不同发育阶段视神经移植物对横断成年大鼠视神经再生修复的影响

Effects of transplanted optic nerve of different ontogenetic stages on regeneration of axons in the optic nerve of adult rat

目的观察不同发育阶段大鼠视神经移植物对成年大鼠中枢神经损伤再生的影响。方法将不同发育阶段的视神经移植到成年大鼠视神经的断端,并与其自身的坐骨神经移植物作对照,运用HE染色、镀银染色及神经示踪等方法观察不同发育阶段大鼠的视神经移植物对成年大鼠横断视神经修复的影响。结果胚胎18天大鼠视神经移植物与坐骨神经移植物一样,在移植到成年大鼠视神经后20天,有大量的轴突穿过了移植区,经HRP伤侧眼球内注射顺行示踪显示,在视神经到达的靶区上丘出现了阳性标记的神经元,但这种现象在出生后大鼠视神经移植物的移植后从未见到,但如果移植物愈早,那么成年大鼠视神经近侧断端长出的纤维就愈多愈长。结论在大鼠中枢神经系统成熟少突胶质细胞的膜上可能存在着抑制神经元突起生长的物质,这些物质可抑制损伤中枢神经系统神经纤维的再生延长及功能重建。

Objective To explore the effects of transplanted optic nerve of different ontogenetic stages on the re- generation of axons in the optic nerve of adult rat. Methods The implants of optic nerve in different ontogenetic stages were transplanted into the gap of transected optic nerve of adult rat, while the sciatic nerve as a control; HE staining, sil- ver staining and nerve tracing were used to detect the axon regeneration of optic nerve in adult rats. Results The same as the sciatic nerve implants, a lot of axons got through the gap of transected optic nerve of adult rat 20 days later in the group that the optic nerve implants of embryonic day 18 rat were grafted, and the HRP nerve tracing demonstrated that the tracer got to the colliculus superior which is the target of optic nerve, but such a situation was never observed in the implantations of other ontogenetic stage of optic nerve graft, the younger the grafts, the more the neurite of optic nerve stump of the adult rat and the longer that extended. Conclusion drocyte from the CNS of rat~ they can inhibit the neurite regeneration Some neurite growth inhibitors must attach to oligoden- and functional reestablishment of injured CNS nerve fibers.