Gamma-aminobutyric acid type A receptor alpha-2 beta-2 gamma-2 (GABA_A receptor α2β2γ2)

The GABA_A receptor α2β2γ2 is a heteropentameric ligand-gated ion channel that serves as a primary mediator of fast inhibitory neurotransmission in the central nervous system [1, 2]. Composed of two α2, two β2, and one γ2 subunits, this specific receptor subtype is predominantly localized in the limbic system, hippocampus, and cerebral cortex [2, 4]. It functions by conducting chloride ions into the neuron upon binding of the neurotransmitter gamma-aminobutyric acid (GABA), leading to membrane hyperpolarization and reduced neuronal excitability [2, 13]. The α2 subunit within this complex is critically linked to the anxiolytic, antidepressant, and muscle-relaxant effects of benzodiazepines, distinguishing it from α1-containing receptors which primarily mediate sedation [4, 7]. Consequently, the α2β2γ2 receptor is a major therapeutic target for treating anxiety disorders, epilepsy, and chronic pain [4, 9]. Pharmacological modulation typically involves positive allosteric modulators like benzodiazepines, which bind at the α/γ subunit interface to enhance GABA's inhibitory action [1, 10]. Dysregulation of this receptor is implicated in the pathogenesis of schizophrenia, alcohol dependence, and various mood disorders [4, 12].

Other names

GABRA2/GABRB2/GABRG2 complex [4]α2β2γ2 GABA-A receptor [1]GABA(A) receptor subunit alpha-2/beta-2/gamma-2 [2]Alpha-2-containing GABA-A receptor [4]

Positive allosteric modulation (PAM) of the GABA_A receptor complex [1, 10]. Drugs like benzodiazepines bind to the extracellular α+γ2− interface, increasing the receptor's affinity for GABA and the frequency of chloride channel opening [1, 2]. This results in an increased influx of chloride ions, causing membrane hyperpolarization and a reduction in neuronal firing [13, 14].