24 hr-survival after a single 3H-thymidine injection on E18 (lateral sagittal)
Figure 92. This lateral sagittal slice through the olfactory bulb on E19 shows heavy label uptake after a 3H-thymidine exposure on the morning of E18, like the medial slice from the same specimen in Figure 91. Note that NEP cells are oozing into the lumen of the olfactory recess—as in all E19 specimens. This slice shows more definite separation of layers in the AOB; the output neurons are in a thick clump, and the granule cell layer is more clearly identified outside the olfactory SVZ. In the MOB, the base of the mitral cell layer is still ragged as migrating cells from the internal plexiform layer move in to settle. Heavy label uptake in the olfactory epithelium shows very active proliferation; the epithelium is cut somewhat tangentially, and the superficial and deep separation of labeled cells is not clear.