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. 2017 Jan;19(1):013003.
doi: 10.1088/2040-8986/19/1/013003. Epub 2016 Dec 14.

Photobiomodulation and the brain: a new paradigm

Madison Hennessy  1 , Michael R Hamblin  2   3   4
Affiliations

Photobiomodulation and the brain: a new paradigm

Madison Hennessy et al. J Opt. 2017 Jan.

Abstract

Transcranial photobiomodulation (PBM) also known as low level laser therapy (tLLLT) relies on the use of red/NIR light to stimulate, preserve and regenerate cells and tissues. The mechanism of action involves photon absorption in the mitochondria (cytochrome c oxidase), and ion channels in cells leading to activation of signaling pathways, up-regulation of transcription factors, and increased expression of protective genes. We have studied PBM for treating traumatic brain injury (TBI) in mice using a NIR laser spot delivered to the head. Mice had improved memory and learning, increased neuroprogenitor cells in the dentate gyrus and subventricular zone, increased BDNF and more synaptogenesis in the cortex. These highly beneficial effects on the brain suggest that the applications of tLLLT are much broader than at first conceived. Other groups have studied stroke (animal models and clinical trials), Alzheimer's disease, Parkinson's disease, depression, and cognitive enhancement in healthy subjects.

Keywords: Alzheimer’s disease; Transcranial photobiomodulation; brain disorders; low level laser therapy; psychiatric diseases; stroke; traumatic brain injury.

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Figures

Figure 1
Figure 1
Photobiomodulation is absorbed by cytochrome c oxidase (unit IV) in the mitochondrial électron transport chain leading to an increase in oxygen consumption and ATP synthesis. ATP, adenosine triphosphate; NADH, nicotinamide adénine dinucleotide reduced form; NIR, near-infrared red
Figure 2
Figure 2
Signaling pathway leading from light absorption to anti-apoptosis and neuroprotection. AKT, alternative term for protein kinase B; Bax, BCL2-associated X protein; GSK3β, glycogen synthase kinase 3β, PBM, photobiomodulation
Figure 3
Figure 3
Light is absorbed by mitochondria producing a brief burst of ROS that activates PKD leading to activation of Ik-B kinase and translocation of NF-kB to the nucleus. Ik-B, inhibitor of NF-kB; NF-kB, nuclear factor kB ; PKD, protein kinase D ; ROS, reactive oxygen species.
Figure 4
Figure 4
In a mouse model of traumatic brain injury caused by controlled cortical impact exposure of the head to 810 nm laser leads to improved neurological performance. At the same time there is upregulation of BDNF, neurogenesis and synaptogenesis in the brain. BDNF, brain derived neurotrophic factor; PBM, photobiomodulation.
Figure 5
Figure 5
(A) Vielight 810 Intranasal; (B) Vielight Neuro left view ; (C) Vielight Neuro right view; (D) 1. Mesial préfrontal cortex ; 2. Precuneus ; 3. Posterior congulate cortex; 4. Inferior pariétal lobe; 5. Hippocampus.
Figure 6
Figure 6
810 nm LED application to the forehead for treatment of dépression and anxiety.
Figure 7
Figure 7
810 nm laser application to the forehead for treatment of dépression.
See this image and copyright information in PMC

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