Nicotinic acetylcholine receptor alpha-3 beta-4 subtype (α3β4 nAChR)

The Nicotinic acetylcholine receptor alpha-3 beta-4 subtype is a pentameric ligand-gated ion channel composed primarily of α3 and β4 subunits. It is highly expressed in autonomic ganglia, where it mediates fast synaptic transmission between preganglionic and postganglionic neurons by increasing sodium and potassium permeability upon activation by acetylcholine. This subtype also appears focally within certain brain regions involved in reward processing. The α3β4 nAChR plays a critical role as a relay between central and peripheral nervous systems—especially within autonomic functions—and has been identified as an important target for developing therapies against addiction due to its involvement in drug-seeking behavior modulation. Structurally, it features a pentameric assembly with ligand-binding sites located at subunit interfaces; recent high-resolution structures have provided insight into its unique pharmacology compared to other nicotinic receptors. Pharmacologically, both endogenous neurotransmitters like acetylcholine/nicotine and various synthetic/plant-derived compounds can activate or inhibit this receptor subtype; some agents show selectivity that makes them useful research tools or potential therapeutic leads. Due to its physiological importance—particularly regarding cardiovascular regulation via autonomic control—and involvement in neuropsychiatric conditions such as addiction, it remains an active area of research both structurally and pharmacologically.

Other names

Alpha-3 beta-4 nicotinic receptorα3β4 receptorGanglion-type nicotinic receptor

Agonists bind to the extracellular ligand-binding domain at subunit interfaces to open the ion channel pore, increasing Na^+^ and K^+^ permeability across the membrane. Antagonists block this action either competitively at the binding site or noncompetitively by blocking ion flow through the open channel or allosterically modulating gating. Some drugs act as partial agonists or selective inhibitors for this subtype.