Ghrelin inhibited serotonin release from hippocampal slices

GHERSI MS.; CASAS S.; ESCUDERO C.; CARLINI VP.; BUTELERA F.; CABRERA RJ.; SCHIÖTHD HB.; BARIOGLOA SR.

PEPTIDES

ELSEVIER SCIENCE INC

Lugar: Amsterdam; Año: 2011 vol. 32 p. 2367 - 2371

0196-9781

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 enhanced memory consolidation in a step down test in rats (b) the effect of Ghr upon memory decreases in animals pretreated with a serotonin (5HT) reuptake inhibitor, Fluoxetine, suggesting that Ghr effects in the hippocampus could be related to the availability of 5HT. It has been demonstrated that Ghr inhibits 5HT release from rat hypothalamic synaptosomes. Taking in mint these evidences, we studied the release of radioactive 5HT to the superfusion medium from hippocampal slices treated with two doses of Ghr (0.3 and 3 nm/ml). Ghr inhibited significantly the 5HT release in relation to those superfused with artificial cerebrospinal fluid (ACSF) (H = 9.48, df = 2, p ≤ 0.05). In another set of experiments, Ghr was infused into the CA1 area of hippocampus of the rats immediately after training in the step down test and the 5HT release from slices was studied 24 h after Ghr injection showing that in this condition also the 5HT release was inhibited (H = 11.72, df = 1, p ≤ 0.05). In conclusion, results provide additional evidence about the neurobiological bases of Ghr action in hippocampus.