Kolinergic

Kolineric, or cholinergic, refers to anything related to acetylcholine, a neurotransmitter used by many neurons in both the central and peripheral nervous systems. The term is sometimes encountered in transliterations as kolinergic. Cholinergic signaling underpins a wide range of functions, from muscle contraction to attention and memory.

Biochemically, acetylcholine is synthesized from choline and acetyl-CoA by the enzyme choline acetyltransferase. It is packed into synaptic vesicles by the vesicular acetylcholine transporter and released into the synaptic cleft in response to an action potential. In the cleft, acetylcholine is rapidly degraded by acetylcholinesterase, terminating signaling, with butyrylcholinesterase providing a secondary path in some tissues. Cholinergic neurons are characterized by the enzyme ChAT and the transporter VAChT.

Cholinergic signaling occurs through two main receptor families: nicotinic receptors, which are ion channels, and muscarinic receptors, which are G protein–coupled. Nicotinic receptors mediate fast synaptic transmission at the neuromuscular junction and in the brain, while muscarinic receptors modulate slower, diverse responses in various organs and brain regions. Subtypes include M1–M5 muscarinic receptors and various nicotinic receptor subtypes.

Physiologically, cholinergic systems regulate muscle contraction, autonomic functions, arousal, learning, and memory. Clinically, disruptions are linked to conditions such as myasthenia gravis, Alzheimer’s disease, and Parkinson’s disease. Pharmacologically, cholinergic agents include agonists that mimic acetylcholine and antagonists that block receptors, as well as acetylcholinesterase inhibitors used in certain diseases and toxicology.