title: Serotonergic activity in rat cerebral arteries depends on dorsal raphe nucleus but not on median raphe nucleus.
abstract: The effect of Chlorimipramine and Muscimol on serotonergic activity in rat cerebral arteries and in dorsal and median raphe nuclei were used to study the presence of a serotonergic innervation in the cerebral blood vessels functionally dependent on the brainstem nuclei activity. Serotonergic activity was appraised in rat cerebral arteries from 5-hydroxyindoleacetic acid (5-HIAA) disappearance rate or 5-hydroxytryptophan (5-HTP) accumulation after inhibiting monoamine oxidase (MAO) or aromatic amino acids decarboxylase, respectively. In dorsal and median raphe nuclei the decay with time of 5-HIAA after MAO inhibition was used to estimate serotonergic activity. Chlorimipramine significantly reduced serotonergic activity in cerebral blood vessels and in both raphe nuclei. 5-HIAA basal levels in these blood vessels were not altered by treatment with the drug. Muscimol evoked only a decrease in the serotonergic activity of the median raphe nucleus. These results suggest that rat cerebral arteries receive serotonergic fibers functionally active arising mainly from dorsal raphe nucleus.
authors.affiliation: Departamento de Fisiología, Universidad Autónoma de Madrid, Spain.
authors.forename: M J
authors.initials: MJ
authors.lastname: Moreno
authors.forename: A L
authors.initials: AL
authors.lastname: López de Pablo
authors.forename: M V
authors.initials: MV
authors.lastname: Conde
authors.forename: M L
authors.initials: ML
authors.lastname: Fraile
authors.forename: E J
authors.initials: EJ
authors.lastname: Marco
mesh_terms: D006916:5-Hydroxytryptophan / Q000378:metabolism; D000818:Animals; D002536:Cerebral Arteries / Q000294:innervation*; D002997:Clomipramine / Q000494:pharmacology; D006897:Hydroxyindoleacetic Acid / Q000097:blood; D008297:Male; D008996:Monoamine Oxidase Inhibitors / Q000494:pharmacology; D009118:Muscimol / Q000494:pharmacology; D010293:Pargyline / Q000494:pharmacology; D011903:Raphe Nuclei / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012701:Serotonin / Q000502:physiology*
chemical_list: D008996:Monoamine Oxidase Inhibitors; D009118:Muscimol; D012701:Serotonin; D006897:Hydroxyindoleacetic Acid; D010293:Pargyline; D006916:5-Hydroxytryptophan; D002997:Clomipramine