| Brain photobiomodulation (PBM) therapy using red to near-infrared (NIR) light is an innovative treatment for a wide range of
neurological and psychological conditions. Red/NIR light is able to stimulate complex IVof the mitochondrial respiratory chain
(cytochrome c oxidase) and increase ATP synthesis. Moreover, light absorption by ion channels results in release of Ca2+ and
leads to activation of transcription factors and gene expression. Brain PBM therapy enhances the metabolic capacity of neurons
and stimulates anti-inflammatory, anti-apoptotic, and antioxidant responses, as well as neurogenesis and synaptogenesis. Its
therapeutic role in disorders such as dementia and Parkinson’s disease, as well as to treat stroke, brain trauma, and depression has
gained increasing interest. In the transcranial PBM approach, delivering a sufficient dose to achieve optimal stimulation is
challenging due to exponential attenuation of light penetration in tissue. Alternative approaches such as intracranial and intranasal
light delivery methods have been suggested to overcome this limitation. This article reviews the state-of-the-art preclinical and
clinical evidence regarding the efficacy of brain PBM therapy |