Acetylcholine is a neurotransmitter found in both the central nervous system and the peripheral nervous system. Acetylcholine plays an important role both in learning and memory and in sending messages from motor nerves to muscles, especially in the heart, bladder and stomach. It also affects glands. There is a marked deficiency of acetylcholine in the brains of patients with Alzheimer's Disease. Drugs with anticholinergic effects target acetylcholine receptors.