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GABA receptors are distributed widely throughout the central nervous system on a variety of cell types. It has become increasingly clear that astrocytes, both in cell culture and tissue slices, express abundant GABA_A receptors. In astrocytes, GABA activates Cl⁻specific channels that are modulated by barbiturates and benzodiazepines; however, the neuronal inverse agonist methyl4ethyl6, 7dimethoxy螃漫carboline3carboxylate enhances the current in a subpopulation of astrocytes. The properties of astrocytic GABA_A receptors, therefore, are remarkably similar to their neuronal counterparts, with only a few pharmacological exceptions. In stellate glial cells of the pituitary pars intermedia, GABA released from neuronal terminals activates postsynaptic potentials directly. The physiological significance of astrocytic GABA_Areceptor activation remains unknown, but it may be involved in extracellular ion …