The properties of GABA receptor-mediated responses were examined in noncultured astrocytes, acutely isolated from the mature rat hippocampus. Whole-cell patch clamping revealed a GABA-activated Cl- conductance that was mimicked by the GABAA receptor agonist muscimol and depressed by the GABAA antagonists bicuculline and picrotoxin. The GABAA-activated currents were potentiated by the barbiturat...

To assess the significance of GABAA-receptor heterogeneity, which is based on a family of at least 15 subunits, the cellular localization and subunit composition of GABAA-receptor subtypes were analyzed immunohistochemically in the rat spinal cord. The distribution of subunits alpha 1, alpha 2, alpha 3, alpha 5, beta 2,3, and gamma 2 was investigated with subunit-specific antibodies, and their ...

Endogenous neurosteroids and neuroactive steroids have potent and widespread actions on the brain via inhibitory GABAA receptors. In recombinant receptors and genetic mouse models their actions depend on the α, β, and δ subunits of the receptor, especially on those that form extrasynaptic GABAA receptors responsible for non-synaptic (tonic) inhibition, but they also act on synaptically enriched...

A major challenge in understanding complex idiopathic generalized epilepsies has been the characterization of their underlying molecular genetic basis. Here, we report that genetic variation within the GABRD gene, which encodes the GABAA receptor delta subunit, affects GABA current amplitude consistent with a model of polygenic susceptibility to epilepsy in humans. We have found a GABRD Glu177A...

Sadeghi H, Taylor HS. HOXA10 regulates endometrial GABAA receptor expression and membrane translocation. Am J Physiol Endocrinol Metab 298: E889 –E893, 2010. First published January 26, 2010; doi:10.1152/ajpendo.00577.2009.—Expression of the GABAA receptor has been described previously in the human endometrium in both luminal epithelium and stroma. Its expression is increased during decidualiza...

Feng, Hua-Jun and Robert L. Macdonald. Proton modulation of 1 3 GABAA receptor channel gating and desensitization. J Neurophysiol 92: 1577–1585, 2004. First published May 19, 2004; 10.1152/jn.00285.2004. GABAA receptor currents are phasic and desensitizing, whereas GABAA receptor currents are tonic and have no fast desensitization. receptors are subsynaptic and mediate phasic inhibition, wherea...

Using human g-aminobutyric acid type A (GABAA) receptor subunit combinations, expressed in cell lines and Xenopus laevis oocytes, the pharmacology of a number of ligands interacting directly with the GABA recognition site has been studied in [H]muscimol binding and electrophysiologically. The binding affinity of GABAA agonist and antagonist ligands showed small but statistically significant dep...

The GABAA receptor 2 subunit mutation R43Q is an autosomal dominant mutation associated with childhood absence epilepsy and febrile seizures. Previously, we demonstrated that homozygous 1 3 2L(R43Q) receptor whole-cell currents had reduced amplitude with unaltered time course, suggesting reduced cell surface expression of functional receptors. In human embryonic kidney 293-T cells, we demonstra...

GABAA receptors are ligand-gated chloride ion channels that are presumed to be pentamers composed of alpha, beta, and gamma subunits. The subunit stoichiometry, however, is controversial, and the subunit arrangement presently is not known. In this study the ratio of subunits in recombinant alpha1beta3gamma2 receptors was determined in Western blots from the relative signal intensities of antibo...

Recent advances in molecular biology and complementary information derived from neuropharmacology, biochemistry and behavior have dramatically increased our understanding of various aspects of GABAA receptors. These studies have revealed that the GABAA receptor is derived from various subunits such as alpha1-alpha6, beta1-beta3, gamma1-gamma3, delta, epsilon, pi, and rho1-3. Furthermore, two ad...