Nicotinic acetylcholine receptor α4β2 (nAChR α4β2)

Nicotinic acetylcholine receptor α4β2 is a heteropentameric ligand-gated ion channel composed primarily of two types of subunits—α4 and β2—that assemble in either 3α:2β or 2α:3β stoichiometries. It is the most abundant subtype of neuronal nicotinic receptors in the brain. The primary function is mediating fast synaptic transmission by allowing cations such as Na⁺, K⁺, and Ca²⁺ to flow into neurons upon binding acetylcholine or exogenous agonists like nicotine. This subtype plays a critical role in modulating cognitive functions such as attention, learning, memory, reward processing, and has been implicated in several neurological disorders including addiction and neurodegeneration. The high affinity for nicotine underlies its importance in tobacco dependence; partial agonists targeting this receptor are used therapeutically for smoking cessation. Structurally classified within the Cys-loop superfamily of pentameric ligand-gated ion channels, it features a characteristic extracellular ligand-binding domain at subunit interfaces where both principal (α) and complementary (β) faces contribute to pharmacology. Recent X-ray crystallography studies have provided detailed insights into its architecture—including mechanisms underlying allosteric gating—and revealed distinct conformational states associated with activation versus desensitization.[1][2][3][4]

Other names

Neuronal nicotinic acetylcholine receptor α4β2CHRNA4/CHRNB2 (gene symbols for subunits)α4β2 nAChRAlpha4Beta2 nicotinic receptor

Agonists bind at the interface between α4 and β2 subunits, causing conformational changes that open the ion channel to allow cation influx, leading to neuronal depolarization and signal transmission[1][2].