Magnitude- and time-dependence of the effect of treadmill exercise on cell proliferation in the dentate gyrus of rats

The effect of treadmill exercise on cell proliferation in the dentate gyrus was studied in Sprague-Dawley rats via 5-bromo-2′-deoxyuridine (BrdU)-specific immunohistochemistry. For studying the dependence of this effect on the magnitude of exercise, animals were divided into the control, light-exercise, moderate-exercise, and severe-exercise groups; different exercise regimens were applied to the groups. To study the temporal dependence of this effect, animals were divided into the control, 1-day-exercise, 3-days-exercise, 7-days-exercise, 14-days-exercise, and 28-days-exercise groups; the regimen used on the light-exercise group was applied to each of the exercise group over the respective number of days. Cell proliferation was most prominent in the light-exercise group (p < 0.001) and reached a maximum level after 7 days of exercise (p < 0.001). In this study, it was shown that cell proliferation is modulated by the intensity and duration of treadmill exercise.