Neuronal nicotinic acetylcholine receptor alpha-3 beta-4 alpha-5 (alpha3beta4alpha5 nAChR)

The neuronal nicotinic acetylcholine receptor alpha-3 beta-4 alpha-5 (alpha3beta4alpha5 nAChR) is a heteropentameric ligand-gated ion channel composed of alpha-3, beta-4, and alpha-5 subunits. These receptors are predominantly expressed in the autonomic ganglia, where they mediate fast synaptic transmission, and in the medial habenula-interpeduncular nucleus (MHb-IPN) pathway of the brain, which is involved in regulating nicotine intake and withdrawal (PMID: 21414311). The alpha-5 subunit acts as an accessory subunit that significantly modifies the biophysical properties and pharmacological sensitivity of the alpha3beta4 receptor complex (PMID: 25635931). Genetic variations within the CHRNA5-CHRNA3-CHRNB4 gene cluster, particularly the rs16969968 polymorphism, are strongly linked to an increased risk of nicotine dependence and lung cancer (NCBI Gene ID: 1137). Pharmacologically, these receptors are targets for smoking cessation aids and treatments for substance use disorders, as they modulate the reward and aversion circuits associated with drug consumption. Drugs such as varenicline and cytisine act as partial agonists, while compounds like mecamylamine and 18-methoxycoronaridine function as antagonists to block the reinforcing effects of nicotine (PubChem CID: 5310966). Due to their presence in the autonomic nervous system, targeting these receptors requires careful consideration of potential cardiovascular and gastrointestinal side effects.

Other names

alpha3beta4alpha5 nAChRCHRNA3-CHRNB4-CHRNA5 complexGanglionic-type nicotinic receptoralpha3beta4* nicotinic acetylcholine receptor

Agonist, partial agonist, and non-competitive antagonist activities depending on the ligand and therapeutic intent.