Muscarinic Acetylcholine Receptors Subtypes M1–M5 in the Somatic Muscles of Earthworm Lumbricus terrestris

Abstract—: This paper reports an immunofluorescence confocal microscopy study of the presence and distribution of muscarinic acetylcholine receptor subtypes M1–M5 family in somatic muscle cells and cholinergic synapses of the body wall of the earthworm Lumbricus terrestris. It has been demonstrated that all subtypes of receptors have uneven distribution patterns in the extrasynaptic zones of muscle cells and are also present in the end plate zones. Receptors belonging to subtypes М2–М5, but not to the M1 subtype, can be detected also in the presynaptic membranes of motor nerve terminals. © 2022, Pleiades Publishing, Ltd.