D-fenfluramine selectively releases 5-HT from dorsal raphe terminals.
The aim of this study was to investigate whether D-fenfluramine (FEN) releases 5-hydroxytryptamine (5-HT) selectively from dorsal raphe (DR) terminals. Male Wistar rats, 180-200 g, were implanted with microdialysis probes ir the amygdala (Am; N = 5) and dorsal hippocampus (DH; N = 6) and 5-HT levels were measured by electrochemical detection. Under basal conditions, 5-HT levels were approximately 50 and 230 fmol per 30 min sample, in the Am and DH, respectively. FEN (10 mg/kg. ip) produced a 3-4-fold increase in 5-HT release in the Am, but not in the DH. Since the Am is mainly innervated by DR fibers while the DH receives 5-HT input chiefly from the median raphe (MR), the present results support the view that FEN selectively releases 5-HT from DR terminals.
Viana
M B
MB
Laboratório de Psicobiologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brasil.
Silveira
R
R
Graeff
F G
FG
D000679:Amygdala / Q000187:drug effects / Q000378:metabolism; D000704:Analysis of Variance; D000818:Animals; D005277:Fenfluramine / Q000494:pharmacology*; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism; D008297:Male; D017551:Microdialysis; D011903:Raphe Nuclei / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012701:Serotonin / Q000378:metabolism*
D005277:Fenfluramine; D012701:Serotonin