Early exercise promotes positive hippocampal plasticity and improves spatial memory in the adult life of rats

GOMES DA SILVA S; UNSAIN NICOLAS; MASCÓ DH; TOSCANO-SILVA M; DE AMORIM HA; SILVA ARAÚJO BH; SIMÕES PS; NAFFAH-MAZZACORATTI MDA G; MORTARA RA; SCORZA FA; CAVALHEIRO EA; ARIDA RM

HIPPOCAMPUS

WILEY-LISS, DIV JOHN WILEY & SONS INC

Lugar: New York; Año: 2012 vol. 22 p. 347 - 358

1050-9631

There is a great deal of evidence showing the capacity of physical exercise to enhance cognitive function, reduce anxiety and depression, and protect the brain against neurodegenerative disorders. Although the effects of exercise are well documented in the mature brain, the influence of exercise in the developing brain has been poorly explored. Therefore, we investigated the morphological and functional hippocampal changes in adult rats submitted to daily treadmill exercise during the adolescent period. Male Wistar rats aged 21 postnatal days old (P21) were divided into two groups: exercise and control. Animals in the exercise group were submitted to daily exercise on the treadmill between P21 and P60. Running time and speed gradually increased over this period, reaching a maximum of 18 m/min for 60 min. After the aerobic exercise program (P60), histological and behavioral (water maze) analyses were performed. The results show that early-life exercise increased mossy fibers density and hippocampal expression of brain-derived neurotrophic factor and its receptor tropomyosin-related kinase B, improved spatial learning and memory, and enhanced capacity to evoke spatial memories in later stages (when measured at P96). It is important to point out that while physical exercise induces hippocampal plasticity, degenerative effects could appear in undue conditions of physical or psychological stress. In this regard, we also showed that the exercise protocol used here did not induce inflammatory response and degenerating neurons in the hippocampal formation of developing rats. Our findings demonstrate that physical exercise during postnatal development results in positive changes for the hippocampal formation, both in structure and function.