Acetylcholine acts on m2-muscarinic receptors to excite rat locus coeruleus neurones.
Intracellular recordings were made from neurones of the rat locus coeruleus in vitro. Acetylcholine increased the firing rate by depolarizing the membrane; both muscarinic and nicotinic antagonists partially reduced this effect. In hexamethonium, pirenzepine shifted the acetylcholine dose-response curve to the right with an equilibrium dissociation constant of 200 nM, indicating an interaction with a m2-type of muscarinic receptor.
D000109:Acetylcholine / Q000494:pharmacology*; D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D001570:Benzodiazepinones / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D006584:Hexamethonium Compounds / Q000494:pharmacology; D008125:Locus Coeruleus / Q000166:cytology*; D009474:Neurons / Q000187:drug effects*; D010095:Oxotremorine / Q000494:pharmacology; D010890:Pirenzepine; D051381:Rats; D011976:Receptors, Muscarinic / Q000187:drug effects*; D012601:Scopolamine / Q000494:pharmacology
D001570:Benzodiazepinones; D006584:Hexamethonium Compounds; D011976:Receptors, Muscarinic; D010890:Pirenzepine; D010095:Oxotremorine; D001285:Atropine; D012601:Scopolamine; D000109:Acetylcholine