Neuronal nicotinic acetylcholine receptor alpha-4 beta-2 (α4β2 nAChR)

The alpha-4 beta-2 (α4β2) nicotinic acetylcholine receptor is a pentameric ligand-gated ion channel primarily expressed in the central nervous system, where it serves as the high-affinity site for nicotine (UniProt P43681, P17677). It plays a pivotal role in the mesolimbic dopamine system, mediating the rewarding effects of nicotine and the release of neurotransmitters involved in mood and cognition (PubMed: 16814751). This receptor is the principal target for smoking cessation pharmacotherapies, such as varenicline, which acts as a partial agonist to alleviate withdrawal symptoms while competitively inhibiting nicotine binding (StatPearls: Varenicline). Beyond addiction, α4β2 receptors are implicated in neurodegenerative disorders like Alzheimer's and Parkinson's diseases due to their role in modulating cholinergic tone and cognitive function (IUPHAR/BPS Guide to Pharmacology). While therapeutic focus is often on the α4β2 subtype, many ligands exhibit secondary affinity for the α7 subtype or peripheral muscle-type receptors, which can influence the overall clinical and safety profile of the drug (PubMed: 21840305).

Other names

Alpha-4 beta-2 nicotinic receptorCHRNA4-CHRNB2 receptorNicotinic acetylcholine receptor alpha-4 subunit and beta-2 subunit complexNeuronal acetylcholine receptor alpha-4 beta-2nAChR alpha4beta2

Partial agonism (e.g., Varenicline) to reduce withdrawal and block nicotine reinforcement; Full agonism (e.g., Nicotine) for replacement therapy; Positive allosteric modulation (e.g., Galantamine) to enhance cholinergic signaling.