GABAA Receptor Benzodiazepine Site

The GABAA receptor benzodiazepine site is a specific modulatory binding site located on the GABAA receptor, a pentameric ligand-gated ion channel that mediates fast inhibitory neurotransmission in the central nervous system. This site is the primary target for benzodiazepines, a class of drugs with sedative, anxiolytic, anticonvulsant, and muscle relaxant properties. It is situated at the interface between an α (typically α1/α2/α3/α5) and γ (usually γ2) subunit in the extracellular domain. Benzodiazepines bind to this site and act as positive allosteric modulators, enhancing the effect of endogenous GABA by increasing chloride ion influx, resulting in hyperpolarization and reduced neuronal excitability. The presence of a histidine residue on the alpha subunit (e.g., His101 on α1) is crucial for high-affinity benzodiazepine binding.

Positive allosteric modulation of GABAA receptor activity, increasing chloride ion influx and neuronal inhibition.