Muscarinic receptors, or mAChRs, are G protein-coupled acetylcholine receptors found in the plasma membranes of certain neurons and other cells. They play several roles, including acting as the main end-receptor stimulated by acetylcholine released from postganglionic fibers in the parasympathetic nervous system. Muscarinic receptors were named as such because they're more sensitive to muscarine than to nicotine. Their counterparts are nicotinic acetylcholine receptors (nAChRs), receptor ion ch… (More on Muscarinic)