Neuronal nicotinic acetylcholine receptor alpha4beta2 subunit combination (α4β2 nAChR)

The neuronal nicotinic acetylcholine receptor alpha4beta2 subtype is a pentameric ligand-gated ion channel composed primarily of alpha 4 and beta 2 subunits. It is the most abundant heteromeric nicotinic acetylcholine receptor subtype in the mammalian brain. Upon binding an agonist such as acetylcholine or nicotine, it mediates rapid cation influx across neuronal membranes, leading to depolarization and downstream signaling. The α4β2 nAChR exists in two main stoichiometries—(α4)₂(β₂)₃ and (α4)₃(β₂)₂—which differ in their pharmacological properties; notably, the 2α:3β form has higher affinity for both acetylcholine and nicotine but lower conductance than the alternative form[1][2]. This receptor plays critical roles in modulating synaptic transmission, cognitive processes such as learning and attention, reward pathways implicated in addiction biology, as well as being involved in several neuropsychiatric conditions. Drugs targeting this receptor include smoking cessation aids like varenicline that act as partial agonists at this site. Chronic exposure to nicotine upregulates its expression—a key mechanism underlying tobacco dependence—and altered levels are observed in various neurological diseases including schizophrenia and Alzheimer’s disease[1][3].

Other names

Alpha4beta2 nicotinic acetylcholine receptorα4β2 nAChRNeuronal α4β2 nicotinic receptorCHRNA4/CHNRB2 (gene-based)

Agonists bind to the orthosteric site, causing channel opening for cation influx[1][2]. Partial agonists produce submaximal activation. Antagonists block the binding site or allosterically inhibit gating.