Methacrylate-embedded E20 embryo in the horizontal plane (dorsal)
Figure 116 grazes the dorsal surfaces of the accessory and main parts of the olfactory bulb in the horizontal plane of an E20 specimen. The slice tangentially cuts through all layers, making them appear thicker than a perpendicular cut. The smaller AOB output neurons are easily distinguished from the larger mitral cells with densely staining cytoplasm. The horizontal cutting plane is always the best to show migration streams, and many spindle-shaped cells are in the MOB internal plexiform layer, which merges with the same layer in the AOB.