Of all the neurotransmitters, acetylcholine was one of the first to be discovered, possibly because it is located in the most convenient neurons for studying, located outside the brain. It is contained in the endings of the neurons that control the muscles of the skeleton. At the junctions of the nerves with the muscles, there is a space similar to a synapse, which is called a neuromuscular junction. When neurons connected to muscle fibers are excited, they release acetylcholine to the neuromuscular junction area, and the muscles contract. Acetylcholine also plays an important role in the brain, but like most other neurotransmitters, its function is not fully understood. Nevertheless, it is known that he is an important regulator of thirst. In the formation of adjectives from a neurotransmitter, the root of the word is simply taken (in this case, choline) and the suffix “ergic” is added to it. So, we call thirst cholinergic function, acetylcholine-containing neurons — cholinergic neurons, and drugs that block acetylcholine — anticholinergic drugs. Presumably, acetylcholine is also an important element of the memory system.
There is evidence that Alzheimer’s disease – progressive memory loss in old age – is associated with impaired functioning of neurons in one of the cholinergic sites. The most recent studies of Alzheimer’s disease are aimed at determining the nature of damage to these areas and developing methods for treating or preventing these injuries. In 1993, the Park-Davis Commission announced that it had received and officially approved the first drug for the treatment of Alzheimer’s disease, takrin (Sodpech), which increases the level of acetylcholine in the brain tissue. Studies of Alzheimer’s disease have provided new evidence that the cause of mental illness is a disruption in the normal functioning of neurotransmitters.