Age-related changes in dividing cells of the olfactory epithelium of the maturing guinea pig.

Changes in dividing cells of the olfactory epithelium from guinea pigs of different ages were examined by immunohistochemical staining using anti-proliferating cell nuclear antigen antibody. Numerous dividing cells were scattered diffusely in the basal layer of the olfactory epithelium at 1 and 2 months following birth and then gradually decreased with maturation until 4 months. Findings then remained constant between 4 and 24 months. Subsequently, cell numbers were found to decrease as animals became older. The number of olfactory receptor cells did not vary significantly between 1 and 30 months. Although no correlation could be found between the numbers of dividing cells and olfactory receptor cells, it is still possible that the longevity of the olfactory receptor cells changes to maintain the overall size of the neuronal population.