To assess the association between neurogenesis and the development of AD, we examined the changes in APP processing pathways by analyzing the level of APP, the C99/C83 ratio by Western blot (WB), the quantity of soluble Aβ1-42, by enzyme-linked immunosorbent assay (ELISA) and the Aβ plaque density by immunohistochemical analyses. Here, APP is linked to Alzheimer disease.