Fig. 3. Scanned image of a quadruple-stained coronal section.

A representative 10 µm coronal section (#1057) stained fluorescently for Hoechst (gray), Ulex europaeus agglutinin-1 (green), olfactory marker protein (magenta), and vesicular glutamate transporter 2 (blue). The image was taken on a PANNORAMIC MIDI II fluorescence digital slide scanner as an extended-focus three-level z-stack. The dimensions of the image are ~1.0 cm wide by ~1.5 cm long. The perpendicular plate of the ethmoid bone (septum) divides the left and right nasal cavities, and the upper part of the perpendicular plate (crista galli) separates the two olfactory bulbs. The nasal cavity is lined by nasal epithelium, the majority of which is respiratory epithelium. The dorsal-superior aspect of the nasal cavity harbors olfactory epithelium, as defined by the presence of OSNs. On the lateral aspect, the olfactory epithelium covers the superior turbinate, and on the septal aspect, it extends below the position equivalent to the curvature of the superior turbinate. Four thick white bars indicate the inferior boundaries of the olfactory epithelium on the superior turbinates and the septum. Within the lamina propria, axons of OSNs group into olfactory axon fascicles of progressively larger diameter that form macroscopically visible fila olfactoria, which traverse ipsilaterally the cribriform plate toward the ipsilateral olfactory bulb. The lamina propria also contains a dense network of arterial vasculature (two asterisks indicate accessory olfactory arteries). Rectangles (a–f) are displayed at higher magnification in Fig. 4a–f; the position of the letter informs the orientation of the high-magnification view. Small tissue folds in the nasal mucosa, mostly in the epithelium, appear as bright white stripe-like patches. The left side of the image corresponds to the right side of the head. lat, lateral; sup, superior.