Gamma-aminobutyric acid type A receptor alpha 2 and alpha 4 subunits (GABA-A receptor α2/α4)

Gamma-aminobutyric acid type A (GABA-A) receptors containing α2 and α4 subunits are ligand-gated chloride channels that play distinct yet complementary roles in regulating neuronal excitability within the central nervous system. The α2 subunit is primarily associated with synaptic receptors that mediate phasic inhibition and is a key target for the anxiolytic and anticonvulsant effects of benzodiazepines (UniProt P47869; PubMed: 11489443). In contrast, the α4 subunit is typically found in extrasynaptic receptors, often paired with the δ subunit, where it mediates tonic inhibition and is generally insensitive to classical benzodiazepines (UniProt P48067; PubMed: 15711585). Both subunits are implicated in the pathophysiology of conditions such as epilepsy, anxiety, and alcohol use disorder, making them significant targets for therapeutic intervention (PubMed: 22403125). Drugs interacting with these subtypes include non-selective benzodiazepines like diazepam (for α2), neurosteroids like brexanolone (for both), and selective modulators like gaboxadol (for α4) (StatPearls: Benzodiazepines; NIH: Ganaxolone). A major goal in drug development is to selectively target these subunits to achieve therapeutic benefits while avoiding the sedation and abuse liability associated with α1-containing receptors.

Other names

GABRA2GABRA4GABA-A receptor alpha 2GABA-A receptor alpha 4GABA(A) receptor subunit alpha-2GABA(A) receptor subunit alpha-4GABA receptor alpha 2/4

Positive allosteric modulation of the GABA-A receptor complex, which increases chloride ion influx upon GABA binding, leading to neuronal hyperpolarization and reduced excitability.