PHYSIOLOGICAL EFFECTS OF PHOTOBIOMODULATION THERAPY IN THE TREATMENT OF MULTIPLE CONCUSSIVE TRAUMATIC BRAIN INJURY
Denis E. Bragin1,2,3, Fazle Kibria1, Olga A. Bragina1, Eduardo Colombari4, Alexey Trofimo5, Dmitriy Atochin6, Satoshi Kashiwagi6, Patric Stanton3, Edwin Nemoto2
1 Lovelace Biomedical Research Institute, Albuquerque, NM, USA
2 University of New Mexico School of Medicine, Albuquerque, NM, USA
3 New York Medical College, Valhalla, NY
4 São Paulo State University, Araraquara, Brazil
5 Privolzhsky Research Medical University, Nizhny Novgorod, Russia
6 Massachusetts General Hospital, Harvard University, Charlestown, MA, USA
Abstract
Repetitive mild traumatic brain injury (rmTBI) disrupts glymphatic and meningeal lymphatic clearance, impairs cerebrovascular function, and erodes synaptic plasticity, contributing to secondary injury and long-term neurological deficits. No therapies specifically target these pathways. We tested whether near-infrared II (NIR-II) transcranial photobiomodulation (tPBM; 1270 nm) delivered in the acute post-injury window could restore vascular and clearance function and mitigate sequelae in mice.
Adult male C57BL/6 mice received three consecutive closed-head impacts to the left medial prefrontal cortex. tPBM (10 mW/cm², ~27 J/cm² per session) began 4 h after the final injury and continued twice daily for 3 days (or as a single acute session). Outcomes included laser speckle contrast and multispectral imaging of perfusion and oxygenation, piezoelectric intracranial pressure waveform analysis, neurological severity scores, Evans blue drainage to deep cervical lymph nodes, serum GFAP and UCH-L1 kinetics, and medial prefrontal cortex long-term potentiation electrophysiology at 2 weeks.
Acute tPBM improved cortical microcirculation, tissue oxygenation, intracranial compliance, and neurological scores. Multiday treatment sustained recovery of regional cerebral blood flow, functional capillary density, and metabolic status while enhancing meningeal lymphatic drainage and accelerating biomarker clearance. rmTBI-induced LTP deficits were fully rescued to near-control amplitudes. These findings indicate that NIR-II tPBM simultaneously improves cerebrovascular function, enhances lymphatic clearance, accelerates biomarker egress, and restores synaptic plasticity after rmTBI, supporting its potential as a non-invasive acute therapy.
Speaker
Denis Bragin
Lovelace Biomedical Research Institute
United States
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