E13 methacrylate-embedded embryo–horizontal slice
Figure 10 is a horizontal slice through the ventral anterior part of the telencephalon at the level of the deepest invagination of the olfactory placode and olfactory epithelium. The presumptive olfactory NEP is lateral to the presumptive septal NEP and anterior to the bulge (eminence) in the lateral telencephalic wall—the presumptive basal telencephalic NEP. The zone of larger cells outside the basal telencephalic NEP are the pioneer neurons in the basal telencephalon. The most superficial cells are most likely those generated on E11; the dense neurons in a deeper location were probably generated on E12; the NEP itself is still busy generating neurons on E13.