Figure 5.

Olfactory bulbectomy enhances horizontal basal cell-derived neurogenesis. Unilateral olfactory bulbectomy was performed on 2-month-old K5.CrePR1 tg/+: R26R^+/− mice. Thirty days later, olfactory epithelium (OE) on the contralateral side of the lesioned bulb (control) and on the ipsilateral side of the lesioned bulb (lesioned) was examined for β-gal activity by X-gal staining (A–F). Both control (A, C, E) and lesioned (B, D, F) tissues shown are from the same animal. (A, C, E) represent every third section through the largest cluster found in control OE, whereas (B, D, F) represent every third section through the largest cluster found in lesioned OE. Arrows point to sustentacular cells, and asterisks indicate cells of Bowman’s glands and ducts (B, D, F). Lesioned OE was examined for β-gal/OMP (G) and β-gal/Notch 2 (H) expression by double immunofluorescence. Dotted lines indicate the position of the basal lamina. The arrow points to a β-gal⁺/OMP⁺ olfactory receptor neuron (G). Arrowheads point to β-gal⁺/Notch 2⁺ sustentacular cells (H). Scale bars = 60 µm (A–F) and 60 µm (G, H). Abbreviations: β-gal, β-galactosidase; OMP, olfactory marker protein.