GHRELIN EFFECTS UPON MEMORY RETENTION AND FOOD INTAKE WERE INHIBITED BY FLUOXETINE

VALERIA PAOLA CARLINI; CECILIA GAYDOU, ROMINA; SUSANA RUBIALES DE BARIOGLIO

Vancouver, British Columbia, Canada

Congreso; 2006 Annual Meeting Society for Psychophysiological Research; 2006

Society for Psychophysiological Research

It has been demonstrated in our laboratory that the intra-hippocampal administration of the orexigenic peptide Ghrelin (Gr) increased both food intake and memory retention. In the present work we analyzed if serotoninergic (5HT) neurotransmition participates in the above mentioned effects by using pharmacological and behavioral approaches (step down test). Short and long term memory retention (STM, LTM), as well as food intake were measured 1 and 24 h after different doses of Gr intra-hippocampal administration in Wistar rats pre-treated intraperitoneatly with a selective 5HT reuptake inhibitor, Fluoxetine (FX). The treatment with FX alone decreased both LTM and food intake, at 1 h post treatment. FX also inhibited the effect on STM, LTM and orexigenic effect induced by Gr administration. In conclusion, these results provide functional evidence about the participation of the brains 5HT system in the increase on food intake and memory retention induced by Gr. The results also reinforce previous findings about the role of Gr in extrahypothalamic structures, such the hippocampus (Hi), modulating feeding and memory. Considering that previous reports have demonstrated that Gr reduces 5HT release in vitro, it can be postulated that the ingestive and memory effects of Gr in Hi could be related to the inhibition of 5HT release induced by the peptide.