1
|
Seo HW, Cha S, Jeong Y, Ahn J, Lee KJ, Kim S, Goo YS. Focal stimulation of retinal ganglion cells using subretinal 3D microelectrodes with peripheral electrodes of opposite current. Biomed Eng Lett 2024; 14:355-365. [PMID: 38374901 PMCID: PMC10874361 DOI: 10.1007/s13534-023-00342-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 10/10/2023] [Accepted: 12/07/2023] [Indexed: 02/21/2024] Open
Abstract
Subretinal prostheses have been developed to stimulate survived retinal ganglion cells (RGCs), indirectly following the physiological visual pathways. However, current spreading from the prosthesis electrode causes the activation of unintended RGCs, thereby limiting the spatial resolution of artificial vision. This study proposes a strategy for focal stimulation of RGCs using a subretinal electrode array, in which six hexagonally arranged peripheral electrodes surround a stimulating electrode. RGCs in an in-vitro condition were subretinally stimulated using a fabricated electrode array coated with iridium oxide, following the three different stimulation configurations (with no peripheral, six electrodes of opposite current, and six ground). In-vitro experiments showed that the stimulation with six electrodes of opposite current was most effective in controlling RGC responses with a high spatial resolution. The results suggest that the effective utilization of return electrodes, such as by applying an opposite current to them, could help reduce current spreading beyond the local area targeted for stimulation and elicit RGC responses only in the vicinity of the stimulating electrode. Supplementary Information The online version contains supplementary material available at 10.1007/s13534-023-00342-3.
Collapse
Affiliation(s)
- Hee Won Seo
- Department of Robotics and Mechatronics Engineering, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, Republic of Korea
| | - Seongkwang Cha
- Department of Physiology, Chungbuk National University School of Medicine, Cheongju, Republic of Korea
| | - Yurim Jeong
- Department of Physiology, Chungbuk National University School of Medicine, Cheongju, Republic of Korea
| | - Jungryul Ahn
- Department of Physiology, Chungbuk National University School of Medicine, Cheongju, Republic of Korea
| | - Kyeong Jae Lee
- Department of Robotics and Mechatronics Engineering, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, Republic of Korea
| | - Sohee Kim
- Department of Robotics and Mechatronics Engineering, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, Republic of Korea
| | - Yong Sook Goo
- Department of Physiology, Chungbuk National University School of Medicine, Cheongju, Republic of Korea
| |
Collapse
|
2
|
Karamali F, Behtaj S, Babaei-Abraki S, Hadady H, Atefi A, Savoj S, Soroushzadeh S, Najafian S, Nasr Esfahani MH, Klassen H. Potential therapeutic strategies for photoreceptor degeneration: the path to restore vision. J Transl Med 2022; 20:572. [PMID: 36476500 PMCID: PMC9727916 DOI: 10.1186/s12967-022-03738-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 10/29/2022] [Indexed: 12/12/2022] Open
Abstract
Photoreceptors (PRs), as the most abundant and light-sensing cells of the neuroretina, are responsible for converting light into electrical signals that can be interpreted by the brain. PR degeneration, including morphological and functional impairment of these cells, causes significant diminution of the retina's ability to detect light, with consequent loss of vision. Recent findings in ocular regenerative medicine have opened promising avenues to apply neuroprotective therapy, gene therapy, cell replacement therapy, and visual prostheses to the challenge of restoring vision. However, successful visual restoration in the clinical setting requires application of these therapeutic approaches at the appropriate stage of the retinal degeneration. In this review, firstly, we discuss the mechanisms of PR degeneration by focusing on the molecular mechanisms underlying cell death. Subsequently, innovations, recent developments, and promising treatments based on the stage of disorder progression are further explored. Then, the challenges to be addressed before implementation of these therapies in clinical practice are considered. Finally, potential solutions to overcome the current limitations of this growing research area are suggested. Overall, the majority of current treatment modalities are still at an early stage of development and require extensive additional studies, both pre-clinical and clinical, before full restoration of visual function in PR degeneration diseases can be realized.
Collapse
Affiliation(s)
- Fereshteh Karamali
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Sanaz Behtaj
- grid.1022.10000 0004 0437 5432Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Queensland, Australia ,grid.1022.10000 0004 0437 5432Menzies Health Institute Queensland, Griffith University, Southport, QLD 4222 Australia
| | - Shahnaz Babaei-Abraki
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Hanieh Hadady
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Atefeh Atefi
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Soraya Savoj
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Sareh Soroushzadeh
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Samaneh Najafian
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Mohammad Hossein Nasr Esfahani
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Henry Klassen
- grid.266093.80000 0001 0668 7243Gavin Herbert Eye Institute, Irvine, CA USA
| |
Collapse
|
3
|
Caravaca-Rodriguez D, Gaytan SP, Suaning GJ, Barriga-Rivera A. Implications of Neural Plasticity in Retinal Prosthesis. Invest Ophthalmol Vis Sci 2022; 63:11. [PMID: 36251317 DOI: 10.1167/iovs.63.11.11] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Retinal degenerative diseases such as retinitis pigmentosa cause a progressive loss of photoreceptors that eventually prevents the affected person from perceiving visual sensations. The absence of a visual input produces a neural rewiring cascade that propagates along the visual system. This remodeling occurs first within the retina. Then, subsequent neuroplastic changes take place at higher visual centers in the brain, produced by either the abnormal neural encoding of the visual inputs delivered by the diseased retina or as the result of an adaptation to visual deprivation. While retinal implants can activate the surviving retinal neurons by delivering electric current, the unselective activation patterns of the different neural populations that exist in the retinal layers differ substantially from those in physiologic vision. Therefore, artificially induced neural patterns are being delivered to a brain that has already undergone important neural reconnections. Whether or not the modulation of this neural rewiring can improve the performance for retinal prostheses remains a critical question whose answer may be the enabler of improved functional artificial vision and more personalized neurorehabilitation strategies.
Collapse
Affiliation(s)
- Daniel Caravaca-Rodriguez
- Department of Applied Physics III, Technical School of Engineering, Universidad de Sevilla, Sevilla, Spain
| | - Susana P Gaytan
- Department of Physiology, Universidad de Sevilla, Sevilla, Spain
| | - Gregg J Suaning
- School of Biomedical Engineering, University of Sydney, Sydney, Australia
| | - Alejandro Barriga-Rivera
- Department of Applied Physics III, Technical School of Engineering, Universidad de Sevilla, Sevilla, Spain.,School of Biomedical Engineering, University of Sydney, Sydney, Australia
| |
Collapse
|
4
|
Hayashida Y, Kameda S, Umehira Y, Ishikawa S, Yagi T. Multichannel stimulation module as a tool for animal studies on cortical neural prostheses. FRONTIERS IN MEDICAL TECHNOLOGY 2022; 4:927581. [PMID: 36176924 PMCID: PMC9513350 DOI: 10.3389/fmedt.2022.927581] [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: 04/24/2022] [Accepted: 08/08/2022] [Indexed: 11/13/2022] Open
Abstract
Intracortical microstimulation to the visual cortex is thought to be a feasible technique for inducing localized phosphenes in patients with acquired blindness, and thereby for visual prosthesis. In order to design effective stimuli for the prosthesis, it is important to elucidate relationships between the spatio-temporal patterns of stimuli and the resulting neural responses and phosphenes through pre-clinical animal studies. However, the physiological basis of effective spatial patterns of the stimuli for the prosthesis has been little investigated in the literature, at least partly because that the previously developed multi-channel stimulation systems were designed specifically for the clinical use. In the present, a 64-channel stimulation module was developed as a scalable tool for animal experiments. The operations of the module were verified by not only dry-bench tests but also physiological animal experiments in vivo. The results demonstrated its usefulness for examining the stimulus-response relationships in a quantitative manner, and for inducing the multi-site neural excitations with a multi-electrode array. In addition, this stimulation module could be used to generate spatially patterned stimuli with up to 4,096 channels in a dynamic way, in which the stimulus patterns can be updated at a certain frame rate in accordance with the incoming visual scene. The present study demonstrated that our stimulation module is applicable to the physiological and other future studies in animals on the cortical prostheses.
Collapse
Affiliation(s)
- Yuki Hayashida
- Division of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka University, Suita, Japan
- Department of Information Engineering, Graduate School of Engineering, Mie University, Tsu, Japan
| | - Seiji Kameda
- Division of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka University, Suita, Japan
| | - Yuichi Umehira
- Division of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka University, Suita, Japan
| | - Shinnosuke Ishikawa
- Division of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka University, Suita, Japan
| | - Tetsuya Yagi
- Division of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka University, Suita, Japan
- Department of Electrical and Electronic Engineering, School of Engineering, Fukui University of Technology, Fukui, Japan
| |
Collapse
|
5
|
Fauvel T, Chalk M. Human-in-the-loop optimization of visual prosthetic stimulation. J Neural Eng 2022; 19. [PMID: 35667363 DOI: 10.1088/1741-2552/ac7615] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 06/06/2022] [Indexed: 11/12/2022]
Abstract
Retinal prostheses are a promising strategy to restore sight to patients with retinal degenerative diseases. These devices compensate for the loss of photoreceptors by electrically stimulating neurons in the retina. Currently, the visual function that can be recovered with such devices is very limited. This is due, in part, to current spread, unintended axonal activation, and the limited resolution of existing devices. Here we show, using a recent model of prosthetic vision, that optimizing how visual stimuli are encoded by the device can help overcome some of these limitations, leading to dramatic improvements in visual perception. APPROACH We propose a strategy to do this in practice, using patients' feedback in a visual task. The main challenge of our approach comes from the fact that, typically, one only has access to a limited number of noisy responses from patients. We propose two ways to deal with this: first, we use a model of prosthetic vision to constrain and simplify the optimization. We show that, if one knew the parameters of this model for a given patient, it would be possible to greatly improve their perceptual performance. Second we propose a preferential Bayesian optimization to efficiently learn these model parameters for each patient, using minimal trials. MAIN RESULTS To test our approach, we presented healthy subjects with visual stimuli generated by a recent model of prosthetic vision, to replicate the perceptual experience of patients fitted with an implant. Our optimization procedure led to significant and robust improvements in perceived image quality, that transferred to increased performance in other tasks. SIGNIFICANCE Importantly, our strategy is agnostic to the type of prosthesis and thus could readily be implemented in existing implants.
Collapse
Affiliation(s)
- Tristan Fauvel
- Institut de la Vision, INSERM, 17 Rue Moreau, Paris, Île-de-France, 75014, FRANCE
| | - Matthew Chalk
- Institut de l a Vision, INSERM, 17 Rue Moreau, Paris, 75014, FRANCE
| |
Collapse
|
6
|
Liu W, Liu S, Li P, Yao K. Retinitis Pigmentosa: Progress in Molecular Pathology and Biotherapeutical Strategies. Int J Mol Sci 2022; 23:ijms23094883. [PMID: 35563274 PMCID: PMC9101511 DOI: 10.3390/ijms23094883] [Citation(s) in RCA: 49] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 04/25/2022] [Accepted: 04/26/2022] [Indexed: 12/13/2022] Open
Abstract
Retinitis pigmentosa (RP) is genetically heterogeneous retinopathy caused by photoreceptor cell death and retinal pigment epithelial atrophy that eventually results in blindness in bilateral eyes. Various photoreceptor cell death types and pathological phenotypic changes that have been disclosed in RP demand in-depth research of its pathogenic mechanism that may account for inter-patient heterogeneous responses to mainstream drug treatment. As the primary method for studying the genetic characteristics of RP, molecular biology has been widely used in disease diagnosis and clinical trials. Current technology iterations, such as gene therapy, stem cell therapy, and optogenetics, are advancing towards precise diagnosis and clinical applications. Specifically, technologies, such as effective delivery vectors, CRISPR/Cas9 technology, and iPSC-based cell transplantation, hasten the pace of personalized precision medicine in RP. The combination of conventional therapy and state-of-the-art medication is promising in revolutionizing RP treatment strategies. This article provides an overview of the latest research on the pathogenesis, diagnosis, and treatment of retinitis pigmentosa, aiming for a convenient reference of what has been achieved so far.
Collapse
|
7
|
Vilkhu RS, Madugula SS, Grosberg LE, Gogliettino AR, Hottowy P, Dabrowski W, Sher A, Litke AM, Mitra S, Chichilnisky EJ. Spatially patterned bi-electrode epiretinal stimulation for axon avoidance at cellular resolution. J Neural Eng 2021; 18. [PMID: 34710857 DOI: 10.1088/1741-2552/ac3450] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 10/28/2021] [Indexed: 11/12/2022]
Abstract
Objective.Epiretinal prostheses are designed to restore vision to people blinded by photoreceptor degenerative diseases by stimulating surviving retinal ganglion cells (RGCs), which carry visual signals to the brain. However, inadvertent stimulation of RGCs at their axons can result in non-focal visual percepts, limiting the quality of artificial vision. Theoretical work has suggested that axon activation can be avoided with current stimulation designed to minimize the second spatial derivative of the induced extracellular voltage along the axon. However, this approach has not been verified experimentally at the resolution of single cells.Approach.In this work, a custom multi-electrode array (512 electrodes, 10μm diameter, 60μm pitch) was used to stimulate and record RGCs in macaque retinaex vivoat single-cell, single-spike resolution. RGC activation thresholds resulting from bi-electrode stimulation, which consisted of bipolar currents simultaneously delivered through two electrodes straddling an axon, were compared to activation thresholds from traditional single-electrode stimulation.Main results.On average, across three retinal preparations, the bi-electrode stimulation strategy reduced somatic activation thresholds (∼21%) while increasing axonal activation thresholds (∼14%), thus favoring selective somatic activation. Furthermore, individual examples revealed rescued selective activation of somas that was not possible with any individual electrode.Significance.This work suggests that a bi-electrode epiretinal stimulation strategy can reduce inadvertent axonal activation at cellular resolution, for high-fidelity artificial vision.
Collapse
Affiliation(s)
- Ramandeep S Vilkhu
- Department of Electrical Engineering, Stanford University, Stanford, CA, United States of America
| | - Sasidhar S Madugula
- Departments of Neurosurgery, Ophthalmology, and Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA, United States of America
| | - Lauren E Grosberg
- Departments of Neurosurgery, Ophthalmology, and Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA, United States of America
| | - Alex R Gogliettino
- Departments of Neurosurgery, Ophthalmology, and Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA, United States of America
| | - Pawel Hottowy
- Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, Krakow 30-059, Poland
| | - Wladyslaw Dabrowski
- Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, Krakow 30-059, Poland
| | - Alexander Sher
- Santa Cruz Institute for Particle Physics, University of California, Santa Cruz, CA, United States of America
| | - Alan M Litke
- Santa Cruz Institute for Particle Physics, University of California, Santa Cruz, CA, United States of America
| | - Subhasish Mitra
- Department of Electrical Engineering, Stanford University, Stanford, CA, United States of America
| | - E J Chichilnisky
- Departments of Neurosurgery, Ophthalmology, and Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA, United States of America
| |
Collapse
|
8
|
Shivdasani MN, Evans M, Burns O, Yeoh J, Allen PJ, Nayagam DAX, Villalobos J, Abbott CJ, Luu CD, Opie NL, Sabu A, Saunders AL, McPhedran M, Cardamone L, McGowan C, Maxim V, Williams RA, Fox KE, Cicione R, Garrett DJ, Ahnood A, Ganesan K, Meffin H, Burkitt AN, Prawer S, Williams CE, Shepherd RK. In vivo feasibility of epiretinal stimulation using ultrananocrystalline diamond electrodes. J Neural Eng 2020; 17:045014. [PMID: 32659750 DOI: 10.1088/1741-2552/aba560] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
OBJECTIVE Due to their increased proximity to retinal ganglion cells (RGCs), epiretinal visual prostheses present the opportunity for eliciting phosphenes with low thresholds through direct RGC activation. This study characterised the in vivo performance of a novel prototype monolithic epiretinal prosthesis, containing Nitrogen incorporated ultrananocrystalline (N-UNCD) diamond electrodes. APPROACH A prototype implant containing up to twenty-five 120 × 120 µm N-UNCD electrodes was implanted into 16 anaesthetised cats and attached to the retina either using a single tack or via magnetic coupling with a suprachoroidally placed magnet. Multiunit responses to retinal stimulation using charge-balanced biphasic current pulses were recorded acutely in the visual cortex using a multichannel planar array. Several stimulus parameters were varied including; the stimulating electrode, stimulus polarity, phase duration, return configuration and the number of electrodes stimulated simultaneously. MAIN RESULTS The rigid nature of the device and its form factor necessitated complex surgical procedures. Surgeries were considered successful in 10/16 animals and cortical responses to single electrode stimulation obtained in eight animals. Clinical imaging and histological outcomes showed severe retinal trauma caused by the device in situ in many instances. Cortical measures were found to significantly depend on the surgical outcomes of individual experiments, phase duration, return configuration and the number of electrodes stimulated simultaneously, but not stimulus polarity. Cortical thresholds were also found to increase over time within an experiment. SIGNIFICANCE The study successfully demonstrated that an epiretinal prosthesis containing diamond electrodes could produce cortical activity with high precision, albeit only in a small number of cases. Both surgical approaches were highly challenging in terms of reliable and consistent attachment to and stabilisation against the retina, and often resulted in severe retinal trauma. There are key challenges (device form factor and attachment technique) to be resolved for such a device to progress towards clinical application, as current surgical techniques are unable to address these issues.
Collapse
Affiliation(s)
- Mohit N Shivdasani
- Graduate School of Biomedical Engineering, University of New South Wales, Kensington, NSW 2033, Australia. The Bionics Institute of Australia, East Melbourne, VIC 3002, Australia
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Sysoev Y, Bazhenova E, Lyakhovetskii V, Kovalev G, Shkorbatova P, Islamova R, Pavlova N, Gorskii O, Merkulyeva N, Shkarupa D, Musienko P. Site-Specific Neuromodulation of Detrusor and External Urethral Sphincter by Epidural Spinal Cord Stimulation. Front Syst Neurosci 2020; 14:47. [PMID: 32774243 PMCID: PMC7387722 DOI: 10.3389/fnsys.2020.00047] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 06/26/2020] [Indexed: 12/18/2022] Open
Abstract
Impairments of the lower urinary tract function including urine storage and voiding are widely spread among patients with spinal cord injuries. The management of such patients includes bladder catheterization, surgical and pharmacological approaches, which reduce the morbidity from urinary tract-related complications. However, to date, there is no effective treatment of neurogenic bladder and restoration of urinary function. In the present study, we examined neuromodulation of detrusor (Detr) and external urethral sphincter by epidural electrical stimulation (EES) of lumbar and sacral regions of the spinal cord in chronic rats. To our knowledge, it is the first chronic study where detrusor and external urethral sphincter signals were recorded simultaneously to monitor their neuromodulation by site-specific spinal cord stimulation (SCS). The data obtained demonstrate that activation of detrusor muscle mainly occurs during the stimulation of the upper lumbar (L1) and lower lumbar (L5-L6) spinal segments whereas external urethral sphincter was activated predominantly by sacral stimulation. These findings can be used for the development of neurorehabilitation strategies based on spinal cord epidural stimulation for autonomic function recovery after severe spinal cord injury (SCI).
Collapse
Affiliation(s)
- Yuriy Sysoev
- Institute of Translational Biomedicine, Saint-Petersburg State University, Saint-Petersburg, Russia.,Department of Pharmacology and Clinical Pharmacology, Saint-Petersburg State Chemical Pharmaceutical University, Saint-Petersburg, Russia
| | - Elena Bazhenova
- Institute of Translational Biomedicine, Saint-Petersburg State University, Saint-Petersburg, Russia.,Pavlov Institute of Physiology, Russian Academy of Sciences (RAS), Saint-Petersburg, Russia
| | - Vsevolod Lyakhovetskii
- Pavlov Institute of Physiology, Russian Academy of Sciences (RAS), Saint-Petersburg, Russia.,Granov Russian Research Center of Radiology and Surgical Technologies, Ministry of Healthcare of the Russian Federation, Saint-Petersburg, Russia
| | - Gleb Kovalev
- Clinic of High Medical Technology named after N.I. Pirogov St. Petersburg State University, Saint-Petersburg, Russia
| | - Polina Shkorbatova
- Pavlov Institute of Physiology, Russian Academy of Sciences (RAS), Saint-Petersburg, Russia
| | - Regina Islamova
- Institute of Chemistry, Saint-Petersburg State University, Saint-Petersburg, Russia
| | - Natalia Pavlova
- Institute of Translational Biomedicine, Saint-Petersburg State University, Saint-Petersburg, Russia.,Pavlov Institute of Physiology, Russian Academy of Sciences (RAS), Saint-Petersburg, Russia
| | - Oleg Gorskii
- Institute of Translational Biomedicine, Saint-Petersburg State University, Saint-Petersburg, Russia.,Pavlov Institute of Physiology, Russian Academy of Sciences (RAS), Saint-Petersburg, Russia.,Granov Russian Research Center of Radiology and Surgical Technologies, Ministry of Healthcare of the Russian Federation, Saint-Petersburg, Russia
| | - Natalia Merkulyeva
- Institute of Translational Biomedicine, Saint-Petersburg State University, Saint-Petersburg, Russia.,Pavlov Institute of Physiology, Russian Academy of Sciences (RAS), Saint-Petersburg, Russia.,Granov Russian Research Center of Radiology and Surgical Technologies, Ministry of Healthcare of the Russian Federation, Saint-Petersburg, Russia
| | - Dmitry Shkarupa
- Clinic of High Medical Technology named after N.I. Pirogov St. Petersburg State University, Saint-Petersburg, Russia
| | - Pavel Musienko
- Institute of Translational Biomedicine, Saint-Petersburg State University, Saint-Petersburg, Russia.,Pavlov Institute of Physiology, Russian Academy of Sciences (RAS), Saint-Petersburg, Russia.,Granov Russian Research Center of Radiology and Surgical Technologies, Ministry of Healthcare of the Russian Federation, Saint-Petersburg, Russia.,Saint-Petersburg State Research Institute of Phthisiopulmonology, Ministry of Healthcare of the Russian Federation, Saint-Petersburg, Russia
| |
Collapse
|
10
|
Seo HW, Kim N, Kim S. Fabrication of Subretinal 3D Microelectrodes with Hexagonal Arrangement. MICROMACHINES 2020; 11:mi11050467. [PMID: 32365472 PMCID: PMC7281732 DOI: 10.3390/mi11050467] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Revised: 04/26/2020] [Accepted: 04/27/2020] [Indexed: 02/01/2023]
Abstract
This study presents the fabrication of three-dimensional (3D) microelectrodes for subretinal stimulation, to accommodate adjacent return electrodes surrounding a stimulating electrode. For retinal prosthetic devices, the arrangement of return electrodes, the electrode size and spacing should be considered together, to reduce the undesired dissipation of electric currents. Here, we applied the hexagonal arrangement to the microelectrode array for the localized activation of retinal cells and better visual acuity. To provide stimuli more efficiently to non-spiking neurons, a 3D structure was created through a customized pressing process, utilizing the elastic property of the materials used in the fabrication processes. The diameter and pitch of the Pt-coated electrodes were 150 μm and 350 μm, respectively, and the height of the protruded electrodes was around 20 μm. The array consisted of 98 hexagonally arranged electrodes, supported by a flexible and transparent polydimethylsiloxane (PDMS) base, with a thickness of 140 μm. Also, the array was coated with 2 μm-thick parylene-C, except the active electrode sites, for more focused stimulation. Finally, the electrochemical properties of the fabricated microelectrodes were characterized, resulting in the mean impedance of 384.87 kΩ at 1 kHz and the charge storage capacity (CSC) of 2.83 mC·cm−2. The fabricated microelectrodes are to be combined with an integrated circuit (IC) for additional in vitro and in vivo experiments.
Collapse
Affiliation(s)
| | | | - Sohee Kim
- Correspondence: ; Tel.: +82-53-785-6217
| |
Collapse
|
11
|
Pfeiffer RL, Marc RE, Jones BW. Persistent remodeling and neurodegeneration in late-stage retinal degeneration. Prog Retin Eye Res 2020; 74:100771. [PMID: 31356876 PMCID: PMC6982593 DOI: 10.1016/j.preteyeres.2019.07.004] [Citation(s) in RCA: 96] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 07/15/2019] [Accepted: 07/18/2019] [Indexed: 02/06/2023]
Abstract
Retinal remodeling is a progressive series of negative plasticity revisions that arise from retinal degeneration, and are seen in retinitis pigmentosa, age-related macular degeneration and other forms of retinal disease. These processes occur regardless of the precipitating event leading to degeneration. Retinal remodeling then culminates in a late-stage neurodegeneration that is indistinguishable from progressive central nervous system (CNS) proteinopathies. Following long-term deafferentation from photoreceptor cell death in humans, and long-lived animal models of retinal degeneration, most retinal neurons reprogram, then die. Glial cells reprogram into multiple anomalous metabolic phenotypes. At the same time, survivor neurons display degenerative inclusions that appear identical to progressive CNS neurodegenerative disease, and contain aberrant α-synuclein (α-syn) and phosphorylated α-syn. In addition, ultrastructural analysis indicates a novel potential mechanism for misfolded protein transfer that may explain how proteinopathies spread. While neurodegeneration poses a barrier to prospective retinal interventions that target primary photoreceptor loss, understanding the progression and time-course of retinal remodeling will be essential for the establishment of windows of therapeutic intervention and appropriate tuning and design of interventions. Finally, the development of protein aggregates and widespread neurodegeneration in numerous retinal degenerative diseases positions the retina as a ideal platform for the study of proteinopathies, and mechanisms of neurodegeneration that drive devastating CNS diseases.
Collapse
Affiliation(s)
- Rebecca L Pfeiffer
- Dept of Ophthalmology, Moran Eye Center, University of Utah, Salt Lake City, UT, USA; Interdepartmental Program in Neuroscience, University of Utah, Salt Lake City, UT, USA.
| | - Robert E Marc
- Dept of Ophthalmology, Moran Eye Center, University of Utah, Salt Lake City, UT, USA; Interdepartmental Program in Neuroscience, University of Utah, Salt Lake City, UT, USA
| | - Bryan William Jones
- Dept of Ophthalmology, Moran Eye Center, University of Utah, Salt Lake City, UT, USA; Interdepartmental Program in Neuroscience, University of Utah, Salt Lake City, UT, USA.
| |
Collapse
|
12
|
Seo HW, Kim N, Ahn J, Cha S, Goo YS, Kim S. A 3D flexible microelectrode array for subretinal stimulation. J Neural Eng 2019; 16:056016. [PMID: 31357188 DOI: 10.1088/1741-2552/ab36ab] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE Various retinal prostheses have been developed to restore the vision for blind patients, and some of them are already in clinical use. In this paper, we present a three-dimensional (3D) microelectrode array for a subretinal device that can effectively stimulate retinal cells. APPROACH To investigate the effect of electrode designs on the electric field distribution, we simulated various electrode shapes and sizes using finite element analysis. Based on the simulation results, the 3D microelectrode array was fabricated and evaluated in in vitro condition. MAIN RESULTS Through the simulation, we verified that an electrode design of square frustum was effective to stimulate with high contrast. Also, the 3D flexible and transparent microelectrode array based on silicon and polydimethylsiloxane was fabricated using micro-electro-mechanical system technologies. In in vitro experiments, the subretinally positioned 3D microelectrodes properly evoked spikes in retinal ganglion cells. The mean threshold current was 7.4 µA and the threshold charge density was 33.64 µC·cm-2 per phase. SIGNIFICANCE The results demonstrate the feasibility of the fabricated 3D microelectrodes as the subretinal prosthesis. The developed microelectrode array would be integrated with the stimulation circuitry and implanted in animals for further in vivo experiments.
Collapse
Affiliation(s)
- Hee Won Seo
- Department of Robotics Engineering, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, Republic of Korea
| | | | | | | | | | | |
Collapse
|
13
|
Li G, Wang F, Yang W, Yang J, Wang Y, Wang W, Liu L. Development of an image biosensor based on an optogenetically engineered cell for visual prostheses. NANOSCALE 2019; 11:13213-13218. [PMID: 31184360 DOI: 10.1039/c9nr01688k] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Visual prostheses provide blind patients with artificial vision via electrical stimulation of surviving visual cells resulting in partial restoration of vision in many patients. However, high-resolution visual perception, long-term biocompatibility and safety remain the significant challenges of existing visual prostheses. Here, we present a novel method to develop a new visual prosthesis using living cells as integrated electronics and implantable microelectrodes. The living cells modified with channelrhodopsin-2 showed excellent light-sensitive properties and encoded image information with cellular deformations triggered by light stimulation. The photoresponsive properties of the cells were determined using a single pixel imaging system, which indicated that the cells can act as a good light-sensitive biosensor. Additionally, the imaging feasibility of the cells was further validated through successful and clear imaging of several object scenes using the same system. This work represents a step toward the design and use of living cells as an image biosensor for the development of a new generation of high-resolution visual prostheses.
Collapse
Affiliation(s)
- Gongxin Li
- State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016, China. and Institutes for Robotics and Intelligent Manufacturing, Chinese Academy of Sciences, Shenyang 110016, China and Key Laboratory of Advanced Process Control for Light Industry (Ministry of Education), Institute of Automation, Jiangnan University, Wuxi 214122, China
| | - Feifei Wang
- Department of Chemistry, Stanford University, Stanford, California 94305, USA
| | - Wenguang Yang
- School of Electromechanical and Automotive Engineering, Yantai University, Yantai 264005, China
| | - Jia Yang
- State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016, China. and Institutes for Robotics and Intelligent Manufacturing, Chinese Academy of Sciences, Shenyang 110016, China and University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yuechao Wang
- State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016, China. and Institutes for Robotics and Intelligent Manufacturing, Chinese Academy of Sciences, Shenyang 110016, China
| | - Wenxue Wang
- State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016, China. and Institutes for Robotics and Intelligent Manufacturing, Chinese Academy of Sciences, Shenyang 110016, China
| | - Lianqing Liu
- State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016, China. and Institutes for Robotics and Intelligent Manufacturing, Chinese Academy of Sciences, Shenyang 110016, China
| |
Collapse
|
14
|
Abstract
Visual prostheses serve to restore visual function following acquired blindness. Acquired blindness (as opposed to congenital blindness) has many causes, including diseases such as retinitis pigmentosa, glaucoma, and macular degeneration, or trauma such as caused by automobile accident or blast damage from explosions. Many of the blindness-causing diseases target the retina or other ocular structure. Often, despite the loss of sensitivity to light, the remainder of the visual pathway is still functional, enabling electrical devices to deliver effective and meaningful visual information to the brain via arrays of electrodes. These arrays can be placed in any part of the early visual pathway, such as the retina, optic nerve, lateral geniculate nucleus, or visual cortex. A camera or other imaging source is used to drive electrical stimulation of remaining healthy cells or structures to create artificial vision and provide restoration of function. In this review, each approach to visual prostheses is described, including advantages and disadvantages as well as assessments of the current state of the art. Most of the work to-date has been targeting stimulation of (a) the retina, with three devices approved for general use and two more in clinical testing; (b) the lateral geniculate nucleus, with efforts still in the pre-clinical stage; and (c) the cortex, with three devices in clinical testing and none currently approved for general use despite the longest history of investigation of the three major approaches. Each class of device has different medical indications, and different levels of invasiveness required for implantation. All contemporary devices deliver relatively poor vision. There has been remarkable progress since the first proof-of-concept demonstration that used stimulation of the primary visual cortex, with the field exploring all viable options for restoration of function. Much of the progress has been recent, driven by advances in microelectronics and biocompatibility. With three devices currently approved for general use in various parts of the world, and a handful of additional devices well along in the pipeline toward approval, prospects for wide deployment of a device-based therapy to treat acquired blindness are good.
Collapse
|
15
|
Fan VH, Grosberg LE, Madugula SS, Hottowy P, Dabrowski W, Sher A, Litke AM, Chichilnisky EJ. Epiretinal stimulation with local returns enhances selectivity at cellular resolution. J Neural Eng 2019; 16:025001. [PMID: 30523958 PMCID: PMC6416068 DOI: 10.1088/1741-2552/aaeef1] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
OBJECTIVE Epiretinal prostheses are designed to restore vision in people blinded by photoreceptor degenerative diseases, by directly activating retinal ganglion cells (RGCs) using an electrode array implanted on the retina. In present-day clinical devices, current spread from the stimulating electrode to a distant return electrode often results in the activation of many cells, potentially limiting the quality of artificial vision. In the laboratory, epiretinal activation of RGCs with cellular resolution has been demonstrated with small electrodes, but distant returns may still cause undesirable current spread. Here, the ability of local return stimulation to improve the selective activation of RGCs at cellular resolution was evaluated. APPROACH A custom multi-electrode array (512 electrodes, 10 μm diameter, 60 μm pitch) was used to simultaneously stimulate and record from RGCs in isolated primate retina. Stimulation near the RGC soma with a single electrode and a distant return was compared to stimulation in which the return was provided by six neighboring electrodes. MAIN RESULTS Local return stimulation enhanced the capability to activate cells near the central electrode (<30 μm) while avoiding cells farther away (>30 μm). This resulted in an improved ability to selectively activate ON and OFF cells, including cells encoding immediately adjacent regions in the visual field. SIGNIFICANCE These results suggest that a device that restricts the electric field through local returns could optimize activation of neurons at cellular resolution, improving the quality of artificial vision.
Collapse
Affiliation(s)
- Victoria H Fan
- Departments of Neurosurgery, Ophthalmology, and Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA, United States of America
| | | | | | | | | | | | | | | |
Collapse
|
16
|
Rathbun DL, Ghorbani N, Shabani H, Zrenner E, Hosseinzadeh Z. Spike-triggered average electrical stimuli as input filters for bionic vision—a perspective. J Neural Eng 2018; 15:063002. [DOI: 10.1088/1741-2552/aae493] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
|
17
|
Stauss S, Honma I. Biocompatible Batteries—Materials and Chemistry, Fabrication, Applications, and Future Prospects. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2018. [DOI: 10.1246/bcsj.20170325] [Citation(s) in RCA: 106] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Sven Stauss
- Chemistry of Energy Conversion Devices Laboratory, Research Center for Sustainable Science & Engineering, Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan
| | - Itaru Honma
- Chemistry of Energy Conversion Devices Laboratory, Research Center for Sustainable Science & Engineering, Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan
| |
Collapse
|
18
|
Barriga-Rivera A, Bareket L, Goding J, Aregueta-Robles UA, Suaning GJ. Visual Prosthesis: Interfacing Stimulating Electrodes with Retinal Neurons to Restore Vision. Front Neurosci 2017; 11:620. [PMID: 29184478 PMCID: PMC5694472 DOI: 10.3389/fnins.2017.00620] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 10/23/2017] [Indexed: 01/06/2023] Open
Abstract
The bypassing of degenerated photoreceptors using retinal neurostimulators is helping the blind to recover functional vision. Researchers are investigating new ways to improve visual percepts elicited by these means as the vision produced by these early devices remain rudimentary. However, several factors are hampering the progression of bionic technologies: the charge injection limits of metallic electrodes, the mechanical mismatch between excitable tissue and the stimulating elements, neural and electric crosstalk, the physical size of the implanted devices, and the inability to selectively activate different types of retinal neurons. Electrochemical and mechanical limitations are being addressed by the application of electromaterials such as conducting polymers, carbon nanotubes and nanocrystalline diamonds, among other biomaterials, to electrical neuromodulation. In addition, the use of synthetic hydrogels and cell-laden biomaterials is promising better interfaces, as it opens a door to establishing synaptic connections between the electrode material and the excitable cells. Finally, new electrostimulation approaches relying on the use of high-frequency stimulation and field overlapping techniques are being developed to better replicate the neural code of the retina. All these elements combined will bring bionic vision beyond its present state and into the realm of a viable, mainstream therapy for vision loss.
Collapse
Affiliation(s)
- Alejandro Barriga-Rivera
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW, Australia
- Faculty of Engineering and Information Technologies, University of Sydney, Sydney, NSW, Australia
- Division of Neuroscience, University Pablo de Olavide, Sevilla, Spain
| | - Lilach Bareket
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW, Australia
- Faculty of Engineering and Information Technologies, University of Sydney, Sydney, NSW, Australia
| | - Josef Goding
- Department of Bioengineering, Imperial College London, London, United Kingdom
| | | | - Gregg J. Suaning
- Faculty of Engineering and Information Technologies, University of Sydney, Sydney, NSW, Australia
| |
Collapse
|