Higher-power photomicrograph of the developing OC shown in Figure 3. The left panels are bright-field images, and the right panels are corresponding dark-field images. A, Expression of HGF/SF is detected in the OM underlying the olfactory neuroepithelium. B, Expression of c-met is confined to the portion of the olfactory neuroepithelium lining the OC. C, Expression of tPA is observed throughout the olfactory neuroepithelium. Scale bar, 80 μm. See legend to Figure 3 for abbreviations.