The effects of swimming exercise on recognition memory for objects and conditioned fear in rats/Os efeitos do exercicio de natacao sobre a memoria para reconhecimento de objetos e de medo condicionados em ratos

Experiments conducted in animals have repeatedly demonstrated the ability of exercise to enhance cognitive function. This study examines the effects of chronic swimming exercise on non-spatial memory in adult rats after 12 weeks of swimming exercise in object recognition and elevated T-maze tests. In the object recognition test, repeated measures analysis of variance revealed a group effect ([F.sub.1,42] = 26,093; p < 0.001), control rats had lower discrimination ratios than the exercise group. However, the swimming exercise did not affect the performance of inhibitory avoidance and escapes, when memory was tested in elevated T-maze. Analysis of variance showed a significant reduction in inhibitory avoidance 24h after the first training ([F.sub.1,42] = 14,552; p < 0.001). Results indicated that regular swimming exercise significantly increased non-spatial memory in object recognition behavior, but did not affect the performance of inhibitory avoidance and escape on elevated T-maze test in adult rats. These findings suggest that the perirhinal cortex plays a role in memory consolidation and storage in addition to that of the amygdala, which could be regarded as the center of a second memory system, separate from those governed by the perirhinal cortex. Keywords: amygdala, elevated T-maze, learning, object recognition, perirhinal cortex, physical exercise. As experiencias realizadas em animais mostram a capacidade do exercicio em melhorar as funcoes cognitivas. Este estudo analisa os efeitos do exercicio cronico de natacao sobre a memoria nao-espacial em ratos adultos apos 12 semanas de exercicio de natacao nos testes de reconhecimento de objetos e labirinto em T elevado. O teste de reconhecimento de objetos, pelas repetidas analises de variancia revelaram um efeito de grupo ([F.sub.1,42] = 26.093; p < 0,001), os ratos controles discriminaram uma razao inferior ao do grupo de exercicio. Entretanto, o exercicio de natacao nao afetou o desempenho de esquiva inibitoria e escape, quando a memoria foi testada no labirinto em T elevado. Analise de variancia mostrou reducao significativa na esquiva inibitoria 24h apos o primeiro treino ([F.sub.1,42] = 14.552; p < 0,001). Os resultados indicam que o exercicio regular de natacao aumenta significativamente a memoria nao-espacial no comportamento de reconhecimento de objetos, mas nao afeta o medo condicionado no teste do labirinto em T elevado em ratos adultos. Estes resultados sugerem que o cortex peririnal desempenha