An integral membrane ion channel in the postsynaptic membrane that opens when it binds acetylcholine. The nicotinic acetylcholine receptor, which is blocked by nicotine, initiates muscle contraction at the neuromuscular junction. The channel is a heteropentamer of related subunits with both the acetylcholine binding site and the ionic channel. The nAChR mediates rapid transduction events (1 ms), unlike G-protein-coupled receptors which operate on millisecond to second time scales. Mutations in various of the subunits cause congenital myasthenic syndrome with either fast or slow channels being affected according to which subunit is affected. See also myasthenia gravis.
Subjects: Medicine and Health.