Adult muscle-type nicotinic acetylcholine receptor (nAChR) (nAChR)

The adult muscle-type nicotinic acetylcholine receptor (nAChR) is a pentameric ligand-gated ion channel located at the postsynaptic membrane of the neuromuscular junction (StatPearls, 2023). It is specifically characterized by its subunit composition of two alpha-1, one beta-1, one delta, and one epsilon subunit, which replaces the gamma subunit found in the fetal isoform (UniProt, 2024). When the neurotransmitter acetylcholine binds to the alpha subunits, the receptor channel opens to allow the influx of sodium and calcium ions, resulting in membrane depolarization and muscle fiber contraction (PubMed, 2012). This receptor is the primary target for neuromuscular blocking agents used in clinical anesthesia to facilitate endotracheal intubation and provide muscle relaxation during surgical procedures (StatPearls, 2023). In autoimmune conditions like Myasthenia gravis, the receptor is targeted by pathogenic antibodies, leading to its degradation and impaired neuromuscular transmission (NIH, 2023). Understanding its structure and function is critical for managing neuromuscular disorders and optimizing the use of muscle relaxants in perioperative care.

Other names

Muscle-type nicotinic acetylcholine receptorNeuromuscular nicotinic acetylcholine receptorAlpha-1-beta-1-delta-epsilon nicotinic receptorCHRN receptorAChR

Competitive antagonism of acetylcholine binding sites (non-depolarizing blockade) or persistent activation leading to receptor desensitization (depolarizing blockade).