ISSN:
1471-4159
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Medicine
Notes:
Abstract: To test for the relative contributions of the dopaminergicand serotoninergic systems in the striatum to the effects ofd-fenfluramine, an indirect serotonin receptor agonist, we assessedthe expression of Fos/Jun proteins induced by d-fenfluramine givenalone or in the presence of dopaminergic or serotoninergic agents. Todetermine the neuronal targets of d-fenfluramine in the striatum, weidentified the phenotypes of striatal neurons in which d-fenfluramineinduced Fos expression. Our results demonstrated that d-fenfluramineevokes nuclear expression of Fos/Jun B proteins in the striatum, and that theFos expression was dose-dependent and accompanied by transient induction ofc-fos mRNA. Fos expression was blocked byp-chloroamphetamine, a serotoninergic neurotoxin. Pretreatment withSCH 23390, a D1-dopamine receptor antagonist, led to a markeddecrease in Fos/Jun B expression in the caudoputamen, but not in the cortex,whereas pretreatment with methiothepin, a nonselective serotonin5-HT1 receptor antagonist, blocked Fos expression completely in thecortex and only partially in the caudoputamen. The expression of Fos/Jun B inthe striatum occurred mainly in dynorphin-containing neurons and in asubpopulation of striatal interneurons that exhibited NADPH-diaphoraseactivity. Most of the enkephalin-containing neurons of the striatum did notshow Fos/Jun B staining. These results suggest that the mechanism by whichd-fenfluramine induces c-fos and jun B expression in the rat caudoputamen depends at least in part on activation of the dopaminergic system by serotonin.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1046/j.1471-4159.2000.0741363.x
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