[Cellular composition of cerebral cortex in rat fetuses exposed to low-dose fractionated radiation]

Using histological and morphometric methods, the peculiarities of sensomotor cortex morphogenesis were studied in rat fetuses subjected to fractionated gamma-irradiation in the period from 6th to 18th prenatal days in doses of 5, 25, 50 and 25-75 cGy. It that an Exposure to a fractionated radiation was found to negatively affect stem cell proliferation in the developing cortex and to increase the intensity of cell destruction in proportion to the radiation dose. The absolute number of macroglial cells was increased in all the cellular zones of developing cortex, that could be the result of both reactive stimulation of their production due to functional insufficiency, and of accelerated transformation of radial gliocytes into macroglia. Irradiation with the doses of 5-75 cGy caused the deceleration of neuroblast migration into the primary cortex, as indicated by the reduction of cell number in neural differon in the neocortical anlage and cell number growth in deeper layers of the developing cortex.