摘要
Abstract
Objective To investigate the changes in distal neurons and skeletal muscles in rats with spinal cord injury (SCI).Methods 20 rats were randomly selected as the research objects and were divided into sham-operated group in which the rats received laminectomy and SCI group in which the rats suffered from 10th thoracic cord injury,10 rats in each group.The chan-ges in sciatic nerve,motor end-plate and inside gastrocnemius muscle were observed in the 1st,2nd,4th,12th and 24th week after successful model.Results 12 weeks after sciatic nerve operation in spinal cord injury rats under the electron microscope,the mye-lin disintegration occurred in myelinated nerve fibers where the lamellar structure was clear,and 24 weeks after successful model the myelinated nerve fibers became indistinct and showed more cataclastic myelin sheaths.In addition,12 weeks later,the unmyeli-nated nerve fibers and thin myelin sheaths were increased.12 weeks after operation at the light microscopic level the most partial muscle cells turned into being blurred but the periphery was clear,connective tissues presented obvious hyperplasia and muscular cell nucleus aggregated.Furthermore,the muscle cells merged together and the lacuna appeared between them accompanied by hugely hyperplastic connective tissues and intensive cell nucleus.In the 12th week,it was difficult to distinguish presynaptic mem-brane and postsynaptic membrane of motor end-plate as well as ruffle membrane observed by electron microscope.Although syn-aptic structure disorder and z-line discontinuity were found,the parazone and diazone of muscle fiber were clear.Similarly,we couldn't make out the presynaptic membrane and postsynaptic membrane by using high-power microscope,found out no synapsis folds and clearly discovered round-like tiny particles and synaptic vesicles,but the muscular plate structure was distinct.Conclusion The peripheral nerves,motor end plates and skeletal muscles can change beneath the injured plane after spinal cord injury in rats,and the significant changes occur in the 12th week and completely damaged changes appear in the 24th week.关键词
脊髓损伤/大鼠/远端神经元/骨骼肌变化Key words
Spinal cord injury/Rats/Distal neurons/Changes in skeletal muscle分类
医药卫生
