大鼠脊髓损伤后轴突病理变化与胶质瘢痕的关系

A study on the pathological changes of axons and the relationship between axons and glial scar after spinal cord injury in rat

目的观察脊髓损伤（SCI）后轴突变化及其与胶质瘢痕的关系。方法应用Allen’S法建立大鼠脊髓损伤模型，通过行为学评分、免疫荧光及神经束路示踪等观察SCI后轴突的病理变化，及其与胶质瘢痕的关系，并测量胶质瘢痕的厚度。结果SCI后损伤处的轴突呈断裂、扭曲状，SCI后1周损伤轴突呈再生趋势，2周时再生明显，与此相应动物运动功能逐渐恢复，4周时胶质瘢痕形成，再生的轴突被瘢痕阻挡。头尾侧胶质瘢痕厚度（107．00±20．12）μm大于两侧边厚度（69．92±24．37）μm。结论SCI后轴突仍具有再生能力，但被胶质瘢痕所阻挡，瘢痕厚度的测量为将来去除胶质瘢痕提供了实验依据。

Objective To observe the changes of axons and the relationship between axons and glial scar after spinal cord injury （SCI）. Methods we established SCI model using Allen＇s weight-drop injury setting, and observed the pathological changes of axons, the relationship between axons and glial scar with cavity after SCI via behavioral scoring, double immunofluorescence and tract tracing. Then, we quantitated the thickness of glial scar. Results Axons in the lesion site seen to be interrupted and distorted. Nevertheless, axons seemed to begin to regrow at 1 week after SCI, and obvious neuroregeneration appeared at 2 weeks postinjury, which was consistent with the gradual functional recovery of injured rat. At 4 weeks post SCI, glial scar came into being and inhibited axonal regeneration. The thickness of glial scar after quantitating showed to be （ 107.00 ± 20. 12 ） μm in the rostral and caudal region to the lesion, and （ 69.92 ± 24.37） μm in the lateral region. Conclusion The axons remain regenerative capability after SCI, which are inhibited by the glial scar. The thickness of glial scar measured in the study will provide experimental evidence for ablating glial scar in the future.