FIGURE 3.

Representative images of sections of the nasal mucosa stained with antibodies against OMP, SOX2, and GAP43 (magnification, 200×). OMP⁺ mature olfactory receptor neurons (ORNs), SOX2⁺ ORN progenitors, and GAP43⁺ immature ORNs in the epithelium were identified by immunohistochemical staining (brown). On day 30, mature OMP⁺ ORNs were sparse (red arrowheads), whereas GAP43⁺ immature ORNs (black arrowheads) were more frequently observed in the epithelium of the nasal septum (NS). In the upper lateral (DL) area, SOX2⁺ cells (black arrows) but no GAP43⁺ or OMP⁺ cells were present in the epithelium. On day 90, neither GAP43⁺ immature ORNs nor OMP⁺ mature ORNs were present in the epithelium of the NS or DL area. Graphs show the number of each cell type per 500 μm of basal layer length. Asterisks indicate a significant difference between the treated and untreated groups. Daggers indicate a significant difference between time points. **P < 0.01; ****P < 0.0001, ^††††P < 0.0001 (n = 6, two-way analysis of variance).