Origin and proliferation of astroglia in the immature rat cerebellar cortex. A double label autoradiographic study

The proliferating astroglia cells of the cerebellar internal granular layer (IGL) were studied by a 3H--14C double label autoradiographic technique in 1 mu thick sections of the resin embedded cerebellum of 6-7 day old rats. It was concluded that the proliferating cells undergo repeated mitotic cycles inside the IGL. Thus claims of their acquisition from the external granular layer could be disproved. Calculated from the ratio of 3H- and 3H + 14C-labelled cells, the length of the S phase was 6 hours.