We have shown previously that near-infrared light (NIr), when applied at the same time as a parkinsonian insult (e.g. 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine; MPTP), reduces behavioural deficits and offers neuroprotection. Here, we explored whether the timing of NIr intervention—either before, at the same time or after the MPTP insult—was important. Mice received MPTP injections (total of 50 mg/kg) and, at various stages in relation to these injections, extracranial application of NIr. Locomotor activity was tested with an open-field test, and brains were processed for immunohistochemistry. Our results showed that regardless of when NIr was applied in relation to MPTP insult, behavioural impairment was reduced by a similar magnitude. The beneficial effect of NIr was fast-acting (within minutes) and long-lasting (for several days). There were more dopaminergic cells in the NIr-treated MPTP groups than in the MPTP group; there was no clear indication that a particular combination of NIr treatment and MPTP injection resulted in a higher cell number. In summary, irrespective of whether it was applied before, at the same time as or after MPTP insult, NIr reduced both behavioural and structural measures of damage by a similar magnitude. There was a broad therapeutic time window of NIr application in relation to the stage of toxic insult, and the NIr was fast-acting and long-lasting.
Parkinson’s disease Photobiomodulation Substantia nigra Neuroprotection Open-field test
Medial geniculate nucleus
Periaqueductal grey matter
Substantia nigra pars compacta
Substantia nigra pars reticulata
Ventral tegmental area
This is a preview of subscription content, log in to check access.
We are forever grateful to Michael J. Fox Foundation, Credit Agricole Sud Rhones Alpes, Fondation Philanthropique Edmond J. Safra, France Parkinson and the French National Research Agency (ANR Carnot Institute), Tenix corp and Salteri family for funding this work. D.M.J. is an Early Career Fellow of the NHMRC, Australia. J.S. was supported by the Foote Foundation and Sir Zelman Cowen Universities Fund; he is Director of CSCM Pty Ltd.
C.M., D.M.J., J.S., A.L.B. and J.M. are full-time members of staff at their respective institutions, while F.R. and N.E.M. are postgraduate students. All authors contributed to the analysis of the data and of the reading and writing of the manuscript. F.R., C.M., N.E.M., A.L.B. and J.M. contributed to the experimental work.
Compliance with ethical standards
Conflict of interest
The authors have no conflict of interest concerning the materials or methods used in this study or the findings specified in this paper, except for the funding provided by the organisations mentioned in the Acknowledgements.
Moro C, El Massri N, Torres N et al (2014) Photobiomodulation inside the brain: a novel method of applying near-infrared light intracranially and its impact on dopaminergic cell survival in MPTP-treated mice. J Neurosurg 120:670–683. doi:10.3171/2013.9.JNS13423CrossRefPubMedGoogle Scholar
Olanow CW, Kieburtz K, Schapira AHV (2008) Why have we failed to achieve neuroprotection in Parkinson’s disease? Ann Neurol 64(Suppl 2):S101–S110. doi:10.1002/ana.21461PubMedGoogle Scholar
Reinhart F, El Massri N, Darlot F et al (2015) Evidence for improved behaviour and neuroprotection after intracranial application of near infrared light in a hemi-parkinsonian rat model. J Neurosurg 27:1–13, PMID: 26613166Google Scholar
Rojas J, Gonzaalez-Lima F (2011) Low-level light therapy of the eye and brain. Eye Brain 3:49–67Google Scholar
Shaw VE, Peoples C, Spana S et al (2012) Patterns of cell activity in the subthalamic region associated with the neuroprotective action of near-infrared light treatment in MPTP-treated mice. Parkinsons Dis 2012:296875. doi:10.1155/2012/296875PubMedPubMedCentralGoogle Scholar
Wallace BA, Ashkan K, Heise CE et al (2007) Survival of midbrain dopaminergic cells after lesion or deep brain stimulation of the subthalamic nucleus in MPTP-treated monkeys. Brain 130:2129–2145. doi:10.1093/brain/awm137CrossRefPubMedGoogle Scholar
Whelan HT, DeSmet KD, Buchmann EV et al (2008) Harnessing the cell’s own ability to repair and prevent neurodegenerative disease. SPIE Newsroom 24:1–3Google Scholar