Effect of treadmill training on the locomotor function in a rat model of dorsal root ganglion resection / 中国组织工程研究

ABSTRACT

BACKGROUND: Peripheral nerve injury can lead to extensive changes in central nervous system, and exercise training can promote the recovery of locomotor function following central nervous system injury. OBJECTIVE: To observe the changes of locomotor function and the expression levels of vesicular glutamate transporter VGLUT1 in the spinal cord in a rat model of dorsal root ganglion resection after treadmill exercise and to explore the effect of treadmill training on the locomotor function after peripheral nerve injury. METHODS: Thirty-nine 10-week-old male Wistar rats were randomized into experimental (n=15), control (n=15) and sham operation (n=9) groups. The rats in the experimental and control groups received the dorsal root ganglion resection at L3and L4segments to establish the model of peripheral nerve injury under local anesthesia, while the rats in the sham operation group were only subjected to dorsal root ganglion exposure. The rats in the experimental group underwent 15 m/minute treadmill training at postoperative 7 days, while rats in the other two groups were in free movement. Gait analysis was performed at preoperative 3 days, postoperative 7, 14, 21, and 28 days, respectively, and the behavioral changes of rats were observed. The tissue sections were obtained from L3segment at postoperative 7, 14, and 28 days to detect the expression levels of VGLUT1 in the spinal cord by immunohistochemistry. RESULTS AND CONCLUSION: The peroneal nerve function index in the experimental and control groups was lower than that before surgery and that in the sham operation group at postoperative different time points (all P ＜ 0.05). The index in the experimental and control groups was the lowest on day 7 postoperatively (P ＜ 0.05), then the index gradually increased, but was still lower than the preoperative level (P ＜ 0.05). The index in the experimental group was significantly higher than that in the control group at postoperative 21 and 28 days (P ＜ 0.05). The expression levels of VGLUT1 in the lamina IX in the experimental and control groups were significantly lower than those in the sham operation group at different time points after surgery (P ＜ 0.01). The levels in the experimental group were significantly higher than those in the control group at postoperative 14 and 28 days (P ＜ 0.05). The levels in both groups on a decline after surgery, especially the control group (P ＜ 0.05). These results suggest that treadmill can promote the recovery of locomotor function post peripheral nerve injury.