Title: Red-shifted channelrhodopsin stimulation restores light responses in blind mice, macaque retina, and human retina
The question the paper is trying to answer is whether or not using red-shifted channelrhodopsin to treat degenerative blindness will work as it did in mice.
This study is important because it could possibly be a way to treat vision loss caused by retinal degeneration.
The results were that red-shifted channelrhodopsin also drives neuronal responses in macaque retinae as well as in the central human retina, the site of high-acuity vision, demonstrating the therapeutic potential of the red-shifted channelrhodopsin molecule.
The models used were rd1 mice, macaque retinal explants and humans.
For the blind mice AAV2 injections through the sclera.
For the primates they were terminally anesthetized and their eyes were removed and the retina was isolated from the vitreous humor and cut into 1 cm pieces. The retinal explants were infected with the AAV2 and AAV8 until the day of electrophysiological recordings or fixation, the AAV infections were performed within 2 hours of the retina explants being put in tissue culture.
For the human experiments postmortem human ocular globes were acquired from the school of surgery, 6 donors, 63 – 95 years old, postmortem delays 9 – 38 hours. Similar proceedings to the primate experiment.
The age range constrained to older ages in humans, the pool of human subjects was small, only 6 people. There were also no live subjects after the mice. This may be an ethical issue.
The controls were appropriate, they tested multiple models in the same manner, though the mice were alive and the primates and humans were not alive.
Figure 1: 3 panels, showing that the channelrhodopsin can be efficiently targeted to the RGC membrane and dendritic arbor of blind mice.
Figure 2: Graphs showing the responses triggered by optogenetic stimulation of the retina.
Figure 3: Different types of graphs showing the triggered responses in the blind mice that were treated with the AAV2.
Figure 4: One of the figures shows the locomotive behavior of the blind mice before and after treatment as well as graphs that correspond with those results.
Figure 5: Graphs showing the light responses in the AAV-infected primate retinae.
Figure 6: I believe these graphs and pictures are demonstrating where and what is activated when the explant has been infected with the AAV.
Figure 7: Pictures of the retina showing part of the foveal pit.
Figure 8: AAV- mediated optogenetic activation of the human retina after it had been incubated for 12 days.
How would such an experiment work on a live human? Would it be conducted more like the mouse experiment?
Treating degenerative blindness, channelrhodopsin used to treat vision loss