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Background & objectives: Mitochondrial dysfunction is one of the main risk factors for neurological diseases which are associated with aging. On the other hand, aerobic exercise has beneficial effects on the brain health and cognitive function, and also improves mitochondrial dynamics. Therefore, the aim of the present study was to investigate the effect of 4 weeks of aerobic exercise on spatial learning, memory performance and mitochondrial dynamics in the hippocampal tissue of old rats.
Methods: For this purpose, 14 male Wistar rats at 20 months of age were randomly divided into 2 groups: aerobic exercise (n=7) and control group (n=7). The exercise group performed 4 weeks of treadmill training (5 days per week at a speed of 10 to 15 m/min). Forty-eight hours after the last training session, the animals underwent behavioral tests. Twenty-four hours after the behavioral test, all rats were killed and hippocampal tissue was extracted. The mRNA expression of OPA1, Mfn2 and Drp1 genes were assayed using Real Time-PCR. The Independent t test was used for statistical analysis.
Conclusion: Aerobic exercise in old animals improved spatial learning and memory performance, increased hippocampal OPA1 gene expression, and decreased Drp1 gene expression compared to the control group (p≤0.01).
Conclusion: It seems that aerobic exercise can improve the function of brain mitochondria by modulating fusion and fission processes and it can be considered as an effective non-pharmacological method to deal with aging-related learning and memory perturbations.

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Background & objectives: Exercise, with beneficial effects on brain health and cognitive function reduces the destructive effects of some neurological diseases such as Alzheimer's. The aim of this study was to evaluate the effect of four weeks of aerobic exercise on cognitive function and expression of Sirt1, CREB and BDNF genes in the hippocampus of male Wistar rats with Alzheimer's disease.
Methods: The statistical population included 18 male Wistar rats from the Pasteur Institute. Rats were randomly divided into three groups including Alzheimer's group, Alzheimer's disease-exercise group and a healthy control group. Alzheimer's disease group was induced by injecting Aβ42 into the hippocampus. Seven days after surgery, the rats performed the aerobic exercise for four weeks (five sessions per week at a speed of 10-15 m/min). They underwent behavioral tests 48 hours after the last training session. Twenty four hours later, rat hippocampal tissue was extracted. Sirt1, CREB and BDNF mRNAs were measured using Real time-PCR.
Results: Learning and spatial memory performance decreased in rats of Alzheimer's disease group compared to a healthy control group (p˂0.001). Decreased mRNA expression of Sirt1, CREB and BDNF genes was observed in the hippocampal tissue of Alzheimer's disease group compared with the healthy control group (p˂0.001). Alzheimer's rats with intermittent aerobic exercise had improved learning function, spatial memory and increased mRNA expression levels of Sirt1, CREB and BDNF genes in comparison with Alzheimer's disease group (p˂0.001).
Conclusions: Periodic aerobic exercise in rats with Alzheimer's disease can improve spatial learning and memory by positively regulating the Sirt1/ CREB/ BDNF signaling pathway in hippocampal tissue.