title: Serotonin-norepinephrine interactions: a voltammetric study on the effect of serotonin receptor stimulation followed in the N. raphe dorsalis and the Locus coeruleus of the rat.
abstract: In vivo voltammetry with carbon fibre electrodes was used to study the effect of the serotoninergic (5-HT) neuronal system on the noradrenergic (NE) system in the Locus coeruleus of the rat. The voltammetric DOPAC signal in the Locus coeruleus, used as a measure of NE neuronal activity, was increased after systemic application of the 5-HT1B agonist CGS-12066B, the 5-HT2 antagonist ritanserin, and, to a lesser extent, by ipsapirone, a 5-HT1A agonist. The findings suggest that the NE neuronal system of the Locus coeruleus is stimulated by 5-HT1A and 5-HT1B receptor activation and inhibited by 5-HT2 receptors. Likewise the 5-HT releaser and uptake inhibitor fenfluramine increased the DOPAC level in the Locus coeruleus. In contrast to the 5-HT1 agonists, which reduced 5-hydroxyindoleacetic acid (5-HIAA) in the Nucleus raphe dorsalis, ritanserin increased the 5-HIAA signal in this nucleus. This finding could help to explain the action of ritanserin as sleep-modulating substance.
authors.affiliation: Department of Neurochemistry, University, Marburg/Lahn, Federal Republic of Germany.
authors.forename: H W
authors.initials: HW
authors.lastname: Clement
authors.forename: D
authors.initials: D
authors.lastname: Gemsa
authors.forename: W
authors.initials: W
authors.lastname: Wesemann
mesh_terms: D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D000818:Animals; D004347:Drug Interactions; D004594:Electrophysiology; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism; D008125:Locus Coeruleus / Q000378:metabolism / Q000502:physiology*; D008297:Male; D008839:Microelectrodes; D009638:Norepinephrine / Q000494:pharmacology*; D011810:Quinoxalines / Q000494:pharmacology; D011903:Raphe Nuclei / Q000378:metabolism / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D011985:Receptors, Serotonin / Q000502:physiology*; D012701:Serotonin / Q000494:pharmacology*
chemical_list: D011810:Quinoxalines; D011985:Receptors, Serotonin; D015102:3,4-Dihydroxyphenylacetic Acid; C052561:CGS 12066B; D012701:Serotonin; D006897:Hydroxyindoleacetic Acid; D009638:Norepinephrine