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通过让受孕的SD大鼠于其妊娠第15d(G—15)或第18d(G—18)接受0.5Gy的X-线照射,研究了低剂量X-线照射对其儿鼠中枢神经系统形态发生的影响。被照射的和未经照射的(对照)幼鼠均在生后第7d 或第26d,以混合醛固定液经心灌流。脑组织经常规组织学程序处理后,于光镜和电镜下检查。结果显示:在 G-15和 G-18接受照射并于出生后第26d 取材的鼠脑中,海马和齿状回内散布着一些深染、固缩的小神经元群.多呈双侧分布。其在 G-15和 G-18受照射的幼鼠中的发生率分别为57%和33%。同时在14%～22%的 G-15或 G-18受照射并于出生后第26d 处死的动物中,见到明显的小脑损害,其皮质颗粒层内呈现许多大小不等的透亮小区,其中含有数量减少的异染色的小细胞,细胞周围的神经毡明显变得稀疏。本实验动物海马结构之所以对电离辐射敏感,可用照射时间正好与细胞形态发生阶段相吻合来解释。小脑皮质颗粒细胞的病理改变可能是电离辐射影响了其前驱细胞或外颗粒层中的增殖细胞和/或迁移细胞所致。
The effects of low-dose X-ray irradiation on the morphology of the central nervous system of the infant rat were studied by exposing the pregnant SD rats to 0.5 Gy of X-ray at 15 days of gestation (G-15) or 18 (G-18) The impact of Both irradiated and non-irradiated (control) pups were perfused with mixed aldehyde fixate fluid on the 7th or 26th day after birth. After routine histological processing of brain tissue, the light and electron microscopy examination. The results showed that in the rat brain irradiated with G-15 and G-18 and taken on the 26th day after birth, some deep-stained and constricted small neurons were scattered in the hippocampus and dentate gyrus, mostly distributed in bilateral . Its incidence in irradiated G-15 and G-18 pups was 57% and 33%, respectively. At the same time, in 14% ~ 22% of G-15 or G-18 irradiated animals and sacrificed on the 26th day after birth, obvious cerebellar damage was observed. There were many translucent cells of different sizes in the cortical granules layer With a reduced number of heterochromatic minicells, the nerve foramina around the cells clearly become sparse. The experimental animal hippocampal structure is sensitive to ionizing radiation, available irradiation time exactly coincides with the stage of cell morphology to explain. Pathological changes in cerebellar cortical granulosa cells may be due to ionizing radiation affecting proliferating and / or migrating cells in their precursor or extragranular layers.