Hexarrelin effects on memory formation in mice model.

VALERIA PAOLA CARLINI; ANA CAROLINA MARTINI; LAURA VICENTI; PATRICIA PUECHAGUT; RUBEN DANIEL RUIZ; SUSANA RUBIALES DE BARIOGLIO; MARTA FIOL DE CUNEO

Huerta Grande-Córdoba

Congreso; XVII Congresss of Biology Society of Córdoba.; 2009

Biology Society of Córdoba

HEXARELIN AFFECTS MEMORY ACQUISITION IN MICE. Carlini V, Martini AC, Vincenti LM, Luque EM, Puechagut P, Ruiz RD, Rubiales de Barioglio S y Fiol de Cuneo M. Instituto de Fisiología, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba. In a previous work, we have demonstrated that ghrelin (Ghr) reverses the deleterious effects upon memory observed in chronic food restricted animals. The objectives of the present study were to evaluate the effects of a ghrelin analogue employed in human therapy, hexarelin (HEX), upon mice memory acquisiton, employing the object recognition test, in two experimental designs: A) HEX administration (100 ó 200 mg/kg/día, sc) to adult mice for 28 days and B) HEX administration (200 mg/kg/día, sc) to pregnant females during different periods, evaluating memory acquisition in their litter at adulthood. In A, HEX diminished memory vs control group (C) in females with both doses assayed (% of time exploring novel object: C 1h: 68.5±2.3, n=14; HEX100 24h: 36.2±6.9, n=7; HEX200 1h: 39.2±4.7, n=8; HEX200 24h: 37.6±3.2, n=8, p<0.05) while in males, only with the mayor one (C 24h: 62.4±2.2, n=11 y HEX200 24h: 48.8±4.5, n=7, p< 0.05). In B, memory was altered (especially in females) only when pregnant females were treated for the whole pregnancy or during the first third. In contrast, this last treatment accelerated the neurobehavioral development (negative geotaxis, surface righting reflex and cliff avoidance, at 8 to 10 postnatal days). These discrepancies could be attributed to differential effects of HEX upon different central nervous system structures.