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ISRN Neurology
Volume 2012 (2012), Article ID 850150, 8 pages
http://dx.doi.org/10.5402/2012/850150
Research Article

Survival of Dopaminergic Amacrine Cells after Near-Infrared Light Treatment in MPTP-Treated Mice

1Discipline of Anatomy & Histology F13, The University of Sydney, Sydney, NSW 2006, Australia
2Discipline of Physiology F13, The University of Sydney, Sydney, NSW 2006, Australia
3Institute of Ophthalmology, University College London, London EC1VGEL, UK
4Department of Optometry and Visual Science, City University, London EC1V7DD, UK

Received 3 February 2012; Accepted 1 April 2012

Academic Editors: G. Meco, J.-I. Satoh, K. F. So, and F. G. Wouterlood

Copyright © 2012 Cassandra Peoples et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

We examined whether near-infrared light (NIr) treatment (photobiomodulation) saves dopaminergic amacrine cells of the retina in an acute and a chronic 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of Parkinson disease. For the acute model, BALB/c mice had MPTP (100 mg/kg) or saline injections over 30 hours, followed by a six-day-survival period. For the chronic model, mice had MPTP (200 mg/kg) or saline injections over five weeks, followed by a three-week-survival period. NIr treatment was applied either at the same time (simultaneous series) or well after (posttreatment series) the MPTP insult. There were four groups within each series: Saline, Saline-NIr, MPTP, and MPTP-NIr. Retinae were processed for tyrosine hydroxylase (TH) immunochemistry, and cell number was analysed. In the MPTP groups, there was a significant reduction in TH+ cell number compared to the saline controls; this reduction was greater in the acute (~50%) compared to the chronic (~30%) cases. In the MPTP-NIr groups, there were significantly more TH+ cells than in the MPTP groups of both series (~30%). In summary, we showed that NIr treatment was able to both protect (simultaneous series) and rescue (posttreatment series) TH+ cells of the retina from parkinsonian insult.