Photobiomodulation Therapy and the Glymphatic System: Promising Applications for Augmenting the Brain Lymphatic Drainage System

• Published in: International journal of molecular sciences Vol. 23; no. 6; p. 2975
• Main Authors: Salehpour, Farzad, Khademi, Mahsa, Bragin, Denis E, DiDuro, Joseph O
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 10.03.2022; MDPI
• Subjects: Alzheimer's disease; Amyloid beta-Peptides - metabolism; amyloid-beta; Animals; Blood-brain barrier; Brain - metabolism; Central nervous system; Cerebrospinal fluid; glymphatic system; Glymphatic System - metabolism; Homeostasis; Inflammation; Light therapy; Low-Level Light Therapy; Lymphatic system; Lymphatic System - metabolism; Membrane permeability; meningeal lymphatic vessels; Metabolism; Metabolites; near-infrared light; neurodegenerative diseases; Neurodegenerative Diseases - metabolism; Neuroprotection; Parkinson's disease; photobiomodulation; Physiology; Review; Sinuses; Toxins; Traumatic brain injury; Vasodilation; amyloid-beta; photobiomodulation; meningeal lymphatic vessels; near-infrared light; neurodegenerative diseases; Alzheimer’s disease; glymphatic system; Parkinson’s disease
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms23062975

The glymphatic system is a glial-dependent waste clearance pathway in the central nervous system, devoted to drain away waste metabolic products and soluble proteins such as amyloid-beta. An impaired brain glymphatic system can increase the incidence of neurovascular, neuroinflammatory, and neurodegenerative diseases. Photobiomodulation (PBM) therapy can serve as a non-invasive neuroprotective strategy for maintaining and optimizing effective brain waste clearance. In this review, we discuss the crucial role of the glymphatic drainage system in removing toxins and waste metabolites from the brain. We review recent animal research on the neurotherapeutic benefits of PBM therapy on glymphatic drainage and clearance. We also highlight cellular mechanisms of PBM on the cerebral glymphatic system. Animal research has shed light on the beneficial effects of PBM on the cerebral drainage system through the clearance of amyloid-beta via meningeal lymphatic vessels. Finally, PBM-mediated increase in the blood-brain barrier permeability with a subsequent rise in Aβ clearance from PBM-induced relaxation of lymphatic vessels via a vasodilation process will be discussed. We conclude that PBM promotion of cranial and extracranial lymphatic system function might be a promising strategy for the treatment of brain diseases associated with cerebrospinal fluid outflow abnormality.