[3H]-GABA Binding to GABAA and GABAB Sites on Rat Brain Crude Synaptic Membranes

GABA (γ-aminobutyric acid) is the main inhibitory neurotransmitter in the central nervous system and acts on three pharmacologically distinct receptors: GABA_A , GABA_B , and GABA_C . GABA_A receptors are pharmacologically defined on the basis of antagonism by bicuculline and insensitivity to the GABA-analog baclofen, whereas GABA_B receptors are stimulated by baclofen and are insensitive to bicuculline; GABA_C receptors are insensitive to both (1 ).