Parasympathetic cholinergic system

The parasympathetic cholinergic system is a major division of the autonomic nervous system that uses acetylcholine (ACh) as its primary neurotransmitter to mediate rest and digest activities (StatPearls, 2023 [1]). It comprises preganglionic neurons originating in the brainstem and sacral spinal cord, which synapse onto postganglionic neurons located near or within target organs (NCBI, 2022 [2]). Signaling is mediated by two main receptor types: nicotinic acetylcholine receptors (nAChRs), which are ligand-gated ion channels, and muscarinic acetylcholine receptors (mAChRs), which are G protein-coupled receptors (PubMed, 2021 [3]). This system regulates vital functions such as slowing heart rate, increasing gastrointestinal motility, and stimulating glandular secretions (Wikipedia, 2024 [4]). Pathological states associated with this system include Alzheimer's disease, characterized by cholinergic deficit, and various autonomic dysfunctions (NIH, 2023 [5]). Therapeutic strategies target this system using acetylcholinesterase inhibitors, muscarinic agonists, or antagonists to treat conditions like glaucoma, overactive bladder, and cognitive decline (PubChem, 2024 [6]).

Other names

Cholinergic systemParasympathetic nervous system (cholinergic component)Cholinergic signaling pathwayMuscarinic-nicotinic system

Drugs targeting this system act by either mimicking acetylcholine (agonists), blocking its receptors (antagonists), or inhibiting the enzyme acetylcholinesterase (AChE) to prevent the breakdown of acetylcholine, thereby increasing its concentration and duration of action at the synaptic cleft (StatPearls, 2023 [1]).