Exploring the effect of phototherapy of Alzheimer disease by advanced optical imaging in Alzheimer's disease mice model

40-Hz visual stimulation (VS) and near-infrared (NIR) light transcranial photobiomodulation (PBM) have been increasingly receiving attention in phototherapy of Alzheimer disease (AD). Both of them can be effectively employed to suppress the progression of AD. The present report includes a comparative study of different light stimulation parameters (40Hz pulsed irradiation from 808 nm laser or visible LED) to assess the therapeutic efficacy. Our research has revealed that PBM irradiation with AD mice model displayed the considerable attenuation of the accumulation of amyloid-β peptide (Aβ) plagues by using fluorescence staining and two-photon excited fluorescence (TPEF) microscopy of Aβ peptide plaques in the brain slices. Meanwhile, we also evaluated the Aβ plagues by in vivo imaging which combined TPEF and coherent anti-Stokes Raman scattering microscopy. The cerebral amyloid angiopathy and multiple Aβ plagues was much less pronounced in AD mice which were treated by PBM.