PSEN1 and Alzheimer disease: Interestingly, the present study also found that APP/PS1 transgenic AD model mice had increased functional activities in some brain regions compared with wild type mice, and the brain regions with increased ALFF, fALFF, and ReHo were mainly the dentate gyrus (left), hippocampus (left), visual cortex (right), insula (right), and temporal cortex (right).