Author: Ms. Shikha Singh
Volume: 01
First Online: 31 August 2024
Pages: 102-117
DOI:

Cholinergic neurotransmitters, primarily acetylcholine (ACh), play crucial roles in the peripheral and central nervous systems. The biosynthesis of acetylcholine occurs in the nerve terminals, where choline is acetylated by the enzyme choline acetyltransferase, using acetyl-CoA as the acetyl donor. Once synthesized, acetylcholine is stored in vesicles and released into the synaptic cleft upon nerve stimulation. The catabolism of acetylcholine is rapid and is primarily carried out by the enzyme acetylcholinesterase, which hydrolyzes ACh into choline and acetate. This breakdown is essential for terminating the neurotransmitter’s action and allowing the nerve cell to reset for the next signal. Cholinergic receptors are classified into muscarinic and nicotinic receptors based on their response to muscarine and nicotine, respectively. Muscarinic receptors are G-proteincoupled receptors found in various tissues, including the heart, smooth muscles, and glands, where they mediate parasympathetic nervous system effects. Nicotinic receptors are ion channel receptors located at neuromuscular junctions, autonomic ganglia, and the central nervous system, playing a critical role in muscle contraction and synaptic transmission. The distribution and function of these receptors highlight the diverse physiological roles of acetylcholine in the body.