Methacrylate-embedded E19 embryo (posterior coronal)
Figure 104. This is a slice from the same specimen in Figure 103 cut farther back into the olfactory peduncle where the accessory olfactory bulb occupies the dorsal surface. The AOB output neurons—much smaller than mitral cells—form a well-defined clump sandwiched between the external and internal plexiform layers. The granule cells of the AOB are settling deep to the internal plexiform layer. In the MOB, the layers are nearly the same as in Figure 103, except that the granule cell layer is indistinguishable from the olfactory SVZ, that is just outside the columnar cells of the olfactory NEP. The pars externa of the anterior olfactory nucleus may be on either side of the AOB, but the rest of the nucleus is farther back in the peduncle and not in this slice.