Nicotinic acetylcholine receptor alpha-2 beta-2 (alpha2beta2 nAChR) (alpha2beta2 nAChR)

The Nicotinic acetylcholine receptor alpha-2 beta-2 (alpha2beta2 nAChR) is a heteromeric, ligand-gated ion channel found predominantly in the mammalian central nervous system [2, 4]. It is composed of alpha-2 (CHRNA2) and beta-2 (CHRNB2) subunits, typically forming a pentameric structure that facilitates the influx of cations like sodium and calcium upon activation by acetylcholine or nicotine [1, 11]. This receptor plays a critical role in modulating neuronal excitability and the release of various neurotransmitters, including dopamine and GABA, particularly in the forebrain and hippocampus [5, 17]. Mutations in the CHRNA2 and CHRNB2 genes are strongly associated with Autosomal Dominant Sleep-related Hypermotor Epilepsy (ADSHE), where gain-of-function mutations lead to nocturnal seizures [3, 8]. Beyond epilepsy, the alpha2beta2 subtype is a target of interest for treating nicotine addiction and cognitive impairments associated with neurodegenerative diseases like Alzheimer's [5, 14]. Pharmacological modulation of this receptor, including the use of partial agonists and positive allosteric modulators, offers a pathway for regulating sleep-related disorders and enhancing cognitive performance [7, 19].

Other names

Neuronal acetylcholine receptor subunit alpha-2/beta-2alpha2beta2 nicotinic receptorCHRNA2/CHRNB2 receptornAChR alpha2beta2CHRNA2-CHRNB2 heteromeric receptor

The alpha-2 beta-2 nicotinic acetylcholine receptor is a ligand-gated cation channel. Upon binding of an agonist such as acetylcholine or nicotine, the receptor undergoes a conformational change that opens a central pore, allowing the influx of sodium (Na+) and calcium (Ca2+) ions. This influx leads to the depolarization of the neuronal membrane, thereby increasing neuronal excitability and triggering the release of neurotransmitters such as dopamine, GABA, and glutamate [1, 9, 11].