Investigation of the effects of two exercise protocols on behavioral and biochemical changes in ovariectomized rats exposed to single prolonged stress.

Our previous study demonstrated that ovariectomy exacerbated stress-induced impairments in rats exposed to single prolonged stress (SPS) and that the treadmill exercise protocol used in that study improved the associated cellular responses. However, this protocol did not alleviate all anxiety-like behaviors. Therefore, the present study aimed to determine whether the voluntary wheel-running protocol used in this study would produce greater improvements in anxiety-like behavior than the previously evaluated treadmill exercise protocol. Female adult Wistar rats were randomly allocated to the control (CON), sham, and ovariectomized (OVX) groups. Following PTSD induction, animals within each group were randomly assigned to sedentary (SED), treadmill running (TR), or wheel running (RW) groups. Twenty days after ovariectomy, PTSD was induced by a Single Prolonged Stress (SPS) model. The exercise began on day 32 and continued for 4 weeks. On the 61st day, Open Field Test (OFT), Object Location Memory Task (OLMT), corticosterone, and neurotrophins levels were assessed. p < 0.05 was considered a significant level. The findings revealed significant differences between the OVX/SPS/TR and OVX/SPS/RW groups in hippocampal and prefrontal cortical BDNF and IGF-1 levels. Significant differences were also observed between the OVX/SPS/SED group and both the OVX/SPS/TR and OVX/SPS/RW groups in the OLMT and OFT. The wheel-running protocol produced greater therapeutic benefits against SPS-induced impairments that were exacerbated by ovariectomy. Based on the results of the present study, the exercise protocol appears to be an important factor in achieving targeted therapeutic outcomes in an animal model of PTSD. Exercise-induced stress load, as well as dose and intensity should be considered when drawing conclusions.