大鼠视网膜内髓鞘形成模型的建立与研究

目的研究体外培养的大鼠纹状体神经干细胞在植入同种视网膜后,向少突胶质细胞分化并产生髓鞘的过程,观察髓鞘形成对视网膜结构的可能影响,建立一种中枢神经髓鞘体内发育的新模型.方法将体外传代培养的胚胎纹状体神经干细胞植入新生大鼠的玻璃体腔内,在移植后不同时期观察视网膜内髓鞘的出现部位以及扩展趋势,利用不同染色方法对标本进行检验分析,利用透射电镜进行超微结构观察.结果移植细胞4周后部分视网膜内开始出现成束髓鞘,只分布于神经纤维层.髓鞘束出现的比例、分布面积和形态变化与移植后动物的存活时间相关.电镜观察可见节细胞轴突外包绕有结构正常的中枢神经样髓鞘.较厚的髓鞘束对视网膜节细胞的分布产生一定影响.结论大鼠纹状体神经干细胞可在同种视网膜内向成熟少突胶质细胞分化,视网膜神经纤维层具有促使髓鞘形成的作用;本实验可能为研究少突胶质细胞分化及髓鞘生成机制提供新的在体模型.

ESTABLISHMENT AND STUDY OF THE MYELIN FORMATION MODEL IN RAT RETINA

Objective The purpose of this experiment is to study the in vivo differentiation and myelin formation of rat striatal neural precursor cells after transplantation into homogeneous retina, observe the order of myelination and its influence on the structure of retina, establish an animal model of CNS myelin formation in vivo. Methods Passage cultured striatal neural precursor cells from embryonic Sprague-Dawley rats were transplanted into the vitreous cavity of neonatal rats. In different stages after transplantion, myelin formation in retina was observed under light and electron microscope and analysed with different stained methods. Results Bundles of myelin appeared in parts of retina 4 weeks later. The distribution and morphology of myelined area expanded with prolonged survival time after cell transplantation. Oligodendrocyte wrapped the naked axons and formed normal myelin limited in the nerve fiber layer. Myelination influenced the distribution of local retinal ganglion cells. Conclusion Striatal neural precursor cells could differentiate into oligodendrecytes and formed myelin after transplanted into retina and the naked axons in retina promoted the myelin formation. This model provides a new method to study the myelin formation and myelin-axon interaction in vivo.