Acetylcholine is an
organic chemical that functions in the brain and body of many types of animals, including humans, as a
neurotransmitter—a chemical released by nerve cells to send signals to other cells. Its name is derived from its chemical structure: it is an
ester of
acetic acid and
choline. Parts in the body that use or are affected by acetylcholine are referred to as
cholinergic. Substances that interfere with acetylcholine activity are called
anticholinergics.