Muscle nicotinic acetylcholine receptor (nAChR) (nAChR)

The muscle nicotinic acetylcholine receptor is a pentameric ligand-gated ion channel located on the postsynaptic membrane of the neuromuscular junction (StatPearls, 2023). In adults, it typically consists of two alpha-1, one beta-1, one delta, and one epsilon subunit, which form a central pore permeable to cations like sodium and potassium (UniProt, 2024). Upon the binding of acetylcholine released from motor neurons, the receptor undergoes a conformational change to open its channel, leading to membrane depolarization and subsequent muscle contraction (PubMed, 2022). This receptor is a critical therapeutic target for neuromuscular blocking agents used during surgical procedures to induce muscle relaxation and facilitate endotracheal intubation (StatPearls, 2023). It is also the primary target of autoimmune attack in Myasthenia Gravis, where antibodies against the receptor lead to impaired neuromuscular transmission and muscle weakness (NIH, 2023).

Other names

Muscle-type nicotinic acetylcholine receptorNeuromuscular nicotinic acetylcholine receptorAdult muscle nAChRFetal muscle nAChRAChR

Drugs targeting the muscle nicotinic acetylcholine receptor act as either depolarizing agonists, which cause persistent activation and subsequent desensitization of the receptor, or non-depolarizing competitive antagonists, which block acetylcholine from binding to the receptor, thereby preventing muscle contraction (StatPearls, 2023).