The effect of 12 weeks of aerobic exercise training on depressive behaviors, testosterone and corticosterone levels in rats with Alzheimer's

Considering the role of hormones on depression's levels that caused by Alzheimer's disease, and also the effect of exercise training on hormone secretion levels in the body, the aim of this study was to investigate the effect of 12 weeks of aerobic exercise training on depressive behaviors and hormones levels of testosterone and corticosterone in Alzheimer's male rats.

For this purpose, 40 male Wistar rats with an average age of 8 weeks and average weight of 237±33 g were randomly divided into four groups of 10: control, exercise, Alzheimer's and exercise + Alzheimer's. To induce Alzheimer's, 3 mg/kg streptozotocin in 5 μl of sterile distilled water was injected into the ventricular region. The training protocol was performed for 12 weeks, 5 sessions/week and 30 minutes in each session at a speed of 10 m/min from the first to the 6 weeks and 12 m/min from the 7 to the 12 weeks. At the end of the training period, Sucrose preference and forced swimming tests were performed as tests for estimating depression. After completing the behavioral tests, testosterone and corticosterone levels were measured by ELISA.

The results showed that 12 weeks of exercise training significantly reduced the immobility time in the forced swimming test (P = 0.001)  and significantly increased the sucrose preference test (P = 0.001) in rats with Alzheimer's disease. Also, a period of exercise training has caused a significant increase in testosterone (P = 0.006) and a significant decrease in corticosterone (P = 0.006) in rats with Alzheimer's disease.

Aerobic exercise training on treadmill appears to be effective in treating depressive behaviors in rats with Alzheimer's disease by increasing testosterone levels and decreasing corticosterone.