Trial of neuronal regeneration after spinal cord injury by implantation of cultured astrocytes and by neurotrophic factor

我们通过脊髓后柱横断建立了脊髓损伤模型。动物受伤后存活，且损伤面积不变。因此，该模型适用于研究脊髓损伤后神经元的恢复。我们培养胎儿星形胶质细胞并用PHA-L标记。先在膜滤膜上培养星形胶质细胞，然后将融合细胞的滤膜涂于损伤腔内。移植的星形胶质细胞在脊髓损伤部位存活，并对损伤轴突有一定的修饰。为了研究中枢神经元损伤的基础数据，我们建立了脑损伤模型。我们研究碱性成纤维细胞生长因子（bFGF）及其受体的表达。我们采用原位杂交法表达信使RNA，免疫染色和Western blotting法表达蛋白质。损伤1 d后梗死周围区神经元和星形胶质细胞中表达bFGF受体mRNA。而FGF mRNA的表达延迟至损伤后3天。另一方面，FGF受体信使RNA的表达发生在术后一天。结果表明，神经元首先表达自己的bFGF受体，如果周围环境没有FGF的供应，它们会重新合成FGF。

We developed a model of spinal cord injury by transection of the posterior column of the spinal cord. The animals survived after injury and the area of injury was constant. Therefore the model is suitable for studying neuronal recovery from spinal cord injury. We cultured fetal astrocytes and marked them by PHA-L. The astrocytes were first cultured on the membrane filter, and the filter with confluent cells was applied to the injured cavity. The transplanted astrocytes survived in the injured site of the spinal cord, and have some modification the injured axons. To study basic data for injury of the central neurons, we then studied the brain injury model. We studied expression of the basic fibroblast growth factor(bFGF)and its receptor. The method we used are in situ hybridization for expression of messenger RNA, and immunostaining and Western blotting for protein expression. The bFGF receptor mRNA was expressed in the neurons and astrocytes of the periinfarcted area one day after injury. Expression of the FGF mRNA however, delayed till 3 days after injury. On the other hand, expression of FGF receptor messenger RNA occurred one day after surgery. The results indicate that neurons express their bFGF receptor firstly, and if there is no supply of FGF from surrounding environments, they make de novo synthesis of FGF.