Red Light Treatment in an Axotomy Model of Neurodegeneration.
Red light has been shown to provide neuroprotective effects. Axotomizing the optic nerve initiates retinal ganglion cell (RGC) degeneration, and an early marker of this is dendritic pruning. We hypothesized that 670 nm light can delay axotomy-induced dendritic pruning in the retinal explant. To test this hypothesis, we monitored the effects of 670 nm light (radiant exposure of 31.7 J cm(-2) ), on RGC dendritic pruning in retinal explants from C57BL/6J mice, at 40 min, 8 h and 16 h post axotomy. For sham-treated retinae, area under the Sholl curve, peak of the Sholl curve and dendritic length at 8 h post axotomy showed statistically significant reductions by 42.3% (P = 0.008), 29.8% (P = 0.007) and 38.4% (P = 0.038), respectively, which were further reduced after 16 h by 40.56% (P < 0.008), 33.9% (P < 0.007), 45.43% (P < 0.006), respectively. Dendritic field area was also significantly reduced after 16 h, by 44.23% (P < 0.019). Such statistically significant reductions were not seen in light-treated RGCs at 8 or 16 h post axotomy. The results demonstrate the ability of 670 nm light to partially prevent ex vivo dendropathy in the mouse retina, suggesting that it is worth exploring as a treatment option for dendropathy-associated neurodegenerative diseases, including glaucoma and Alzheimer's disease.
School of Optometry and Vision Sciences, Cardiff University, Cardiff, UK.|Cardiff Institute for Tissue Engineering and Repair, Cardiff University, Cardiff, UK.
Kathy
K
Beirne
School of Optometry and Vision Sciences, Cardiff University, Cardiff, UK.|Cardiff Institute for Tissue Engineering and Repair, Cardiff University, Cardiff, UK.
Malgorzata
M
Rozanowska
School of Optometry and Vision Sciences, Cardiff University, Cardiff, UK.|Cardiff Institute for Tissue Engineering and Repair, Cardiff University, Cardiff, UK.|Cardiff Eye Unit, University Hospital of Wales, Cardiff, UK.
Marcela
M
Votruba
D000818:Animals; D019771:Axotomy; D003712:Dendrites / Q000528:radiation effects; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009410:Nerve Degeneration; D010778:Photochemotherapy; D012160:Retina / Q000166:cytology; D012165:Retinal Ganglion Cells / Q000528:radiation effects*; D046509:Tissue Culture Techniques