Abstract
Purpose :
In blind people with retinal diseases such as retinitis pigmentosa, although photoreceptor cells are dead, other retinal neurons are still alive, and ganglion cells can send visual information to the brain. Okayama University-type retinal prosthesis (OURePTM) is a novel type of retinal prostheses, so called photoelectric dye-coupled thin film retinal prosthesis. The dye-coupled film generates electric potential in response to light. In this study, spike discharges were recorded from mouse retinal ganglion cells to test whether the dye-coupled film would trigger spike discharges in response to the light stimulus.
Methods :
The retina was isolated from wild-type C57BL/6J mice. The dye-coupled film was placed on the glass bottom of the recording chamber, and the isolated retia was overlaid on the film (ganglion cell layer up). The retina was continuously superfused with oxygenated artificial cerebrospinal fluid. Spike discharges were recorded from ganglion cells using a tungsten electrode attached to the amplifier. Flash-light stimuli were presented with a LED, and L-AP4 was bath applied to suppress ON responses of ganglion cells originated from photoreceptors of ganglion cells. The plain film was also used in the control condition.
Results :
In the control condition, with the plain film, ON responses were observed at the onset of light stimuli. During the application of L-AP4 ON responses were suppressed. ON responses recovered after washout of L-AP4. In the test condition, with the dye-coupled film, ON responses from ganglion cells remained during application of L-AP4.
Conclusions :
With the plain film, ON responses were suppressed by L-AP4, and recovered after washout. This result indicates that our experimental condition is physiologically appropriate for evaluation of the efficacy of the dye-coupled film. With the dye coupled film, ON responses were remained during application of L-AP4 suggesting that the dye coupled film could work as retinal prostheses which could trigger spike discharges of ganglion cells without photoreceptors.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.