Histological alterations in the fetal mouse cerebellum after neutron irradiation: a light and electron microscopic...

Histological effects of in utero neutron irradiation (0.5 Gy) were investigated in fetal mouse cerebellum. Irradiation was performed on the 18th embryonic day. Histological alterations were examined at 2, 6 and 12 h after irradiation. The effect was most pronounced in the EGL, 6 h after irradiation. In some cells (about 24%) karyopycnosis, destruction of cytoplasmic organelles and shrinkage were observed. Remnants of destroyed cells--the pycnotic nuclei with some cytoplasmic debris around them--were rapidly phagocytized by the surrounding cells. In addition to glial elements, the EGL germinal cells also showed phagocytic activity. Dense particles appearing light-microscopically as pycnotic nuclei, proved to be mostly remnants of destroyed, phagocytized cells under electron microscope.