We found that the AD mice at 8 months old showed a significant neuronal and dendritic loss in the hippocampus compared to WT control mice (25.9% reduction of NeuN, P <0.01; 35% reduction of MAP-2, P <0.0001; 13.5% reduction of synaptophysin, P <0.05; Fig. 5B, C, E), whereas THz waves exposure remarkably reversed the neuronal and dendritic loss in the AD-THz mice compared to the AD control mice, as shown by the changes of positive staining area fraction (24.1%, 34.2%, and 14.4% increase of NeuN, MAP-2, and synaptophysin, respectively, all P <0.05; Fig. 5B, C, E). This evidence concerns the gene SYP and Alzheimer disease.