title: Serotonin and forskolin enhance both magnitude of contraction and relaxation rate of Aplysia dorsal extrinsic muscle independently of acetylcholine receptor.
abstract: Hexamethonium bromide (Hex. Br.) blocks acetylcholine (ACh) elicited contractions but not electrically elicited contractions of isolated preparations of Aplysia californica dorsal extrinsic muscle. Serotonin (5-hydroxytryptamine, 5-HT) enhances both magnitude and relaxation rate of ACh and electrically elicited contractions. In the presence of Hex. Br., 5-HT still exhibits its modulatory effects on electrically elicited contractions. Forskolin enhances both magnitude and relaxation rate of ACh and electrically elicited contractions. Forskolin (10(-5) M) increases the cyclic AMP content of the accessory radula closer and dorsal extrinsic muscles.
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001048:Aplysia / Q000502:physiology*; D005576:Colforsin; D000242:Cyclic AMP / Q000378:metabolism; D004224:Diterpenes / Q000494:pharmacology*; D004558:Electric Stimulation; D000431:Ethanol / Q000494:pharmacology; D006584:Hexamethonium Compounds / Q000494:pharmacology; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects*; D009126:Muscle Relaxation / Q000187:drug effects*; D009132:Muscles / Q000378:metabolism; D011950:Receptors, Cholinergic / Q000378:metabolism; D012701:Serotonin / Q000494:pharmacology*
chemical_list: D004224:Diterpenes; D006584:Hexamethonium Compounds; D011950:Receptors, Cholinergic; D005576:Colforsin; D012701:Serotonin; D000431:Ethanol; D000242:Cyclic AMP; D000109:Acetylcholine