目的探讨Reelin在皮质片层化形成及细胞分化、极性化中的作用及相关机制。方法取reeler小鼠和野生型(WT)小鼠受孕17 d(E17)至出生21d(P21)各年龄点脑部共96例。免疫荧光标记技术与5’-溴脱氧尿嘧啶核苷(Brd U)法检测两组小鼠大脑发育中放射状胶质细胞、增殖的神经干细胞及极性蛋白的表达,并使用Nissl染色技术及Di I示踪技术分别对新皮质分子层发育、海马CA1区锥体细胞极性方位以及皮质锥体细胞极性程度进行统计。结果 Reeler小鼠大脑发育中齿状回内放射状胶质细胞数量减少,极性紊乱,Brd U阳性细胞散在分布,数量减少;由于极性细胞未得到适当的终止信号越过皮质Ⅱ层进入分子层,皮质片层化紊乱;大脑皮质及海马锥体细胞极性发生改变。结论 Reelin在神经细胞迁移、神经元增殖和皮质片层化的过程中发挥重要作用,尤其对锥体细胞极性起着至关重要的影响。
Objective To investigate the role of Reelin in the process of cortical lamination, cell differentiation and polarization as well as the relevant regulatory effects of Reelin signaling pathway. Methods A total of 96 wild-type (WT) mice and reeler mice from embryonic day 17 (El7) to postnatal day 21 (P21) were used in this study. The radial glial cells, neural stem cells, and polarity protein were visualized by utilizing immunofluorescent labeling, Nissl staining,5- bromo-deoxyuridine (BrdU) assay and DiI tracing method. The polarity of pyramidal cells in cerebral cortex and hippocampus were also measured. Results Comparing with WT mice, the cortical lamination was disordered due to the lack of Reelin in reeler mice. The orientations of radial glial cells were disorder accompanied with number decreases. BrdU positive cells were arranged in dispersion accompanied with number increase. Conclusion Reelin plays an important role in the development of neuronal migration, neural proliferation and cortical lamination, especially in the process of polarization of pyramidal cells.