Neuronal nicotinic acetylcholine receptor subunit alpha-3 and beta-4 (α3β4 nicotinic receptor)

The neuronal nicotinic acetylcholine receptor subunit alpha-3 and beta-4 (α3β4 nicotinic receptor) forms heteropentameric ligand-gated cation channels highly expressed in autonomic ganglia and the habenulo-interpeduncular tract, where it mediates excitatory synaptic transmission through high calcium permeability and cation influx upon acetylcholine or nicotine binding. These receptors assemble with stoichiometries such as (α3)m(β4)n where m+n=5, often incorporating accessory subunits like α5, and exhibit distinct kinetics including slower inactivation compared to other subtypes like α4β2. In the autonomic nervous system, α3β4 receptors serve as the principal relay between central and peripheral neurons, regulating functions like smooth muscle contraction and neurotransmitter release. They also modulate mesolimbic dopamine pathways in reward circuits, contributing to behaviors such as drug-seeking and addiction vulnerability. Antagonists targeting α3β4 show promise as anti-addictive agents by attenuating nicotine reinforcement without broadly impacting other nicotinic receptors. Structural studies reveal agonist binding at α-β subunit interfaces, with lipid environments influencing conductance and selectivity. Therapeutic challenges include balancing efficacy against potential autonomic side effects from ganglionic blockade.

Other names

alpha-3 beta-4 nicotinic receptorα3β4 receptorganglion-type nicotinic receptorganglionic nicotinic receptor

Ligand-gated cation channel activation leading to increased Na+ and K+ permeability and postsynaptic excitation, Antagonism to inhibit receptor activity and modulate drug-seeking behavior