Gamma-aminobutyric acid (GABA) is the main chemical inhibitory neurotransmitter in the brain. In the central nervous system (CNS) it acts on two distinct types of receptor: an ion channel, i.e., an "ionotropic" receptor permeable to Cl -and HCO 3 -(GABA A receptors) and a G-protein coupled "metabotropic" receptor that is linked to various effector mechanisms (GABA B receptors). This review will summarize novel developments in the physiology and pharmacology of GABA A receptors (GABA A Rs), specifically those found outside synapses. The focus will be on a particular combination of GABA A R subunits responsible for mediating tonic inhibition and sensitive to concentrations of ethanol legally considered to be sobriety impairing. Since the same receptors are also a preferred target for the metabolites of steroid hormones synthesized in the brain (neurosteroids), the ethanol-sensitive tonic inhibition may be a common pathway for interactions between the effects of alcohol and those of ovarian and stress-related neurosteroids.