Near‐infrared light is neuroprotective in a monkey model of Parkinson disease

Abstract

Objective: To examine whether near-infrared light (NIr) treatment reduces clinical signs and/or offers neuroprotection in a subacute 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) monkey model of Parkinson disease. Methods: We implanted an optical fiber device that delivered NIr (670nm) to the midbrain of macaque monkeys, close to the substantia nigra of both sides. MPTP injections (1.5-2.1mg/kg) were made over a 5-to 7-day period, during which time the NIr device was turned on. This was then followed by a 3-week survival period. Monkeys were evaluated clinically (eg, posture, bradykinesia) and behaviorally (open field test), and their brains were processed for immunohistochemistry and stereology. Results: All monkeys in the MPTP group developed severe clinical and behavioral impairment (mean clinical scores 5 21-34; n 5 11). By contrast, the MPTP-NIr group developed much less clinical and behavioral impairment (n 5 9); some monkeys developed moderate clinical signs (mean scores 5 11-15; n 5 3), whereas the majority-quite remarkably-developed few clinical signs (mean scores 5 1-6; n 5 6). The monkeys that developed moderate clinical signs had hematic fluid in their optical fibers at postmortem, presumably limiting NIr exposure and overall clinical improvement. NIr was not toxic to brain tissue and offered neuroprotection to dopaminergic cells and their terminations against MPTP insult, particularly in animals that developed few clinical signs. Interpretation: Our findings indicate NIr to be an effective therapeutic agent in a primate model of the disease and create the template for translation into clinical trials.

Improving Mitochondrial Function Protects Bumblebees from Neonicotinoid Pesticides

“…In fly models of Parkinson’s, 808nm has been shown to improve complex IV dependent respiration, ATP production and reduce flight defects [19]. In primates where drugs that initiate the disease target mitochondria in the brain stem, 670nm light delivered via fiber optics specifically to this region when disease is initiated, results in significantly fewer clinical signs [20]. These studies that span widely separated species are important and relevant because immobility is a key feature in Imidacloprid exposed bees, and near infrared light impacts positively on both mammals and insects in this respect.…”

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“…Generally speaking, and as alluded to earlier, VIS Red and NIR wavelengths have been shown to: (a) bestow remedial effects in living systems impacted by oxidative stress; (b) ameliorate some aspects of coronary/ artery disease; and (c) restore a significant measure of function in people suffering from Alzheimer's disease and Parkinson's disease (Sutkowsky et al 2014;Enwemaka 2004;Quirk et al 2012;Darlot et al 2016;Beirne et al IN PRESS citing others). However, because all of the foregoing explanations tend to focus on meso-scale levels of explication and analysis, the potential role of EZs or nanostructured forms of water (and thus TOSH) being in the mix are seldom, if ever mentioned in these aforementioned studies.…”

Is near‐infrared light neuroprotective?

“…1 I believe that the authors have adopted an inconclusive design and overlooked several parameters that could have a major effect on their analysis and conclusions. 1 I believe that the authors have adopted an inconclusive design and overlooked several parameters that could have a major effect on their analysis and conclusions.…”

“…1 I believe that the authors have adopted an inconclusive design and overlooked several parameters that could have a major effect on their analysis and conclusions. 1,2 We wanted to give every opportunity for the NIr to protect the cells. In the cited publications, however, neither of these regimens was used.…”

“…1,2 We wanted to give every opportunity for the NIr to protect the cells. We used a subacute model, one very different to the more-chronic models used by Bezard and his team.…”