The GABA_A receptor is a pentameric, membrane-spanning ligand-gated chloride channel with distinct binding sites for different drug classes, and receptor subtype distribution across brain regions (cortex, thalamus, limbic system) determines the physiological effects produced. Benzodiazepines act as positive allosteric modulators, binding at the interface between the alpha and gamma subunits to increase the frequency of channel opening (rather than duration or conductance), thereby potentiating GABA-mediated chloride influx and neuronal inhibition. This mechanism underlies benzodiazepine pharmacology in psychopharmacology/pharmacology, distinguishing it from other GABAergic modulators such as barbiturates, which act at a separate transmembrane site on the alpha subunit.
The GABA_A receptor is a pentameric, membrane-spanning ligand-gated chloride channel with distinct binding sites for different drug classes, and receptor subtype distribution across brain regions (co…