Search results for "GABA"
showing 10 items of 390 documents
Phencyclidine inhibits the activity of thalamic reticular gamma-aminobutyric acidergic neurons in rat brain.
2014
Póster presentado en el IX Simposi de Neurobiologia Experimental, celebrado los días 22 y 23 de octubre de 2014 en Barcelona y organizado por la Societat Catalana de Biologia del Institut d'Estudis Catalans
Effects of 8-OH-DPAT on open field performance of young and aged rats prenatally exposed to diazepam: a tool to reveal 5-HT1A receptor function
2003
Central GABAergic and serotoninergic systems interact with one another and are implicated in controlling different behaviours. A gentle early long-lasting handling can prevent the deficits in locomotion and exploration in open field (O.F.) in 3-month-old male rats prenatally exposed to diazepam (DZ). Purpose of this study was to extend the research to older handled rats prenatally exposed to DZ and to assess the activity of 5-HT1A receptors (Rs), evaluating the performance in O.F. at 3 and 18 months of age following 8-OH-DPAT administration. A single daily s.c. injection of DZ (1.5 mg/kg) from gestation day 14 to gestation day 20 induced in aged, but not in young rats, a decrease in total d…
Organotypic rat cerebellar slice culture as a model to analyze the molecular pharmacology of GABAA receptors
2002
The preservation of the neuronal circuitry in rat cerebellar slice cultures provides an advantage in monitoring the development and characterizing the pharmacology of GABA(A) receptor subtypes. Sprague-Dawley rats, 8-11 days of age, were decapitated, their cerebella were cut into 400-microm slices and transferred into culture dishes. Cell viability and organotypic cerebellar organization of the culture remained well preserved up to 3 weeks. Autoradiographic procedures were introduced in these advanced culture technique and employed [(3)H]Ro 15-4513 in the absence and presence of 10 microM diazepam to visualize all benzodiazepine (BZD) and diazepam-insensitive (DIS) binding sites, respective…
Characterization of γ-aminobutyrate type A receptors with atypical coupling between agonist and convulsant binding sites in discrete brain regions
2001
Abstract γ-Aminobutyric acid type A (GABA A ) receptor ionophore ligand t -[ 35 S]butylbicyclophosphorothionate ([ 35 S]TBPS) was used in an autoradiographic assay on brain cryostat sections to visualize and characterize atypical GABA-insensitive [ 35 S]TBPS binding previously described in certain recombinant GABA A receptors and the cerebellar granule cell layer. Picrotoxinin-sensitive but 1-mM GABA-insensitive [ 35 S]TBPS binding was present in the rat cerebellar granule cell layer, many thalamic nuclei, subiculum and the internal rim of the cerebral cortex, amounting in these regions up to 6% of the basal binding determined in the absence of exogenous GABA. Similar binding properties wer…
Behavioral Effects of GABAA Receptor Stimulation and GABA-Transporter Inhibition
2000
Abstract The present analysis addressed behavioral changes after treatment with 4.5 mg/kg or 18.5 mg/kg of the GABA-uptake inhibitor tiagabine combined with either the benzodiazepine diazepam (1.5 mg/kg) or the imidazopyridine zolpidem (0.05 mg/kg), the latter two acting differentially on GABA A receptor subtypes. The study included 97 male PVG/OIaHsd rats. A standard open field, an enriched open field, and an elevated plus-maze was used to study rat behavior. Treatment with the low dose of tiagabine alone induced no specific behavioral effects, whereas the high dose had an anxiolytic-like potential. Furthermore, diazepam but not zolpidem displayed anxiolytic-like effects. Combination of ea…
Specific Hippocampal Interneurons Shape Consolidation of Recognition Memory
2020
Summary A complex array of inhibitory interneurons tightly controls hippocampal activity, but how such diversity specifically affects memory processes is not well understood. We find that a small subclass of type 1 cannabinoid receptor (CB1R)-expressing hippocampal interneurons determines episodic-like memory consolidation by linking dopamine D1 receptor (D1R) signaling to GABAergic transmission. Mice lacking CB1Rs in D1-positive cells (D1-CB1-KO) display impairment in long-term, but not short-term, novel object recognition memory (NOR). Re-expression of CB1Rs in hippocampal D1R-positive cells rescues this NOR deficit. Learning induces an enhancement of in vivo hippocampal long-term potenti…
Altered receptor subtypes in the forebrain of GABAA receptor δ subunit-deficient mice: recruitment of γ2 subunits
2002
A GABA(A) receptor delta subunit-deficient mouse line was created by homologous recombination in embryonic stem cells to investigate the role of the subunit in the brain GABA(A) receptors. High-affinity [(3)H]muscimol binding to GABA sites as studied by ligand autoradiography was reduced in various brain regions of delta(-/-) animals. [(3)H]Ro 15-4513 binding to benzodiazepine sites was increased in delta(-/-) animals, partly due to an increment of diazepam-insensitive receptors, indicating an augmented forebrain assembly of gamma 2 subunits with alpha 4 subunits. In the western blots of forebrain membranes of delta(-/-) animals, the level of gamma 2 subunit was increased and that of alpha …
GABA receptors are involved in the modulation of the release of 5-hydroxytryptamine from the vascularly perfused small intestine of the guinea-pig
1989
Isolated small intestinal segments of the guinea-pig were perfused arterially and the release of 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) into the portal venous effluent was determined by HPLC with electrochemical detection. Test substances were applied intraarterially. Muscimol (1 microM) time dependently first increased then decreased the release of 5-HT and 5-HIAA. The stimulatory effect was prevented by tetrodotoxin (TTx) or scopolamine, indicating that it was mediated by the release of acetylcholine. Bicuculline concentration dependently decreased (1 microM) or increased (10, 50 microM) the release of 5-HT and 5-HIAA, indicating that endogenous GABA also activ…
Pregabalin as add-on treatment to botulinum toxin in idiopathic hemifacial spasm
2007
Botulinum toxin (BTX) is the medical therapy of choice in hemifacial spasm (HFS). However, in some patients, its therapeutic effect is insufficient. ### Patient 1. A 64-year-old man with a 10-year history of left-sided HFS was treated with BTX over a period of 6 years with good results. However, in the last 2 years the spasms were never sufficiently relieved by BTX. The patient felt significantly impaired, but declined to undergo neurosurgical intervention. The EDB test showed a decrease in the CMAP amplitude of 60%. Without changing the BTX regime, pregabalin (initially 75 mg/day increased every 5 days by 75 mg to 150 mg twice daily) was added for a 1-month trial period in the absence of a…
A restricted population of CB1 cannabinoid receptors with neuroprotective activity.
2014
The CB1 cannabinoid receptor, the main molecular target of endocannabinoids and cannabis active components, is the most abundant G protein-coupled receptor in the mammalian brain. Of note, CB1 receptors are expressed at the synapses of two opposing (i.e., GABAergic/inhibitory and glutamatergic/excitatory) neuronal populations, so the activation of one and/or another receptor population may conceivably evoke different effects. Despite the widely reported neuroprotective activity of the CB1 receptor in animal models, the precise pathophysiological relevance of those two CB1 receptor pools in neurodegenerative processes is unknown. Here, we first induced excitotoxic damage in the mouse brain b…