Along with dopamine, serotonin and norepinephrine, acetylcholine is a neural transmitter. Some substances act as mediators and others, including acetylcholine, simulate or act…ive the next nerve cell as impulses pass down the a nerve. Once it has performed this action by passing across the synapse (neural junction between two nerve cells) it is broken down by an enzyme called acetylcholine esterase into an acetyl group and choline. Acetylcholine also passes across the neural muscular junction, similar to the synapse between neurons (nerve cells) and also between nerve endings and muscle cells stimulating them and thus causing your muscles to move..
Acetylcholine is also involved in memory and learning and is in particularly short supply in people with Alzheimer's disease. A recently released drug helps Alzheimers sufferers by inhibiting the action of acetylcholine esterase. ( Full Answer )