大鼠脊髓T_3节段全横断后损伤节段神经元超微结构的观察

OBSERVATION OF ULTRASTRUCTURES OF NEURONS IN INJURED SEGMENT AFTER COMPLETE SPINAL CORD TRANSECTION OF T_3 SEGMENT IN RATS

目的:观察大鼠脊髓T3节段全横断后损伤节段神经元超微结构的变化。方法:48只大鼠随机分为假手术组和脊髓T3完全横断损伤1d组、2d组、7d组、14d组、21d组,每组8只。各组大鼠BBB运动功能评分后取损伤节段脊髓,透射电镜观察脊髓神经元超微结构的变化。结果:脊髓损伤(SCI)各组大鼠的BBB评分明显低于假手术组(P<0.01);随着损伤时间的延长,SCI各组大鼠的BBB评分逐渐升高(P<0.01)。电镜下观察,大鼠脊髓神经元在损伤后2d病理变化最为严重,表现为神经元明显肿胀,线粒体等细胞器严重受损,核固缩,染色质凝集;损伤后7d时,脊髓神经元的病理变化有所减轻;损伤后21d,脊髓神经元的病理变化明显减轻,甚至接近正常。结论:大鼠脊髓损伤后2d脊髓神经元的病理变化最为严重,后逐渐减轻。

Objective：To observe the ultrastructural changes of neurons in injured segment after complete spinal cord transectionofT3 segmentinrats.Methods：48 rats were randomly divided into sham-operationgroup,spinalcordinjury（SCI） 1d group, SCI 2d group, SCI 7d group, SCI 14d group and SCI 21d group, with 8 rats in each group. The SCI rats’model was made by completely transected theT3 segment.Transmission electron microscope was used to observe the ultrastructural changes of neurons in injured segment after the rats were evaluated by BBB scale. Results：The BBB score of rats in each SCI group were all obviously lower than that in sham-operation group （P〈0.01）. With extension of injury time, the BBB score of rats in SCI groups gradually increased （P〈0.01）. 2d after injury, the ultrastructural changes of neurons were the most serious： neurons swelled obviously, organelles such as mitochondria seriously damaged, karyopyknosis and chromatic agglutination; 7d after injury, pathological changes of neurons lessened; 21d after injury, the pathological changes of neurons lessened obviously, even closed to normal. Conclusions： The pathological changes of neurons in spinal cord are the most serious2d after SCI, and then gradually lessen.