Gamma-aminobutyric acid type A receptor (GABA₊ receptor) (GABA₊ receptor)

Gamma-aminobutyric acid type A receptors are pentameric ligand-gated ion channels that mediate most fast inhibitory neurotransmission in the vertebrate central nervous system. Upon binding of GABA, the receptor opens a central pore, primarily allowing chloride ions to flow into the neuron, which typically results in hyperpolarization of the membrane and inhibition of neuronal action potential firing. GABA₊ receptors are composed of combinatorial assemblies of subunits (α, β, γ, δ, ε, π, θ, and ρ), and their functional diversity is shaped by subunit composition. These receptors are essential for brain function, modulating anxiety, sleep, muscle tone, and are targeted by a wide range of drugs, including anxiolytics, hypnotics, anesthetics, antiepileptics, and muscle relaxants. Dysregulation of GABA₊ receptor function or expression is associated with a variety of neurological and psychiatric disorders. In addition to the nervous system, GABA₊ receptors also play roles in other tissues, such as pancreatic islets, affecting insulin secretion and cell growth.

Other names

GABA-gated chloride channelIonotropic GABA receptorGABA₊ receptorGABAergic chloride channelGABA receptor type A

Positive allosteric modulation (e.g., benzodiazepines enhance GABA effect); Direct agonism (e.g., muscimol mimics GABA); Channel blockage (e.g., picrotoxin and some convulsants block Cl⁻ influx); Negative allosteric modulation (inverse agonists, antagonists)