Acetylcholine is a neurotransmitter that helps transmit nerve impulses to muscle cells, signaling them to contract. It responds to nicotine and is implicated as a factor in addiction to tobacco. Too little acetylcholine has also been suggested as a factor in the development of Alzheimer’s disease. In 1906, a German scientist named Alois Alzheimer performed the first autopsy on the brain of a person who had died from old age dementia. Dr. Alzheimer found that the patient’s acetylcholine pathways were severely damaged in what he called “tangles”, and that the patient’s brain had an excess of plaque as well. Today, Alzheimer’s patients can take three kinds of cholinesterase inhibitors that affect neurotransmission in the brain, and may slow the progression of this disease.
Chemical imbalances of acetylcholine can also contribute to the development of Parkinson’s disease. Drugs such as Tolerodine, Selective Serotonin Reuptake Inhibitors (SSRIs) and cannabinoids modify the way acetylcholine works in the body and are used in the treatment of multiple sclerosis. Acetylcholine may also play a major role in bipolar disease and the mood states of depression and mania.