X-ray irradiation of mice and morphological analysis. A, X-ray irradiation was performed on anaesthetized adult mice placed in a circular Perspex pie chamber, covered with a lead shield (red) to protect the whole body except the nose snout. The OB were protected from irradiation, leaving the ON exposed. B,C, Photomicrographs showed the anatomy of the mouse ON stained with H&E. B, Coronal section/anteroposterior section of the ON showing the approximate location of the 5 areas analyzed for all immunohistochemical analysis, corresponding to the middle of the nasal septum (1), one more superior and one more inferior area of both the left (2, 3) and right (4, 5) turbinates. C, Higher magnification of the ON at the level of the turbinates, showing the basal lamina (BL) in the basal layer, the sustentacular cell nuclei layer (SUS) in the apical layer, the olfactory sensory neurons (OSN) in the intermediate layer and globose basal cells (GBC) also in the basal layer, and the underlying lamina propria (LP). * Bowl-like areas.