Far Infrared Light Irradiation Enhances Microglial Aβ Clearance and Ameliorates Cognitive Deficit in Alzheimer’s Disease-Like Mice

Abstract BackgroundExposure to sunlight may decrease the risk of developing Alzheimer’s disease (AD). However, the wavelength of the light with this therapeutic effect and the related mechanism remain elusive. MethodWe evaluated the behaviors of AD-like mice treated by light of different wavelengths and showed that far infrared (FIR) light (λ = 3 - 25 μm) had a great potential in ameliorating cognition dysfunction. ResultsFIR light treatment promoted the recruitment of microglia to Aβ plaques, enhanced the phagocytosis of Aβ and decreased neuroinflammatory responses. Thus, FIR light treatment had a broad spectrum of beneficial effects on the brain, including alleviating the Aβ burden and neuroinflammation. ConclusionsAs a result, FIR light treatment ameliorates the learning and memory impairment in AD-like mice. Our findings uncovered a previously unappreciated function of FIR light, suggesting that FIR light treatment may be a potential therapeutic strategy for AD.