Gamma-aminobutyric acid type A receptor; Gamma-aminobutyric acid type B receptor (GABA-A receptor (for type A), GABA-B receptor (for type B))

Gamma-aminobutyric acid (GABA) receptors are the main inhibitory neurotransmitter receptors in the mammalian CNS and play critical roles in regulating neuronal excitability and synaptic transmission. There are two principal GABA receptor types: GABA-A receptor is a pentameric ligand-gated ion channel permeable to chloride ions, mediating fast synaptic inhibition in the brain. It is assembled from a large set of subunits (19 known types), enabling substantial pharmacological diversity and tissue specificity. GABA-A receptors are modulated by many clinically important drugs such as benzodiazepines, barbiturates, and anesthetics[1][7][8]. GABA-B receptor is an obligate heterodimeric G protein-coupled receptor (GPCR) consisting of GABAB1 and GABAB2 subunits. It mediates slow synaptic inhibition via G protein–dependent signaling pathways, mainly inhibiting adenylyl cyclase, reducing cAMP, and modulating ion channel activity. GABA-B receptor agonists (e.g., baclofen) are used for spasticity, and positive allosteric modulators are in development for various neurological and gastrointestinal disorders[3][5][6].

Other names

GABAA receptorGABA(A) receptorGABA_ARGABAB receptorGABA(B) receptorGABA_BR

GABA-A: Positive allosteric modulators (enhance GABAergic inhibition by increasing channel opening frequency, e.g. benzodiazepines; increase duration, e.g. barbiturates), direct agonists (e.g. muscimol), antagonists (e.g. picrotoxin), channel blockers. GABA-B: Agonists (activate G-protein signaling to inhibit neuronal activity, e.g. baclofen), positive allosteric modulators, antagonists