Gamma-aminobutyric acid type A receptor alpha-2 beta-gamma-2 subtype (GABA_A receptor alpha2 subtype)

The Gamma-aminobutyric acid type A (GABA_A) receptor alpha-2 beta-gamma-2 subtype is a heteropentameric ligand-gated ion channel that serves as a primary mediator of fast inhibitory neurotransmission in the central nervous system [2, 17, 18]. It is typically composed of two alpha-2 subunits, two beta subunits (most commonly beta-2 or beta-3), and one gamma-2 subunit, with the benzodiazepine binding site located at the interface of the alpha and gamma subunits [6, 15, 17]. This specific subtype is highly expressed in brain regions associated with emotional regulation, such as the hippocampus and amygdala, and is functionally distinct from the more prevalent alpha-1 subtype [1, 2, 14]. While alpha-1-containing receptors primarily mediate sedation and anticonvulsant activity, the alpha-2 subtype is specifically responsible for the anxiolytic and antihyperalgesic effects of benzodiazepines [1, 2, 8]. Consequently, it is a major therapeutic target for the development of "anxioselective" drugs designed to treat generalized anxiety disorder and chronic pain without the sedative side effects or cognitive impairment associated with non-selective GABAergic modulators [3, 4, 16]. Genetic variations and dysregulation of this receptor subtype are also implicated in the pathogenesis of epilepsy, schizophrenia, and alcohol dependence [1, 2, 7, 20].

Other names

alpha2-containing GABA_A receptorGABRA2-containing GABA_A receptorGABA(A) receptor alpha2 subunit-containing subtypealpha2beta2gamma2 GABA_A receptorGABRA2/GABRB/GABRG2 receptorGABRA2-GABRB2-GABRG2 receptor

Positive allosteric modulation of the GABA_A receptor at the benzodiazepine binding site (alpha/gamma interface), increasing chloride ion conductance and inducing neuronal hyperpolarization [6, 15, 17, 18].