Physiology, Cholinergic Receptors

Excerpt

Cholinergic receptors function in signal transduction of the somatic and autonomic nervous systems. The receptors are named because they become activated by the ligand acetylcholine. These receptors subdivide into nicotinic and muscarinic receptors, which are named secondary to separate activating ligands that contributed to their study. Nicotinic receptors are responsive to the agonist nicotine, while muscarinic receptors are responsive to muscarine.

The two receptors differ in function as ionotropic ligand-gated and G-protein coupled receptors, respectively. Nicotinic receptors function within the central nervous system and at the neuromuscular junction. While muscarinic receptors function in both the peripheral and central nervous systems, mediating innervation to visceral organs. The difference in signal transduction of the two receptor types confers separate physiological functions upon receptor activation. Furthermore, differences in receptor subtypes create unique implications for pharmacologic targets and pathogenesis of the disease.