Alzheimer’s Disease

Photobiomodulation with near infrared light mitigates Alzheimer’s disease-related pathology in cerebral cortex – evidence from two transgenic mouse models

Curr Alzheimer Res. 2015;12(9):860-9.

Cognitive Improvement by Photic Stimulation in a Mouse Model of Alzheimer’s Disease.

Zhang Y, Wang F, Luo X, Wang L, Sun P, Wang M, Jiang Y, Zou J, Uchiumi O, Yamamoto R, Sugai T, Yamamoto K, Kato N1.

Author information

  • 1Department of Physiology, Kanazawa Medical University, Ishikawa 920-0293, Japan.


We previously reported that activity of the large conductance calcium-activated potassium (big-K, BK) channel is suppressed by intracellular A? in cortical pyramidal cells, and that this suppression was reversed by expression of the scaffold protein Homer1a in 3xTg Alzheimer’s disease model mice. Homer1a is known to be expressed by physiological photic stimulation (PS) as well. The possibility thus arises that PS also reverses A?-induced suppression of BK channels, and thereby improves cognition in 3xTg mice. This possibility was tested here. Chronic application of 6-hour-long PS (frequency, 2 Hz; duty cycle, about 1/10; luminance, 300 lx) daily for 4 weeks improved contextual and tone-dependent fear memory in 3xTg mice and, to a lesser extent, Morris water maze performance as well. Hippocampal long-term potentiation was also enhanced after PS. BK channel activity in cingulate cortex pyramidal cells and lateral amygdalar principal cells, suppressed in 3xTg mice, were facilitated. In parallel, neuronal excitability, elevated in 3xTg mice, was recovered to the control level. Gene expression of BK channel, as well as that of the scaffold protein Homer1a, was found decreased in 3xTg mice and reversed by PS. It is known that Homer1a is an activity-dependently inducible immediate early gene product. Consistently, our previous findings showed that Homer1a induced by electrical stimulation facilitated BK channels. By using Homer1a knockouts, we showed that the present PS-induced BK channel facilitation is mediated by Homer1a expression. We thus propose that PS might be potentially useful as a non-invasive therapeutic measure against Alzheimer’s disease.


BMC Neurosci. 2016 May 18;17(1):21. doi: 10.1186/s12868-016-0259-6.

Comparative assessment of phototherapy protocols for reduction of oxidative stress in partially transected spinal cord slices undergoing secondary degeneration.

Ashworth BE1,2, Stephens E1,2, Bartlett CA1, Serghiou S3, Giacci MK1, Williams A3, Hart NS1,4, Fitzgerald M5.

Author information

  • 1Experimental and Regenerative Neurosciences, School of Animal Biology, The University of Western Australia, Crawley, WA, Australia.
  • 2Department of Biology and Biochemistry, The University of Bath, Bath, UK.
  • 3Centre for Regenerative Medicine, University of Edinburgh, Edinburgh, UK.
  • 4Department of Biological Sciences, Macquarie University, Sydney, NSW, 2109, Australia.
  • 5Experimental and Regenerative Neurosciences, School of Animal Biology, The University of Western Australia, Crawley, WA, Australia.



Red/near-infrared light therapy (R/NIR-LT) has been developed as a treatment for a range of conditions, including injury to the central nervous system (CNS). However, clinical trials have reported variable or sub-optimal outcomes, possibly because there are few optimized treatment protocols for the different target tissues. Moreover, the low absolute, and wavelength dependent, transmission of light by tissues overlying the target site make accurate dosing problematic.


In order to optimize light therapy treatment parameters, we adapted a mouse spinal cord organotypic culture model to the rat, and characterized myelination and oxidative stress following a partial transection injury. The ex vivo model allows a more accurate assessment of the relative effect of different illumination wavelengths (adjusted for equal quantal intensity) on the target tissue. Using this model, we assessed oxidative stress following treatment with four different wavelengths of light: 450 nm (blue); 510 nm (green); 660 nm (red) or 860 nm (infrared) at three different intensities: 1.93 × 10(16) (low); 3.85 × 10(16) (intermediate) and 7.70 × 10(16) (high) photons/cm(2)/s. We demonstrate that the most effective of the tested wavelengths to reduce immunoreactivity of the oxidative stress indicator 3-nitrotyrosine (3NT) was 660 nm. 860 nm also provided beneficial effects at all tested intensities, significantly reducing oxidative stress levels relative to control (p ? 0.05).


Our results indicate that R/NIR-LT is an effective antioxidant therapy, and indicate that effective wavelengths and ranges of intensities of treatment can be adapted for a variety of CNS injuries and conditions, depending upon the transmission properties of the tissue to be treated.

J Exp Neurosci. 2016 Feb 1;10:1-19. doi: 10.4137/JEN.S33444. eCollection 2016.

Neuroprotective Effects Against POCD by Photobiomodulation: Evidence from Assembly/Disassembly of the Cytoskeleton.

Liebert AD1, Chow RT2, Bicknell BT3, Varigos E4.
Author information
1University of Sydney, Sydney, NSW, Australia.
2Brain and Mind Institute, University of Sydney, Sydney, NSW, Australia.
3Australian Catholic University, Sydney, NSW, Australia.
4Olympic Park Clinic, Melbourne, VIC, Australia.
Postoperative cognitive dysfunction (POCD) is a decline in memory following anaesthesia and surgery in elderly patients. While often reversible, it consumes medical resources, compromises patient well-being, and possibly accelerates progression into Alzheimer’s disease. Anesthetics have been implicated in POCD, as has neuroinflammation, as indicated by cytokine inflammatory markers. Photobiomodulation (PBM) is an effective treatment for a number of conditions, including inflammation. PBM also has a direct effect on microtubule disassembly in neurons with the formation of small, reversible varicosities, which cause neural blockade and alleviation of pain symptoms. This mimics endogenously formed varicosities that are neuroprotective against damage, toxins, and the formation of larger, destructive varicosities and focal swellings. It is proposed that PBM may be effective as a preconditioning treatment against POCD; similar to the PBM treatment, protective and abscopal effects that have been demonstrated in experimental models of macular degeneration, neurological, and cardiac conditions.
Front Neurosci. 2016 Jan 11;9:500. doi: 10.3389/fnins.2015.00500. eCollection 2015.

Turning On Lights to Stop Neurodegeneration: The Potential of Near Infrared Light Therapy in Alzheimer’s and Parkinson’s Disease.

Johnstone DM1, Moro C2, Stone J1, Benabid AL2, Mitrofanis J2.
Author information
1Department of Physiology, University of Sydney Sydney, NSW, Australia.
2University Grenoble Alpes, CEA, LETI, CLINATEC, MINATEC Campus Grenoble, France.
Alzheimer’s and Parkinson’s disease are the two most common neurodegenerative disorders. They develop after a progressive death of many neurons in the brain. Although therapies are available to treat the signs and symptoms of both diseases, the progression of neuronal death remains relentless, and it has proved difficult to slow or stop. Hence, there is a need to develop neuroprotective or disease-modifying treatments that stabilize this degeneration. Red to infrared light therapy (? = 600-1070 nm), and in particular light in the near infrared (NIr) range, is emerging as a safe and effective therapy that is capable of arresting neuronal death. Previous studies have used NIr to treat tissue stressed by hypoxia, toxic insult, genetic mutation and mitochondrial dysfunction with much success. Here we propose NIr therapy as a neuroprotective or disease-modifying treatment for Alzheimer’s and Parkinson’s patients.
J Mol Neurosci. 2014 Jul 4. [Epub ahead of print]

Low-Level Laser Therapy Ameliorates Disease Progression in a Mouse Model of Alzheimer’s Disease.

Farfara D1, Tuby H, Trudler D, Doron-Mandel E, Maltz L, Vassar RJ, Frenkel D, Oron U.

Author information

  • 1Department of Neurobiology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel.


Low-level laser therapy (LLLT) has been used to treat inflammation, tissue healing, and repair processes. We recently reported that LLLT to the bone marrow (BM) led to proliferation of mesenchymal stem cells (MSCs) and their homing in the ischemic heart suggesting its role in regenerative medicine. The aim of the present study was to investigate the ability of LLLT to stimulate MSCs of autologous BM in order to affect neurological behavior and ?-amyloid burden in progressive stages of Alzheimer’s disease (AD) mouse model. MSCs from wild-type mice stimulated with LLLT showed to increase their ability to maturate towards a monocyte lineage and to increase phagocytosis activity towards soluble amyloid beta (A?). Furthermore, weekly LLLT to BM of AD mice for 2 months, starting at 4 months of age (progressive stage of AD), improved cognitive capacity and spatial learning, as compared to sham-treated AD mice. Histology revealed a significant reduction in A? brain burden. Our results suggest the use of LLLT as a therapeutic application in progressive stages of AD and imply its role in mediating MSC therapy in brain amyloidogenic diseases.

Alzheimers Res Ther. 2014; 6(1): 2.
Published online Jan 3, 2014. doi:  10.1186/alzrt232

Photobiomodulation with near infrared light mitigates Alzheimer’s disease- related pathology in cerebral cortex – evidence from two transgenic mouse models.

Photobiomodulation with near infrared light mitigates Alzheimer’s disease-related pathology in cerebral cortex – evidence from two transgenic mouse models

Photobiomodulation with near infrared light mitigates Alzheimer’s disease-related pathology in cerebral cortex – evidence from two transgenic mouse models

Photobiomodulation with near infrared light mitigates Alzheimer’s disease-related pathology in cerebral cortex – evidence from two transgenic mouse models

Sivaraman Purushothuman,1,2 Daniel M Johnstone,corresponding author1,2 Charith Nandasena,1,2 John Mitrofanis,1,3 and Jonathan Stone1,2

Alzheimer’s disease (AD) is a chronic, debilitating neurodegenerative disease with limited therapeutic options; at present there are no treatments that prevent the physical deterioration of the brain and the consequent cognitive deficits. Histopathologically, AD is characterised by neurofibrillary tangles (NFTs) of hyperphosphorylated tau protein and amyloid-beta (A?) plaques [1,2]. The extent of these histopathological features is considered to vary with and to determine clinical disease severity [2]. While the initiating pathogenic events underlying AD are still debated, there is strong evidence to suggest that oxidative stress and mitochondrial dysfunction have important roles in the neurodegenerative cascade [35]. Therefore, it has been proposed that targeting mitochondrial dysfunction could prove valuable for AD therapeutics [6].

One safe, simple yet effective approach to the repair of damaged mitochondria is photobiomodulation with near-infrared light (NIr). This treatment, which involves the irradiation of tissue with low intensity light in the red to near-infrared wavelength range (600 to 1000 nm), was originally pioneered for the healing of superficial wounds [7] but has been recently shown to have efficacy in protecting the central nervous system. While the mechanism of action remains to be elucidated, there is evidence that NIr preserves and restores cellular function by reversing dysfunctional mitochondrial cytochrome c oxidase (COX) activity, thereby mitigating the production of reactive oxygen species and restoring ATP production to normal levels [8,9].

To date, NIr treatment has yielded neuroprotective outcomes in animal models of retinal damage [9,10], traumatic brain injury [11,12], Parkinson’s disease [1315] and AD [16,17]. Furthermore, NIr therapy has yielded beneficial outcomes in clinical trials of human patients with mild to moderate stroke [18] and depression [19]. This treatment represents a promising alternative to drug therapy because it is safe, easy to apply and has no known side-effects at levels even higher than optimal doses [20].

The aim of this study was to assess the efficacy of NIr in mitigating the brain pathology and associated cellular damage that characterise AD. We utilised two mouse models, each manifesting distinct AD-related pathologies: the K3 tau transgenic model, which develops NFTs [21,22]; and the APP/PS1 transgenic model, which develops amyloid plaques [23]. Here, we present histochemical evidence that NIr treatment over a period of 1 month reduces the severity of AD-related pathology and oxidative stress and restores mitochondrial function in brain regions susceptible to neurodegeneration in AD, specifically the neocortex and hippocampus. The findings extend our previous NIr work in models of acute neurodegeneration [13,14] to demonstrate that NIr is also effective in protecting the brain against chronic insults due to AD-related genetic aberrations, a pathogenic mechanism that is likely to more closely model the human neurodegenerative condition.:


Mouse models

The K3 transgenic mouse model, originally generated as a model of frontotemporal dementia [21,22], harbours a human tau gene with the pathogenic K369I mutation; expression is driven by the neuron-specific mThy1.2 promoter. This model manifests high levels of hyperphosphorylated tau and NFTs by 2 to 3 months of age and cognitive deficits by about 4 months of age [21,22]. We commenced our experiments on K3 mice and matched C57BL/6 wildtype (WT) controls at 5 months of age, when significant neuropathology is already present.

The APPswe/PSEN1dE9 (APP/PS1) transgenic mouse model, obtained from the Jackson Laboratory (Stock number 004462; Bar Harbor, ME, USA), harbours two human transgenes: the amyloid beta precursor protein gene (APP) containing the Swedish mutation; and the presenilin-1 gene (PS1) containing a deletion of exon 9 [23]. The APP/PS1 mice exhibit increased A? and amyloid plaques by 4 months of age [24] and cognitive deficits by 6 months of age [25]. We commenced our experiments on APP/PS1 mice and matched C57BL/6 × C3H WT controls at 7 months of age, when numerous amyloid plaques and associated cognitive deficits are present.

Genotyping of mice was achieved by extracting DNA from tail tips through a modified version of the Hot Shot preparation method [26] and amplifying the transgene sequence by polymerase chain reaction. As reported previously, K3 mice were identified using the primers 5-GGGTGTCTCCAATGCCTGCTTCTTCAG-3 (forward) and 5-AAGTCACCCAGCAGGGAGGTGCTCAG-3 (reverse) [21,22] and APP/PS1 mice were genotyped using primers 5-AGGACTGACCACTCGACCAG-3 (forward) and 5-CGGGGGTCTAGTTCTGCAT-3 (reverse) [23].

Experimental design

For each series of experiments on K3 mice (aged 5 months) or APP/PS1 mice (aged 7 months) there were three experimental groups: untreated WT mice, untreated transgenic mice and NIr-treated transgenic mice (n = 5 mice per experimental group for the K3 series, 15 mice in total; n = 6 mice per experimental group for the APP/PS1 series, 18 mice in total). Our design did not include a WT control group exposed to NIr because NIr has no detectable impact on the survival and function of cells in normal healthy brain [1315]. Given the consistency of the previous results, use of animals for this extra control group did not seem justified [27].

Mice in the NIr-treated groups were exposed to one 90-second cycle of NIr (670 nm) from a light-emitting device (LED) (WARP 10; Quantum Devices, Barneveld, WI, USA) for 5 days per week over 4 consecutive weeks. Light energy emitted from the LED during each 90-second treatment equates to 4 Joule/cm2; a total of 80 Joule/cm2 was delivered to the skull over the 4 weeks. Our measurements of NIr penetration across the fur and skull of a C57BL/6 mouse indicate that ~2.5% of transmitted light reaches the cortex.

For each treatment, the mouse was restrained by hand and the LED was held 1 to 2 cm above the head. The LED light generated no heat and reliable delivery of the radiation was achieved [1315]. For the sham-treated WT, K3 and APP/PS1 groups, animals were restrained in the same way and the device was held over the head, but the light was not switched on. This treatment regime is similar to that used in previous studies where beneficial changes to neuropathology and behavioural signs were reported [1315].

Experimental animals were housed two or more to a cage and kept in a 12-hour light (<5 lux)/dark cycle at 22°C; food pellets and water were available ad libitum. All protocols were approved by the Animal Ethics Committee of the University of Sydney.

Histology and immunohistochemistry

At the end of the experimental period, mice were anaesthetised by intraperitoneal injection of sodium pentobarbital (60 mg/kg) and perfused transcardially with 4% buffered paraformaldehyde. Brains were post fixed for 3 hours, washed with phosphate-buffered saline and cryoprotected in 30% sucrose/phosphate-buffered saline. Tissue was embedded in OCT compound (ProSciTech, Thuringowa, QLD, Australia) and coronal sections of the neocortex and the hippocampus (between bregma ?1.8 and ?2.1) were cut at 20 ?m thickness on a Leica cryostat (Nussloch, Germany).


For most antibodies, antigen retrieval was achieved using sodium citrate buffer with 0.1% Triton. Sections were blocked in 10% normal goat serum and then incubated overnight at 4°C with a mouse monoclonal antibody – paired helical filaments-tau AT8, 1:500 (Innogenetics, Ghent, Belgium); 4-hydroxynonenal (4-HNE), 1:200 (JaICA, Fukuroi, Shizuoka, Japan); 8-hydroxy-2?-deoxyguanosine (8-OHDG), 1:200 (JaICA); COX, 1:200 (MitoSciences, Eugene, OR, USA) – and/or a rabbit polyclonal antibody (200 kDa neurofilament, 1:500; Sigma, St. Louis, MO, USA). Sections were then incubated for 3 hours at room temperature in Alexa Fluor-488 (green) and/or Alexa Fluor-594 (red) tagged secondary antibodies specific to host species of the primary antibodies (1:1,000; Molecular Probes, Carlsbad, CA, USA). Sections were then counterstained for nuclear DNA with bisbenzimide (Sigma).

Two different but complementary antibodies were used to label A? peptide: 6E10, which recognises residues 1 to 16; and 4G8, which recognises residues 17 to 24. We have previously used these two antibodies in combination to validate A? labelling, demonstrating identical labelling patterns in the rat neocortex and hippocampus [28]. For double labelling using 6E10 antibodies (1:500; Covance, Princeton, NJ, USA) and anti-glial fibrillary acidic protein antibodies (1:1,000; DAKO, Glostrup, Denmark), antigen retrieval was achieved by incubation in 90% formic acid for 10 minutes, and primary antibody incubation was carried out overnight at room temperature. For labelling using the 4G8 (1:500; Covance) antibody, slides were treated with 3% H2O2 in 50% methanol, incubated in 90% formic acid and then washed several times in dH2O before the blocking step, as described previously [28]. After blocking, sections were incubated overnight at room temperature with 4G8 antibody. Sections were then incubated in biotinylated goat anti-mouse IgG for 1 hour followed by ExtrAvidin peroxidase for 2.5 hours. The sections were then washed and developed with 3,3?-Diaminobenzidine.

Negative control sections were processed in the same fashion as described above except that primary antibodies were omitted. These control sections were immunonegative. Fluorescent images were taken using a Zeiss Apotome 2, Carl Zeiss, Oberkochen, Germany. Brightfield images were taken using a Nikon Eclipse E800, Nikon Instruments, Melville, NY, USA.


NFTs were assessed using the Bielschowsky silver staining method, as described previously [21,22]. Briefly, sections were placed in prewarmed 10% silver nitrate solution for 15 minutes, washed and then placed in ammonium silver nitrate solution at 40°C for a further 30 minutes. Sections were subsequently developed for 1 minute and then transferred to 1% ammonium hydroxide solution for 1 minute to stop the reaction. Sections were then washed in dH2O, placed in 5% sodium thiosulphate solution for 5 minutes, washed, cleared and mounted in dibutyl phathalate xylene.

As described previously [28], A? plaques were studied by staining with Congo red, a histological dye that binds preferentially to compacted amyloid with a ?-sheet secondary structure [29]. Briefly, sections were treated with 2.9 M sodium chloride in 0.01 M NaOH for 20 minutes and were subsequently stained in filtered alkaline 0.2% Congo red solution for 1 hour.

Morphological analysis

Staining intensity and area measurements

To quantify the average intensity and area of antibody labelling within the neocortex and hippocampal regions, an integrated morphology analysis was undertaken using MetaMorph software. For each section, the level of nonspecific staining (using an adjacent region of unstained midbrain) was adjusted to a set level to ensure a standard background across different groups. Next, outlines of retrosplenial cortex area 29 and hippocampal CA1 region were traced and the average intensity and area of immunostaining were calculated by the program. Measurements were conducted on ?4 representative sections per animal and ?3 animals per experimental group. Statistical analyses were performed in Prism 5.0 (Graphpad, La Jolla, CA, USA) using one-way analysis of variance with Tukey’s multiple comparison post test. All values are given as mean ± standard error of mean.

Amyloid-beta plaque measurements

Digital brightfield images of 4G8 staining in the neocortical and hippocampal regions (between bregma ?1.8 and ?2.1) were taken at 4× magnification and analysed with Metamorph, Molecular Devices LLC, Sunnyvale, CA, USA. The software was programmed to measure the number of plaques and the average size of plaques after thresholding for colour. The percentage of area covered by plaques (plaque burden) was calculated by multiplying the number of plaques by the average size of plaques, divided by the area of interest, as described previously [30]. The average number of Congo red-positive plaques in the APP/PS1 brain regions was estimated using the optical fractionator method (StereoInvestigator; MBF Science, Williston, VT, USA), as outlined previously [14]. Briefly, systematic random sampling of sites was undertaken using an unbiased counting frame (100 ?m × 100 ?m). All plaques that came into focus within the frame were counted. Measurements were conducted on ?4 representative sections per animal and ?3 animals per experimental group. Plaque numbers and size were analysed using a two-tailed unpaired t test (when variances were equal) or Welch’s t test (when variances were unequal). All values are given as mean ± standard error of mean. For all analyses, investigators were blinded to the experimental groups.


Evidence of NIr-induced neuroprotection is presented from the neocortex (retrosplenial area) and the hippocampus (CA1 and subiculum), two cortical regions affected in the early stages of human AD [2].

Near-infrared light mitigates the tau pathology of K3 cortex

Hyperphosphorylation of the neuronal microtubule stabilising protein tau and the resulting NFTs are much studied features of dementia pathology [2,31]. The K3 mouse model manifests hyperphosphorylated tau and NFTs by 2 to 3 months of age and cognitive deficits by about 4 months of age [21,22]. We observe strong labelling for hyperphosphorylated tau in the neocortex and the hippocampus at 6 months of age; expression appears to plateau after this age, with similar labelling observed in 12-month-old mice (Figure 1A,B,C,D,E,F).

Figure 1

Time course of the natural development of cortical pathology in K3 and APP/PS1 mice. (A), (B), (C), (D), (E), (F) Micrographs of hyperphosphorylated tau labelling (red), using the AT8 antibody, in the neocortex (A to C) and hippocampus (D toF) of untreated 

In the retrosplenial area of the neocortex there was a significant overall difference in AT8 immunolabelling for tau between the experimental groups, both when considering average intensity of labelling (P < 0.01 by analysis of variance; Figure 2A) and labelled area (P < 0.01; Figure 2B). Tukeypost hoc testing revealed significant differences between the untreated K3 group and the other two groups; labelling was much stronger and more widespread in K3 mice than WT controls (17-fold higher intensity, P < 0.01), and this labelling was reduced by over 70% in NIr-treated mice (P < 0.05). Interestingly, there was no significant difference between the WT and K3-NIr groups, suggesting that NIr treatment had reduced hyperphosphorylated tau to control levels in K3 mice. A similar trend was observed when considering the NFT pathology (Figure 2C,D,E). In contrast to WT brain, which showed no NFT-like lesions (Figure 2C), the K3 brain contained many ovoid shaped NFT-like lesions (that is, spheroids; Figure 2D). Such structures were less frequent in the K3-NIr brain (Figure 2E).

Figure 2

Effect of near-infrared light treatment on hyperphosphorylated tau and neurofibrillary tangles in the neocortex of K3 mice. (A), (B) Quantification of tau AT8 immunolabelling, based on average labelling intensity (A) and labelled area (B). All error bars 

Similar effects were observed in the hippocampus (Figure 3). There was a significant overall difference between the experimental groups in AT8 immunolabelling of the CA1 pyramidal cells (P < 0.01). As for the neocortex, K3 mice showed far greater labelling than WT mice (17-fold higher intensity, P < 0.01) and this was reduced over 65% by NIr treatment (P < 0.01). Again, there were no significant differences between the WT and K3-NIr groups (P > 0.05). Bielschowsky silver staining of the subiculum (Figure 3C,D,E) revealed axonal swellings and spheroids in the hippocampal region of K3 mice (Figure 3D), which were less pronounced in mice from the K3-NIr group (Figure 3E). No pathology was observed in the hippocampus of WT mice (Figure 3C).

Figure 3

Effect of near-infrared light treatment on hyperphosphorylated tau and neurofibrillary tangles in the hippocampus of K3 mice. (A), (B) Quantification of tau AT8 immunolabelling, based on average labelling intensity (A) and labelled area (B). All error 

One should note that the large white matter pathways associated with the hippocampus were labelled intensely by silver staining in all three groups (Figure 3C,D,E). This labelling has been described previously and is not associated with any neuropathology [32].

Near-infrared light reduces oxidative stress in K3 cortex

Oxidative stress and damage are common features of neurodegenerative diseases such as AD, and may be a precursor to neuronal death [35]. We assessed two common markers of oxidative stress: 4-HNE, a toxic end-product of lipid peroxidation that may bind to proteins that then trigger mitochondrial dysfunction and cellular apoptosis in AD [33]; and 8-OHDG, a marker for nuclear and mitochondrial DNA oxidation, which is elevated in AD brains [34].

Overall, 4-HNE immunoreactivity in the neocortex was significantly different between the experimental groups (Figure 4), by both average labelling intensity (P < 0.01) and labelled area (P < 0.001). As with AT8 labelling above, the K3 group showed a much higher average 4-HNE labelling intensity and area than the WT group (fivefold and 20-fold, respectively) and this labelling was significantly reduced (by 50% and 80%, respectively) in the K3-NIr group. Again, these measures showed no significant differences between the WT and K3-NIr groups (P > 0.05).

Figure 4

Effect of near-infrared light treatment on oxidative stress markers in the neocortex of K3 mice. (A), (B), (F), (G)Quantification of immunolabelling of two oxidative stress markers, 4-hydroxynonenal (4-HNE; A, B) and 8-hydroxy-2?-deoxyguanosine 

Similar patterns were observed for 8-OHDG immunoreactivity. Overall, there was a significant difference between the groups for 8-OHDG immunolabelling, by both average intensity (P < 0.0001) and labelled area (P < 0.0001). Again the K3 group showed significantly higher 8-OHDG labelling intensity and area than the WT group (sixfold and 17-fold, respectively), and the 8-OHDG labelling intensity and area were significantly reduced in the K3-NIr group relative to untreated K3 (65% and 85% reduction, respectively). The intensity and area of 8-OHDG labelling did not differ significantly between the WT and the K3-NIr groups (P > 0.05), suggesting that NIr treatment reduces markers of oxidative stress to control levels. The representative photomicrographs of 8-OHDG immunoreactivity in the retrosplenial area (Figure 4H,I,J) reflect the quantitative data, with many 8-OHDG+ structures in the K3 group (Figure 4I) but not in the WT and K3-NIr groups (Figure 4H,J).

Near-infrared light mitigates mitochondrial dysfunction in K3 cortex

We assessed expression patterns of the mitochondrial enzyme COX in the neocortex and the hippocampus as a marker of mitochondrial function. Overall, there were statistically significant differences in the patterns of COX immunoreactivity between the different experimental groups, both in the neocortex and the hippocampus (both P < 0.0001; Figure 5). Relative to WT mice, the COX labelling intensity and area were reduced in K3 mice in both the neocortex and the hippocampus (>70% and >75% reductions, respectively). The K3-NIr mice showed a significant recovery of COX immunoreactivity relative to untreated K3 mice in both the neocortex (>1.7-fold increase, P < 0.05) and the hippocampus (>3.4-fold increase, P < 0.001). However, recovery was not complete, with K3-NIr mice having significantly lower COX immunoreactivity than WT mice in the neocortex (~50%, P < 0.001) and significantly lower COX labelling intensity (~20%, P < 0.05) in the hippocampus. These two groups did not differ significantly in COX labelling area in the hippocampus (P > 0.05).

Figure 5

Effect of near-infrared light treatment on cytochrome coxidase labelling in the neocortex and hippocampus of K3 mice. (A), (B), (F), (G) Quantification of immunolabelling of the mitochondrial marker cytochrome c oxidase (COX) in the neocortex retrosplenial 

Near-infrared mitigates amyloid pathology in APP/PS1 cortex

Along with NFTs, A? plaques are considered a primary pathological hallmark of AD and A? load is often used as a marker of AD severity [1,35]. We assessed the distribution of A? plaques and more immature forms of the A? peptide in the neocortex and hippocampus of APP/PS1 mice aged 7 months; this age is after the first signs of intracellular A? within cells (at 3 months; Figure 1G) and extracellular A? plaques (at 4.5 and 12 months; Figure 1H and ?and1I,1I, respectively).

Three quantitative measures of plaque pathology were used: percentage plaque burden, average plaque size and number of plaques. Immunohistochemical labelling with the anti-A? antibody 4G8 revealed a significant reduction in percentage plaque burden (Figure 6A,D), average plaque size (Figure 6B,E) and number of plaques (Figure 6C,F) in both the neocortex and the hippocampus of NIr-treated APP/PS1 mice relative to untreated APP/PS1 controls. Percentage plaque burden was reduced by over 40% in the neocortex (Figure 6A; P < 0.001) and over 70% in the hippocampus (Figure 6D; P < 0.01), average plaque size was reduced 25% in the neocortex (Figure 6B) and 30% in the hippocampus (Figure 6E), and the number of plaques was reduced by over 20% in the neocortex (Figure 6C) and by over 55% in the hippocampus (Figure 6F; all P < 0.05).

Figure 6

Effect of near-infrared light on amyloid-beta and plaque pathology in APP/PS1 mice. (A), (B), (C), (D), (E), (F)Quantification of amyloid-beta (A?) 4G8 immunolabelling of amyloid plaques in the neocortex (A, B, C) and hippocampus (D, E, F), based 

The photomicrographs of the 4G8 immunoreactivity in Figure 6 reflect the quantitative data described earlier. The WT brain is free of plaques (Figure 6H,K); many 4G8+ plaques (arrows) are present in the neocortex (Figure 6I) and the hippocampus (Figure 6L) of untreated APP/PS1 mice, and fewer plaques are present in NIr-treated APP/PS1 mice (Figure 6J,M). Comparable immunolabelling was achieved using the 6E10 anti-A? antibody (data not shown).

A similar but less pronounced trend was observed when staining with Congo red (Figure 7), which stains only mature plaques. Mean counts of plaques in the neocortex (Figure 7A) and the hippocampus (Figure 7B) of NIr-treated APP/PS1 brains were lower than mean counts in untreated APP/PS1 brains (reductions >30%). However, the differences did not reach statistical significance; given the findings described above with the 4G8 and 6E10 anti-A? antibodies, this suggests that NIr may have greatest effect on recently formed A? deposits. The micrographs in Figure 7 show that mature plaques were absent from the WT brain (Figure 7C,D) but were present in the neocortex (Figure 7E) and hippocampus (Figure 7F) of untreated APP/PS1 brains. There appeared to be fewer plaques in the NIr-treated APP/PS1 brains (Figure 7G,H).

Figure 7

Effect of near-infrared light on Congo red-positive plaque numbers in APP/PS1 mice. (A), (B) Quantification of Congo red-positive plaque counts in the neocortex (A) and hippocampus(B). All error bars indicate standard error of the mean. (C), (D), (E), 


Using two mouse models with distinct AD-related pathologies (tau pathology in K3, amyloid pathology in APP/PS1), we report evidence that NIr treatment can mitigate the pathology characteristic of AD as well as reduce oxidative stress and restore mitochondrial function in brain regions affected early in the disease. Further, the extent of mitigation – to levels less than at the start of treatment – suggests that NIr can reverse some elements of AD-related pathology.

The present results add to our previous findings of NIr-induced neuroprotection in models of toxin-induced acute neurodegeneration (that is, MPTP-induced parkinsonism). When incorporated into the growing body of evidence that NIr can also protect against CNS damage in models of stroke, traumatic brain injury and retinal degeneration [912,36], the findings provide a basis for trialling NIr treatment as a strategy for protection against neurodegeneration from a range of causes. Present evidence is based on the use of multiple methods, immunohistochemical and histological, to demonstrate pathological features (for example, 4G8 antibody labelling and Congo red staining for amyloid plaques, AT8 antibody labelling and Bielschowsky silver staining for NFTs).

Relationship to previous studies

The present study focused on pathological features considered characteristic of AD, as well as on signs of cellular damage (for example, oxidative stress, mitochondrial dysfunction) that have been demonstrated in AD and in animal models [24]. Our observations in the K3 strain add to previous studies by providing the first evidence in this strain of extensive oxidative damage and mitochondrial dysfunction [27].

Our findings are consistent with previous reports of the effects of red to infrared light on AD pathology in animal models. De Taboada and colleagues assessed the capacity of 808 nm laser-sourced infrared radiation, delivered three times per week over 6 months, to reduce pathology in an APP transgenic model of A? amyloidosis [17]. Treatment led to a reduction in plaque number, amyloid load and inflammatory markers, an increase in ATP levels and mitochondrial function, and mitigation of behavioural deficits. De Taboada and colleagues commenced treatment at 3 months of age, before the expected onset of amyloid pathology and cognitive effects. Similarly, Grillo and colleagues reported that 1,072 nm infrared light, applied 4 days per week for 5 months, reduces AD-related pathology in another APP/PS1 transgenic mouse model (TASTPM) [16]. These investigators also initiated light treatment before the onset of pathology, at 2 months of age. Both studies thus provide evidence that infrared radiation can slow the progression of cerebral degeneration in these models. The present results confirm these observations, in two distinct transgenic strains; they also confirm that the wound-healing and neuroprotective effects of red-infrared length do not vary qualitatively with wavelength, over a wide range.

Evidence of reversal of pathology

Previous reports have described the natural history of the K3 [21,22] and APP/PS1 transgenic models [24,37]. Based on these previous reports and our own baseline data (Figure 1), significant brain pathology and functional deficits are present in both models at the ages when we commenced treatment. Our results therefore suggest that significant reversal of pathology has been induced by the NIr treatment. This has implications for clinical practice, where most patients are not diagnosed until pathogenic mechanisms have already been initiated and resultant neurologic symptoms manifest [15,27].

This evidence that AD-related neuropathology can be transient – appear then disappear – is not novel. Garcia-Alloza and colleagues described evidence of the transient deposition of A?, including the formation of plaque-like structures, in a transgenic model of A? deposition [24]. Reversal of such pathology, by interventions such as NIr treatment, may therefore be possible. However our results suggest that reversal may also be limited to recently formed, immature plaques, as we observed a significant NIr-induced reduction in immunolabelling with the 4G8 and 6E10 antibodies but no significant difference in Congo red staining. Because the 4G8 and 6E10 antibodies recognise various forms of A?, while Congo red stains only mature, compacted plaques, a reasonable deduction is that NIr treatment reduces only the transient, recently formed A? deposits, with no substantial effect on mature plaques. As there is still no consensus as to the pathogenic roles of different forms of A?, it is unclear how this might impact on the therapeutic potential of NIr in a clinical setting.


The mechanisms underlying the neuroprotective actions of red to infrared light are not completely understood. There is considerable evidence that NIr photobiomodulation enhances mitochondrial function and ATP synthesis by activating photoacceptors such as COX and increasing electron transfer in the respiratory chain, while also reducing harmful reactive oxygen species [3840]. NIr photobiomodulation could also upregulate protective factors such as nerve growth factor and vascular endothelial growth factor [41,42] and mesenchymal stem cells [43] that could target specific areas of degeneration.

The ability of NIr to reduce the expression of hyperphosphorylated tau, which in turn reduces oxidative stress [44], may be key to its neuroprotective effect. Oxidative stress and free radicals increase the severity of cerebrovascular lesions [45,46], mitochondrial dysfunction [4,47], oligomerisation of A? [5,48] and tauopathies and cell death [48,49] in AD. Considering the brain’s high consumption of oxygen and consequent susceptibility to oxidative stress, mitigating such stressors would probably have a pronounced protective effect [50].


Overall, our results in two transgenic mouse models with existing AD-related pathology suggest that low-energy NIr treatment can reduce characteristic pathology, oxidative stress and mitochondrial dysfunction in susceptible regions of the brain. These results, when taken together with those in other models of neurodegeneration, strengthen the notion that NIr is a viable neuroprotective treatment for a range of neurodegenerative conditions. We believe this growing body of work provides the impetus to begin trialling NIr treatment as a broad-based therapy for AD and other neurodegenerations.


A?: Amyloid-beta; AD: Alzheimer’s disease; APP: Amyloid beta precursor protein gene; COX: Cytochrome c oxidase; 4-HNE: 4-hydroxynonenal; LED: Light-emitting diode; NFT: Neurofibrillary tangle; NIr: Near-infrared light; 8-OHDG: 8-hydroxy-2?-deoxyguanosine; PS1: Presenilin 1; WT: Wildtype.

Competing interests

The authors declare that they have no competing interests.

Authors’ contributions

SP undertook the bulk of the experimental work and analysis and wrote the manuscript. DMJ and JM were involved with the analysis of the data and the writing of the manuscript. CN was involved with genotyping and treating the animals. JS was involved in conceiving and designing the study and the writing of the manuscript. All authors read and approved the final manuscript.


The authors thank Tenix Corporation, Sir Zelman Cowen Universities Fund and Bluesand Foundation for funding. They are grateful to Prof. Lars Ittner for providing the breeding litter for K369I mice, and to Dr Louise Cole and the Bosch Advanced Microscopy facility for the help with MetaMorph. Sharon Spana was splendid for her technical help. DMJ is supported by a National Health and Medical Research Council of Australia (NHMRC) Early Career Fellowship.


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J Neuroinflammation.  2012 Sep 18;9(1):219. [Epub ahead of print]

Low-level laser therapy regulates microglial function through Src-mediated signaling pathways: implications for neurodegenerative diseases.

Song S, Zhou F, Chen WR, Xing D.




Activated microglial cells are an important pathological component in brains of patients with neurodegenerative diseases. The purpose of this study was to investigate the effect of He-Ne (632.8 nm, 64.6 mW/cm2) low-level laser therapy (LLLT), a non-damaging physical therapy, on activated microglia, and the subsequent signaling events of LLLT-induced neuroprotective effects and phagocytic responses.


To model microglial activation, we treated the microglial BV2 cells with lipopolysaccharide (LPS). For the LLLT-induced neuroprotective study, neuronal cells with activated microglial cells in a Transwell[trade mark sign] cell-culture system were used. For the phagocytosis study, fluorescence-labeled microspheres were added into the treated microglial cells to confirm the role of LLLT.


Our results showed that LLLT (20 J/cm2) could attenuate toll-like receptor (TLR)-mediated proinflammatory responses in microglia, characterized by down-regulation of proinflammatory cytokine expression and nitric oxide (NO) production. LLLT-triggered TLR signaling inhibition was achieved by activating tyrosine kinases Src and Syk, which led to MyD88 tyrosine phosphorylation, thus impairing MyD88-dependent proinflammatory signaling cascade. In addition, we found that Src activation could enhance Rac1 activity and F-actin accumulation that typify microglial phagocytic activity. We also found that Src/PI3K/Akt inhibitors prevented LLLT-stimulated Akt (Ser473 and Thr308) phosphorylation and blocked Rac1 activity and actin-based microglial phagocytosis, indicating the activation of Src/PI3K/Akt/Rac1 signaling pathway.


The present study underlines the importance of Src in suppressing inflammation and enhancing microglial phagocytic function in activated microglia during LLLT stimulation. We have identified a new and important neuroprotective signaling pathway that consists of regulation of microglial phagocytosis and inflammation under LLLT treatment. Our research may provide a feasible therapeutic approach to control the progression of neurodegenerative diseases.

Postepy High Med Dosw (Online).  2011 Feb 17;65:73-92.

The role of biological sciences in understanding the genesis and a new therapeutic approach to Alzheimer’s disease.

Tegowska E, Wosinska A.

Zaklad Toksykologii Zwierz?a, Wydzial Biologii i Nauk o Ziemi, Uniwersytet Mikolaja Kopernika w Toruniu.


The paper contrasts the historical view on causal factors in Alzheimer’s disease (AD) with the modern concept of the symptoms’ origin. Biological sciences dealing with cell structure and physiology enabled comprehension of the role of mitochondrial defects in the processes of formation of neurofibrillary tangles and ?-amyloid, which in turn gives hope for developing a new, more effective therapeutic strategy for AD. It has been established that although mitochondria constantly generate free radicals, from which they are protected by their own defensive systems, in some situations these systems become deregulated, which leads to free radical-based mitochondrial defects. This causes an energetic deficit in neurons and a further increase in the free radical pool. As a result, due to compensation processes, formation of tangles and/or acceleration of ?-amyloid production takes place. The nature of these processes is initially a protective one, due to their anti-oxidative action, but as the amount of the formations increases, their beneficial effect wanes. They become a storage place for substances enhancing free radical processes, which makes them toxic themselves. It is such an approach to the primary causal factor for AD which lies at the roots of the new view on AD therapy, suggesting the use of methylene blue-based drugs, laser or intranasally applied insulin. A necessary condition, however, for these methods’ effectiveness is definitely an earlier diagnosis of the disease. Although there are numerous diagnostic methods for AD, their low specificity and high price, often accompanied by a considerable level of patient discomfort, make them unsuitable for early, prodromal screening. In this matter a promising method may be provided using an olfactory test, which is an inexpensive and non-invasive method and thus suitable for screening, although as a test of low specificity, it should be combined with other methods. Introducing new methods of AD treatment does not mean abandoning the traditional ones, based on enhancing cholinergic transmission. They are valuable as long as the therapy starts when abundant brain inclusions disturb the transmissions.<br />

Photomed Laser Surg.  2010 Oct;28(5):663-7.

Long-term safety of single and multiple infrared transcranial laser treatments in Sprague-Dawley rats.

McCarthy TJ, De Taboada L, Hildebrandt PK, Ziemer EL, Richieri SP, Streeter J.


PhotoThera, Inc., 5925 Priestly Drive, Suite 120, Carlsbad, California, USA.



Growing interest exists in the use of near-infrared laser therapies for the treatment of numerous neurologic conditions, including acute ischemic stroke, traumatic brain injury, Parkinson’s disease, and Alzheimer’s disease. In consideration of these trends, the objective of this study was to evaluate the long-term safety of transcranial laser therapy with continuous-wave (CW) near-infrared laser light (wavelength, 808?±?10?nm, 2-mm diameter) with a nominal radiant power of 70?mW; power density, 2,230?mW/cm(2), and energy density, 268?J/cm(2) at the scalp (10?mW/cm(2) and 1.2?J/cm(2) at the cerebral cortical surface) in healthy Sprague-Dawley rats.


In this study, 120 anesthetized rats received sequential transcranial laser treatments to the right and left parietal areas of the head on the same day (minimum of 5?min between irradiation of each side), on either Day 1 or on each of Days 1, 3, and 5. Sixty anesthetized rats served as sham controls. Rats were evaluated 1 year after treatment for abnormalities in clinical hematology and brain and pituitary gland histopathology.


No toxicologically important differences were found in the clinical hematology results between sham-control and laser-treated rats for any hematologic parameters examined. All values fell within historic control reference ranges for aged Sprague-Dawley rats. Similarly, brain and pituitary gland histopathology showed no treatment-related abnormalities or induced neoplasia.


Single and multiple applications of transcranial laser therapy with 808-nm CW laser light at a nominal power density of 10?mW/cm(2) at the surface of the cerebral cortex appears to be safe in Sprague-Dawley rats 1 year after treatment.

The Efficacy of 904 nm Laser Therapy for Alzheimer’s Diseases

Kazuyoshi Zenba, Vice president of Kanagawa Acupuncture Massage Association

Prof. Masayuki Inoue, Secretary of JLPLTPA


Although we had reported about the possible efficacy of low power laser therapy (LPLT) for Senile Dementia(S D) 3 times from 1993 at the annual meetings of Japan Society for Laser Medicine, there was no practically useful treatment found for Alzheimer’s disease(AD) and Parkinson disease and other Senile Dementia even after the start of elderly-care-insurance system in Japan. As we have continued above said laser therapy for SD at home care visit of elderly persons and felt very useful and effective, we would like to report about recent situation of laser therapy for AD patients.

Especially recently, the number of Alzheimer’s disease patients is increasing by the arrival of super-aged world in Japan. However the cause of this disease is not known and there is no effective treatment established at present. As to the mechanism of LPLT, its main mechanism is mostly elucidated by the progress in the field of Molecular biology and widely used for the removal of pain, decrease of swelling and treatment of wound. However its application for the treatment of Brain diseases is hardly practiced.

We have continued the treatment of Senile Dementia patients by LPL considering it as to be one of practical and effective treatment of this disease

LPLT is very useful for the medical treatment of the senile dementia patients at home for the expansion of ADL, pain relief, mitigation of inflammation, prevention of bed sore, the treatment of hemiplegia in a brain blood vessel obstacle and the braking of aggravation of Alzheimer’s disease without any fear of side effects by the irradiation of LPL to the head of patients.

It will be not to exaggerate to say LPLT can be one of main treatments of senior patients at home in near future.

(Object of study)

To study the practical usefulness of LPLT for the treatment of Alzheimer’s disease patients at home in terms of improvement of ADL and QOL and also for the reduction of burden of families of the care of patients.

(Method of treatment)

15 Alzheimer’s disease patients, 5 male and 10 female, received irradiation of LPL for 2 minutes at each points, 2-3 times a week for one year. Laser irradiation points were as follows. Acupuncture points established as effective based on long history of Oriental medicine .

(1) Acupuncture point to improve blood circulation (2) Acupuncture point for the treatment of stroke (3) Acupuncture point for adjustment of blood pressure (4) Acupuncture point for adjustment of balance of autonomous nerve.( the forehead, the right and left temple, occiput)

In addition, the method (based on papers in Russia and Armenia that intravenous LPL irradiation  improved the viscosity of blood) of irradiating LPL to the place which touches the pulse of an artery under collarbone was used as an additional medical treatment point.

(LPL instrument)


Among evaluation items, cooperativeness and the lack of composure were observed as useful as an effect, the effect appeared half a year after and continued after one year and later on.

It was suggested that LPLT was useful for the improvement of orientation disturbance, normalization of clothing and the dress. Because, many families and the care workers talked us LPL was very helpful since the present condition could be maintained, without getting worse.

After the start of LPL treatment, It was reported that the coldness of hands and legs of patients vanished and joints and muscular stiffness were also mitigated. Therefore, the joint movable region was also secured comparatively.

Also in excretion care, it became very easy to carry out the care of patients.

It was able to say about all patients that their expression became quiet and came to show understanding to directions of a care worker. It is suggested by this that LPLT as one of practical treatment of patients at home by the improvement of care power at home.


Since the senile-dementia-of-Alzheimer-type has a feature of advance of condition and it was said that condition became gradually critical, we tried this treatment expecting the maintenance of condition, and examination whether there was any delay effect. It is considered to have been suggested at least there was an effect of maintaining present condition in a certain field.

About the effect over the brain of laser irradiation, it was reported at the annual meeting of Japan Society for Laser Surgery and Medicine meeting in 1991 by Jun-Ichi Nishimura et al., of  Department of Physiology, Yokohama City University School of Medicine. The 780 nm wavelength and 1mW laser irradiation to the inner core of rats made the increase of cerebral blood flows at hippocampus by the amount of about 20% in average (control:15, laser:15). Although after 30 minute it was confirmed having maintained the increase of 10%.

In 1992 at the same medical conference, Takayuki Obata et. al., of the same University reported that laser irradiation of 780nm wavelength10mW to the head surface of rats activated cranial nerves activities (control:16, laser:15).

These reports suggested the possible usefulness of LPL treatment to Senile Dementia and other brain diseases patients. Unfortunately these findings did not much attention of medical world In Japan.

However, recently a possibility that ATP and cellmembrane potential of brain neuron could be controlled specifically by the irradiation of near infrared lasers (830nm wavelength) on the surface of heads of rats was reported by Oda-Mochizuki University, Synchrotron Light Life Science Center.

It was suggested by this research center that the condition of Epilepsy could be stabilized by Irradiating infrared laser from out side of heads of patients and decreasing the unusual excitement of cerebral neurons and in case of cerebral infarction, the aggravation of progress of Necrosis and Apotosis of cerebral neurons could be stopped by making stabilize the electric potential of cell membrane of cerebral neurons.

Development of future research in this field is expected as what supports scientifically the medical treatment of LPL and the result of condition improvements, such as Senile Dementia, brain blood vessel obstacles, hemiplegia and Parkinson patients.

Although the wavelength of LPL used for “Examination of the validity of LPL to Senile Dementia Patients” which we announced at the annual meetings of Japan Society for Laser Surgery and Medicine meeting over three years from 1993, was 780nm and out put was10mW, and 1mw.  The LPL used for this examination was of the wavelength of 904nm and the peak value of a pulse was 5W and the average output was 5mW. However, the same medical treatment effect was confirmed. Although it is thought that there was no wavelength dependability of laser to the efficacy over the Alzheimer’s diseases of LPL(780,830,904nm lasers are equally effective for pain removal and wound healing), how is it sure enough? A question remains.

By this examination, at least following effects were confirmed. Namely (1) the advance of condition of Alzheimer’s diseases has been blocked (2) and the expression of patients changed to smiling from disinterestedness, cooperativeness came out , an understanding came to be shown to a partner (3) We received comments from many families that the care of patients became much easier than before. It is considered that the head irradiation of near infrared laser light makes the cerebral blood flow improve, activates nerve activities and have applied brakes to the advance of the apotosis of brain cells as animal experiments are proving. Since the medical treatment efficacy is seldom acknowledged to middle degree class and a serious  patient, although it is hard to call it the fundamental cure for Alzheimer’s disease by the present method, if medical a treatment is started in early stage and continued, it may be possible to call it one of practical cures which can stop subsequent advance of disease.

Based on this experience, collecting newest information overseas, research results in the biology field, we will continue to study the possible LPL method for the dramatic cure of Alzheimer’s diseases by changing the wavelength of laser, the output and the irradiation method and also combination with other therapies