Acetylcholine

Acetylcholine, an acetyl ester of choline found in the body of a vertebrate animal that functions as a neurotransmitter, conducting electrical impulses across synapses between nerve cells, and from nerve cells to muscle cells, causing the muscle cells to contract. The effect of acetylcholine is then hydrolysed by an enzyme called cholinesterase, which is found in the synaptic cleft. Acetylcholine acts on target cells via two distinct groups of receptors: muscarinic and nicotinic.

See Brain; Neurophysiology.