Ghrelin inhibited serotonin release from hippocampal slices

GHERSI MARISA; CASAS S; ESCUDERO C; BUTELER F; VALERIA PAOLA CARLINI; CABRERA JR; SUSANA RUBIALES DE BARIOGLIO

Córdoba

Congreso; II Reunión Conjunta de Neurociencia; 2010

Sociedad Argentina de Investigación en Neurociencias

Ghrelin (Ghr) is a peptide produced peripherally and centrally. It participates in the modulation of different biological processes. In our laboratory we have shown that a) Ghr administration, either intracerebroventricular or directly into the hippocampus(Hi) enhanced memory consolidation in a step down test (SDT) in rats b) the effect of Ghr upon memory decreases in animals pretreated with a 5-HT reuptake inhibitor fluoxetine suggesting that Ghr effects in the Hi could be related to the availability of 5-HT. It has been demonstrated that Ghr inhibits 5-HT release (R) from rat hypothalamic synaptosomes. Taking in mint these evidences, we studied the R of radioactive 5-HT to the superfusion media from hippocampal slices treated with two doses of Ghr (0.3 and 3nm/ul). Ghr inhibited significantly the 5HT R in relation to those superfused with artificial cerebrospinal fluid (ACSF) (33.2±4.3 vs 1.8±1.8 Ghr 3). In a other set of experiments, Ghr was infused in the CA1 area of Hi of the rats immediately after training in the SDT and the 5-HT R from slices was studied 24 hs after Ghr injection showing that in this condition also the 5HT R was inhibited (107.0±11.4 vs 2.5±2.5 Ghr 3). In conclusion, results provide additional evidence about the neurobiological bases of Ghr action.