Inhibitory Effect of Serotonin on Feeding Behavior in Goldfish: Involvement of CRF

Abstract

De Pedro, N., M. L. Pinillos, A. I. Valenciano, M. Alonso-Bedate and M. J. Delgado. Inhibitory effect of serotonin on feeding behavior in goldfish: involvement of CRF. Peptides 19(3) 505–511, 1998.—The possible action of 5-HT on feeding behavior in goldfish has been studied. Food intake was significantly reduced by intracerebroventricular (ICV) injection of serotonin (5-HT, 10 μg) at 2 h postinjection. After peripheral (intraperitoneal) administration of 5-HT (1 and 10 μg/g bw), no significant modifications in food intake were detected. Thus, it can be concluded that there is a central anoretic action of 5-HT in teleost fish. Taking in mind the inhibitory effect of corticotropin releasing factor (CRF) on feeding in teleosts and the interactions between 5-HT and CRF described in mammals, we investigated the possible involvement of CRF as mediator of the 5-HT anoretic action in goldfish. The ICV pretreatment with α-Helical CRF [9-41] (20 μg) partially blocked the inhibitory effect of 5-HT on food consumption in goldfish. These results show that CRF mediates, at least in part, the 5-HT-induced feeding inhibition in goldfish. On the other hand, the alterations in hypothalamic indoleamines content evoked by ICV treatments would suggest that the activation of CRF neurons by 5-HT appears to inhibit hypothalamic serotoninergic transmission, supporting the intermediate role of this neuropeptide in the central anoretic effect of 5-HT in goldfish.