Nicotinic acetylcholine receptor alpha-3 beta-4 (alpha3beta4 nAChR)

The alpha-3 beta-4 (alpha3beta4) nicotinic acetylcholine receptor is a pentameric ligand-gated ion channel primarily expressed in the autonomic ganglia and adrenal medulla, as well as specific brain regions such as the medial habenula and interpeduncular nucleus [1][2][3]. It consists of alpha-3 and beta-4 subunits, which assemble to form a cation-selective pore that mediates fast excitatory neurotransmission and hormone secretion, such as catecholamine release [1][4]. In the peripheral nervous system, it is frequently referred to as the 'ganglionic-type' nicotinic receptor and is essential for signal transduction from the central nervous system to the periphery [2][3]. Within the central nervous system, the alpha3beta4 subtype is implicated in reward circuits and the aversive aspects of drug withdrawal, making it a key target for anti-addiction therapies [2][3][10]. Genetic studies have linked the CHRNA3-CHRNA5-CHRNB4 gene cluster on chromosome 15q25 to nicotine dependence and an increased risk of lung cancer [9][13]. Pharmacological agents targeting this receptor include agonists like nicotine and cytisine, and antagonists like mecamylamine and 18-methoxycoronaridine [1][7]. However, therapeutic development faces challenges due to potential autonomic side effects resulting from the receptor's widespread expression in the peripheral nervous system [12].

Other names

Alpha3beta4 nicotinic receptorGanglionic nicotinic receptorGanglion-type nicotinic receptorNeuronal acetylcholine receptor subunit alpha-3/beta-4alpha3beta4 nAChR

Agonists bind to the orthosteric site to induce a conformational change that opens a cation-selective pore, leading to sodium and calcium influx and cellular depolarization; antagonists block this pore or compete for the binding site to inhibit these excitatory effects.