Effect of ghrelin on short-term and long-term memory

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

Pinamar

Congreso; X Congress of the Panamerican Association for Biochemistry and Molecular Biology (PABMB), the XLI Annual Meeting of the Argentine Society for Biochemistry and Molecular Biology (SAIB) and the XX Annual Meeting of the Argentine Society for Neurochemistry (; 2005

Ghrelin (Gr) is a orexigenic peptide produced by the stomach In a previous work we have showed that hipocampus (Hi), dorsal raphe nucleus and amygdala participates in the central effects of Gr (Carlini et al, 2002; 2004) and that Gr induces increase in long term memory (LTM) retention concomitantly with feeding behavior. In the present work we analyzed the participation of Gr on the formation and retention of short-term memory (STM) and LTM using step down test in rats. Gr (0.03, 0.3, y 3.0 nmol/l) was administrated in Hi or into the third ventricle (icv) 0 min post training (for memory retention (MR)) or 15 min pre training (for memory formation (MF)). Hipocampal Gr administration did not modifies STM formation and LTM formation increases only with the dose of 3nmol/l. On the contrary icv administration increases latency time when the rats were injected pre and postraining in a dose related manner indicating that icv injection increases MR and MF (STM and LTM). In conclusion the differences observed between icv and Hi with Gr treatment suggest that an other structure is necessary for the memory formation induced by GR