24 hr survival after a single 3H-thymidine injection on E20 (posterior coronal)
Figure 128 is a posterior coronal slice through the olfactory peduncle from the same specimen in Figure 127. This slice contains the AOB in a dorsal position, the MOB medially, and the AON laterally. Most cells in the parenchyma are unlabeled, the few labeled cells are most likely locally-multiplying glia or rapidly migrating neurons generated on E20. The AOB has a densely-packed layer of output neurons, surrounded by loosely packed cells in the internal and external plexiform layers. Unlabeled cells outside the olfactory SVZ are the AOB granule cells. In the MOB, the mitral cell layer is the densely-packed cell group sandwiched by the internal and external plexiform layers. The olfactory nerve is full of labeled glial cells that sharply differentiate it from the fibers in the cell-sparse external plexiform layer. The olfactory epithelium is full of labeled cells, some parts separated into superficial and deep proliferating populations.