Norton S, Kimler B F
University of Kansas Medical Center, Kansas City 66103.
Radiat Res. 1990 Nov;124(2):235-41.
Pregnant rats were exposed to gamma radiation from a 137Cs irradiator on gestational Day 15. Fetuses that received 0.25, 0.5, 0.75, or 1.0 Gy were examined 24 h after irradiation for changes in the cells of the cerebral mantle of the developing brain. The extent of changes following 0.5 Gy was studied at 3, 6, 12, or 24 h after exposure. Cortical thickness of the cerebral mantle was not significantly altered. The number of pyknotic cells, number of macrophages, nuclear area, and number of mitotic cells were altered in a dose-related way. The number of pyknotic cells was significantly increased at all doses. A positive correlation between the number of pyknotic cells and the number of macrophages developed with time. At 3 h after irradiation about 60% of pyknotic cells were found in the subventricular zone and about 25% in the intermediate zone and cortical plate. The number of such cells in the upper layers of the cortex steadily increased up to 24 h, at which time about 70% of pyknotic cells were in these two layers. The relationship of the movement of pyknotic cells to migration of postmitotic neuroblasts is discussed.
怀孕大鼠在妊娠第15天接受来自137Cs辐照器的γ射线照射。接受0.25、0.5、0.75或1.0 Gy辐射的胎儿在辐照后24小时接受检查，以观察发育中大脑脑皮质细胞的变化。在照射后3、6、12或24小时研究0.5 Gy照射后的变化程度。脑皮质的厚度没有显著改变。固缩细胞数量、巨噬细胞数量、核面积和有丝分裂细胞数量呈剂量相关变化。所有剂量下固缩细胞数量均显著增加。固缩细胞数量与巨噬细胞数量之间随时间呈正相关。照射后3小时，约60%的固缩细胞位于脑室下区，约25%位于中间区和皮质板。皮质上层此类细胞的数量在24小时内稳步增加，此时约70%的固缩细胞位于这两层。本文讨论了固缩细胞的移动与有丝分裂后神经母细胞迁移的关系。
