The Effect Of Swimming Training On Neurogenesis In The Hippocampal Dentate Gyrus And Functional Ability After Focal Ischemic Stroke In Rats

Abstract

The present study was aimed at investigating the effect of swimming training on brain function after focal cerebral ischemia in rats. PURPOSE: This study was examined on neurogenesis in dentate gyrus of hippocampus using 5-bromo-2′-deoxyuridine (BrdU) to label proliferating cells and assessed the neurological response following focal cerebral ischemia in rats using neurological motor behavioral test. METHODS: In an observer-blinded fashion twenty male Sprague-Dawley (280~310g, 7 weeks old) rats were divided into four groups: MCAO plus swimming group (ME, n1 =5), MCAO plus control group (MC, n2 =5), SHAM plus swimming group (SE, n3 =5), SHAM plus control group (SC, n4 =5). RESULTS: The limb placing time before and after swimming in the ME group were significantly longer than he MC group (p<.05), the SE group were significantly longer than the SC group (p<.01). The balance beam scores before and after swimming in the ME group was higher than the SE group, the MC group was higher than the SC group but was not significantly difference. The foot fault index before and after swimming training in ME group was significantly lower (i.e., im proved) than the MC group (p<.001) and the SE group (p<.001), the SE group was significantly lower (i.e., improved) than the SC group (p<.001). The mean number of BrdU-positive cells in the dentate gyrus in the ME group was significantly higher than the MC group (p<.001) and the SE group (p<.01). The MC group and the SE group was sig nificantly higher than the SC group (p<.001). There was significantly correlation between limb placing time and number of BrdU-positive cells on swimming training, there is positive correlation (r=0.807, p=.000) and between foot fault index and BrdU-positive cells number, there is negative correlation (r=−0.503, p=.05). However, between balance beam scores and BrdU-positive cells number, there is no correlation. CONCLUSION: The present study demonstrates that the role of swimming training improves behavioral motor function probably by enhancing cell proliferation in that hippocampus.