EFFECT OF GHRELIN ON SHORT-TERM AND LONG-TERM MEMORY.

ROMINA C ; CARLINI VALERIA P AND DE BARIOGLIO, SUSANA RUBIALES

Pinamar, Buenos Aires, Argentina.

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

EFFECT OF GHRELIN ON SHORT-TERM AND LONG-TERM MEMORY.

Gaydou Romina C ; Carlini Valeria P and de Barioglio, Susana .

Departamento de Farmacología. Facultad de Ciencias Químicas. Universidad Nacional de Córdoba. Ciudad Universitaria, 5000-Córdoba.  Argentina.

E-mail: rgaydou@mail.fcq.unc.edu.a

 

Ghrelin (Gr) is an orexigenic peptide produced by the stomach and The Central Nervous System.  In a previous work we have shown that hippocampus (Hi), dorsal raphe nucleus and amygdala participate in the central effects of Gr (Carlini et al, 2002; 2004) and that Gr increase 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 task in rats. Gr (0.03, 0.3, y 3.0 nmol/ml) was administrated in Hi or intracerebroventriculary (icv) 15 min pre training (memory formation) or immediately after training (memory retention). The animals were tested twice: 1 h and 24 hs after training 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 rats were injected pre and pos-training in a dose related manner indicating that icv injection increased memory formation and memory retention (STM and LTM).

In conclusion, differences observed between icv and Hi treatment suggest that another structure would be necessary for the memory formation induced by GR.