Search results for "GABA"
showing 10 items of 390 documents
Modulation of in vivo GABA-evoked responses by nitric oxide-active compounds in the globus pallidus of rat.
2012
Nitric oxide (NO) is a gaseous molecule acting as a messenger in both the peripheral and the central nervous systems. NO affects synaptic activity by modulating neurotransmitter release and/or receptor function. We previously observed that NO-active compounds modify the bioelectric activity of basal ganglia (BG) units. In this study, we applied microiontophoresis to extracellular in vivo recordings to investigate the effect of NO-active compounds on GABA-evoked responses in the globus pallidus (GP) of anesthetized rats. The changes induced by NO-active drugs on the GABA-induced inhibition were used as indicators of NO modulation. The response to GABA release was tested on recorded GP neuron…
Effects of desipramine and alprazolam in the forced swim test in rats after long-lasting termination of chronic exposure to picrotoxin and pentylenet…
1993
Abstract Rats were treated for 5 weeks with three subconvulsant doses of picrotoxin (PTX) and pentylenetetrazol (PTZ) per week to induce a persistent reduction of the GABA A receptor function which results in chemical kindling. Fifteen days after termination of this treatment schedule, the effect of desipramine (DMI) and alpraxolam (ALP) on immobility time in the forced swim test (FST) was evaluated. Chronic PTX and PTZ did not alter the immobility time. Acute PTX and PTZ reduced the immobility of rats chronically treated with vehicle but not of those exposed chronically to PTX and PTZ. Chronic PTX did not influence the anti-immobility effect of DMI, but blocked that of ALP. Chronic PTZ mar…
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…
Brain-Derived Neurotrophic Factor But Not Forced Arm Use Improves Long-Term Outcome After Photothrombotic Stroke and Transiently Upregulates Binding …
2008
Background and Purpose— Both application of neurotrophic factors like brain-derived neurotrophic factor (BDNF) and constraint-induced movement therapy like forced arm use have been shown to potentially improve outcome after stroke. The aim of the present study was to check whether postischemic long-term outcome correlates to specific modifications in the abundance of various neurotransmitter receptors. Methods— Adult male Wistar rats were subjected to photothrombotic ischemia and assigned to various treatment groups (n=5 each) with end points at 3 and 6 weeks: (1) ischemic control (saline); (2) BDNF (ischemia, 20 μg BDNF); (3) forced arm use (ischemia, saline, and ipsilateral plaster cast …
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.
Role(s) of the 5-HT2C receptor in the development of maximal dentate activation in the hippocampus of anesthetized rats.
2014
Aims: Substantial evidence indicates that 5-HT2C receptors are involved in the control of neuronal network excitability and in seizure pathophysiology. Here, we have addressed the relatively unexplored relationship between temporal lobe epilepsy (TLE), the most frequent type of intractable epilepsy, and 5-HT2CRs. Methods: In this study, we investigated this issue using a model of partial complex (limbic) seizures in urethane-anesthetized rat, based on the phenomenon of maximal dentate activation (MDA) using 5-HT2C compounds, electrophysiology, immunohistochemistry, and western blotting techniques. Results: The 5-HT2C agonists mCPP (1 mg/kg, i.p) and lorcaserin (3 mg/kg, i.p), but not RO60-0…
Effects of the benzodiazepine inverse agonist FG7142 on the structure of anxiety-related behavior of male Wistar rats tested in hole board
2016
Little is known about the structural characteristics of the behavior of rats with enhanced anxiety level. To fill this gap, a study was undertaken where effects of an anxiogenic drug were examined on behavioral structure of rats tested in hole board.This study investigates effects of increased anxiety level on the structure of the behavior of rats tested in hole board METHODS: Different doses of FG7142 (1, 4, 8 mg/kg IP), a potent anxiety-inducing drug, were administered to three groups of male Wistar rats. A further group was administered saline. Experiments were recorded through a digital camera. Quantitative and multivariate approaches were applied.Percent distributions and durations sho…
Interaction Between Uridine and GABA-Mediated Inhibitory Transmission: Studies In Vivo and In Vitro
1985
Na+-independent [3H]gamma-aminobutyric acid (GABA) binding to membrane preparations from frontal cortex, hippocampus, and thalamus is competitively inhibited by the in vitro addition of a naturally occurring pyrimidinic compound, uridine. Moreover, the intraperitoneal injection of uridine produces a dose-related decrease in the cerebellar content of cyclic GMP and antagonizes its increase elicited by bicuculline. The pyrimidinic compound also shows an antagonism toward bicuculline-induced seizures. The relationship between the anti-convulsant actions of uridine and GABA-mediated inhibitory neurotransmission is discussed in terms of an activation of GABA receptor function by the naturally oc…
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…
Short-term adaptation of conditioned fear responses through endocannabinoid signaling in the central amygdala
2010
International audience; Both, the cannabinoid receptor type 1 (CB1) and the central nucleus of the amygdala (CeA) are known to play crucial roles in the processing of fear and anxiety, whereby they appear to be especially involved in the control of fear states. However, in contrast to many other brain regions including the cortical subregions of the amygdala, the existence of CB1 in the CeA remains enigmatic. Here we show that CB1 is expressed in the CeA of mice and that CB1 in the CeA mediates short-term synaptic plasticity, namely depolarization-induced suppression of excitation (DSE) and inhibition (DSI). Moreover, the CB1 antagonist AM251 increased both excitatory and inhibitory postsyn…