes: 1) a large mass greater than 10 µm in diameter (Type I), 2) deposition associated with dead R cells or matrix vesicles (Type II), 3) intracellular deposition (Type III), and 4) other than Types I–III (Type IV). Type II was the most frequent (44.5%) and Type III was the least (6.8%). Gap junction was observed frequently between 1) R cells, 2) S cells, 3) between R cells and S cells. The frequency of gap junctions in collagen gels decreased statistically (X2-test; p〈0.001), when calcification was initiated. This cell culture system can be regarded as a useful model to analyze the initiation of cell mediated calcification in hard tissue. Gap junctions might function in cell communication and a decrease in their numbers could lead to cell death and, subsequently to calcification.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02399048
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  • 180
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    Ontogenetic alterations in the gross tooth morphology of Dicamptodon and Rhyacotriton (amphibia, urodela, and dicamptodontidae) (1989)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 199 (1989), S. 165-174 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: During ontogeny, the apical and basal components of dicamptodontid teeth exhibit three major developmental stages: nonpedicellate, subpedicellate, and pedicellate. Premetamorphic larvae tend to have nonpedicellate teeth, incompletely or recently metamorphosed individuals tend to have subpedicellate teeth, and fully transformed adults usually have pedicellate teeth. In concert with this transition, cusp morphology is modified from a larval monocuspid, to an incipiently bicuspid, to definitive adult bicuspid, and finally to an adult monocuspid condition. Thus, the larval and adult monocuspid conditions are ontogenetically distinct. The morphology of the larval monocuspid, adult bicuspid, and adult monocuspid conditions differs between Dicamptodon and Rhyacotriton. However, the incipient bicuspid condition in these two genera is very similar in appearance, suggesting that Dicamptodon and Rhyacotriton may be more closely related to each other than to the family Ambystomatidae in which they both sometimes are placed. The method of establishing ontogenetic trajectories seems to be preferable to comparisons based on adult structure, since similarities in the morphology of adults often is owing to convergent or parallel evolution.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051990204
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    Comparative morphology and evolution of the female reproductive tract in macroglossine bats (mammalia, chiroptera) (1989)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 199 (1989), S. 207-221 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Comparative morphological analysis of the female reproductive tract in macroglossine bats was undertaken to test the hypothesis that nectarivory arose at least twice within Old World fruit bats. Given that features of the female reproductive tract are not directly involved in adaptations for feeding, this data set should provide a test of the monophyly of macroglossine bats. A cladistic analysis of variation in the structure of the ovaries, oviducts, uterus, and external genitalia supports the hypothesis that Megaloglossus has developed a nectar-feeding habit independent of other macroglossine genera. Most of the variation in female reproductive organs among pteropodids is found in the development of derived external and internal features of the uterus. Fusion of uterine cornua, expansion of the common uterine body, and elaboration of the cervical region are found in a group which includes species of Pteropus, Dobsonia, Nyctimene, and the macroglossines (excluding Megaloglossus). Results of this study are concordant with independent data sets, thus providing a phylogenetic framework to evaluate critically structural and functional design in the evolution of pteropodid feeding mechanisms.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051990207
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  • 182
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    Ontogeny of bone and the role of heterochrony in the myobatrachine genera Uperoleia, Crinia, and Pseudophryne (anura: Leptodactylidae: Myobatrachinae) (1989)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 200 (1989), S. 269-300 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Descriptive data are provided for ontogeny of bone to metamorphosis in the myobatrachine species Uperoleia trachyderma; in pre- and postmetamorphic specimens of U. lithomoda, Crinia signifera, and Pseudophryne bibroni; and in postmetamorphic specimens of U. laevigata. Data derived from postmetamorphic U. laevigata indicate that dermal and endochondral elements ossify independently of each other in Uperoleia. Crinia signifera does not show the same degree of independence of ossification of dermal and endochondral elements as Uperoleia, whereas dermal and endochondral elements are not independent in P. bibroni. Ten (or possibly eleven) features are identified as being influenced by heterochrony within Uperoleia, confirming that the genus represents a highly pedomorphic lineage, four elements are influenced by heterochrony in Crinia, but only two in Pseudophryne.
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1052000305
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  • 183
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    Development of the ethmoidal structures of the endocranium in the anuran Pipa pipa (1989)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 200 (1989), S. 301-319 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Investigation of eight developmental stages by means of serial sections and subsequent graphic or wax model reconstructions, as well as by means of cleared-and-stained and dissected material, revealed that the ethmoidal endocranium in Pipa pipa consists in early states of a single horizontal ethmoid plate lacking labial cartilages. Later in the course of development, structures comparable with those in other anurans appear, though modified and of reduced size. These adult structures arise from the new cartilaginous tissue located above the former larval ethmoid plate, whereas the latter entirely disappear. This phenomenon can be observed also in P. carvalhoi and in Xenopus laevis; hence, it supposedly occurs in all pipids. On the other hand, in anuran larvae, which develop cornua trabecularum in the ethmoidal region, these persist in adults as part of the nasal septum. Positional and developmental differences suggest that, although the ethmoid plate and the cornua trabecularum arise from the same region of the cranial neural crest, they are not fully corresponding structures. Comparison with adults of other pipid genera confirmed the conclusion of some earlier investigators that P. pipa is the most specialized among pipids.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1052000306
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  • 184
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    Major ocular glands (Harderian gland and lacrimal gland) of the musk shrew (Suncus murinus) with a review on the comparative anatomy and histology of the mammalian lacrimal glands (1989)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 201 (1989), S. 39-57 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The Harderian gland of the musk shrew Suncus murinus is elongated anteroposteriorly from in front of the eye to behind the ear. The gland is divided into two portions: an anterior portion (A portion) and a posterior portion (P portion). The single secretory duct of the gland emerges from the anterior end of the P portion, receives several secretory ducts of the A portion during the course along it, runs around the ventral aspect of the eyeball, and finally opens into the anterior corner of conjunctival sacs. The two portions of the gland show a fundamentally similar histological structure, having a poorly developed intraglandular duct system and wide tubular alveoli. The quantity of lipid vacuoles and stromal connective tissue in the A portion is greater than in the P portion. The lipid vacuoles in both portions are surrounded by unit membranes, but their contents appear different.The lacrimal gland of the musk shrew is located along the ventral side of the P portion of the Harderian gland. The lacrimal duct emerges from its anterior end, runs around the ventral and anterior aspects of the ear, crosses the A portion of the Harderian gapos; and, and finally opens at the posterior corner of conjunctival sacs. The lobules of the lacrimal gland comprise a branched duct system and terminal acini with two types of secretory cells: (1) acidic cells positive both for the periodic acid-Schiff reaction (PAS) and for Alcian blue (AB) and (2) neutral cells positive for PAS and negative for AB. Both cell types tend to make separate acini, but when present in the same acinus, the acidic cells occupy relatively peripheral positions in the acinus. Both cell types lack intercellular canaliculi.On the basis of the present study as well as previous descriptions in the literature, the author suggests that the mammalian lacrimal glands can be divided into two sets: (1) a Glandula lacrimalis superior with multiple secretory ducts associated with the upper eyelid and (2) a Glandula lacrimalis inferior with a single secretory duct opening into the lateral corner of the conjunctival sacs. These glands have a fundamentally similar histological structure; but in the rabbit, which possesses both sets of lacrimal glands, they are different. On the other hand, the secretory cells of lacrimal glands generally have no intercellular secretory canaliculi, which are characteristically present between the serous secretory cells of the salivary glands.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1052010105
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    Histochemical analysis of newly synthesized and accumulated sulfated glycosaminoglycans during musculogenesis in the embryonic chick leg (1989)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 201 (1989), S. 85-103 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The leg musculature from 11, 14, and 17 day chick embryos was analyzed histochemically to investigate the temporal and spatial distribution of various types of sulfated glycosaminoglycans present during skeletal muscle development. Types of glycans were identified by selective degradation with specific glycosidases and nitrous acid coupled with Alcian blue staining procedures for sulfated polyanions and with [35S]sulfate autoradiography. On day 11, radiolabeled chondroitin sulfate glycosaminoglycans are localized extracellularly in both the myogenic and connective tissue cell populations. By day 17, incorporation of [35S]sulfate into chondroitin sulfate is substantially reduced, although Alcian blue-stained chondroitin sulfate molecules are still detectable. With increasing age and developmental state of the tissues, radiolabeled and stained dermatan sulfate and heparan sulfate progressively increase in relative quantity compared to chondroitin sulfate both in muscle and in associated connective tissue elements. These changes in glycosaminoglycans correlate well with similar changes previously determined biochemically and further document the alterations in extracellular matrix components during embryonic skeletal myogenesis.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1052010108
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  • 186
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    Comparative study of the choanosome of porifera: II. The keratose sponges (1989)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 201 (1989), S. 119-129 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The aquiferous system of representatives of the orders Dictyocer-atida, Dendroceratida, and Verongida has been studied to note its relevance to the systematics of the groups. The volume of the choanocyte chamber, the size and shape of the choanocytes, the number of choanocytes per chamber, the relative development of the mesohyl, and the features of endopinacocytes are estimated from scanning and transmission electron microscopic observations of representatives of most families of the three orders. Although the Dysideidae have a reticulate skeleton and were classified in the order Dictyoceratida, they are actually closer to the Aplysillidae (Dendroceratida) than to dictyoceratids. The anatomy and cytology of the Halisarcidae differ profoundly from those of these three orders and are clearly more closely related to nonkeratose sponges. Some changes in classification lead to a pattern with highly homogeneous orders that clearly differ in their anatomic and cytologic features, which does not support the hypothesis of a common origin of the “keratose” sponges.
    Additional Material: 20 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1052010203
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    Lungs of Polypterus and Erpetoichthys (1989)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 201 (1989), S. 161-178 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The wall of the asymmetrical saclike lungs of the fishes Polypterus and Erpetoichthys consists of several functionally different tissue layers. Their lumen is lined by a surface epithelium composed of (1) highly attenuated cells, termed pneumocytes I; (2) pneumocytes II with lamellar bodies, presumably indicating surfactant production; (3) mucous cells; and (4) ciliated cells. Underlying the pneumocytes I is a dense capillary net. The thin continuous endothelium of this net, together with the pneumocytes I, constitute the very thin blood-air barrier. The basement membrane of epithelium and endothelium fuse in the area of the blood-air barrier (thickness 210 m̈m). Secretory and ciliary cells form longitudinal rows in the epithelium. Below the zone with a gas-exchanging tissue, a layer of connective tissue containing collagen and special elastic fibers occurs. The blood vessels that give rise to or drain the superficial capillary plexus are located in this connective tissue. The outermost layer of the lung consists of muscle cells, a narrow inner zone with smooth muscle cells, and an outer, broader zone with cross-striated muscle cells. The lung is innervated by myelinated and nonmyelinated nerve fibers. The morphology of the gas-exchange tissue in the lungs of these primitive bony fish is fundamentally very similar to that of the lungs of tetrapod vertebrates. The morphologic observations are in close agreement with physiologic data, disclosing well-developed respiratory capacities. Structural simplicity can be regarded as a model from which the lungs of the higher vertebrates derived. In addition to respiratory function, the lungs seem also to have hydrostatic tasks.
    Additional Material: 20 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1052010206
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  • 188
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    Failure to turn eggs during incubation: Development of the area vasculosa and embryonic growth (1989)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 201 (1989), S. 179-186 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Effect of turning of the egg during incubation on development of the area vasculosa of the chick embryo was investigated. The size of the area vasculosa was determined by two methods: direct measurement with calipers and measurement of a template cut from the eggshell by use of an automatic surface area recorder. The effects of turning and additionally the effects of lowered temperature (36°C) on both growth of the area vasculosa by day 7 and embryo growth by day 14 of incubation were investigated. The effects of turning during a critical period for turning, from 3 to 7 days of incubation, were also recorded. Generally, failure to turn eggs retarded growth of the area vasculosa. Turning during the critical period stimulated the extent of growth of the area vasculosa by day 7 of incubation and of subsequent embryonic growth by day 14. Incubation at low temperature resulted both in reduced expansion of the area vasculosa and retarded embryonic growth in a pattern similar to that observed for unturned eggs. It is suggested that turning stimulates development of blood vessels in the area vasculosa via localized increases in blood pressure. The effect of a reduced area vasculosa is considered to retard embryonic development through restricted nutrient uptake from the yolk. The prevailing hypothesis that turning prevents deleterious membrane adhesions is questioned in light of these observations. It is suggested that the physiological basis for the need for turning lies in maximizing the growth rate of the area vasculosa to maximize yolk use and embryonic growth rate.
    Additional Material: 6 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1052010207
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  • 189
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    Analysis of the endocardium and cardiac jelly in truncal development in the cardiac lethal mutant axolotl Ambystoma mexicanum (1989)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 200 (1989), S. 123-130 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Recessive mutant gene c in axolotls results in a failure of the heart to function because of abnormal embryonic induction processes. The myocardium in this mutant lacks organized sarcomeric myofibrils. The present study was undertaken to determine if developmental abnormalities were evident in other areas of the heart besides the myocardium. A detailed comparative survey of the structure of developing normal and mutant hearts, including the endocardium, its cellular derivatives, and the extracellular matrix, known as cardiac jelly, showed that in the mutant there are fewer than the normal number of endocardial cells lining the heart lumen, the number of mesenchyme cells is reduced, and the cardiac jelly area is greatly enlarged in the posterior part of the truncus adjacent to the ventricle.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1052000202
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  • 190
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    Chemical access to the vomeronasal organs of a plethodontid salamander (1989)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 200 (1989), S. 163-174 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Plethodontid salamanders have unique nasolabial grooves that may function as “capillary tubes” to convey chemicals to the vomeronasal organ when these animals nose-tap. 3H-proline was placed at the base of these grooves in Plethodon cinereus, and autoradiography revealed large concentrations of radioactive material in the vomeronasal organs. There was no significant accumulation of radioactive material in the main olfactory epithelium. Salamanders with blocked nasolabial grooves lacked significant accumulation of material in their nasolabial grooves or vomeronasal epithelia, although some salamanders had radioactive material in the posterior portion of their vomeronasal organ that had entered through the internal nares. Anteriorly placed vomeronasal organs situated adjacent to the posterior limits of the nasolabial grooves may insure that nose-tapping primarily stimulates the vomeronasal sensory epithelium.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1052000206
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  • 191
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    Masthead (1989)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 200 (1989) 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1052000301
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  • 192
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    Functional morphology of the pharyngeal jaw apparatus in perciform fishes: An experimental analysis of the haemulidae (1989)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 200 (1989), S. 231-245 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A new mechanical model for function of the pharyngeal jaw apparatus in generalized perciform fishes is developed from work with the family Haemulidae. The model is based on anatomical observations, patterns of muscle activity during feeding (electromyography), and the actions of directly stimulated muscles. The primary working stroke of the pharyngeal apparatus involves simultaneous upper jaw depression and retraction against a stabilized and elevating lower jaw. The working stroke is characterized by overlapping activity in most branchial muscles and is resolved into three phases. Four muscles (obliquus dorsalis 3, levator posterior, levator externus 3/4, and obliquus posterior) that act to depress the upper jaws become active in the first phase. Next, the retractor dorsalis, the only upper jaw retracting muscle, becomes active. Finally, there is activity in several muscles (transversus ventrales, pharyngocleithralis externus, pharyngohyoideus, and protractor pectoralis) that attach to the lower jaws. The combined effect of these muscles is to elevate and stabilize the lower jaws against the depressing and retracting upper jaws.The model identifies a novel mechanism of upper jaw depression, here proposed to be the primary component of the perciform pharyngeal jaw bite. The key to this mechanism is the joint between the epibranchial and toothed pharyngobranchial of arches 3 and 4. Dorsal rotation of epibranchials 3 and 4 about the insertion of the obliquus posterior depresses the lateral border of pharyngobranchials 3 and 4 (upper jaw). The obliquus dorsalis 3 muscle crosses the epibranchial-pharyngo-branchial joint in arches 3 and 4, and several additional muscles effect epibranchial rotation. Five upper jaw muscles cause upper jaw depression upon electrical stimulation: the obliquus dorsalis 3, levator posterior, levator externus 3/4, obliquus posterior, and transversus dorsalis. This result directly contradicts previous interpretations of function for the first three muscles. The presence of strong depression of the upper pharyngeal jaws explains the ability of many generalized perciform fishes to crush hard prey in their pharyngeal apparatus.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1052000302
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  • 193
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    Allometric changes during growth and reproduction in Eleutheria dichotoma (hydrozoa, athecata) and the problem of estimating body size in a microscopic animal (1989)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 200 (1989), S. 255-267 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Changes in body morphology during growth and reproduction in the hydromedusa Eleutheria dichotoma are described in terms of variations in eight different characters: umbrella diameter, total surface area, tentacle area, umbrella area, tentacle knob diameter, number of embryos, and diameter and area of buds. Sexually (sex) and vegetatively (veg) reproducing medusae differ significantly in their body morphometrics. Statistically significant allometric relations exist between umbrella diameter and (1) central area (sex and veg); (2) tentacle area (veg); (3) total area (veg); (4) tentacle knob diameter (veg); (5) bud diameter; and (6) number of embryos. A significant correlation between umbrella diameter and area is also found in undetached buds. During sexual reproduction, umbrella area shows positive allometry and loses its correlations to total area, tentacle area, and tentacle knob diameter. Linear and nonlinear bivariate allometric coefficients allow estimation of total body size from only one or two easily measurable attributes, e.g., umbrella and tentacle knob diameter. Curve fitting by the classic allometric equation (y = bxc) is only negligibly worse than that obtained with a “full” equation (y = a + c), and statistical confidence is better.Chemical analyses for carbon and nitrogen content allow estimation of biomass from the projection area of the body surface. The relation factors are 1.06 μgC mm-2 (sex) and 1.14 μgC mm-2 (veg) for carbon and 0.293 μgN mm-2 (sex) and 0.287 μgN mm-2 (veg) for nitrogen. The C:N ratios are 3.6 and 4.0 for sexual and vegetative medusae, respectively. The use of allometric regression formulas to calculate surface areas and to relate these to carbon content provides quick estimations of body size in a microscopic animal.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1052000304
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  • 194
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    Neuronal organization of the accessory olfactory bulb of the lizard Podarcis hispanica: Golgi study (1989)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 202 (1989), S. 13-28 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The neuronal organization of the accessory olfactory bulb (AOB), which receives sensory information from the vomeronasal organ, was described in a squamate reptile (Podarcis hispanica) by means of light microscopy. Using the Golgi-impregnation method, seven neuronal types could be distinguished:Periglomerular cells constitute a morphologically heterogeneous population of small neurons located between and around the glomeruli.The mitral cells are diffusely distributed in the AOB. Their cell bodies are usually located within the mitral cell layer, but some of them could be also observed in the plexiform layers. Mitral cells were classified into three subgroups on the basis of their sizes and dendritic tree morphologies. Thus, the “outer mitral cells” have the biggest cell bodies, and their distal secondary dendrites are mainly distributed rostrocaudally in the external plexiform layer. The “inner mitral cells” have large cell bodies, and their secondary dendrites are distributed dorsoventrally and are located deeper than those of the other two subgroups. The third type, the “small mitral cells,” is the smallest one among mitral cells in the AOB, and from their cell bodies, only two main dendritic trunks arise.The granule cells are composed of several categories based on their different cell body locations and dendritic tree morphologies. Thus, the “superficial granule cells” are located exclusively in the external plexiform layer and have small dendritic fields. The “middle granule cells” have fusiform cell bodies - situated in the internal plexiform layer - and present a wide dendritic projection area. Finally, the “deep granule cells” are distributed throughout the granule cell layer and include a great variety of dendritic tree morphologies.The distribution and morphological features of all neuronal types constituting the AOB of Podarcis were compared with those reported on other vertebrates. The results suggest that the lamination pattern and neuronal organization of the AOB in lizards are more similar to that of mammals than to that of the remaining vertebrates.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1052020103
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  • 195
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    Structure and development of iridescent butterfly scales: Lattices and laminae (1989)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 202 (1989), S. 69-88 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Iridescent butterfly scales are structurally colored, relying upon the interaction of light with detailed architecture to produce their color. In some iridescent scales, the reflective elements are contained within the body of the scale and come in two basic forms, lattices that produce diffraction colors (analogous to those produced by opal), and stacks of laminae that produce thin-film interference colors (analogous to those produced by soap or oil films). Both structures are remarkably complex and precise, yet each is only part of the total edifice built by the cell that makes the scale.To understand better how a cell can produce lattices or thin-film laminae, I studied the development of iridescent scales from two lycaenid butterflies. The presence of diffraction and thin-film scales in the same family (and in some cases on the same individual) suggests that the two types must be developmentally related; yet these results yield no clear explanation as to how. The diffraction lattice appears to be shaped within the boundaries of the scale cell by means of a convoluted series of membranes in which the smooth endoplasmic reticulum plays an important part. The thin-film interference laminae appear to result from the condensation of a network of filaments and tubes secreted outside the boundaries of the cell. This paper outlines the developmental histories of both types of scale and discusses the developmental implications of the mechanisms by which they form.
    Additional Material: 24 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1052020106
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  • 196
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    Structure of the stridulatory apparatus and analysis of the sound produced by Smicronyx fulvus and Smicronyx sordidus (coleoptera, curculionidae, erirrhininae, smicronychini) (1989)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 201 (1989), S. 69-84 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Wing folding spicules, elytral binding patches, and elytral locking devices of adult male and female seed weevils, Smicronyx fulvus LeConte and S. sordidus LeConte, involved in stridulation are described. Sound is produced by both sexes of the two species when the plectrum, paired conical teeth located along the anterior margin of the dorsally elevated seventh sternite, is struck against an elongate file, the pars stridens, on the under surface of the apical portion of each elytron. A second plectrum, on the sixth tergite, is well-developed in males of both species and is used by males to produce sound before and during mating.Sex-specific and species-specific differences in the sound produced is attributed to structural variation in the pars stridens and the elytra. The pars stridens determines frequencies, while the elytra may further modify the sound. The frequency range for male S. fulvus is 1,000 cycles per second (cps) through 13,000 cps and for male S. sordidus is 2,500 cps through 13,000 cps. The frequency range for female S. fulvus is 2,000 cps through 11,500 cps and for female S. sordidus is 900 cps through 11,500 cps.
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1052010107
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  • 197
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    Neuromast morphology and lateral line trunk canal ontogeny in two species of cichlids: An SEM study (1989)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 202 (1989), S. 53-68 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A study of neuromast ontogeny and lateral line canal formation in Oreochromis aureus and Cichlasoma nigrofasciatum reveals the existence of two classes of neuromasts: those that arise just before hatching (presumptive canal neuromasts, dorsal superficial neuromasts, gap neuromasts, and caudal fin neuromasts) and pairs of neuromasts that arise on each lateral line scale lateral to each canal segment at the same time as canal formation. In the anterior trunk canal segment, each presumptive canal neuromast is accompanied by a dorsoventrally oriented superficial neuromast forming an orthogonal neuromast pair. It is suggested that each of these dorsoventrally oriented superficial neuromasts is homologous to the transverse superficial neuromast row described by Münz (Zoomorphology 93:73-86, '79) in other cichlids. It is further suggested that the longitudinal lines described by Münz (Zoomorphology 93:73-86, '79) are derived from the pair of superficial neuromasts that arise during canal formation. Distinct changes in neuromast topography are documented. Neuromast formation, scale formation, and lateral line canal formation are three distinct and sequential processes. The distribution of neuromasts is correlated with myomere configuration; there is always one presumptive canal neuromast on each myomere. A single scale forms beneath each presumptive canal neuromast. Canal segment formation is initiated with the enclosure of each presumptive canal neuromast by an epithelial bridge which later ossifies. The distinction of these three processes raises questions as to the causal relationships among them.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1052020105
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  • 198
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    Sex differentiation and early gonadal development in Bombina orientalis (anura: Discoglossidae) (1989)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 199 (1989), S. 299-311 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Gonadal differentiation in premetamorphic Bombina orientalis is described and staged. The pattern of events during differentiation in Bombina differs in several respects from that previously described in other anurans. The Bombina gonad initially develops on the ventral surface of the vena cava, where there is no pre-existent somatic genital ridge prior to the arrival of the germ cells. The sexually undifferentiated gonad does not have a distinct cortex and medulla; instead, medullary cells ingress from the mesonephric blastema during sexual differentiation. Formation of a testis or an ovary appears to depend on the ability (or lack of ability) of the medulla to invade the germ cell-containing cortex. In the germ line, sexual differetiation can be recognized by a premeiotic increase in oogonial cell volume.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051990306
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  • 199
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    Lungs of the gecko Rhacodactylus leachianus (reptilia: Gekkonidae): A correlative gross anatomical and light and electron microscopic study (1989)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 199 (1989), S. 23-40 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The lungs of the New Caldeonian gecko Rhacodactylus leachianus were examined by means of gross dissection and light and electron microscopy. This tropical species, which is the largest living gecko, possesses two simple, single-chambered lungs. Right and left lungs are of similar size and shape. The lung volume (27.2 ml · 100 g-1) is similar to that of the tokay (Gekko gecko) but differs in that the gas exchange tissue is approximately homogeneously distributed, and the parenchymal units (ediculae) are very large, ∼2 mm in diameter. The parenchymal depth varies according to the location in the lung, being deepest near the middle of the lung and shallowest caudally. Scanning and transmission electron microscopy reveal an unusual distribution of ciliated cells in patches on the edicular walls as well as on the trabeculae. Secretory cell are very numerous, particularly in the bronchial epithelium, where they greatly outnumber the ciliated cells. The secretory cells form a morphological continuum characterized by small secretory droplets apically and large vacuoles basally. This continuum includes cells resembling type II pneumocytes but which are devoid of lamellar bodies. Type I pneumocytes similar to those of other reptiles cover the respiratory capillaries, where they form a thin, air-blood barrier together with the capillary endothelial cells and the fused basement laminae. The innervation, musculature, and vascular distribution in R. leachianus are also characterized. Apparent simplification of the lungs in this taxon may be related to features of its sluggish habits, whereas peculiarities of cell tissue composition may reflect demands of its mesic habitat.
    Additional Material: 18 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051990104
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  • 200
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    Masthead (1989)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 199 (1989) 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051990201
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