Gamma-aminobutyric acid type A receptor alpha6beta2delta subtype (α6β2δ GABAAR)

The GABA_A receptor α6β2δ subtype is a specific heteropentameric assembly of the gamma-aminobutyric acid type A receptor, primarily localized to the extrasynaptic membranes of cerebellar granule cells [2, 9]. Unlike synaptic GABA_A receptors that mediate fast phasic inhibition, the α6β2δ subtype is characterized by high GABA affinity and slow desensitization, making it a key mediator of tonic inhibition which regulates the baseline excitability of neurons [3, 12, 13]. This subtype plays a crucial role in motor learning and the filtering of sensory information entering the cerebellum [2, 3]. Dysregulation or hypofunction of α6-containing receptors is linked to various neuropsychiatric conditions, including essential tremor, migraine, and stress-related disorders [2, 9]. Pharmacologically, these receptors are distinct because they are insensitive to classical benzodiazepines like diazepam but can be modulated by neurosteroids such as THDOC, certain pyrazoloquinolinones like CGS 9895, and the ligand Ro15-4513 [4, 11, 12]. Targeting this specific subtype offers a potential therapeutic avenue for treating cerebellar-related motor and cognitive deficits with reduced side effects compared to broad-spectrum GABAergic drugs [2, 6].

Other names

alpha6beta2delta GABA-A receptorα6β2δ GABA-A receptorExtrasynaptic alpha6-containing GABA-A receptorGABRA6-GABRB2-GABRD complex

Positive allosteric modulation or direct activation of the chloride ion channel, leading to increased chloride influx, membrane hyperpolarization, and tonic inhibition of neuronal activity [1, 3, 12].