Fig. 5. The CDK inhibitors p16Ink4a, p19Ink4d, and p21 Cip1 are rather localized in differentiated neurons in the developing and mature OE. A, lectin histochemistry with UEA and DBA on comparative sections were used to localize differentiating and mature neurons, respectively, in the OE of newborn mice. Arrowhead, the basal lamina (bl) lining the OE. Some labeled cells are indicated by an arrow; nc, nasal cavity; ch, chorion; bc, basal cells; on, olfactory neurons; sc, supporting cells; scale bar, 100 µm. Immunohistochemical localization at a higher magnification of GAP 43, a marker of differentiating neurons. Scale bar, 40 µm; nc, nasal cavity; sc, supporting cells; on, olfactory neurons; bc, basal cells; ch, chorion; arrowhead, basal lamina. B, immunohistochemical localization of the CDK inhibitors p16Inka, p19Ink4d, and p21Cip1 in the olfactory mucosa from newborn mice. C, immunohistochemical localization of p16Ink4a, p21Cip1, and, for comparison, Gap43 in the olfactory mucosa of adult mouse.