Search results for "ZEPA"
showing 10 items of 106 documents
Diazepam has no beneficial effects on stress-induced behavioural and endocrine changes in male tree shrews.
2000
Abstract VAN KAMPEN, M., U. SCHMITT, C. HIEMKE AND E. FUCHS. Diazepam has no beneficial effects on stress-induced behavioural and endocrine changes in male tree shrews. PHARMACOL BIOCHEM BEHAV 65 (3) 539–546, 2000.—The present study evaluated the effect of subchronic oral treatment of psychosocially stressed male tree shrews with diazepam on locomotor activity, marking behavior, avoidance behavior, and urinary cortisol and noradrenaline. To mimic a realistic situation of anxiolytic intervention, the treatment started 14 days after the beginning of psychosocial stress; at that time, the stress-induced behavioral and endocrine alterations had been established. The drug (5 mg/kg/day) was admin…
Behavioral analysis indicates benzodiazepine-tolerance mediated by the benzodiazepine binding-site at the GABA(A)-receptor.
2001
Abstract 1. GABA A -receptor induced changes in locomotion and anxiety-like behaviors were studied in rats using an open-field and an elevated plus-maze. Acute and chronic doses of the benzodiazepine diazepam without and in combination with the GABA uptake inhibitor SKF-89976A were investigated. 2. Fifty-six male rats of the strain PVG/OlaHsd (PVG; 180–200g body wt) were used to assess the influence of the benzodiazepine binding-site to the development of tolerance. Rats were divided into six groups: The first receiving saline (0.9%), the second and third diazepam (10.0 mg/kg) daily for 23 days with or without an acute challenge of 2.0 mg/kg diazepam. The fourth group received diazepam (10.…
The gamma(2)-MSH peptide mediates a central analgesic effect via a GABA-ergic mechanism that is independent from activation of melanocortin receptors.
2001
Using the latency for tail-flick after thermal stimulation we have assessed the effects of alpha-, gamma(1)- and gamma(2)-MSH on nociceptive threshold in the mice. Intracisternal injections of gamma(2)-MSH induced a distinct analgesia, while gamma(1)-MSH in the same doses gave only a minor analgesia. Intracisternal alpha-MSH instead gave a short-term hyperalgesia. The effect of gamma(2)-MSH was not blocked by any of the MC(4)/MC(3)receptor antagonist HS014, naloxone or by the prior intracisternal administrations of gamma(1)-MSH. However, the gamma(2)-MSH analgesic response was completely attenuated by treating animals with the GABA(A)antagonist bicuculline. The gamma(2)-MSH analgesic effect…
The effects of diazepam on the behavioral structure of the rat's response to pain in the hot-plate test: Anxiolysis vs. pain modulation
2011
The aim of the present study was to evaluate, by means of quantitative and multivariate analyses, the effects of diazepam on the behavioral structure of the rat's response to pain in the hot-plate test as well as whether such changes are associated with drug-induced effects on anxiety and/or nociception. To this purpose, ten groups of male Wistar rats were intraperitoneally injected with saline, diazepam (0.25, 0.5 and 2 mg/kg), FG-7142 (1, 4 and 8 mg/kg) or morphine (3, 6 and 12 mg/kg). The mean number and mean latency to first appearance were calculated for each behavioral component. In addition, multivariate cluster and adjusted residual analyses based on the elaboration of transition ma…
Neurosteroid modulation of the presynaptic NMDA receptors regulating hippocampal noradrenaline release in normal rats and those exposed prenatally to…
2003
Abstract Prenatal exposure to diazepam (DZ), a positive allosteric modulator of the γ-aminobutyric acidA (GABAA) receptor complex, exerts profound effects that become more evident during puberty and in many cases are sex-specific, suggesting that such exposure interferes with the activity of steroid hormones. Apart from their well known effects on the genome, the reduced metabolites of many steroid hormones also interact directly with membrane receptors, including those for N-methyl- d -aspartate (NMDA). In this study, we compared the effects of several neurosteroids on NMDA receptors from normal rats and those exposed in utero to DZ (1.25 mg/kg per day) from the 14th through the 20th day o…
Long-lasting handling affects behavioural reactivity in adult rats of both sexes prenatally exposed to diazepam
2001
Environmental stressors can substantially affect the adaptive response of rats to novelty in a sexually dimorphic manner. Gender-related differences are also observed in neurochemical and behavioural patterns of adult rats following prenatal exposure to diazepam (DZ). In the present study the behavioural reactivity to novelty is investigated in open field (OF) and in acoustic startle reflex (ASR) tests, in non handled (NH), short-lasting handled (SLH) and long-lasting handled (LLH) adult male and female rats prenatally exposed to DZ. A single daily s.c. injection of DZ (1.5 mg/kg) over gestation days 14-20 decreases GABA/BDZ receptor function in both sexes, as shown by the decreased electro…
Lateral differences in the GABAergic system of the rat striatum.
1985
Asymmetric differences have been found in the pre- and postsynaptic activity of the GABAergic system of the left and right striata of the rat. 3H-GABA binding shows a higher dissociation constant (KD) and a higher number of sites (Bmax) in the left striatum than in the right. Moreover, 3H-diazepam binding seems to be more extensively activated by GABA in the right striatum suggesting a more sensitive postsynaptic GABAergic activity than on the left side. However, when the presynaptic marker (GAD activity) was measured, the asymmetry was in the opposite direction. The results provide further neurochemical evidence of the functional asymmetry of the rat brain.
Modification of depressant and disinhibitory action of flurazepam during short term treatment in the rat
1972
Employing a fixed-interval schedule of reinforcement (temporal discrimination), alternated punished (fixed-ratio) and unpunished (variable-ratio) schedules of reinforcement, a Conditioned Avoidance Response, and studying its interaction with Pentobarbital on general anaesthesia, it has been shown that flurazepam hydrochloride after a single treatment induces very intense depressant effects and slight disinhibitory effects. Short term treatment at longer than daily intervals reduces the depressant effect and unmasks the disinhibitory effect. The phenomenon is probably caused by selective tolerance concerning the depressant action. The results are discussed from the point of view of the signi…
Free-choice ethanol consumption under the influence of GABAergic drugs in rats.
2002
Background: Neurobiological mechanisms leading from controlled alcohol consumption to addiction are poorly understood. Among multiple neurotransmitters γ-amino-butyric acid (GABA) is suggested to play a role. The present investigation studied effects of drugs interacting with the GABAergic system on the motivation of ethanol consumption. Methods: Fifty male PVG/OlaHsd rats were analyzed for free-choice ethanol drinking behavior without and with pre-exposure to drugs acting on the GABAergic system. For pretreatment, animals received the benzodiazepine agonists or antagonists diazepam, flumazenil, or Ro15-4513, or the GABA uptake inhibitor tiagabine via the drinking water for 4 weeks (day −21…
T-pattern analysis of diazepam-induced modifications on the temporal organization of rat behavioral response to anxiety in hole board.
2010
Rationale: By means of t-pattern analysis, it has been observed that the different events, characterizing rat behavior in hole board (HB), present close interrelationships which occur sequentially and with significant constraints on the interval lengths separating them. Objectives: The aim of present research was to study, by means of descriptive and multivariate t-pattern analyses, the effects of the reference anxiolytic drug diazepam (DZP) on temporal structure of a rat’s anxiety-related behavior in HB. Methods: Fifty-six male Wistar rats were tested for 10 min in HB. Video files, collected for each animal, were coded by means of a software coder, and event log files, generated for each s…