What roles do acetylcholinesterase play?

The primary role of acetylcholinesterase is to hydrolyze acetylcholine into its components - acetic acid and choline – at nerve synapses. This terminates the signal that acetylcholine produces, preventing communication between the neuron and muscle cell and resulting in the relaxation of a muscle fiber.  

Acetylcholinesterase (AChE) is a cholinergic enzyme that is primarily found at postsynaptic neuromuscular junctions, particularly in the nerves and muscles. Acetylcholine (ACh) is a naturally occurring neurotransmitter that triggers muscles to contract and promotes various bodily movements. 

When acetylcholinesterase breaks down acetylcholine in the synaptic cleft, it ends the neuronal transmission and signaling between synapses. This inhibits ACh from activating nearby receptors and inhibits excessive muscle stimulation and contraction. As a result, the muscle relaxes, preventing muscle fatigue, muscle spasms, and muscle cramps.