SYP and Alzheimer disease: The protein levels of postsynaptic density 95 (PSD95), synaptophysin and neural cell adhesion molecule (NCAM) were decreased markedly in the hippocampus of the 3 × Tg-AD mice group, while the synaptic degeneration was significantly alleviated through upregulation of the synaptic protein expression in the hippocampal neurons of mice receiving DDB treatment (Figure 6A,B).