小鼠小脑皮质的生长发育

目的：探讨小鼠小脑皮质的组织发生过程。方法：应用光镜和电镜技术对胚胎和生后小脑皮质进行形态学观察，对各层厚度和细胞密度进行测量。结果：胚胎12d（E12）小脑原基有室管膜层、套层和边缘层构成，约出生当日（P0）出现外颗粒层、分子层、Purkinje细胞层和内颗粒层。外颗粒层P6／7达最厚，至P20消失。P0至P30内颗粒层细胞逐步分化发育成熟，Purkinje细胞树突树逐渐形成，约P7时Purkinje细胞排列成单层。结论：E12至P0片层化小脑主要经历了细胞增殖、分化与迁移；P0至P30片层化结构逐渐发育成熟，外颗粒层消亡以细胞迁移和凋亡为主，其他各层细胞主要经历了分化发育与凋亡。

Development of the cerebellar cortex in the mouse

The cerebellum is a highly conserved structure in the central nervous system of vertebrates, and is involved in the coordination of voluntary motor behavior. Supporting this function, the cerebellar cortex presents a layered structure which requires precise spatial and temporal coordination of proliferation, migration, differentiation, and apoptosis events. The formation of the layered structure in the developing cerebellum remains unclear. The present study investigated the development of the cerebellar cortex. The results demonstrate that the primordium of the cerebellum comprises the ependymal, mantle, and marginal layers at embryonic day 12 (E12). Subsequently, the laminated cerebellar cortex undergoes cell proliferation, differentiation, and migration, and at about postnatal day 0 (P0), the cerebellar cortex presents an external granular layer, a molecular layer, a Purkinje layer, and an internal granular layer. The external granular layer is thickest at P6/7 and disappears at P20. From P0 to P30, the internal granular cells and the Purkinje cells gradually differentiate and develop until maturity. Apoptotic neurons are evident in the layered structure in the developing cerebellar cortex. The external granular layer disappears gradually because of cell migration and apoptosis. The cells of the other layers primarily undergo differentiation, development, and apoptosis.