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Title: Neural Responses to Multielectrode Stimulation of Healthy and Degenerate Retina
Authors: Halupka, Kerry
Abbott, Carla
Wong, Yan
Cloherty, Shaun
Grayden, David
Burkitt, Anthony
Sergeev, Evgeni
Brandli, Alice
Allen, Penelope
Meffin, Hamish
Shivdasani, Mohit
Keywords: Retinal prosthesis
Retinal degeneration
In vivo electrophysiology
Electrical stimulation
Computational modelin
Issue Date: Jul-2017
Publisher: IOVS
Citation: Halupka, K. J., C. J. Abbott, Y. T. Wong, S. L. Cloherty, D. B. Grayden, A. N. Burkitt, E. N. Sergeev, C. D. Luu, A. Brandli, P. J. Allen, H. Meffin, and M. N. Shivdasani. 2017. Neural Responses to Multielectrode Stimulation of Healthy and Degenerate Retina. Investigative Ophthalmology & Visual Science. 58(9): 3770-84.
Abstract: Purpose: Simultaneous stimulation of multiple retinal electrodes in normally sighted animals shows promise in improving the resolution of retinal prostheses. However, the effects of simultaneous stimulation on degenerate retinae remain unknown. Therefore, we investigated the characteristics of cortical responses to multielectrode stimulation of the degenerate retina. Methods: Four adult cats were bilaterally implanted with retinal electrode arrays in the suprachoroidal space after unilateral adenosine triphosphate (ATP)-induced retinal photoreceptor degeneration. Functional and structural changes were characterized by using electroretinogram a-wave amplitude and optical coherence tomography. Multiunit activity was recorded from both hemispheres of the visual cortex. Responses to single- and multielectrode stimulation of the ATP-injected and fellow control eyes were characterized and compared. Results: The retinae of ATP-injected eyes displayed structural and functional changes consistent with mid- to late-stage photoreceptor degeneration and remodeling. Responses to multielectrode stimulation of the ATP-injected eyes exhibited shortened latencies, lower saturated spike counts, and higher thresholds, compared to stimulation of the fellow control eyes. Electrical receptive field sizes were significantly larger in the ATP-injected eye than in the control eye, and positively correlated with the extent of degeneration. Conclusions: Significant differences exist between cortical responses to stimulation of healthy and degenerate retinae. Our results highlight the importance of using a retinal degeneration model when evaluating the efficacy of novel stimulation paradigms.
URI: http://repository.bionicsinstitute.org:8080/handle/123456789/250
ISSN: 0146-0404
Appears in Collections:Bionic Vision Research Publications

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