scholarly journals Ectopic Expression of Multiple Microbial Rhodopsins Restores ON and OFF Light Responses in Retinas with Photoreceptor Degeneration

2009 ◽  
Vol 29 (29) ◽  
pp. 9186-9196 ◽  
Author(s):  
Y. Zhang ◽  
E. Ivanova ◽  
A. Bi ◽  
Z.-H. Pan
Keyword(s):  
Ectopic Expression ◽  
Photoreceptor Degeneration ◽  
Light Responses

scholarly journals Loss of Responses to Visual But Not Electrical Stimulation in Ganglion Cells of Rats With Severe Photoreceptor Degeneration

2009 ◽  
Vol 102 (6) ◽  
pp. 3260-3269 ◽  
Author(s):  
Chris Sekirnjak ◽  
Clare Hulse ◽  
Lauren H. Jepson ◽  
Pawel Hottowy ◽  
Alexander Sher ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Retinal Ganglion Cells ◽  
Vision Loss ◽  
Ganglion Cells ◽  
Transgenic Rat ◽  
Direct Electrical Stimulation ◽  
Retinal Ganglion ◽  
Photoreceptor Degeneration ◽  
Wild Type ◽  
Light Responses

Retinal implants are intended to help patients with degenerative conditions by electrically stimulating surviving cells to produce artificial vision. However, little is known about how individual retinal ganglion cells respond to direct electrical stimulation in degenerating retina. Here we used a transgenic rat model to characterize ganglion cell responses to light and electrical stimulation during photoreceptor degeneration. Retinas from pigmented P23H-1 rats were compared with wild-type retinas between ages P37 and P752. During degeneration, retinal thickness declined by 50%, largely as a consequence of photoreceptor loss. Spontaneous electrical activity in retinal ganglion cells initially increased two- to threefold, but returned to nearly normal levels around P600. A profound decrease in the number of light-responsive ganglion cells was observed during degeneration, culminating in retinas without detectable light responses by P550. Ganglion cells from transgenic and wild-type animals were targeted for focal electrical stimulation using multielectrode arrays with electrode diameters of ∼10 microns. Ganglion cells were stimulated directly and the success rate of stimulation in both groups was 60–70% at all ages. Surprisingly, thresholds (∼0.05 mC/cm2) and latencies (∼0.25 ms) in P23H rat ganglion cells were comparable to those in wild-type ganglion cells at all ages and showed no change over time. Thus ganglion cells in P23H rats respond normally to direct electrical stimulation despite severe photoreceptor degeneration and complete loss of light responses. These findings suggest that high-resolution epiretinal prosthetic devices may be effective in treating vision loss resulting from photoreceptor degeneration.

scholarly journals Ectopic Expression of a Microbial-Type Rhodopsin Restores Visual Responses in Mice with Photoreceptor Degeneration

Neuron ◽  
2006 ◽  
Vol 50 (1) ◽  
pp. 23-33 ◽  
Author(s):  
Anding Bi ◽  
Jinjuan Cui ◽  
Yu-Ping Ma ◽  
Elena Olshevskaya ◽  
Mingliang Pu ◽  
...  
Keyword(s):  
Ectopic Expression ◽  
Photoreceptor Degeneration ◽  
Visual Responses
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