Benzodiazepine action

The BZ receptors form part of a GABAA receptorchloride ion channel macromolecular complex, a pentameric structure assembled from 5 subunits each with 4 transmembrane domains. A major isoform of the GABAA receptor consists of 2 α1, 2 β2, and 1 γ 2 subunits. In this isoform, the binding site for benzodiazepines is between an α1 and the γ 2 subunit. However, benzodiazepines also bind to other GABAA receptor isoforms that contain α2, α3, and α5 subunits.Binding of benzodiazepines facilitates the inhibitory actions of GABA, which are exerted through increased chloride ion conductance Benzodiazepines increase the frequency of GABA-mediated chloride ion channel opening.