Effect of regular treadmill exercise on astrocyte proliferation-related proteins in the motor cortex and hippocampus after traumatic brain injury

The purpose of this study was to investigate whether regular treadmill exercise after traumatic brain injury (TBI) positively affects the regenerative environment in the motor cortex and hippocampus of the brain. Subjects were randomly divided into three groups: the normal control (Norm, n=8), the TBI+sedentary group (TBI+SED, n=8), and the TBI+ treadmill exercise group (TBI+Ex, n=8). Following a 2-week post-TBI recovery period, treadmill exercise was performed regularly for 4 weeks. The results showed that regular walking exercise after TBI increased the expression of growth associated protein-43 and tropomyosin receptor kinase-B, which are associated with neuronal survival, in both the motor cortex and hippocampus. The TBI+SED exhibited elevated glial fibrillary acidic protein and phosphorylated mammalian target of rapamycin signaling in both the motor cortex and hippocampus of the brain. In contrast, phosphorylated phosphatase and tensin homolog (p-PTEN) expression showed region-specific patterns: in the motor cortex, p-PTEN levels were higher in the TBI+SED than the Norm group and further increased following treadmill exercise, whereas in the hippocampus, p-PTEN expression decreased after TBI but was significantly elevated in the TBI+Ex group. These findings indicated that regular exercise after TBI might reduce glial scar formation and promote neural regeneration by elevating PTEN expression and inhibiting the mammalian target of rapamycin signaling pathway.