APP and Alzheimer disease: In the same study, Aβ1-42 oligomers decreased FNDC5 expression in neuro-2a (n2a) mouse neuroblasts and induced a suppressive effect on BDNF expression that was reversed by FNDC5 overexpression, and intranasal BDNF delivery was shown to reduce Aβ aggregation and cognitive decline in the brains of APP/PS1 AD-like mice [220].