Prior short-term exercise prevents behavioral and biochemical abnormalities induced by single prolonged stress in a rat model of posttraumatic stress disorder

Abstract

Posttraumatic stress disorder (PTSD) is an anxiety disorder that occurs following exposure to somatic or psychotic trauma. Physical activity is known to improve symptoms of certain neuropsychiatric disorders. However, the role of exercise on acquired PTSD-like phenotype was not examined. The present study investigated the effects of prior moderate treadmill exercise on anxiety-like behaviors, serum corticosterone and BDNF levels, hippocampal BDNF and mRNA expression of apoptotic - related proteins in the single prolonged stress (SPS) as an animal model of PTSD in rats. Male and female rats underwent a regular treadmill exercise regimen (4 weeks, 5 days per week). Following the exercise, rats were exposed to SPS (restraint for 2 h, forced swimming for 20 min and ether anesthesia), and then they were kept undisturbed for 14 days. After testing anxiety-like behaviours in the elevated plus maze, the levels of corticosterone and BDNF in serum and BDNF and apoptosis markers (Bax, Bcl-2, and Caspase) in hippocampus were measured. Sedentary male and female SPS rats significantly (Ps ranging <0.05 to <0.0001) exhibited increased anxiety levels in the elevated plus maze, enhanced serum corticosterone, reduced serum and hippocampal BDNF and enhanced hippocampal apoptosis than the corresponding control group. Prior exercise significantly (Ps ranging <0.05 to <0.001) alleviated all SPS-induced behavioral and biochemical alterations as compared with the sedentary SPS rats. There were no significant differences in serum and hippocampal BDNF and serum corticosterone levels and hippocampal apoptotic markers between male and female rats in all of groups. Our findings strongly support that short term prior exercise training can prevent the harmful effects of traumatic events, and the resulting trauma-related disorders in both sexes.