Adult skeletal muscle nicotinic acetylcholine receptor (nAChR)

The adult skeletal muscle nicotinic acetylcholine receptor (nAChR) is a pentameric ligand-gated ion channel located at the postsynaptic membrane of the neuromuscular junction [1]. It is composed of five subunits: two alpha1, one beta1, one delta, and one epsilon subunit, which distinguishes it from the fetal form that contains a gamma subunit instead of the epsilon subunit [3]. The receptor's primary biological function is to mediate fast excitatory neurotransmission by converting chemical signals (acetylcholine) from motor neurons into electrical impulses (endplate potentials) that trigger muscle contraction [1, 2]. Upon binding of acetylcholine, the receptor undergoes a conformational change that opens a central pore, allowing the influx of sodium and calcium ions and the efflux of potassium ions [1]. This receptor is a major therapeutic target for neuromuscular blocking agents used in anesthesia to induce muscle relaxation [2]. It is also the primary target of autoimmune attacks in myasthenia gravis and is affected by genetic mutations in various congenital myasthenic syndromes [4].

Other names

Muscle-type nicotinic acetylcholine receptorAdult muscle nAChRCHRNA1/CHRNB1/CHRND/CHRNE complexNeuromuscular nicotinic receptorN1 acetylcholine receptor

Drugs targeting the adult skeletal muscle nAChR primarily act through competitive antagonism of acetylcholine binding or persistent agonism leading to depolarization-induced inactivation [1, 2].