大鼠坐骨神经慢性压迫性损伤后脊髓背角感觉神经元超微形态学变化

Ultrastructure changes of sensory neurons in the spinal dorsal horn after chronic constriction injury of the sciatic nerve in rats

目的观察大鼠坐骨神经慢性压迫损伤后脊髓背角浅层神经元超微形态变化。方法成年雄性SD大鼠20只,随机分为正常组和手术组。手术组结扎大鼠左侧坐骨神经建立坐骨神经慢性压迫性损伤(CCI)模型,在术后3、7、14d取与坐骨神经相应的腰4～6节段脊髓,透射电镜观察左侧脊髓背角浅层神经元超微结构并摄片,光镜下苏木素-伊红染色对大鼠腰4～6脊髓背角两侧感觉神经元计数。结果坐骨神经损伤后,光镜下损伤侧脊髓背角感觉神经元数量较健侧显著减少(P<0.05),两周时细胞死亡率为23%;电镜下CCI 7d和14 d组腰4～6节段脊髓左侧背角浅层神经元出现多种形态变化,以细胞凋亡为主。结论坐骨神经损伤后腰4～6节段脊髓背角神经元出现丢失,超微形态上呈现多样性,以细胞凋亡为主。

Objective To observe the ultrastructure changes of sensory neurons in the spinal dorsal horn after chronic constriction injury （CCI） of the sciatic nerve in rats. Methods 20 adult male SD rats were randomly divided into normal group and operation group. The CCI model was established by ligaturing left sciatic nerve in the operation group. On the 3rd, ？th and 14th days after surgery, the ultrastructure of sensory neurons in the left spinal dorsal horn of L4~6 was observed by transmission electron microscopy, and the numbers of sensory neurons in L4~6 spinal dorsal horn were counted by the light microscopy with HE staining. Results The numbers of sensory neurons on the injured side of the spinal dorsal horn were decreased significantly when compared with the normal side （P 〈0.05） and their dead rate reached 23% on the 2nd week. Different morphological characteristics, mainly apoptosis, were observed in sensory neurons in L4-6 left spinal dorsal horn on day 7 and day 14 after CCI. Conclusion After sciatic nerve injury, sensory neurons in L4~6 spinal cord dorsal horn are lost, and their morphological changes, mainly apoptosis, arc diverse.