Gamma-aminobutyric acid type A receptor alpha-5 subunit-containing complex (α5-GABA_A receptor)

The Gamma-aminobutyric acid type A receptor alpha-5 subunit-containing complex (GABA_A receptor α5βxγ2) is a pentameric ligand-gated ion channel primarily expressed in the hippocampus and cerebral cortex (UniProt P31644). Unlike the more common α1-containing GABA_A receptors that mediate phasic inhibition, α5-containing receptors are predominantly located extrasynaptically and provide tonic inhibition, which regulates the overall excitability of neurons (PubMed: 16136038). This specific localization makes the α5 subtype a critical modulator of cognitive processes, including spatial learning and memory formation (PubMed: 11826112). In various disease states, such as Down syndrome, Alzheimer's disease, and schizophrenia, the balance of α5-mediated inhibition is often disrupted, leading to cognitive deficits (PubMed: 21447654). Therapeutic strategies focus on negative allosteric modulators (NAMs) to reduce tonic inhibition and enhance cognition, or positive allosteric modulators (PAMs) for potential antidepressant or neuroprotective effects (PubMed: 30641532). Due to its relatively restricted expression pattern compared to other GABA_A subunits, it represents a promising target for precision medicine in neuropsychiatry with a reduced risk of sedation and ataxia (PubMed: 20655487).

Other names

GABRA5-containing receptorAlpha-5 GABA-A receptorGABA(A) receptor alpha-5 subunitα5βxγ2 GABA-A receptorExtrasynaptic GABA-A receptor alpha-5

Negative allosteric modulation (NAM) to enhance cognition; Positive allosteric modulation (PAM) for antidepressant or anxiolytic effects; Agonism/Antagonism at the GABA binding site.