Physical exercise has proven to be beneficial to mitigate several deleterious effects associated with neurodegenerative diseases, including Alzheimer's Disease (AD). Here, we investigated the role of long-term exercise as a preventive and therapeutic tool against AD cognitive and behavioral impairments using a sporadic AD-like rat model, established through the administration of streptozotocin (STZ) inside both cerebral ventricles (icv). Six-weeks-old Wistar male rats (56) were divided into groups (either saline or STZ): sedentary (Sed), voluntary physical activity (VPA), VPA + endurance treadmill training (VPA + ET) and VPA + ET only after the injection (VPA + ET-post). Surgeries occurred at 16wks and the animals were sacrificed at 28 wks. VPA, VPA + ET, and VPA + ET-post had continuous access to the running wheels during the entire experimental protocol. VPA + ET (entire protocol) and VPA + ET-post (only after surgical procedure) ran 60 min/d, 25 m/min, 5d/wk in a treadmill. Both ET regimens led to significant improvements in the compromised spatial learning and long-term memory of STZ-infused animals that were not observed neither in the saline Sed nor in VPA STZ groups. General activity patterns and exploration habits were also ameliorated with chronic-exercise in STZ treated animals, while freezing patterns were decreased in these groups. these results were further. Positive alterations were seen in mitochondrial oxygen consumption endpoints (synaptosomal and non-synaptosomal brain mitochondria) that might underlie the neurobehavioral improvements observed. Data suggest that VPA alone was not able to counteract the AD-related deleterious consequences, although when accompanied by endurance training (either lifelong or later-life) may be able to prevent and reverse cognitive and phenotypic impairments associated with AD.
Keywords: Brain mitochondria; Cognition improvement; Dementia; Endurance training; Streptozotocin.
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