Gamma-aminobutyric acid type A receptor containing delta subunit (GABA_A receptor (delta subunit-containing))

Gamma-aminobutyric acid type A receptor containing the delta subunit is a type of pentameric ligand-gated chloride channel (Cys-loop family) that mediates inhibitory neurotransmission in the central nervous system. Unlike the synaptic (gamma subunit-containing) GABA_A receptors which mediate rapid (phasic) inhibition, delta subunit-containing receptors are typically located extrasynaptically or perisynaptically and are responsible for persistent (tonic) inhibition in neurons[2][5][8]. These receptors are often composed of alpha4 or alpha6, beta2 or beta3, and delta subunits, and are highly expressed in cerebellar and hippocampal granule cells, thalamus, and cortex[5][8]. They have high sensitivity to ambient GABA levels and unique pharmacological profiles, leading to interest as therapeutic targets for neuropsychiatric disorders such as epilepsy, anxiety, sleep disorders, and pain[2][4][5]. Few drugs are selective for these receptors; gaboxadol is a known direct agonist, while neurosteroids and some anesthetics are prominent modulators[4][5][8]. Challenges for clinical development include limited subtype selectivity and concerns about side effects related to generalized CNS depression[4][5][8].

Other names

GABA_A receptor delta subunit-containingExtrasynaptic GABA_A receptorGABRD-containing GABA_A receptor

Positive allosteric modulation (e.g., neurosteroids, certain anesthetics) Direct agonism (e.g., gaboxadol) Enhancement of tonic chloride currents