CAJ | 학술논문

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。
배경：목전침대척수손상병조적연구교다，이대척수손상후원단신경、기육급운동종판삼자형태결구실시변화관찰화연구적문헌흔소。 　　목적：관찰대서척수손상후원단지체신경、운동종판화골격기수시간추이형태학변화적자연병정。 　　방법：장50지자성SD대서수궤분위대조조5지(불주처리)、가수술조10지화척수손상조35지，가수술조행단순추판절제술，척수손상조재추판절제기출상，용횡단법제성T10완전척수손상모형，연후재제1，2，4，12，24주분별관찰3조대서좌골신경-운동종판-내측비장기적형태변화。 　　결과여결론：①척수손상조대서4주시부분유수신경섬유수초출현판층분리；24주시붕해수초판층이모호、쇄렬수초증다，박수여무수신경섬유교12주시증다。②척수손상조대서운동종판재척수손상12주시명현퇴변돌촉결구여교완정돌촉결구병존；24주시이조불도운동종판。③척수손상조대서내측비장기재척수손상24주시，기세포융합，세포핵밀집，융합세포간가견대소불일공극，결체조직증생경가명현。결과표명대서재완전성횡단성척수손상후자연병정중，손상평면이하주위신경、운동종판、골격기적형태결구균정규률성개변，손상후12주시이유현저변화，24주시정결구훼배성개변。
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-myelinated and 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 changes in morphology of peripheral nerve, motor endplate and skeletal muscles caudal to the lesion at 12 weeks, and the changes were destructive at 24 weeks.