asetýlkolín

Acetylcholine is a neurotransmitter, a chemical messenger that transmits signals between nerve cells and also between nerve cells and muscles. It is the primary neurotransmitter of the parasympathetic nervous system and plays a role in both the central and peripheral nervous systems.

In the peripheral nervous system, acetylcholine is crucial for muscle contraction. It is released at the neuromuscular junction, the site where a motor neuron connects with a muscle fiber, and binds to receptors on the muscle cell, triggering a cascade of events that leads to contraction. It is also involved in the function of various organs controlled by the parasympathetic nervous system, such as slowing heart rate and increasing digestion.

Within the central nervous system, acetylcholine is involved in a wide range of functions, including memory, learning, attention, and arousal. It is synthesized in specific areas of the brain and projects widely, influencing neuronal activity throughout the brain. Disruptions in acetylcholine signaling have been implicated in various neurological and psychiatric disorders, most notably Alzheimer's disease, where a significant loss of cholinergic neurons is observed. The breakdown of acetylcholine is primarily carried out by an enzyme called acetylcholinesterase.