Zahra Hosseini Bajestani - Student Research Committee, Mazandaran University of Medical Sciences, Sari, Iran
Pouya Darzi - Student Research Committee, Mazandaran University of Medical Sciences, Sari, Iran
Reza Yakhkeshi - Student Research Committee, Mazandaran University of Medical Sciences, Sari, Iran
Fatemeh Roshani - Student Research Committee, Mazandaran University of Medical Sciences, Sari, Iran

traumatic stress disorder (PTSD) is a condition that develops after an individual has experienced a major trauma. Currently, selectiveserotonin reuptake inhibitors (SSRIs) like fluoxetine are the first-line choice in PTSD drug treatment but their moderate response rates and side effects indicate an urgent need for the development of new treatment. Physical activity is known to improve symptoms of certain neuropsychiatric disorders. The present study investigated the effects of moderate treadmill exercise, the antidepressant fluoxetine and the combined treatment on mRNA expression of apoptosis - related proteins in a rat model of PTSD: the single prolonged stress (SPS)model. Materials and Methods: Rats were exposed to SPS (restraint for 2 h, forced swimming for 20 min and ether anesthesia) and were then kept undisturbed for 14 days. After that, SPS rats were subjected to chronic treatment with fluoxetine (10 mg/kg/day, for 4 weeks), moderate treadmill running (4 weeks, 5 day per week) and the combined treatment (fluoxetine plus treadmill exercise), followed by apoptosis markersassessments. Results: This study showed that SPS significantly increased the mRNA expression of the protein Caspase-3 in the hippocampus, increase in apoptotic factor in hippocampus causing of cell death. We found that all treatments (fluoxetine, exercise and the combined treatment) down regulated Caspase-3 mRNA in the hippocampus, which shifted to the cell survival. Conclusion: The anti-apoptotic effects of the combined treatment (exercise + fluoxetine) were much stronger than those of either treatment alone, suggesting a synergistic effect between them in the hippocampus