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Carleton M, Oesch NW. Differences in the spatial fidelity of evoked and spontaneous signals in the degenerating retina. Front Cell Neurosci 2022; 16:1040090. [PMID: 36419935 PMCID: PMC9676928 DOI: 10.3389/fncel.2022.1040090] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Accepted: 10/20/2022] [Indexed: 07/01/2024] Open
Abstract
Vision restoration strategies aim to reestablish vision by replacing the function of lost photoreceptors with optoelectronic hardware or through gene therapy. One complication to these approaches is that retinal circuitry undergoes remodeling after photoreceptor loss. Circuit remodeling following perturbation is ubiquitous in the nervous system and understanding these changes is crucial for treating neurodegeneration. Spontaneous oscillations that arise during retinal degeneration have been well-studied, however, other changes in the spatiotemporal processing of evoked and spontaneous activity have received less attention. Here we use subretinal electrical stimulation to measure the spatial and temporal spread of both spontaneous and evoked activity during retinal degeneration. We found that electrical stimulation synchronizes spontaneous oscillatory activity, over space and through time, thus leading to increased correlations in ganglion cell activity. Intriguingly, we found that spatial selectivity was maintained in rd10 retina for evoked responses, with spatial receptive fields comparable to wt retina. These findings indicate that different biophysical mechanisms are involved in mediating feed forward excitation, and the lateral spread of spontaneous activity in the rd10 retina, lending support toward the possibility of high-resolution vision restoration.
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Affiliation(s)
- Maya Carleton
- Department of Psychology, University of California, San Diego, La Jolla, CA, United States
| | - Nicholas W. Oesch
- Department of Psychology, University of California, San Diego, La Jolla, CA, United States
- Department of Ophthalmology, University of California, San Diego, La Jolla, CA, United States
- The Neurosciences Graduate Program, University of California, San Diego, La Jolla, CA, United States
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2
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Yunzab M, Soto-Breceda A, Maturana M, Kirkby S, Slattery M, Newgreen A, Meffin H, Kameneva T, Burkitt AN, Ibbotson M, Tong W. Preferential modulation of individual retinal ganglion cells by electrical stimulation. J Neural Eng 2022; 19. [PMID: 35917811 DOI: 10.1088/1741-2552/ac861f] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Accepted: 08/01/2022] [Indexed: 11/12/2022]
Abstract
OBJECTIVE Retinal prostheses have been able to recover partial vision in blind patients with retinal degeneration by electrically stimulating surviving cells in the retina, such as retinal ganglion cells (RGCs), but the restored vision is limited. This is partly due to non-preferential stimulation of all RGCs near a single stimulating electrode, which include cells that conflict in their response properties and their contribution to the vision process. Our study proposes a stimulation strategy to preferentially stimulate individual RGCs based on their temporal electrical receptive fields (tERFs). APPROACH We recorded the responses of RGCs using whole-cell current-clamp and demonstrated the stimulation strategy, first using intracellular stimulation, then via extracellular stimulation. MAIN RESULTS We successfully reconstructed the tERFs according to the RGC response to Gaussian white noise current stimulation. The characteristics of the tERFs were extracted and compared according to the morphological and light response types of the cells. By re-delivering stimulation trains that are composed of the tERFs obtained from different cells, we could target individual RGCs as the cells showed lower activation thresholds to their own tERFs. SIGNIFICANCE This proposed stimulation strategy implemented in the next generation of recording and stimulating retinal prostheses may improve the quality of artificial vision.
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Affiliation(s)
- Molis Yunzab
- National Vision Research Institute, Australian College of Optometry, Corner of Keppel and Cardigan Streets, Carlton, Victoria, 3053, AUSTRALIA
| | - Artemio Soto-Breceda
- National Vision Research Institute, Australian College of Optometry, Corner of Keppel and Cardigan Streets, Carlton, Victoria, 3053, AUSTRALIA
| | - Matias Maturana
- National Vision Research Institute, Australian College of Optometry, Corner of Keppel and Cardigan Streets, Carlton, Victoria, 3053, AUSTRALIA
| | - Stephanie Kirkby
- National Vision Research Institute, Australian College of Optometry, Corner of Keppel and Cardigan Streets, Carlton, Victoria, 3053, AUSTRALIA
| | - Maximilian Slattery
- National Vision Research Institute, Australian College of Optometry, Corner of Keppel and Cardigan Streets, Carlton, Victoria, 3053, AUSTRALIA
| | - Anton Newgreen
- National Vision Research Institute, Australian College of Optometry, Corner of Keppel and Cardigan Streets, Carlton, Victoria, 3053, AUSTRALIA
| | - Hamish Meffin
- Biomedical Engineering, The University of Melbourne, Grattan Street, Melbourne, Victoria, 3010, AUSTRALIA
| | - Tatiana Kameneva
- School of Science, Engineering, and Computing Technologies, Swinburne University of Technology, School of Science, Engineering, and Computing Technologies, Swinburne University of Technology, Hawthorn, Victoria, 3122, AUSTRALIA
| | - Anthony N Burkitt
- Department of Biomedical Engineering, University of Melbourne, University of Melbourne, Parkville, Victoria, 3010, AUSTRALIA
| | - Michael Ibbotson
- National Vision Research Institute, Australian College of Optometry, Corner of Keppel and Cardigan Streets, Carlton, Victoria, 3053, AUSTRALIA
| | - Wei Tong
- University of Melbourne, School of Physics, University of Melbourne, Parkville, Melbourne, Victoria, 3010, AUSTRALIA
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Cessac B. Retinal Processing: Insights from Mathematical Modelling. J Imaging 2022; 8:14. [PMID: 35049855 PMCID: PMC8780400 DOI: 10.3390/jimaging8010014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 01/11/2022] [Accepted: 01/12/2022] [Indexed: 02/04/2023] Open
Abstract
The retina is the entrance of the visual system. Although based on common biophysical principles, the dynamics of retinal neurons are quite different from their cortical counterparts, raising interesting problems for modellers. In this paper, I address some mathematically stated questions in this spirit, discussing, in particular: (1) How could lateral amacrine cell connectivity shape the spatio-temporal spike response of retinal ganglion cells? (2) How could spatio-temporal stimuli correlations and retinal network dynamics shape the spike train correlations at the output of the retina? These questions are addressed, first, introducing a mathematically tractable model of the layered retina, integrating amacrine cells' lateral connectivity and piecewise linear rectification, allowing for computing the retinal ganglion cells receptive field together with the voltage and spike correlations of retinal ganglion cells resulting from the amacrine cells networks. Then, I review some recent results showing how the concept of spatio-temporal Gibbs distributions and linear response theory can be used to characterize the collective spike response to a spatio-temporal stimulus of a set of retinal ganglion cells, coupled via effective interactions corresponding to the amacrine cells network. On these bases, I briefly discuss several potential consequences of these results at the cortical level.
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Affiliation(s)
- Bruno Cessac
- France INRIA Biovision Team and Neuromod Institute, Université Côte d'Azur, 2004 Route des Lucioles, BP 93, 06902 Valbonne, France
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Stinchcombe AR, Hu C, Walch OJ, Faught SD, Wong KY, Forger DB. M1-Type, but Not M4-Type, Melanopsin Ganglion Cells Are Physiologically Tuned to the Central Circadian Clock. Front Neurosci 2021; 15:652996. [PMID: 34025341 PMCID: PMC8134526 DOI: 10.3389/fnins.2021.652996] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 04/07/2021] [Indexed: 12/31/2022] Open
Abstract
Proper circadian photoentrainment is crucial for the survival of many organisms. In mammals, intrinsically photosensitive retinal ganglion cells (ipRGCs) can use the photopigment melanopsin to sense light independently from rod and cone photoreceptors and send this information to many brain nuclei such as the suprachiasmatic nucleus (SCN), the site of the central circadian pacemaker. Here, we measure ionic currents and develop mathematical models of the electrical activity of two types of ipRGCs: M1, which projects to the SCN, and M4, which does not. We illustrate how their ionic properties differ, mainly how ionic currents generate lower spike rates and depolarization block in M1 ipRGCs. Both M1 and M4 cells have large geometries and project to higher visual centers of the brain via the optic nerve. Using a partial differential equation model, we show how axons of M1 and M4 cells faithfully convey information from the soma to the synapse even when the signal at the soma is attenuated due to depolarization block. Finally, we consider an ionic model of circadian photoentrainment from ipRGCs synapsing on SCN neurons and show how the properties of M1 ipRGCs are tuned to create accurate transmission of visual signals from the retina to the central pacemaker, whereas M4 ipRGCs would not evoke nearly as efficient a postsynaptic response. This work shows how ipRGCs and SCN neurons' electrical activities are tuned to allow for accurate circadian photoentrainment.
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Affiliation(s)
| | - Caiping Hu
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI, United States
| | - Olivia J Walch
- Department of Neurology, University of Michigan, Ann Arbor, MI, United States
| | - Samuel D Faught
- Department of Mathematics, University of Michigan, Ann Arbor, MI, United States
| | - Kwoon Y Wong
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI, United States.,Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, United States
| | - Daniel B Forger
- Department of Mathematics, University of Michigan, Ann Arbor, MI, United States.,Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, United States.,Michigan Institute for Data Science, University of Michigan, Ann Arbor, MI, United States
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Ho E, Shmakov A, Palanker D. Decoding network-mediated retinal response to electrical stimulation: implications for fidelity of prosthetic vision. J Neural Eng 2020; 17. [PMID: 33108781 PMCID: PMC8284336 DOI: 10.1088/1741-2552/abc535] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 10/27/2020] [Indexed: 02/07/2023]
Abstract
Objective. Patients with photovoltaic subretinal implant PRIMA demonstrated letter acuity ∼0.1 logMAR worse than sampling limit for 100 μm pixels (1.3 logMAR) and performed slower than healthy subjects tested with equivalently pixelated images. To explore the underlying differences between natural and prosthetic vision, we compare the fidelity of retinal response to visual and subretinal electrical stimulation through single-cell modeling and ensemble decoding. Approach. Responses of retinal ganglion cells (RGCs) to optical or electrical white noise stimulation in healthy and degenerate rat retinas were recorded via multi-electrode array. Each RGC was fit with linear–nonlinear and convolutional neural network models. To characterize RGC noise, we compared statistics of spike-triggered averages (STAs) in RGCs responding to electrical or visual stimulation of healthy and degenerate retinas. At the population level, we constructed a linear decoder to determine the accuracy of the ensemble of RGCs on N-way discrimination tasks. Main results. Although computational models can match natural visual responses well (correlation ∼0.6), they fit significantly worse to spike timings elicited by electrical stimulation of the healthy retina (correlation ∼0.15). In the degenerate retina, response to electrical stimulation is equally bad. The signal-to-noise ratio of electrical STAs in degenerate retinas matched that of the natural responses when 78 ± 6.5% of the spikes were replaced with random timing. However, the noise in RGC responses contributed minimally to errors in ensemble decoding. The determining factor in accuracy of decoding was the number of responding cells. To compensate for fewer responding cells under electrical stimulation than in natural vision, more presentations of the same stimulus are required to deliver sufficient information for image decoding. Significance. Slower-than-natural pattern identification by patients with the PRIMA implant may be explained by the lower number of electrically activated cells than in natural vision, which is compensated by a larger number of the stimulus presentations.
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Affiliation(s)
- Elton Ho
- Department of Physics, Stanford University, Stanford, California, UNITED STATES
| | - Alexander Shmakov
- Department of Computer Science, University of California Irvine, Irvine, California, UNITED STATES
| | - Daniel Palanker
- Hansen Experimental Physics Laboratory, Stanford University, Stanford, California, UNITED STATES
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