Acetylcholine also known as ACh refers to one (1) of the major neurotransmitters of the autonomic nervous system which is released by neurons to activate muscles and linked with memory processes that is found both in the brain and in the parasympathetic branch of the autonomic nervous system Acetylcholine is a chemical similar to an amino acid, except that the NH2 group has been replaced by an N(CH3)3 group. Acetylcholine is also known as Choline.