2 hr survival after a 3H-thymidine injection on E18 (lateral sagittal)
Figure 79. A lateral sagittal slice through the olfactory bulb and nasal cavity from the same specimen shown in Figure 78. The NEP is the most active region of label uptake, followed by a fair number of locally-multiplying cells in the surrounding SVZs, especially in the basal ganglia and cerebral cortex. Layers are like those in Figures 74 and 78. Differentiating neurons outside the NEP are expanding the parenchyma in all parts of the forebrain. Layers are becoming distinct in the bulb, and an MOB and AOB are easily distinguished. The olfactory epithelium is actively proliferating with heavy label uptake along the lumen of the nasal cavity and another layer of uptake at the superficial border of the epithelium—indicating two different populations of proliferating cells.