Photomicrographs of frontal sections through the olfactory bulb of a saline treated control (A, A1) and a ZnSO4 treated mouse (B, B1, C, C1) showing anterograde transport of WGA-HRP. Medial is to the left and dorsal is to the top. As shown in A, all glomeruli in saline treated mice were filled with dense WGA-HRP reaction product. In mice of the Zn- group WGA-HRP reaction product was observed only in the vomeronasal nerve (labeled N in B1 and C1) and the AOB (C, C1). A1, B1, and C1 show details of the areas outlined in the A, B, and C figures.