Gamma-aminobutyric acid type A receptor alpha-5 beta-3 gamma-2 subtype (GABA-A receptor α5β3γ2)

The Gamma-aminobutyric acid type A receptor alpha-5 beta-3 gamma-2 subtype is a pentameric ligand-gated ion channel that serves as a primary mediator of inhibitory neurotransmission in the central nervous system. This specific subtype is highly localized in the hippocampus and cerebral cortex, where it is predominantly found in extrasynaptic locations and facilitates tonic inhibition—a persistent inhibitory current that regulates overall neuronal excitability [PMID: 22403570]. By maintaining a constant inhibitory tone, these receptors regulate the threshold for neuronal excitation and play a critical role in modulating synaptic plasticity and cognitive functions such as spatial learning and memory [PMID: 17088420]. Dysregulation of this receptor subtype is implicated in several neurological and psychiatric conditions, including Alzheimer's disease, Down syndrome, and schizophrenia, where altered GABAergic signaling contributes to cognitive impairment [PMID: 24903309]. Pharmacologically, the α5β3γ2 subtype is a significant target for the development of cognitive enhancers; negative allosteric modulators (NAMs) that selectively target the α5 subunit can enhance memory performance by reducing tonic inhibition without the seizure-inducing risks of non-selective GABA antagonists [PMID: 11511163]. Conversely, positive allosteric modulators (PAMs) are being investigated for their potential to treat conditions involving neuronal hyperexcitability or specific deficits in inhibitory control [PMID: 28843491].

Other names

GABRA5/GABRB3/GABRG2 receptorα5-containing GABA-A receptorGABA(A) receptor subunit alpha-5/beta-3/gamma-2GABRA5-GABRB3-GABRG2 complex

Positive allosteric modulation, negative allosteric modulation, and agonism at the benzodiazepine binding site located at the α5/γ2 subunit interface [PMID: 16472498]