脊髓损伤大鼠远端神经元及骨骼肌的变化  

Change of motor neurons and skeletal muscles distal to the lesion after spinal cord injury in rats

作　　者：王元元[1] 洪毅[2,3] 王雪菲[3] 蔡青[4] 唐和虎[2,3] 李想[2,3] 梁广旭 张军卫[2,3] 

机构地区：[1]北京市第二医院,北京市100031 [2]中国康复研究中心脊柱脊髓外科,北京市100068 [3]首都医科大学康复医学院,北京市100069 [4]首都医科大学实验与测试中心,北京市100069

出　　处：《中国组织工程研究》2014年第33期5323-5328,共6页Chinese Journal of Tissue Engineering Research

摘　　要：背景:目前针对脊髓损伤病灶的研究较多,而对脊髓损伤后远端神经、肌肉及运动终板三者形态结构实时变化观察和研究的文献很少。目的:观察大鼠脊髓损伤后远端肢体神经、运动终板和骨骼肌随时间推移形态学变化的自然病程。方法:将50只雌性SD大鼠随机分为对照组5只(不做处理)、假手术组10只和脊髓损伤组35只,假手术组行单纯椎板切除术,脊髓损伤组在椎板切除基础上,用横断法制成T10完全脊髓损伤模型,然后在第1,2,4,12,24周分别观察3组大鼠坐骨神经-运动终板-内侧腓肠肌的形态变化。结果与结论:1脊髓损伤组大鼠4周时部分有髓神经纤维髓鞘出现板层分离;24周时崩解髓鞘板层已模糊、碎裂髓鞘增多,薄髓与无髓神经纤维较12周时增多。2脊髓损伤组大鼠运动终板在脊髓损伤12周时明显退变突触结构与较完整突触结构并存;24周时已找不到运动终板。3脊髓损伤组大鼠内侧腓肠肌在脊髓损伤24周时,肌细胞融合,细胞核密集,融合细胞间可见大小不一空隙,结缔组织增生更加明显。结果表明大鼠在完全性横断性脊髓损伤后自然病程中,损伤平面以下周围神经、运动终板、骨骼肌的形态结构均呈规律性改变,损伤后12周时已有显著变化,24周时呈结构毁坏性改变。BACKGROUND：The majority of studies focus on the lesions of spinal cord injury, while little evidence is available on the change of morphology and structure of distal nerve, muscle and motor endplates fol owing spinal cord injury. OBJECTIVE：To investigate the time window change of the morphology of motor neurons and skeletal muscles caudal to the lesion after spinal cord injury in rats. METHODS：Fifty healthy adult Sprague-Dawley rats were randomly divided into three groups：control group （n=5;without treatment）, sham operation group （n=10）, and spinal cord injury group （n=35）. The sham operated rats only received laminectomy. In the spinal cord injury group, rats were subject to complete T 10 spinal cord injury by total laminectomy and cord transverse resection. Then the morphological change including sciatic nerve, motor endplate and median gastrocnemius was observed for each group at 1, 2, 4, 12, 24 weeks after injury. RESULTS AND CONCLUSION：（1） The myelin sheath layers of sciatic nerve were separated partial y at 4 weeks in rats with spinal cord injury, the myelin sheaths were fragmented with the regeneration of thin-myelinated and unmyelinated axons at 12 weeks. There was a decrease in myelinated axons and an increase in thin-myelinatedand unmyelinated axons at 24 weeks. （2） The synaptic gutters of motor endplate, the presynaptic and postsynaptic membrane and synaptic space were distinct at 4 weeks in rats with spinal cord injury, the degenerated motor endplates coexsisted with the intact ones at 12 weeks. The motor endplate disappeared at 24 weeks. （3） There was a slight decrease in muscle cross-sectional area at 2 weeks in rats with spinal cord injury, but no structural change was found, the membrane of myocytes was partial y weakened at 4 weeks, the border of myocytes was obscure with hyperplasia of connective tissue at 12 weeks, and myocytes gathered and in fusion at 24 weeks. As natural history of completely transected spinal cord injury in rats, there were significant

关 键 词：组织构建 组织工程 脊髓损伤 坐骨神经 运动终板 腓肠肌 髓鞘板层 突触 透射电镜 

分 类 号：R318[医药卫生—生物医学工程]