Nicotinic acetylcholine receptor (autonomic ganglia subtype) (nAChR (α3β4 subtype))

The **nicotinic acetylcholine receptor of the autonomic ganglia** is a pentameric ligand-gated ion channel primarily composed of α3 and β4 subunits. It mediates fast synaptic transmission at the interface between preganglionic and postganglionic neurons within both sympathetic and parasympathetic branches of the peripheral nervous system. Upon binding two molecules of acetylcholine released from preganglionic fibers, this receptor undergoes a conformational change that opens its central pore—allowing sodium influx and potassium efflux—which depolarizes the postsynaptic neuron to propagate neural signals. The α3β4 subtype is highly expressed in autonomic ganglia but also found in certain brain regions involved in reward circuitry. This makes it a therapeutic target for conditions involving dysregulation of autonomic function or addiction. Pharmacologically, it can be modulated by agonists that mimic ACh or antagonists such as mecamylamine or hexamethonium that block signal transduction through these channels. Because these receptors are essential for normal involuntary bodily functions regulated by the ANS—including cardiovascular tone—broad inhibition leads to significant safety concerns related to loss of homeostatic control over multiple organ systems[1][2][3][4].

Other names

Autonomic ganglia nicotinic acetylcholine receptorα3β4 nicotinic acetylcholine receptorNeuronal nicotinic acetylcholine receptor (autonomic ganglia)Ganglionic nAChR

Agonists bind to the extracellular domain, causing conformational change and opening the cation channel for Na⁺ and K⁺ ions. Antagonists block ACh binding or stabilize closed/desensitized states, inhibiting synaptic transmission.