APP and Alzheimer disease: In experimental models of AD, dendritic complexity was demonstrated to be reduced in the hippocampi of amyloid precursor protein/presenilin 1 (APP/PS1)-TG mice [114,277,280], apolipoprotein E4 (APOE4)-TG mice [281], and primary cultured hippocampal neurons of miR-34c-transfected mice [282].