The pyramidal cell layer (PCL) and the stratum radiatum (SR) of the CA1 region and granular cell layer (GCL) of the dentate gyrus (DG) were systematically evaluated firstly in 3-month-old mice, an age when APP/PS1 mice present minimal or no amyloid plaques and cognitive impairment [37]. The gene discussed is APP; the disease is Cognitive impairment.