Developmental neuropathology of mouse neocortex following early fetal X-irradiation.

X-irradiation of mice at a dose of 2.0 Gy on days 12 or 13 p.c. results in a clustering of neocortical ventricular-layer cells to rosettes and in the development of focal alterations consisting of glial cells in a typical radial arrangement. Both structures collapse at birth, either due to the invasion by thalamocortical axons, which results in disintegration of the rosettes, or to successive conversion of the glial spongioblasts to rather large astrocytes. The histogenesis of these perinatal events is described with special emphasis on the topographical differences in the developing brain.