中文摘要：

目的：分离大鼠胚胎的脊髓神经干细胞进行体外培养，探讨维甲酸（RA）、音猬因子（Shh）诱导其向运动神经元样细胞分化。方法：应用无血清培养技术分离培养脊髓神经干细胞，通过5-溴-2-脱氧尿苷标记、免疫荧光显色检测细胞增殖、分化情况；培养液分组添加Shh、RA或shh＋RA，观察神经干细胞向运动神经元样细胞的分化情况。结果：大鼠胚胎脊髓可成功分离神经干细胞，分化后可表达神经元、星形胶质细胞的特异性抗原；诱导分化后结果显示Shh组未检测到胆碱乙酰转移酶阳性细胞，RA组为20．63％，shh＋RA组为66．84％，其差异具统计学意义。结论：从大鼠胚胎脊髓可成功分离神经干细胞，Shh、RA可不同程度地诱导脊髓神经干细胞分化为运动神经元样细胞。

英文摘要：

Objective： To explore the effect of retinoic acid （RA）, sonic hedgehog （Shh） and their mixture on in vitro differ- entiation of rat spinal cord derived neural stem cells into motor neuron like cells. Methods： Neural stem cells from the rat spinal cord were isolated and cultured in serum-free medium, labeled by 5-bromo-2-deoxyuridine （BrdU）, and then identified by means of single or double irnmunofluorescence staining against nestin and neural cell specific antigens. After adding RA, Shh or their mixture, the differenatiation of neural stem cells into motor neuron like cells was detected. Results： Neural stem cells derived from the rat embryonic （El） 14） spinal cord expressed nestin. After being induced with RA, 20. 63% cells dis- played positive to CHAT, and increased to 66.84% when the additional Shh was added. No ChAT positive cell was found in Shh treated neural stem cells. Conclusion ： Shh can enhance the capability of RA that induce the rat embryonic spinal cord derived neural stem cells into motor neuron like cells, though Shh cannot induce the neural stem cells into motor neuron like cells.