Roper S N, Abraham L A, Streit W J
Department of Neurological Surgery, University of Florida and Gainesville VA Medical Center, 32610-0265, USA.
Dev Neurosci. 1997;19(6):521-8. doi: 10.1159/000111249.
In utero exposure of fetal rats to gamma-irradiation produces diffuse cortical dysplasia and neuronal heterotopia. This study examined the effects of in utero irradiation on radial glia and astrocytes in the perinatal period in order to better understand the specific mechanisms which produce cortical dysgenesis in this model. Fetal rats were exposed to 225 cGy of gamma-irradiation on embryonic day 17. Vibratome sections were processed for cresyl violet staining and immunohistochemistry with Rat-401 and an antibody for glial fibrillary acidic protein (GFAP) on E20, P0, P2, and P4. In utero irradiation produced a profound disruption of the radial glia which lasted throughout the perinatal period. This injury coincided with the location of the most severe cortical dysplasia in this model. In addition, there was increased GFAP immunoreactivity in the cortex and the striatum when compared to nonirradiated controls on P0, P2, and P4. Our results demonstrate that in utero irradiation has a lasting, injurious effect on radial glia and also incites a reactive astrocytic response. This suggests that disruption of radial glial fibers by gamma-irradiation is a major factor in the pathogenesis of cortical dysgenesis in this model.
将胎鼠在子宫内暴露于γ射线照射会导致弥漫性皮质发育异常和神经元异位。本研究检测了子宫内照射对围产期放射状胶质细胞和星形胶质细胞的影响，以便更好地理解在该模型中导致皮质发育异常的具体机制。在胚胎第17天，将胎鼠暴露于225 cGy的γ射线照射下。在胚胎第20天、出生后第0天、第2天和第4天，将振动切片进行甲酚紫染色以及用Rat-401和胶质纤维酸性蛋白（GFAP）抗体进行免疫组织化学染色。子宫内照射导致放射状胶质细胞严重破坏，这种破坏在整个围产期持续存在。这种损伤与该模型中最严重的皮质发育异常的位置一致。此外，与未照射的对照组相比，在出生后第0天、第2天和第4天，皮质和纹状体中的GFAP免疫反应性增加。我们的结果表明，子宫内照射对放射状胶质细胞有持久的损伤作用，并且还引发反应性星形胶质细胞反应。这表明γ射线照射对放射状胶质纤维的破坏是该模型中皮质发育异常发病机制的一个主要因素。
