Article
Electrophysiological Differences in Retinae of Wild Type and rd10 Mice influence the Electrical Stimulation Efficiency
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Authors
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Christine Haselier
- Aachen, Germany
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S. Hesse
- Aachen, Germany
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S. Johnen
- Aachen, Germany
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G. Thumann
- Genève, Switzerland
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F. Müller
- Jülich, Germany
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P. Walter
- Aachen, Germany
| Published: | February 13, 2014 |
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Outline
Text
Introduction: Retinal degenerative diseases, like retinitis pigmentosa (RP), begin with the loss of photoreceptors, followed by a remodeling process of the remaining inner retina. Retinal prostheses, used to restore vision in RP patients, are not adjusted to these changes. We examine whether electrical stimulation patterns of newly developed prostheses need to be adapted to the electrophysiological properties of degenerated retinae.
Methods: To investigate the changes in electrophysiological properties of degenerated retinae and their reaction to electrical stimulation in comparison to healthy retinae, we recorded in vitro from whole mount retinae using a microelectrode array (MEA) system. Recordings from retinae of wild type (wt) and retinal degeneration 10 (rd10) mice in different phases of degeneration were carried out. Biphasic current pulses of different amplitudes and durations were applied to one predefined electrode.
Results: As described previously, spontaneous activity differed between wt and rd10 retinae. In wt, baseline was stable and spikes appeared in different frequencies in a stochastic manner. In rd10, oscillatory potentials of 3-6 Hz (“slow waves”, SW) were recorded. Occasionally, SW appeared and disappeared over time and a phase-locking behaviour between SW and spiking was observed. Increasing spiking frequencies due to electrical stimulation were recorded both in wt and rd10. However, the evoked responses in rd10 retinae, in which photoreceptors were already degenerated, differed from wt retinae.
Conclusion: Our results showed that, regarding stimulation behaviour, there are non-negligible differences between the electrophysiological properties of healthy and degenerated retinae. Therefore, these results confirmed the necessity to account for changes that occur during the remodeling process in the degenerated retina in the design of new retinal prostheses. Stimulation devices that can adjust the stimulation parameters to the acute electrophysiological status may be favorable for successful retinal stimulation.
DFG-Grant: Pak469, TH 603/15-1, MU 3036/3-1
