E17 to E18 Survival Archived Images-Sagittal
The following images are from a sagittally-sectioned head of an E18 rat embryo exposed to tritiated thymidine on E17–24 hr survival. Note the heavily-labeled cells just outside the germinal zones are now mainly in the diencephalon and forebrain. These are postmitotic young neurons generated ON E17. Note that the banded labeling is prominent outside the neocortical neuroepithelium. Many of the germinal zones in the brainstem have become transformed into the primitive ependyma, and the entire brainstem is becoming more mature; the only primitive area is the cerebellum, where the external germinal layer is now more prominent.