Gamma-aminobutyric acid type A receptor alpha-3 subunit-containing benzodiazepine site (GABA_A receptor α3-BZD site)

The GABA_A receptor is a pentameric ligand-gated chloride channel that serves as the primary mediator of fast inhibitory neurotransmission in the mammalian central nervous system (UniProt P34903). The benzodiazepine (BZD) binding site is a distinct allosteric site located at the interface of the alpha (α) and gamma-2 (γ2) subunits, specifically requiring the presence of α1, α2, α3, or α5 subunits to be pharmacologically active (IUPHAR/BPS Guide to Pharmacology). Receptors containing the α3 subunit are highly expressed in the thalamic reticular nucleus, spinal cord dorsal horn, and brainstem, where they play a critical role in modulating anxiety, muscle tone, and the processing of nociceptive signals (Rudolph & Knoflach, 2011, Nat Rev Drug Discov). Pharmacological targeting of the α3-containing GABA_A receptor is primarily associated with anxiolytic and muscle-relaxant effects, as well as potential analgesic properties in chronic pain states. Unlike non-selective benzodiazepines that cause significant sedation via the α1 subunit, selective positive allosteric modulators of α2 and α3 subunits are being developed as 'non-sedating' anxiolytics and novel treatments for neuropathic pain (Atack, 2011, Adv Pharmacol).

Other names

GABRA3-containing GABA_A receptorAlpha-3 subunit-containing GABA_A receptorGABA(A) receptor alpha-3 subunitBenzodiazepine receptor alpha-3 subtypeα3βxγ2 GABA_A receptor

Positive allosteric modulation (PAM) of the GABA_A receptor, which enhances the inhibitory effect of GABA by increasing the frequency of chloride channel opening upon GABA binding (Sigel & Steinmann, 2012, CNS Drugs).