Neurotransmitter of the central and peripheral nervous system especially involved in muscle contraction and attention.
Produced in cholinergic neurons by the enzyme choline acetyltransferase (ChAT), acetylcholine is synthesized from choline and acetyl-CoA (acetyl-coenzyme A). When a cholinergic neuron depolarizes, acetylcholine is released into the synapse, activates nicotinic (ionotropic) or muscarinic (metabotropic) receptors, and is rapidly hydrolyzed by acetylcholinesterase, ensuring brief and accurate transmission.
Key Physiological Roles of Acetylcholine
In the peripheral system, acetylcholine controls muscle contraction via the neuromuscular junction. In the brain, clusters of cholinergic neurons — notably in the forebrain basal and pedunculopontin nucleus — modulate attention, arousal, synaptic plasticity and certain forms of memory. Variations in cholinergic activity influence the ability to concentrate, associative learning, and sleep–wake cycle.
Pathological and therapeutic implications
Cholinergic dysfunction is implicated in many neurological diseases. Loss of cholinergic neurons is observed in Alzheimer’s disease, partly explaining memory and attentional disorders; some treatments aim to inhibit acetylcholinesterase to prolong the action of acetylcholine. In contrast, toxins (botulism) or antibodies (myasthenia) disrupt the release or receipt of acetylcholine, resulting in muscle weakness or motor dysfunction.
- Neurotransmitters :
- A neurotransmitter is a chemical molecule produced and released by a neuron that transmits messages by binding to other cells.