Aminergic and peptidergic amplification of intracellular cyclic AMP levels in a molluscan neural network

• Published in: Cellular and molecular neurobiology Vol. 7; no. 3; p. 291
• Main Authors: Yamane, T, Gelperin, A
• Format: Journal Article
• Language: English
• Published: United States 01.09.1987
• Subjects: Animals; Cyclic AMP - biosynthesis; Dopamine - pharmacology; Ergonovine - pharmacology; Intracellular Fluid - metabolism; Mollusca - metabolism; Nerve Net - drug effects; Nerve Net - metabolism; Nervous System - metabolism; Neuropeptides - pharmacology; Neurotransmitter Agents - pharmacology; Serotonin - pharmacology
• ISSN: 0272-4340
• DOI: 10.1007/BF00711305

1. Serotonin (5-hydroxytryptamine; 5-HT), dopamine (DA), and small cardioactive peptide B (SCPB) can activate adenylate cyclase and increase the intracellular cyclic AMP (cAMP) levels in the Limax procerebrum (PC), with differing time courses and to differing extents. 5-HT and SCPB are potent stimulators of adenylate cyclase, and when both were applied simultaneously, an additive effect was observed. 2. In contrast, DA shows a great variability in the time course of cAMP synthesis and is a weak stimulator. Ergonovine, a DA antagonist, failed to inhibit cyclase activation, indicating that ergonovine-sensitive receptors are absent or ergonovine-sensitive DA receptors are not coupled to adenylate cyclase. 3. 5-HT and SCPB cause a rapid synthesis of cAMP, reaching the maximum 20- to 30-fold increase within a minute. DA's effect is slow in onset and very prolonged, reaching a maximum of only a two- to three-fold increase in the cAMP level. Reasons for variability in DA action are discussed.