Muscarinic acetylcholine receptor

Muscarinic acetylcholine receptors, or mAChRs, are acetylcholine receptors that form G protein-receptor complexes in the cell 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.

In 2015, a large German study found 29% of ME/CFS patients had elevated autoantibodies to M3 and M4 muscarinic acetylcholine receptors, as well as ß2 adrenergic receptors.