This study established changes in FC and investigated the relationship between FC and cognitive decline in an Aβ mouse model of AD, Cg-Tg(APPswe,PSEN1dE9)85Dbo (APP/PS1) throughout disease progression, including before plaque deposition, at the beginning stage of plaque deposition, and after significant plaque deposition throughout the brain. This evidence concerns the gene PSEN1 and Alzheimer disease.