| Keywords |
Spinal cord injury ; Cdc2 ; p-ERK1/2 ; Corticospinal tract ; Exercise ; Astrocyte ; Proliferation |
| Abstract |
Physical exercise is recommended as a therapeutic tool for improving functional and histological deficits in spinal cord contusion injury (SCI). Cell division cycle 2 (Cdc2) and Extracellular signal-regulated kinase 1/2 (ERK1/2) have been known to regulate proliferation of non-neuronal cells in both central and peripheral nervous system. Here we investigated the effect of activated Cdc2 and ERK1/2 by treadmill exercise on axonal regeneration of corticospinal tract and proliferation of astrocytes within the cavity after spinal cord contusion injury. The rats were divided into three groups: the control group (n = 20), the spinal cord injury group (n = 20), and spinal cord injury and treadmill exercise group (n = 20). We carried out Basso-Beattie-Bresnahan (BBB) test to determine functional recovery after spinal cord injury and treadmill exercise for 4 weeks significantly improved SCI-induced behavioral deficits (F = 25.457, p < .001). We also found that Cdc2 (F = 34.548, p < .001) and p-ERK1/2 expression (F = 311.507, p < .001) levels in the injured areas were further facilitated by treadmill exercise when compared to non-exercise group. Exercise-induced Cdc2 and p-ERK1/2 levels after SCI were associated with astrocyte proliferation within the cavity of the injury site. Also the results of present study suggested that treadmill exercise increased axonal sprouting of injured corticospinal tract post SCI. Our data provide evidence that treadmill exercise may be an important intervention for mediating axonal regeneration and biochemical alteration after SCI. |