Gamma-aminobutyric acid type A receptor (GABAA receptor) (GABAA receptor)

The **Gamma-aminobutyric acid type A receptor (GABAA receptor)** is a pentameric ligand-gated chloride ion channel that mediates the major form of fast inhibitory neurotransmission in the central nervous system. It is composed of five subunits, often two α, two β, and one γ, drawn from 19 possible gene products, resulting in a range of receptor subtypes with distinct regional and pharmacological profiles[1][2][5]. GABAA receptors have a central chloride-conducting pore that is gated by the binding of the endogenous neurotransmitter GABA. For benzodiazepine sensitivity, the receptor must contain both an α and a γ subunit, with the benzodiazepine binding site located at their interface[2][5]. Benzodiazepines and related compounds act as positive allosteric modulators, increasing the frequency of chloride channel opening and thereby enhancing neuronal inhibition[2][5]. Dysfunction of GABAA receptor activity is implicated in several neuropsychiatric and neurological disorders, forming the basis for the therapeutic action of benzodiazepines, barbiturates, Z-drugs, some anesthetics, and other CNS depressants[1][2][5]. Extensive diversity in subunit composition confers distinct pharmacological properties to different GABAA receptor subtypes, accounting for drug selectivity and variable biological effects, including anxiolysis, sedation, anticonvulsant activity, and muscle relaxation[2][5].

Other names

GABAA-benzodiazepine receptorbenzodiazepine receptorGABA-benzodiazepine receptor complexGABA-A receptorGABA receptor subtype A

Positive allosteric modulation of receptor (benzodiazepines, Z-drugs, neurosteroids, some anesthetics); Agonism at GABA binding site (agonists, e.g., muscimol); Antagonism at benzodiazepine site (e.g., flumazenil); Channel openers (modulators increase chloride influx); Negative allosteric modulation (some compounds)