Neuromuscular Junction (NMJ)

The neuromuscular junction (NMJ) is a specialized chemical synapse between a motor neuron and a muscle fiber. It is responsible for transmitting nerve impulses to muscles, enabling voluntary movement and maintaining muscle tone. It consists of a presynaptic terminal, synaptic cleft, and postsynaptic membrane (motor end plate) containing nicotinic acetylcholine receptors (nAChRs). Acetylcholine (ACh) released from the presynaptic terminal binds to nAChRs, initiating muscle contraction. Acetylcholinesterase rapidly degrades ACh to terminate the signal. The NMJ is a target for various diseases and drugs.

Other names

synapssis neuromuscularisjunctio neuromuscularisMotor end plate

The NMJ is the site where motor neuron action potentials are converted into muscle fiber contraction. Drugs can target various steps including acetylcholine release, receptor binding, or acetylcholine degradation.