Gamma-aminobutyric acid type A receptor alpha6beta3delta subtype (α6β3δ GABA_A receptor)

The GABA_A receptor alpha6beta3delta subtype is a specific heteropentameric ligand-gated ion channel primarily located extrasynaptically in the cerebellar granule cells and trigeminal ganglia. Unlike the more common synaptic GABA_A receptors that mediate phasic inhibition, this subtype is responsible for tonic inhibition, providing a persistent inhibitory current that regulates the baseline excitability of neurons and enhances the signal-to-noise ratio in sensory processing. It is structurally distinct due to the presence of the alpha6 and delta subunits, which render it insensitive to classical benzodiazepines like diazepam but highly sensitive to neurosteroids and specific agonists like gaboxadol. This receptor subtype plays a significant role in motor control and sensory transmission, making it a promising therapeutic target for neurological conditions such as essential tremor, tinnitus, and trigeminal neuralgia. Research into selective positive allosteric modulators of this subtype aims to provide relief for these disorders without the sedative and cognitive side effects associated with non-selective GABAergic drugs.

Other names

alpha6beta3delta GABA_A receptorGABRA6-GABRB3-GABRD receptor complexExtrasynaptic alpha6-containing GABA_A receptorGABA(A) receptor alpha6beta3delta subtype

Positive allosteric modulation or direct activation of the chloride ion channel, leading to increased chloride influx, neuronal hyperpolarization, and enhanced tonic inhibition.