Effect of Ghrelin on Short Term and Long Term memory

Pinamar

Congreso; X Congress of the Panamerican Association for Biochemistry and Molecular Biology (PABMB), the XI 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 an orexigenic peptide produced by the stomach andThe Central Nervous System. In a previous work we have shownthat hippocampus (Hi), dorsal raphe nucleus and amygdalaparticipate in the central effects of Gr (Carlini et al., 2002; 2004)and that Gr increase long term memory (LTM) retentionconcomitantly with feeding behavior.In the present work we analyzed the participation of Gr on theformation and retention of short-term memory (STM) and LTMusing step down task in rats. Gr (0.03, 0.3, y 3.0 nmol/μl) wasadministrated in Hi or intracerebroventriculary (icv) 15 min pretraining (memory formation) or immediately after training (memoryretention). The animals were tested twice: 1 h and 24 hs aftertraining in order to measure STM and LTM respectively.Hippocampal Gr administration did not modify STM formation;however LTM formation increased only with the dose of 3nmol/ul.Contrarily icv administration increased latency time when the ratswere injected pre and pos-training in a dose related manner indicatingthat icv injection increased memory formation and memory retention(STM and LTM).In conclusion, differences observed between icv and Hi treatmentsuggest that another structure would be necessary for the memoryformation induced by GR