Nicotinic Acetylcholine Receptor (Muscle Type) (nAChR (muscle type))

The muscle-type nicotinic acetylcholine receptor (nAChR) is a ligand-gated ion channel found primarily at the neuromuscular junction, where it mediates synaptic transmission between motor neurons and skeletal muscle fibers. Activation of this receptor by acetylcholine leads to rapid depolarization of the postsynaptic membrane, triggering muscle contraction. The receptor is a heteropentamer composed of five subunits arranged symmetrically around a central pore. The adult form is composed of 2 α1, 1 β1, 1 δ, and 1 ε subunit while the fetal form is composed of 2 α1, 1 β1, 1 δ, and 1 γ subunit.

Other names

Muscle-type nAChRNeuromuscular nicotinic receptorAcetylcholine receptor subunit alpha-1AChR

Upon binding acetylcholine, the channel opens transiently to allow cations (Na+, K+) to flow through, resulting in an excitatory postsynaptic potential (EPSP) that can trigger an action potential in muscle fibers leading to contraction. Antagonists block acetylcholine binding or the ion channel itself, preventing depolarization and muscle contraction.