FNDC5 and infection: Using ELISA and qPCR, shFndc5 infection successfully interfere the LIPUS-drove enhancement of hippocampal Fndc5/irisin in VaD mice (LIPUS vs. shFndc5: Fndc5 mRNA: P = 0.002; Fig. 4B; irisin concentration: P = 0.013; Fig. 4C), but shLuc (control) infection did not exhibit this effect (LIPUS vs. shLuc: Fndc5 mRNA: P = 0.649; Fig. 4B; irisin concentration: P = 0.886; Fig. 4C).