Short-Term Repeated Treadmill Exercise More Potently Increases Cell Proliferation and Brain-Derived Neurotrophic Factor Expression in the Hippocampus of Rats

Physical exercise enhances cell proliferation and/or neurogenesis in the hippocampal dentate gyrus. Brain-derived neurotrophic factor (BDNF) is implicated in the modulation of neurotransmitters turnover, neurite genesis, and neuronal survival. BDNF binds to the tyrosine kinas B (TrK). In this study, we compared the effects of the one bout of long-duration treadmill exercise and the repeated short-duration treadmill exercise on cell proliferation and expressions of BDNF and TrKB in the hippocampus. Adult male Sprague-Dawley rats, weighing 200±5 g, were randomly divided into three groups (n=8 in each group): control group, one hour-one bout-treadmill exercise group, and ten minutes-six bouts-treadmill exercise group. The rats in the one hour-one bout-treadmill exercise group were forced to run on a motorized treadmill for 60 min once a day (at 16:00). The rats in the ten minutes-six bouts-treadmill exercise group were forced to run on a treadmill once 10 minutes per six times for a day (at 10:00, 11:00, 14:00, 15:00, 19:00, 20:00). Treadmill exercise was continued for 7 consecutive days. The rats in the control group were left without running. Both types of treadmill exercise increased cell proliferation and enhanced expressions of BDNF and TrkB in the hippocampus. Cell proliferation and BDNF expression was more potently increased by the ten minutes-six bouts treadmill exercise than the one hour-one bout treadmill exercise. These results showed that repeated bouts of short-duration treadmill exercise may achieve more useful results for the brain functions than one-bout long-duration treadmill exercise. (Korean J Str Res 2010;18:295∼303)