Acetylcholine

Acetylcholine is a neurotransmitter released at neuromuscular junctions and synapses. It activates receptors to stimulate muscle contraction and modulate neuronal excitability. In the autonomic nervous system, it mediates parasympathetic effects, while in the CNS it participates in attention, learning, and memory processes. Its name reflects its chemical origins: an acetyl group linked to choline.