减重平板训练对脊髓损伤大鼠运动功能及远端脊髓形态学的影响

关键词：脊髓损伤  运动功能  减重平板运动  大鼠

Keywords:spinal cord injury  motor activity  body-weight-support-treadmill training  rat

摘要：

      摘要 目的：明确减重平板训练对脊髓损伤大鼠运动功能及远端脊髓形态学的影响。 方法：成年雌性SD大鼠30只，随机分为正常组、对照组和减重平板组。采用改良Allen's撞击法制作T9不完全性脊髓损伤模型。损伤后1周开始训练，30min/d，共4周。分别在损伤前、损伤后1d、1周、2周、3周、4周、5周时采用斜板试验、改良Tarlov评分、Basso-Beattie-Bresnahan(BBB)评分进行运动功能评定。损伤后5周，通过光镜和电镜观察脊髓及腓肠肌形态变化，计算肌纤维横截面积和直径大小。 结果：①减重平板组三项运动功能评分在训练后各个时间点均较对照组显著增加（P＜0.05）。②减重平板组肌肉横截面积和直径与对照组相比显著增加（P＜0.05），并接近正常组数值（P＞0.05）。③光镜显示减重平板组远端脊髓的运动神经元仍保留有较多突起，尼氏体无明显减少；电镜显示减重平板组髓鞘分离程度明显减轻，轴索与髓鞘间的空隙减少，结构趋于完整。 结论：减重平板运动可有效促进脊髓损伤大鼠运动功能及神经肌肉功能的恢复；促进远端脊髓形态的恢复，减轻远端神经元的继发损害。

Abstract:

      Abstract Objective: To explore the promotion effect of body-weight-support-treadmill training(BWSTT) and the changes of secondary lesion in distal spinal motor neuron in rats after spinal cord injury (SCI). Method: Thirty female adult Sprague-Dawley rats were used. An animal model of incomplete SCI was created using a modification of Allen's method at T9 spinal cord. Taking the uninjured rats as normal group, and the injured rats without training as control group. One group of injured rats was trained by BWSTT. Exercise training began 1 week post injury, lasted 30 min per day, 5 days a week for 4 weeks. Locomotor function was evaluated by using inclined plane test, modified Tarlov score and Basso-Beattie-Bresnahan (BBB) scale before injury and on the 1st day, and the 1st, 2nd, 3rd, 4th, 5th week post injury. Histomorphological changes of L5 spinal cord and gastrocnemius muscle were observed by light microscope and electromicroscope, and the cross section area and diameter of the gastrocnemius muscle fibers were analyzed by specialty computer software. Result: ①The angles of inclined plane test, Tarlov scores and BBB scores of BWSTT group increased significantly compared with control group at any time points of observation(P<0.05). ②Compared the shape, and the cross section area and the diameter of gastrocnemius muscle fibers, it showed that the improvement of amyotrophy of BWSTT group was significant. It's cross section area and diameter were nearly closed to those of normal group (P>0.05). ③The observation through light microscope and electronmicroscope of L5 spinal cord of each group showed that the improvement of BWSTT group was significant. After 4 weeks of BWSTT, neurites and Nissl bodies didn't decreased greatly, the shapes of myelin sheath and neuraxis were mostly integrity, and the vacuoles in cell matrix were decreased significantly. Conclusion: The body-weight-support-treadmill training can significantly improve the motor activity of SCI rats, and effectively decrease the secondary lesion in distal spinal motor neuron.