Study on the condition for central nerve regeneration-grafting of ependymal cells and cell proliferation by neuregulin-

将成年大鼠（Wistar）第4脑室的脉络膜丛切成小块，移植到同一品系成年大鼠脊髓C2水平的背索内。电镜和荧光组织化学显示，移植的脉络膜丛室管膜细胞与生长的轴突密切相互作用，支持再生轴突的大量生长。在坐骨神经注射HRP显示，大量HRP标记的股薄束再生纤维在移植7天后延伸到移植物中。这些来自股束的再生轴突维持了至少10个月，其中一些轴突向后伸长至背束。移植后8 ~ 10个月大鼠在病灶吻侧约5mm处记录长时间诱发电位。这些发现表明，脉络膜丛室管膜细胞在体内具有促进轴突生长的能力，这表明它们可能是促进脊髓神经再生的有希望的移植物共培养实验：将出生后1 ~ 5天的小鼠第4脑室脉络膜丛机械分离，并将其镀于铜连蛋白包被培养皿中。培养3周时室管膜细胞呈单层扩散，内皮细胞较少。在脉络膜丛室管膜细胞单层上共培养背根神经节（DRG）。结果表明，在S100 β染色的室管膜细胞表面，神经元延伸出许多具有精细分支的长神经突。与室管膜细胞相比，星形胶质细胞和层粘连蛋白包被板上培养的DRG神经元具有更少、更短的初级神经突和更少的分支。这些结果表明，脉络膜丛室管膜细胞在体外培养的DRG神经元中具有促进神经突生长的能力。

1 Grafting into spinal cordThe choroid plexus from the 4th ventricle of adult rats (Wistar) were minced into small fragments and grafted into the dorsal funiculus at the C2 level in adult rat spinal cord from the same strain. Electron microscopy and fluorescence histochemistry showed that ependymal cells of the grafted choroid plexus intimately interacted with growing axons, serving to support the massive growth of regenerating axons. HRP injection at the sciatic nerve showed that numerous HRP-labeled regenerating fibers from the fasciculus gracilis extended into the graft 7 days after grafting. These regenerating axons from the fasciculus gracilis were maintained for at least 10 months, with some axons elongating rostrally into the dorsal funiculus. Evoked potentials of long duration were recorded at a level ca. 5mm rostral to the lesion in the rats 8 to 10 months after grafting. These findings indicate that choroid plexus ependymal cells have the ability to facilitate axonal growth in vivo, suggesting that they may be a promising candidate as graft for the promotion of nerve regeneration in the spinal cord.2 Coculture experimentChoroid plexuses from the 4th ventricle of postnatal day-1 to -5 mice, were mechanically dissociated and plated in bronectin-coated culture dishes. Ependymal cells spread in monolayer with few endothelial cells at 3-week culture. Dorsal root ganglia (DRG) were cocultured on the choroid plexus ependymal cell monolayer. It was demonstrated that neurons extended many long neurites with elaborate branchings on the surface of S100 β-stained ependymal cells. In contrast, DRG neurons cultured on the astrocytes and laminin-coated plates had much fewer and shorter primary neurites with fewer branches than those cultured on the ependymal cells. These results suggest that choroid plexus ependymal cells have a great capacity to promote neurite outgrowth from DRG neurons in vitro.