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Mim MS, Knight C, Zartman JJ. Quantitative insights in tissue growth and morphogenesis with optogenetics. Phys Biol 2023; 20:061001. [PMID: 37678266 PMCID: PMC10594237 DOI: 10.1088/1478-3975/acf7a1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 08/15/2023] [Accepted: 09/07/2023] [Indexed: 09/09/2023]
Abstract
Cells communicate with each other to jointly regulate cellular processes during cellular differentiation and tissue morphogenesis. This multiscale coordination arises through the spatiotemporal activity of morphogens to pattern cell signaling and transcriptional factor activity. This coded information controls cell mechanics, proliferation, and differentiation to shape the growth and morphogenesis of organs. While many of the molecular components and physical interactions have been identified in key model developmental systems, there are still many unresolved questions related to the dynamics involved due to challenges in precisely perturbing and quantitatively measuring signaling dynamics. Recently, a broad range of synthetic optogenetic tools have been developed and employed to quantitatively define relationships between signal transduction and downstream cellular responses. These optogenetic tools can control intracellular activities at the single cell or whole tissue scale to direct subsequent biological processes. In this brief review, we highlight a selected set of studies that develop and implement optogenetic tools to unravel quantitative biophysical mechanisms for tissue growth and morphogenesis across a broad range of biological systems through the manipulation of morphogens, signal transduction cascades, and cell mechanics. More generally, we discuss how optogenetic tools have emerged as a powerful platform for probing and controlling multicellular development.
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Affiliation(s)
- Mayesha Sahir Mim
- Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN 46556, United States of America
| | - Caroline Knight
- Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN 46556, United States of America
| | - Jeremiah J Zartman
- Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN 46556, United States of America
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2
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Won SM, Cai L, Gutruf P, Rogers JA. Wireless and battery-free technologies for neuroengineering. Nat Biomed Eng 2023; 7:405-423. [PMID: 33686282 PMCID: PMC8423863 DOI: 10.1038/s41551-021-00683-3] [Citation(s) in RCA: 101] [Impact Index Per Article: 101.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Accepted: 12/28/2020] [Indexed: 12/16/2022]
Abstract
Tethered and battery-powered devices that interface with neural tissues can restrict natural motions and prevent social interactions in animal models, thereby limiting the utility of these devices in behavioural neuroscience research. In this Review Article, we discuss recent progress in the development of miniaturized and ultralightweight devices as neuroengineering platforms that are wireless, battery-free and fully implantable, with capabilities that match or exceed those of wired or battery-powered alternatives. Such classes of advanced neural interfaces with optical, electrical or fluidic functionality can also combine recording and stimulation modalities for closed-loop applications in basic studies or in the practical treatment of abnormal physiological processes.
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Affiliation(s)
- Sang Min Won
- Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon, South Korea
| | - Le Cai
- Biomedical Engineering, College of Engineering, The University of Arizona, Tucson, AZ, USA
| | - Philipp Gutruf
- Biomedical Engineering, College of Engineering, The University of Arizona, Tucson, AZ, USA.
- Bio5 Institute and Neuroscience GIDP, University of Arizona, Tucson, AZ, USA.
- Department of Electrical and Computer Engineering, University of Arizona, Tucson, AZ, USA.
| | - John A Rogers
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL, USA.
- Center for Bio-Integrated Electronics, Northwestern University, Evanston, IL, USA.
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, USA.
- Center for Advanced Molecular Imaging, Northwestern University, Evanston, IL, USA.
- Department of Mechanical Engineering, Northwestern University, Evanston, IL, USA.
- Department of Chemistry, Northwestern University, Evanston, IL, USA.
- Department of Neurological Surgery, Northwestern University, Evanston, IL, USA.
- Department of Electrical and Computer Engineering, Northwestern University, Evanston, IL, USA.
- Simpson Querrey Institute for BioNanotechnology, Northwestern University, Evanston, IL, USA.
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3
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Spampinato GLB, Ronzitti E, Zampini V, Ferrari U, Trapani F, Khabou H, Agraval A, Dalkara D, Picaud S, Papagiakoumou E, Marre O, Emiliani V. All-optical inter-layers functional connectivity investigation in the mouse retina. CELL REPORTS METHODS 2022; 2:100268. [PMID: 36046629 PMCID: PMC9421538 DOI: 10.1016/j.crmeth.2022.100268] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 06/03/2022] [Accepted: 07/19/2022] [Indexed: 06/01/2023]
Abstract
We developed a multi-unit microscope for all-optical inter-layers circuits interrogation. The system performs two-photon (2P) functional imaging and 2P multiplexed holographic optogenetics at axially distinct planes. We demonstrated the capability of the system to map, in the mouse retina, the functional connectivity between rod bipolar cells (RBCs) and ganglion cells (GCs) by activating single or defined groups of RBCs while recording the evoked response in the GC layer with cell-type specificity and single-cell resolution. We then used a logistic model to probe the functional connectivity between cell types by deriving the "cellular receptive field" describing how RBCs impact each GC type. With the capability to simultaneously image and control neuronal activity at axially distinct planes, the system enables a precise interrogation of multi-layered circuits. Understanding this information transfer is a promising avenue to dissect complex neural circuits and understand the neural basis of computations.
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Affiliation(s)
| | - Emiliano Ronzitti
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France
| | - Valeria Zampini
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France
| | - Ulisse Ferrari
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France
| | - Francesco Trapani
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France
| | - Hanen Khabou
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France
| | | | - Deniz Dalkara
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France
| | - Serge Picaud
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France
| | | | - Olivier Marre
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France
| | - Valentina Emiliani
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France
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Chen B, Cui M, Wang Y, Shi P, Wang H, Wang F. Recent advances in cellular optogenetics for photomedicine. Adv Drug Deliv Rev 2022; 188:114457. [PMID: 35843507 DOI: 10.1016/j.addr.2022.114457] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 06/13/2022] [Accepted: 07/11/2022] [Indexed: 11/26/2022]
Abstract
Since the successful introduction of exogenous photosensitive proteins, channelrhodopsin, to neurons, optogenetics has enabled substantial understanding of profound brain function by selectively manipulating neural circuits. In an optogenetic system, optical stimulation can be precisely delivered to brain tissue to achieve regulation of cellular electrical activity with unprecedented spatio-temporal resolution in living organisms. In recent years, the development of various optical actuators and novel light-delivery techniques has greatly expanded the scope of optogenetics, enabling the control of other signal pathways in non-neuronal cells for different biomedical applications, such as phototherapy and immunotherapy. This review focuses on the recent advances in optogenetic regulation of cellular activities for photomedicine. We discuss emerging optogenetic tools and light-delivery platforms, along with a survey of optogenetic execution in mammalian and microbial cells.
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Affiliation(s)
- Bing Chen
- Department of Materials Science and Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong SAR, China; City University of Hong Kong Shenzhen Research Institute, Shenzhen 518057, China
| | - Meihui Cui
- School of Life Sciences, Tianjin University, Tianjin 300072, China
| | - Yuan Wang
- Department of Biomedical Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong SAR, China
| | - Peng Shi
- Department of Biomedical Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong SAR, China.
| | - Hanjie Wang
- School of Life Sciences, Tianjin University, Tianjin 300072, China.
| | - Feng Wang
- Department of Materials Science and Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong SAR, China; City University of Hong Kong Shenzhen Research Institute, Shenzhen 518057, China.
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5
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Kim S, Roh H, Im M. Artificial Visual Information Produced by Retinal Prostheses. Front Cell Neurosci 2022; 16:911754. [PMID: 35734216 PMCID: PMC9208577 DOI: 10.3389/fncel.2022.911754] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Accepted: 05/18/2022] [Indexed: 11/18/2022] Open
Abstract
Numerous retinal prosthetic systems have demonstrated somewhat useful vision can be restored to individuals who had lost their sight due to outer retinal degenerative diseases. Earlier prosthetic studies have mostly focused on the confinement of electrical stimulation for improved spatial resolution and/or the biased stimulation of specific retinal ganglion cell (RGC) types for selective activation of retinal ON/OFF pathway for enhanced visual percepts. To better replicate normal vision, it would be also crucial to consider information transmission by spiking activities arising in the RGC population since an incredible amount of visual information is transferred from the eye to the brain. In previous studies, however, it has not been well explored how much artificial visual information is created in response to electrical stimuli delivered by microelectrodes. In the present work, we discuss the importance of the neural information for high-quality artificial vision. First, we summarize the previous literatures which have computed information transmission rates from spiking activities of RGCs in response to visual stimuli. Second, we exemplify a couple of studies which computed the neural information from electrically evoked responses. Third, we briefly introduce how information rates can be computed in the representative two ways – direct method and reconstruction method. Fourth, we introduce in silico approaches modeling artificial retinal neural networks to explore the relationship between amount of information and the spiking patterns. Lastly, we conclude our review with clinical implications to emphasize the necessity of considering visual information transmission for further improvement of retinal prosthetics.
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Affiliation(s)
- Sein Kim
- Brain Science Institute, Korea Institute of Science and Technology, Seoul, South Korea
| | - Hyeonhee Roh
- Brain Science Institute, Korea Institute of Science and Technology, Seoul, South Korea
- School of Electrical Engineering, College of Engineering, Korea University, Seoul, South Korea
| | - Maesoon Im
- Brain Science Institute, Korea Institute of Science and Technology, Seoul, South Korea
- Division of Bio-Medical Science & Technology, KIST School, University of Science and Technology, Seoul, South Korea
- *Correspondence: Maesoon Im, ,
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Walter P. Innovative Technologies for Optimized Artificial Vision. Laryngorhinootologie 2022; 101:S79-S89. [PMID: 35605613 DOI: 10.1055/a-1671-1825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Despite significant advances in the treatment of severe eye diseases, certain forms of blindness cannot be cured or improved to this day. These include, for example, retinitis pigmentosa, a hereditary degeneration of photoreceptors. Technology approaches with implantable visual prostheses based on electrical stimulation of remaining neurons in the retina or cortex, have already been tested in a number of patients with limited results. New findings in the biology of these diseases as well as new technological developments give hope for better results in the future.
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Bansal H, Gupta N, Roy S. Theoretical analysis of optogenetic spiking with ChRmine, bReaChES and CsChrimson-expressing neurons for retinal prostheses. J Neural Eng 2021; 18. [PMID: 34229315 DOI: 10.1088/1741-2552/ac1175] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 07/06/2021] [Indexed: 01/10/2023]
Abstract
Objective.Optogenetics has emerged as a promising technique for neural prosthetics, especially retinal prostheses, with unprecedented spatiotemporal resolution. Newly discovered opsins with high light sensitivity and fast temporal kinetics can provide sufficient temporal resolution at safe light powers and overcome the limitations of presently used opsins. It is also important to formulate accurate mathematical models for optogenetic retinal prostheses, which can facilitate optimization of photostimulation factors to improve the performance.Approach.A detailed theoretical analysis of optogenetic excitation of model retinal ganglion neurons (RGNs) and hippocampal neurons expressed with already tested opsins for retinal prostheses, namely, ChR2, ReaChR and ChrimsonR, and also with recently discovered potent opsins CsChrimson, bReaChES and ChRmine, was carried out.Main results.Under continuous illumination, ChRmine-expressing RGNs begin to respond at very low irradiances ∼10-4mW mm-2, and evoke firing upto ∼280 Hz, highest among other opsin-expressing RGNs, at 10-2mW mm-2. Under pulsed illumination at randomized photon fluxes, ChRmine-expressing RGNs respond to changes in pulse to pulse irradiances upto four logs, although very bright pulses >1014photons mm-2s-1block firing in these neurons. The minimum irradiance threshold for ChRmine-expressing RGNs is lower by two orders of magnitude, whereas, the first spike latency in ChRmine-expressing RGNs is shorter by an order of magnitude, alongwith stable latency of subsequest spikes compared to others. Further, a good set of photostimulation parameters were determined to achieve high-frequency control with single spike resolution at minimal power. Although ChrimsonR enables spiking upto 100 Hz in RGNs, it requires very high irradiances. ChRmine provides control at light powers that are two orders of magnitude smaller than that required with experimentally studied opsins, while maintaining single spike temporal resolution upto 40 Hz.Significance.The present study highlights the importance of ChRmine as a potential opsin for optogenetic retinal prostheses.
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Affiliation(s)
- Himanshu Bansal
- Department of Physics and Computer Science, Dayalbagh Educational Institute, Agra 282005, India
| | - Neha Gupta
- Department of Physics and Computer Science, Dayalbagh Educational Institute, Agra 282005, India
| | - Sukhdev Roy
- Department of Physics and Computer Science, Dayalbagh Educational Institute, Agra 282005, India
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8
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Abstract
The retinal output is the sole source of visual information for the brain. Studies in non-primate mammals estimate that this information is carried by several dozens of retinal ganglion cell types, each informing the brain about different aspects of a visual scene. Even though morphological studies of primate retina suggest a similar diversity of ganglion cell types, research has focused on the function of only a few cell types. In human retina, recordings from individual cells are anecdotal or focus on a small subset of identified types. Here, we present the first systematic ex-vivo recording of light responses from 342 ganglion cells in human retinas obtained from donors. We find a great variety in the human retinal output in terms of preferences for positive or negative contrast, spatio-temporal frequency encoding, contrast sensitivity, and speed tuning. Some human ganglion cells showed similar response behavior as known cell types in other primate retinas, while we also recorded light responses that have not been described previously. This first extensive description of the human retinal output should facilitate interpretation of primate data and comparison to other mammalian species, and it lays the basis for the use of ex-vivo human retina for in-vitro analysis of novel treatment approaches.
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9
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Optical Waveguides and Integrated Optical Devices for Medical Diagnosis, Health Monitoring and Light Therapies. SENSORS 2020; 20:s20143981. [PMID: 32709072 PMCID: PMC7411870 DOI: 10.3390/s20143981] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Revised: 06/26/2020] [Accepted: 07/13/2020] [Indexed: 02/06/2023]
Abstract
Optical waveguides and integrated optical devices are promising solutions for many applications, such as medical diagnosis, health monitoring and light therapies. Despite the many existing reviews focusing on the materials that these devices are made from, a systematic review that relates these devices to the various materials, fabrication processes, sensing methods and medical applications is still seldom seen. This work is intended to link these multidisciplinary fields, and to provide a comprehensive review of the recent advances of these devices. Firstly, the optical and mechanical properties of optical waveguides based on glass, polymers and heterogeneous materials and fabricated via various processes are thoroughly discussed, together with their applications for medical purposes. Then, the fabrication processes and medical implementations of integrated passive and active optical devices with sensing modules are introduced, which can be used in many medical fields such as drug delivery and cardiovascular healthcare. Thirdly, wearable optical sensing devices based on light sensing methods such as colorimetry, fluorescence and luminescence are discussed. Additionally, the wearable optical devices for light therapies are introduced. The review concludes with a comprehensive summary of these optical devices, in terms of their forms, materials, light sources and applications.
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Shim S, Eom K, Jeong J, Kim SJ. Retinal Prosthetic Approaches to Enhance Visual Perception for Blind Patients. MICROMACHINES 2020; 11:E535. [PMID: 32456341 PMCID: PMC7281011 DOI: 10.3390/mi11050535] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 05/22/2020] [Accepted: 05/22/2020] [Indexed: 12/14/2022]
Abstract
Retinal prostheses are implantable devices that aim to restore the vision of blind patients suffering from retinal degeneration, mainly by artificially stimulating the remaining retinal neurons. Some retinal prostheses have successfully reached the stage of clinical trials; however, these devices can only restore vision partially and remain insufficient to enable patients to conduct everyday life independently. The visual acuity of the artificial vision is limited by various factors from both engineering and physiological perspectives. To overcome those issues and further enhance the visual resolution of retinal prostheses, a variety of retinal prosthetic approaches have been proposed, based on optimization of the geometries of electrode arrays and stimulation pulse parameters. Other retinal stimulation modalities such as optics, ultrasound, and magnetics have also been utilized to address the limitations in conventional electrical stimulation. Although none of these approaches have been clinically proven to fully restore the function of a degenerated retina, the extensive efforts made in this field have demonstrated a series of encouraging findings for the next generation of retinal prostheses, and these could potentially enhance the visual acuity of retinal prostheses. In this article, a comprehensive and up-to-date overview of retinal prosthetic strategies is provided, with a specific focus on a quantitative assessment of visual acuity results from various retinal stimulation technologies. The aim is to highlight future directions toward high-resolution retinal prostheses.
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Affiliation(s)
- Shinyong Shim
- Department of Electrical and Computer Engineering, College of Engineering, Seoul National University, Seoul 08826, Korea;
- Inter-university Semiconductor Research Center, College of Engineering, Seoul National University, Seoul 08826, Korea
| | - Kyungsik Eom
- Department of Electronics Engineering, College of Engineering, Pusan National University, Busan 46241, Korea
| | - Joonsoo Jeong
- School of Biomedical Convergence Engineering, College of Information and Biomedical Engineering, Pusan National University, Yangsan 50612, Korea
| | - Sung June Kim
- Department of Electrical and Computer Engineering, College of Engineering, Seoul National University, Seoul 08826, Korea;
- Inter-university Semiconductor Research Center, College of Engineering, Seoul National University, Seoul 08826, Korea
- Institute on Aging, College of Medicine, Seoul National University, Seoul 08826, Korea
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11
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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: 88] [Impact Index Per Article: 22.0] [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.
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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.
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12
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Abstract
Retinal degenerative diseases caused by photoreceptor cell death are major causes of irreversible vision loss. As only primates have a macula, the nonhuman primate (NHP) models have a crucial role not only in revealing biological mechanisms underlying high-acuity vision but also in the development of therapies. Successful translation of basic research findings into clinical trials and, moreover, approval of the first therapies for blinding inherited and age-related retinal dystrophies has been reported in recent years. This article explores the value of the NHP models in understanding human vision and reviews their contribution to the development of innovative therapeutic strategies to save and restore vision.
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13
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Ostrovsky MA, Kirpichnikov MP. Prospects of Optogenetic Prosthesis of the Degenerative Retina of the Eye. BIOCHEMISTRY (MOSCOW) 2019; 84:479-490. [PMID: 31234763 DOI: 10.1134/s0006297919050031] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The review discusses the prospects of using rhodopsin as an optogenetic tool for prosthetics of degenerative (blind) eye retina and the principles of optogenetic techniques. Retinal-containing proteins that depolarize/hyperpolarize the plasma membrane of nerve cells and, accordingly, excite/inhibit physiological activity of neurons, are described. The problem of what cells of the degenerative retina can be treated with what particular rhodopsins is discussed in detail. Viruses and promoters required for the rhodopsin gene delivery into the degenerative retina cells are described. In conclusion, main concepts and tasks associated with the optogenetic prosthetic treatment of degenerative retina employing rhodopsins are presented.
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Affiliation(s)
- M A Ostrovsky
- Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, Moscow, 119334, Russia. .,Lomonosov Moscow State University, Biological Faculty, Department of Molecular Physiology, Moscow, 119991, Russia
| | - M P Kirpichnikov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, 117997, Russia. .,Lomonosov Moscow State University, Biological Faculty, Department of Bioengineering, Moscow, 119991, Russia
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Li W, Lin J, Wang T, Huang P. Photo-triggered Drug Delivery Systems for Neuron-related Applications. Curr Med Chem 2019; 26:1406-1422. [PMID: 29932026 DOI: 10.2174/0929867325666180622121801] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Revised: 04/09/2018] [Accepted: 04/18/2018] [Indexed: 12/11/2022]
Abstract
The development of materials, chemistry and genetics has created a great number of systems for delivering antibiotics, neuropeptides or other drugs to neurons in neuroscience research, and has also provided important and powerful tools in neuron-related applications. Although these drug delivery systems can facilitate the advancement of neuroscience studies, they still have limited applications due to various drawbacks, such as difficulty in controlling delivery molecules or drugs to the target region, and trouble of releasing them in predictable manners. The combination of optics and drug delivery systems has great potentials to address these issues and deliver molecules or drugs to the nervous system with extraordinary spatiotemporal selectivity triggered by light. In this review, we will introduce the development of photo-triggered drug delivery systems in neuroscience research and their neuron-related applications including regulating neural activities, treating neural diseases and inducing nerve regenerations.
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Affiliation(s)
- Wei Li
- Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging, Laboratory of Evolutionary Theranostics, School of Biomedical Engineering, Health Science Center, Shenzhen University, Shenzhen 518060, China.,School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta GA 30332, United States
| | - Jing Lin
- Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging, Laboratory of Evolutionary Theranostics, School of Biomedical Engineering, Health Science Center, Shenzhen University, Shenzhen 518060, China
| | - Tianfu Wang
- Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging, Laboratory of Evolutionary Theranostics, School of Biomedical Engineering, Health Science Center, Shenzhen University, Shenzhen 518060, China
| | - Peng Huang
- Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging, Laboratory of Evolutionary Theranostics, School of Biomedical Engineering, Health Science Center, Shenzhen University, Shenzhen 518060, China
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15
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A light in the dark: state of the art and perspectives in optogenetics and optopharmacology for restoring vision. Future Med Chem 2019; 11:463-487. [DOI: 10.4155/fmc-2018-0315] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
In the last decade, innovative therapeutic strategies against inherited retinal degenerations (IRDs) have emerged. In particular, chemical- and opto-genetics approaches or a combination of them have been identified for modulating neuronal/optical activity in order to restore vision in blinding diseases. The ‘chemical-genetics approach’ (optopharmacology) uses small molecules (exogenous photoswitches) for restoring light sensitivity by activating ion channels. The ‘opto-genetics approach’ employs light-activated photosensitive proteins (exogenous opsins), introduced by viral vectors in injured tissues, to restore light response. These approaches offer control of neuronal activities with spatial precision and limited invasiveness, although with some drawbacks. Currently, a combined therapeutic strategy (optogenetic pharmacology) is emerging. This review describes the state of the art and provides an overview of the future perspectives in vision restoration.
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Mansouri M, Strittmatter T, Fussenegger M. Light-Controlled Mammalian Cells and Their Therapeutic Applications in Synthetic Biology. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2019; 6:1800952. [PMID: 30643713 PMCID: PMC6325585 DOI: 10.1002/advs.201800952] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 08/21/2018] [Indexed: 05/12/2023]
Abstract
The ability to remote control the expression of therapeutic genes in mammalian cells in order to treat disease is a central goal of synthetic biology-inspired therapeutic strategies. Furthermore, optogenetics, a combination of light and genetic sciences, provides an unprecedented ability to use light for precise control of various cellular activities with high spatiotemporal resolution. Recent work to combine optogenetics and therapeutic synthetic biology has led to the engineering of light-controllable designer cells, whose behavior can be regulated precisely and noninvasively. This Review focuses mainly on non-neural optogenetic systems, which are often used in synthetic biology, and their applications in genetic programing of mammalian cells. Here, a brief overview of the optogenetic tool kit that is available to build light-sensitive mammalian cells is provided. Then, recently developed strategies for the control of designer cells with specific biological functions are summarized. Recent translational applications of optogenetically engineered cells are also highlighted, ranging from in vitro basic research to in vivo light-controlled gene therapy. Finally, current bottlenecks, possible solutions, and future prospects for optogenetics in synthetic biology are discussed.
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Affiliation(s)
- Maysam Mansouri
- Department of Biosystems Science and EngineeringETH ZurichMattenstrasse 26CH‐4058BaselSwitzerland
| | - Tobias Strittmatter
- Department of Biosystems Science and EngineeringETH ZurichMattenstrasse 26CH‐4058BaselSwitzerland
| | - Martin Fussenegger
- Department of Biosystems Science and EngineeringETH ZurichMattenstrasse 26CH‐4058BaselSwitzerland
- Faculty of ScienceUniversity of BaselMattenstrasse 26CH‐4058BaselSwitzerland
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17
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Mattingly M, Weineck K, Costa J, Cooper RL. Hyperpolarization by activation of halorhodopsin results in enhanced synaptic transmission: Neuromuscular junction and CNS circuit. PLoS One 2018; 13:e0200107. [PMID: 29969493 PMCID: PMC6029800 DOI: 10.1371/journal.pone.0200107] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Accepted: 06/19/2018] [Indexed: 12/22/2022] Open
Abstract
Optogenetics offers a unique method to regulate the activity of select neural circuits. However, the electrophysiological consequences of targeted optogenetic manipulation upon the entire circuit remain poorly understood. Analysis of the sensory-CNS-motor circuit in Drosophila larvae expressing eHpHR and ChR2-XXL revealed unexpected patterns of excitability. Optical stimulation of motor neurons targeted to express eNpHR resulted in inhibition followed by excitation of body wall contraction with repetitive stimulation in intact larvae. In situ preparations with direct electrophysiological measures showed an increased responsiveness to excitatory synaptic activity induced by sensory stimulation within a functional neural circuit. To ensure proper function of eNpHR and ChR2-XXL they were expressed in body wall muscle and direct electrophysiological measurements were obtained. Under eNpHR induced hyperpolarization the muscle remained excitable with increased amplitude of excitatory postsynaptic synaptic potentials. Theoretical models to explain the observations are presented. This study aids in increasing the understanding of the varied possible influences with light activated proteins within intact neural circuits.
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Affiliation(s)
- Matthew Mattingly
- Department of Biology and Center for Muscle Biology, University of Kentucky, Lexington, Kentucky, United States of America
| | - Kristin Weineck
- Department of Biology and Center for Muscle Biology, University of Kentucky, Lexington, Kentucky, United States of America
- Goethe University Frankfurt am Main, Frankfurt, Germany
| | - Jennifer Costa
- Department of Biology and Center for Muscle Biology, University of Kentucky, Lexington, Kentucky, United States of America
| | - Robin L. Cooper
- Department of Biology and Center for Muscle Biology, University of Kentucky, Lexington, Kentucky, United States of America
- * E-mail:
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18
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Colombo L, Montesano G, Sala B, Patelli F, Maltese P, Abeshi A, Bertelli M, Rossetti L. Comparison of 5-year progression of retinitis pigmentosa involving the posterior pole among siblings by means of SD-OCT: a retrospective study. BMC Ophthalmol 2018; 18:153. [PMID: 29940899 PMCID: PMC6019320 DOI: 10.1186/s12886-018-0817-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 06/08/2018] [Indexed: 12/17/2022] Open
Abstract
Background The aim of this study is to analyze and compare the progression of photoreceptor atrophy among siblings affected by retinitis pigmentosa by means of spectral SD-OCT. Methods Fifty three eyes of 27 patients belonging to 12 family clusters were analyzed. To assess the annual progression rate of photoreceptor atrophy, the ellipsoid zone (EZ) line was measured in OCT sections through the fovea. We used multivariate generalized mixed effects to model the rate of progression and its relation to the initial ellipsoid zone line width. Results During our 4.84 years (± 1.44) mean follow up time (range 3–7) 53 eyes were examined. The ellipsoid zone line width declined with a yearly average rate of 76.4 μm (4.16% / year) (p-value < 0.0001). Progression rates were poorly correlated within family clusters (p-value = 0.23) and showed statistical difference between affected siblings (p-value = 0.007). There was no correlation between inter-familiar progression rate and mode of inheritance (p-value = 0.98) as well as between age and ellipsoid zone line width among siblings (p-value = 0.91). Conclusion RP could be extremely heterogeneous even among siblings: an accurate and sensitive method to follow the progression of the disease is fundamental for future development of clinical trials and therapy strategies.
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Affiliation(s)
- Leonardo Colombo
- Department of Ophthalmology, San Paolo Hospital, University of Milan, Via A. Di Rudinì 8, 20142, Milan, Italy.
| | - Giovanni Montesano
- Department of Ophthalmology, San Paolo Hospital, University of Milan, Via A. Di Rudinì 8, 20142, Milan, Italy.,Optometry and Visual Science, School of Health Sciences, City University London, London, UK
| | - Barbara Sala
- Department of Ophthalmology, San Paolo Hospital, University of Milan, Via A. Di Rudinì 8, 20142, Milan, Italy
| | - Fabio Patelli
- Department of Ophthalmology, San Paolo Hospital, University of Milan, Via A. Di Rudinì 8, 20142, Milan, Italy
| | - Paolo Maltese
- MAGI Human Medical Genetics Institute, Rovereto, Italy
| | - Andi Abeshi
- MAGI Human Medical Genetics Institute, Rovereto, Italy
| | | | - Luca Rossetti
- Department of Ophthalmology, San Paolo Hospital, University of Milan, Via A. Di Rudinì 8, 20142, Milan, Italy
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19
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Young AT, Cornwell N, Daniele MA. Neuro-Nano Interfaces: Utilizing Nano-Coatings and Nanoparticles to Enable Next-Generation Electrophysiological Recording, Neural Stimulation, and Biochemical Modulation. ADVANCED FUNCTIONAL MATERIALS 2018; 28:1700239. [PMID: 33867903 PMCID: PMC8049593 DOI: 10.1002/adfm.201700239] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Neural interfaces provide a window into the workings of the nervous system-enabling both biosignal recording and modulation. Traditionally, neural interfaces have been restricted to implanted electrodes to record or modulate electrical activity of the nervous system. Although these electrode systems are both mechanically and operationally robust, they have limited utility due to the resultant macroscale damage from invasive implantation. For this reason, novel nanomaterials are being investigated to enable new strategies to chronically interact with the nervous system at both the cellular and network level. In this feature article, the use of nanomaterials to improve current electrophysiological interfaces, as well as enable new nano-interfaces to modulate neural activity via alternative mechanisms, such as remote transduction of electromagnetic fields are explored. Specifically, this article will review the current use of nanoparticle coatings to enhance electrode function, then an analysis of the cutting-edge, targeted nanoparticle technologies being utilized to interface with both the electrophysiological and biochemical behavior of the nervous system will be provided. Furthermore, an emerging, specialized-use case for neural interfaces will be presented: the modulation of the blood-brain barrier.
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Affiliation(s)
- Ashlyn T Young
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill, and North Carolina State University, 911 Oval Dr., Raleigh, NC 27695, USA
| | - Neil Cornwell
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill, and North Carolina State University, 911 Oval Dr., Raleigh, NC 27695, USA
| | - Michael A Daniele
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill, and North Carolina State University, 911 Oval Dr., Raleigh, NC 27695, USA
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20
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Gene-Based Neuromodulation. Neuromodulation 2018. [DOI: 10.1016/b978-0-12-805353-9.00030-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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21
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Hanna J, Yücel YH, Zhou X, Mathieu E, Paczka-Giorgi LA, Gupta N. Progressive loss of retinal blood vessels in a live model of retinitis pigmentosa. CANADIAN JOURNAL OF OPHTHALMOLOGY 2017; 53:391-401. [PMID: 30119795 DOI: 10.1016/j.jcjo.2017.10.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Revised: 10/27/2017] [Accepted: 10/31/2017] [Indexed: 11/19/2022]
Abstract
OBJECTIVE To assess retinal blood vessels in a live retinitis pigmentosa (RP) model with rd1 mutation and green fluorescent protein (GFP) expressed in vascular endothelium. METHODS Homozygous (hm) Tie2-GFP mice with rd1 mutation and known retinal degeneration were crossed with wild-type CD1 mice to generate control heterozygous (ht) Tie2-GFP mice. The retinas of 16 live hm mice were evaluated at 2 weeks and 3, 5, and 8 months of age, and compared with age-matched control ht and CD1 mice by optical coherence tomography (OCT) and confocal scanning laser ophthalmoscopy (cSLO). Fluorescence intensity was measured and compared between strains at 3, 5, and 8 months. In vivo findings were validated by immunostaining with collagen IV and isolectin histopathology. RESULTS All hm Tie2-GFP mice showed progressive outer retinal degeneration by OCT. Loss of small branches of blood vessels and then larger main vessels was seen by cSLO. Retinal tissue and vessels were preserved in control ht mice. At all ages, measurements of fluorescence intensity were reduced in hm compared with ht mice (p < 0.001). In all strains, intensity at 8 months was reduced compared with 3 months (p < 0.001) and 5 months (p = 0.021). Histopathological studies confirmed in vivo findings and revealed a pattern of blood vessel regression in the deep plexus, followed by intermediate and superficial retinal plexuses. CONCLUSIONS This is the first evidence of progressive loss of retinal blood vessels in a live mouse model of RP. These findings may be highly relevant to understanding retinal degeneration in RP to prevent blindness.
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Affiliation(s)
- Joseph Hanna
- Keenan Research Centre at the Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ont; Department of Laboratory Medicine and Pathobiology, Faculty of Medicine, University of Toronto, Toronto, Ont
| | - Yeni H Yücel
- Keenan Research Centre at the Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ont; Department of Laboratory Medicine and Pathobiology, Faculty of Medicine, University of Toronto, Toronto, Ont; Department of Ophthalmology and Vision Sciences, Faculty of Medicine, University of Toronto, Toronto, Ont; Ophthalmic Pathology Laboratory, University of Toronto, Toronto, Ont
| | - Xun Zhou
- Keenan Research Centre at the Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ont
| | - Emily Mathieu
- Keenan Research Centre at the Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ont; Department of Laboratory Medicine and Pathobiology, Faculty of Medicine, University of Toronto, Toronto, Ont
| | - Luz A Paczka-Giorgi
- Keenan Research Centre at the Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ont
| | - Neeru Gupta
- Keenan Research Centre at the Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ont; Department of Laboratory Medicine and Pathobiology, Faculty of Medicine, University of Toronto, Toronto, Ont; Department of Ophthalmology and Vision Sciences, Faculty of Medicine, University of Toronto, Toronto, Ont; Dalla Lana School of Public Health, University of Toronto, Toronto, Ont.
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22
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Chaffiol A, Caplette R, Jaillard C, Brazhnikova E, Desrosiers M, Dubus E, Duhamel L, Macé E, Marre O, Benoit P, Hantraye P, Bemelmans AP, Bamberg E, Duebel J, Sahel JA, Picaud S, Dalkara D. A New Promoter Allows Optogenetic Vision Restoration with Enhanced Sensitivity in Macaque Retina. Mol Ther 2017; 25:2546-2560. [PMID: 28807567 PMCID: PMC5675708 DOI: 10.1016/j.ymthe.2017.07.011] [Citation(s) in RCA: 92] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 07/15/2017] [Accepted: 07/16/2017] [Indexed: 01/28/2023] Open
Abstract
The majority of inherited retinal degenerations converge on the phenotype of photoreceptor cell death. Second- and third-order neurons are spared in these diseases, making it possible to restore retinal light responses using optogenetics. Viral expression of channelrhodopsin in the third-order neurons under ubiquitous promoters was previously shown to restore visual function, albeit at light intensities above illumination safety thresholds. Here, we report (to our knowledge, for the first time) activation of macaque retinas, up to 6 months post-injection, using channelrhodopsin-Ca2+-permeable channelrhodopsin (CatCh) at safe light intensities. High-level CatCh expression was achieved due to a new promoter based on the regulatory region of the gamma-synuclein gene (SNCG) allowing strong expression in ganglion cells across species. Our promoter, in combination with clinically proven adeno-associated virus 2 (AAV2), provides CatCh expression in peri-foveolar ganglion cells responding robustly to light under the illumination safety thresholds for the human eye. On the contrary, the threshold of activation and the proportion of unresponsive cells were much higher when a ubiquitous promoter (cytomegalovirus [CMV]) was used to express CatCh. The results of our study suggest that the inclusion of optimized promoters is key in the path to clinical translation of optogenetics.
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Affiliation(s)
- Antoine Chaffiol
- INSERM U968, Institut de la Vision, 75012 Paris, France; UMRS968, Institut de la Vision, Sorbonne Universités, Pierre et Marie Curie University (UPMC) University Paris 06, 75012 Paris, France; Centre National de la Recherche Scientifique (CNRS) UMR7210, Institut de la Vision, 75012 Paris, France
| | - Romain Caplette
- INSERM U968, Institut de la Vision, 75012 Paris, France; UMRS968, Institut de la Vision, Sorbonne Universités, Pierre et Marie Curie University (UPMC) University Paris 06, 75012 Paris, France; Centre National de la Recherche Scientifique (CNRS) UMR7210, Institut de la Vision, 75012 Paris, France
| | - Céline Jaillard
- INSERM U968, Institut de la Vision, 75012 Paris, France; UMRS968, Institut de la Vision, Sorbonne Universités, Pierre et Marie Curie University (UPMC) University Paris 06, 75012 Paris, France; Centre National de la Recherche Scientifique (CNRS) UMR7210, Institut de la Vision, 75012 Paris, France
| | - Elena Brazhnikova
- INSERM U968, Institut de la Vision, 75012 Paris, France; UMRS968, Institut de la Vision, Sorbonne Universités, Pierre et Marie Curie University (UPMC) University Paris 06, 75012 Paris, France; Centre National de la Recherche Scientifique (CNRS) UMR7210, Institut de la Vision, 75012 Paris, France
| | - Mélissa Desrosiers
- INSERM U968, Institut de la Vision, 75012 Paris, France; UMRS968, Institut de la Vision, Sorbonne Universités, Pierre et Marie Curie University (UPMC) University Paris 06, 75012 Paris, France; Centre National de la Recherche Scientifique (CNRS) UMR7210, Institut de la Vision, 75012 Paris, France
| | - Elisabeth Dubus
- INSERM U968, Institut de la Vision, 75012 Paris, France; UMRS968, Institut de la Vision, Sorbonne Universités, Pierre et Marie Curie University (UPMC) University Paris 06, 75012 Paris, France; Centre National de la Recherche Scientifique (CNRS) UMR7210, Institut de la Vision, 75012 Paris, France
| | - Laëtitia Duhamel
- INSERM U968, Institut de la Vision, 75012 Paris, France; UMRS968, Institut de la Vision, Sorbonne Universités, Pierre et Marie Curie University (UPMC) University Paris 06, 75012 Paris, France; Centre National de la Recherche Scientifique (CNRS) UMR7210, Institut de la Vision, 75012 Paris, France
| | - Emilie Macé
- INSERM U968, Institut de la Vision, 75012 Paris, France; UMRS968, Institut de la Vision, Sorbonne Universités, Pierre et Marie Curie University (UPMC) University Paris 06, 75012 Paris, France; Centre National de la Recherche Scientifique (CNRS) UMR7210, Institut de la Vision, 75012 Paris, France
| | - Olivier Marre
- INSERM U968, Institut de la Vision, 75012 Paris, France; UMRS968, Institut de la Vision, Sorbonne Universités, Pierre et Marie Curie University (UPMC) University Paris 06, 75012 Paris, France; Centre National de la Recherche Scientifique (CNRS) UMR7210, Institut de la Vision, 75012 Paris, France
| | - Patrick Benoit
- Sanofi Ophthalmology Unit, 17 rue Moreau, 75012 Paris, France
| | - Philippe Hantraye
- Département des Sciences du Vivant (DSV), MIRCen, Institut d'Imagerie Biomédicale (I2BM), Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Fontenay-aux-Roses 92260, France; Neurodegenerative Diseases Laboratory, CNRS UMR9199, Université Paris-Sud, Université Paris-Saclay, Fontenay-aux-Roses 92260, France
| | - Alexis-Pierre Bemelmans
- Département des Sciences du Vivant (DSV), MIRCen, Institut d'Imagerie Biomédicale (I2BM), Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Fontenay-aux-Roses 92260, France; Neurodegenerative Diseases Laboratory, CNRS UMR9199, Université Paris-Sud, Université Paris-Saclay, Fontenay-aux-Roses 92260, France
| | - Ernst Bamberg
- Department of Biophysical Chemistry, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany
| | - Jens Duebel
- INSERM U968, Institut de la Vision, 75012 Paris, France; UMRS968, Institut de la Vision, Sorbonne Universités, Pierre et Marie Curie University (UPMC) University Paris 06, 75012 Paris, France; Centre National de la Recherche Scientifique (CNRS) UMR7210, Institut de la Vision, 75012 Paris, France.
| | - José-Alain Sahel
- INSERM U968, Institut de la Vision, 75012 Paris, France; UMRS968, Institut de la Vision, Sorbonne Universités, Pierre et Marie Curie University (UPMC) University Paris 06, 75012 Paris, France; Centre National de la Recherche Scientifique (CNRS) UMR7210, Institut de la Vision, 75012 Paris, France; CHNO des Quinze-Vingts, DHU Sight Restore, INSERM-DHOS CIC, 28 rue de Charenton, 75012 Paris, France; Fondation Ophtalmologique Adolphe de Rothschild, 75019 Paris, France.
| | - Serge Picaud
- INSERM U968, Institut de la Vision, 75012 Paris, France; UMRS968, Institut de la Vision, Sorbonne Universités, Pierre et Marie Curie University (UPMC) University Paris 06, 75012 Paris, France; Centre National de la Recherche Scientifique (CNRS) UMR7210, Institut de la Vision, 75012 Paris, France.
| | - Deniz Dalkara
- INSERM U968, Institut de la Vision, 75012 Paris, France; UMRS968, Institut de la Vision, Sorbonne Universités, Pierre et Marie Curie University (UPMC) University Paris 06, 75012 Paris, France; Centre National de la Recherche Scientifique (CNRS) UMR7210, Institut de la Vision, 75012 Paris, France.
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Affiliation(s)
- Arthur Planul
- Inserm, Institut de la Vision, UMR S968, 75012 Paris, France;,
- Sorbonne Universités, UPMC Université Paris 6, UMR S968, 75012 Paris, France
- CNRS, UMR 7210, 75012 Paris, France
| | - Deniz Dalkara
- Inserm, Institut de la Vision, UMR S968, 75012 Paris, France;,
- Sorbonne Universités, UPMC Université Paris 6, UMR S968, 75012 Paris, France
- CNRS, UMR 7210, 75012 Paris, France
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24
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Zhang F, Tzanakakis ES. Optogenetic regulation of insulin secretion in pancreatic β-cells. Sci Rep 2017; 7:9357. [PMID: 28839233 PMCID: PMC5571193 DOI: 10.1038/s41598-017-09937-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 08/01/2017] [Indexed: 02/06/2023] Open
Abstract
Pancreatic β-cell insulin production is orchestrated by a complex circuitry involving intracellular elements including cyclic AMP (cAMP). Tackling aberrations in glucose-stimulated insulin release such as in diabetes with pharmacological agents, which boost the secretory capacity of β-cells, is linked to adverse side effects. We hypothesized that a photoactivatable adenylyl cyclase (PAC) can be employed to modulate cAMP in β-cells with light thereby enhancing insulin secretion. To that end, the PAC gene from Beggiatoa (bPAC) was delivered to β-cells. A cAMP increase was noted within 5 minutes of photostimulation and a significant drop at 12 minutes post-illumination. The concomitant augmented insulin secretion was comparable to that from β-cells treated with secretagogues. Greater insulin release was also observed over repeated cycles of photoinduction without adverse effects on viability and proliferation. Furthermore, the expression and activation of bPAC increased cAMP and insulin secretion in murine islets and in β-cell pseudoislets, which displayed a more pronounced light-triggered hormone secretion compared to that of β-cell monolayers. Calcium channel blocking curtailed the enhanced insulin response due to bPAC activity. This optogenetic system with modulation of cAMP and insulin release can be employed for the study of β-cell function and for enabling new therapeutic modalities for diabetes.
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Affiliation(s)
- Fan Zhang
- Department of Chemical and Biological Engineering, Tufts University, Medford, MA, 02155, USA.
| | - Emmanuel S Tzanakakis
- Department of Chemical and Biological Engineering, Tufts University, Medford, MA, 02155, USA. .,Clinical and Translational Science Institute, Tufts Medical Center, Boston, MA, 02111, USA.
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25
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Jalligampala A, Sekhar S, Zrenner E, Rathbun DL. Optimal voltage stimulation parameters for network-mediated responses in wild type and rd10 mouse retinal ganglion cells. J Neural Eng 2017; 14:026004. [PMID: 28155848 DOI: 10.1088/1741-2552/14/2/026004] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
To further improve the quality of visual percepts elicited by microelectronic retinal prosthetics, substantial efforts have been made to understand how retinal neurons respond to electrical stimulation. It is generally assumed that a sufficiently strong stimulus will recruit most retinal neurons. However, recent evidence has shown that the responses of some retinal neurons decrease with excessively strong stimuli (a non-monotonic response function). Therefore, it is necessary to identify stimuli that can be used to activate the majority of retinal neurons even when such non-monotonic cells are part of the neuronal population. Taking these non-monotonic responses into consideration, we establish the optimal voltage stimulation parameters (amplitude, duration, and polarity) for epiretinal stimulation of network-mediated (indirect) ganglion cell responses. We recorded responses from 3958 mouse retinal ganglion cells (RGCs) in both healthy (wild type, WT) and a degenerating (rd10) mouse model of retinitis pigmentosa-using flat-mounted retina on a microelectrode array. Rectangular monophasic voltage-controlled pulses were presented with varying voltage, duration, and polarity. We found that in 4-5 weeks old rd10 mice the RGC thresholds were comparable to those of WT. There was a marked response variability among mouse RGCs. To account for this variability, we interpolated the percentage of RGCs activated at each point in the voltage-polarity-duration stimulus space, thus identifying the optimal voltage-controlled pulse (-2.4 V, 0.88 ms). The identified optimal voltage pulse can activate at least 65% of potentially responsive RGCs in both mouse strains. Furthermore, this pulse is well within the range of stimuli demonstrated to be safe and effective for retinal implant patients. Such optimized stimuli and the underlying method used to identify them support a high yield of responsive RGCs and will serve as an effective guideline for future in vitro investigations of retinal electrostimulation by establishing standard stimuli for each unique experimental condition.
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Affiliation(s)
- Archana Jalligampala
- Institute for Ophthalmic Research, Eberhard Karls University, D-72076 Tübingen, Germany. Werner Reichardt Centre for Integrative Neuroscience (CIN), D-72076 Tübingen, Germany. Graduate Training Center of Neuroscience/International Max Planck Research School, D-72074 Tübingen, Germany
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26
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Abstract
Light and optical techniques have made profound impacts on modern
medicine, with numerous lasers and optical devices being currently used in
clinical practice to assess health and treat disease. Recent advances in
biomedical optics have enabled increasingly sophisticated technologies —
in particular those that integrate photonics with nanotechnology, biomaterials
and genetic engineering. In this Review, we revisit the fundamentals of
light–matter interactions, describe the applications of light in
imaging, diagnosis, therapy and surgery, overview their clinical use, and
discuss the promise of emerging light-based technologies.
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Affiliation(s)
- Seok Hyun Yun
- Wellman Center for Photomedicine, Massachusetts General Hospital, 65 Landsdowne Street, Cambridge, MA 02139, USA.,Department of Dermatology, Harvard Medical School, 25 Shattuck Street, Boston, MA 02115.,Harvard-MIT Health Sciences and Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
| | - Sheldon J J Kwok
- Wellman Center for Photomedicine, Massachusetts General Hospital, 65 Landsdowne Street, Cambridge, MA 02139, USA.,Harvard-MIT Health Sciences and Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
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27
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Functional Maturation of Human Stem Cell-Derived Neurons in Long-Term Cultures. PLoS One 2017; 12:e0169506. [PMID: 28052116 PMCID: PMC5215418 DOI: 10.1371/journal.pone.0169506] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 12/19/2016] [Indexed: 12/31/2022] Open
Abstract
Differentiated neurons can be rapidly acquired, within days, by inducing stem cells to express neurogenic transcription factors. We developed a protocol to maintain long-term cultures of human neurons, called iNGNs, which are obtained by inducing Neurogenin-1 and Neurogenin-2 expression in induced pluripotent stem cells. We followed the functional development of iNGNs over months and they showed many hallmark properties for neuronal maturation, including robust electrical and synaptic activity. Using iNGNs expressing a variant of channelrhodopsin-2, called CatCh, we could control iNGN activity with blue light stimulation. In combination with optogenetic tools, iNGNs offer opportunities for studies that require precise spatial and temporal resolution. iNGNs developed spontaneous network activity, and these networks had excitatory glutamatergic synapses, which we characterized with single-cell synaptic recordings. AMPA glutamatergic receptor activity was especially dominant in postsynaptic recordings, whereas NMDA glutamatergic receptor activity was absent from postsynaptic recordings but present in extrasynaptic recordings. Our results on long-term cultures of iNGNs could help in future studies elucidating mechanisms of human synaptogenesis and neurotransmission, along with the ability to scale-up the size of the cultures.
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28
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Arens-Arad T, Farah N, Ben-Yaish S, Zlotnik A, Zalevsky Z, Mandel Y. Head mounted DMD based projection system for natural and prosthetic visual stimulation in freely moving rats. Sci Rep 2016; 6:34873. [PMID: 27731346 PMCID: PMC5059752 DOI: 10.1038/srep34873] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 09/19/2016] [Indexed: 02/04/2023] Open
Abstract
Novel technologies are constantly under development for vision restoration in blind patients. Many of these emerging technologies are based on the projection of high intensity light patterns at specific wavelengths, raising the need for the development of specialized projection systems. Here we present and characterize a novel projection system that meets the requirements for artificial retinal stimulation in rats and enables the recording of cortical responses. The system is based on a customized miniature Digital Mirror Device (DMD) for pattern projection, in both visible (525 nm) and NIR (915 nm) wavelengths, and a lens periscope for relaying the pattern directly onto the animal's retina. Thorough system characterization and the investigation of the effect of various parameters on obtained image quality were performed using ZEMAX. Simulation results revealed that images with an MTF higher than 0.8 were obtained with little effect of the vertex distance. Increased image quality was obtained at an optimal pupil diameter and smaller field of view. Visual cortex activity data was recorded simultaneously with pattern projection, further highlighting the importance of the system for prosthetic vision studies. This novel head mounted projection system may prove to be a vital tool in studying natural and artificial vision in behaving animals.
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Affiliation(s)
- Tamar Arens-Arad
- Faculty of Life Sciences, Optometry Track, Bar Ilan University, Ramat Gan, Israel
- Bar Ilan’s Institute for Nanotechnology and Advanced Materials (BINA), Bar Ilan University, Ramat Gan, Israel
| | - Nairouz Farah
- Faculty of Life Sciences, Optometry Track, Bar Ilan University, Ramat Gan, Israel
- Bar Ilan’s Institute for Nanotechnology and Advanced Materials (BINA), Bar Ilan University, Ramat Gan, Israel
| | - Shai Ben-Yaish
- Faculty of Engineering, Bar Ilan University, Ramat Gan, Israel
| | - Alex Zlotnik
- Faculty of Engineering, Bar Ilan University, Ramat Gan, Israel
| | - Zeev Zalevsky
- Bar Ilan’s Institute for Nanotechnology and Advanced Materials (BINA), Bar Ilan University, Ramat Gan, Israel
- Faculty of Engineering, Bar Ilan University, Ramat Gan, Israel
| | - Yossi Mandel
- Faculty of Life Sciences, Optometry Track, Bar Ilan University, Ramat Gan, Israel
- Bar Ilan’s Institute for Nanotechnology and Advanced Materials (BINA), Bar Ilan University, Ramat Gan, Israel
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Colombo E, Feyen P, Antognazza MR, Lanzani G, Benfenati F. Nanoparticles: A Challenging Vehicle for Neural Stimulation. Front Neurosci 2016; 10:105. [PMID: 27047327 PMCID: PMC4803724 DOI: 10.3389/fnins.2016.00105] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Accepted: 03/04/2016] [Indexed: 12/12/2022] Open
Abstract
Neurostimulation represents a powerful and well-established tool for the treatment of several diseases affecting the central nervous system. Although, effective in reducing the symptoms or the progression of brain disorders, the poor accessibility of the deepest areas of the brain currently hampers the possibility of a more specific and controlled therapeutic stimulation, depending on invasive surgical approaches and long-term stability, and biocompatibility issues. The massive research of the last decades on nanomaterials and nanoscale devices favored the development of new tools to address the limitations of the available neurostimulation approaches. This mini-review focuses on the employment of nanoparticles for the modulation of the electrophysiological activity of neuronal networks and the related transduction mechanisms underlying the nanostructure-neuron interfaces.
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Affiliation(s)
- Elisabetta Colombo
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia Genova, Italy
| | - Paul Feyen
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia Genova, Italy
| | - Maria Rosa Antognazza
- Center for Nano Science and Technology, Istituto Italiano di Tecnologia Milan, Italy
| | - Guglielmo Lanzani
- Center for Nano Science and Technology, Istituto Italiano di TecnologiaMilan, Italy; Department of Physics, Politecnico di MilanoMilan, Italy
| | - Fabio Benfenati
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di TecnologiaGenova, Italy; Department of Experimental Medicine, Università di GenovaGenova, Italy
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30
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Evans BD, Jarvis S, Schultz SR, Nikolic K. PyRhO: A Multiscale Optogenetics Simulation Platform. Front Neuroinform 2016; 10:8. [PMID: 27148037 PMCID: PMC4834562 DOI: 10.3389/fninf.2016.00008] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 02/19/2016] [Indexed: 01/07/2023] Open
Abstract
Optogenetics has become a key tool for understanding the function of neural circuits and controlling their behavior. An array of directly light driven opsins have been genetically isolated from several families of organisms, with a wide range of temporal and spectral properties. In order to characterize, understand and apply these opsins, we present an integrated suite of open-source, multi-scale computational tools called PyRhO. The purpose of developing PyRhO is three-fold: (i) to characterize new (and existing) opsins by automatically fitting a minimal set of experimental data to three-, four-, or six-state kinetic models, (ii) to simulate these models at the channel, neuron and network levels, and (iii) provide functional insights through model selection and virtual experiments in silico. The module is written in Python with an additional IPython/Jupyter notebook based GUI, allowing models to be fit, simulations to be run and results to be shared through simply interacting with a webpage. The seamless integration of model fitting algorithms with simulation environments (including NEURON and Brian2) for these virtual opsins will enable neuroscientists to gain a comprehensive understanding of their behavior and rapidly identify the most suitable variant for application in a particular biological system. This process may thereby guide not only experimental design and opsin choice but also alterations of the opsin genetic code in a neuro-engineering feed-back loop. In this way, we expect PyRhO will help to significantly advance optogenetics as a tool for transforming biological sciences.
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Affiliation(s)
- Benjamin D Evans
- Centre for Bio-Inspired Technology, Institute of Biomedical Engineering, Department of Electrical and Electronic Engineering, Imperial College London London, UK
| | - Sarah Jarvis
- Centre for Neurotechnology, Institute of Biomedical Engineering, Department of Bioengineering, Imperial College London London, UK
| | - Simon R Schultz
- Centre for Neurotechnology, Institute of Biomedical Engineering, Department of Bioengineering, Imperial College London London, UK
| | - Konstantin Nikolic
- Centre for Bio-Inspired Technology, Institute of Biomedical Engineering, Department of Electrical and Electronic Engineering, Imperial College London London, UK
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31
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Antognazza MR, Martino N, Ghezzi D, Feyen P, Colombo E, Endeman D, Benfenati F, Lanzani G. Shedding Light on Living Cells. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2015; 27:7662-7669. [PMID: 25469452 DOI: 10.1002/adma.201403513] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Revised: 10/01/2014] [Indexed: 06/04/2023]
Abstract
An overview of the optical methods available to modulate the cellular activity in cell cultures and biological tissues is presented, with a focus on the use of exogenous functional materials that absorb electromagnetic radiation and transduce it into a secondary stimulus for cell excitation, with high temporal and spatial resolution. Both organic and inorganic materials are critically evaluated, for in vitro and in vivo applications. Finally, as a direct practical application of optical-stimulation techniques, the most recent results in the realization of artificial visual implants are discussed.
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Affiliation(s)
- Maria Rosa Antognazza
- Center for Nano Science and Technology, @PoliMi, Istituto Italiano di Tecnologia, Via Pascoli 70/3, Milano, 20133, Italy
| | - Nicola Martino
- Center for Nano Science and Technology, @PoliMi, Istituto Italiano di Tecnologia, Via Pascoli 70/3, Milano, 20133, Italy
- Politecnico di Milano, Dipartimento di Fisica, Piazza L. da Vinci 32, Milano, 20133, Italy
| | - Diego Ghezzi
- Istituto Italiano di Tecnologia, Neuroscience and Brain Technologies Department, Via Morego 30, Genova, 16163, Italy
| | - Paul Feyen
- Istituto Italiano di Tecnologia, Neuroscience and Brain Technologies Department, Via Morego 30, Genova, 16163, Italy
| | - Elisabetta Colombo
- Center for Nano Science and Technology, @PoliMi, Istituto Italiano di Tecnologia, Via Pascoli 70/3, Milano, 20133, Italy
- Istituto Italiano di Tecnologia, Neuroscience and Brain Technologies Department, Via Morego 30, Genova, 16163, Italy
| | - Duco Endeman
- Istituto Italiano di Tecnologia, Neuroscience and Brain Technologies Department, Via Morego 30, Genova, 16163, Italy
| | - Fabio Benfenati
- Istituto Italiano di Tecnologia, Neuroscience and Brain Technologies Department, Via Morego 30, Genova, 16163, Italy
| | - Guglielmo Lanzani
- Center for Nano Science and Technology, @PoliMi, Istituto Italiano di Tecnologia, Via Pascoli 70/3, Milano, 20133, Italy
- Politecnico di Milano, Dipartimento di Fisica, Piazza L. da Vinci 32, Milano, 20133, Italy
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32
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Lorach H, Kung J, Beier C, Mandel Y, Dalal R, Huie P, Wang J, Lee S, Sher A, Jones BW, Palanker D. Development of Animal Models of Local Retinal Degeneration. Invest Ophthalmol Vis Sci 2015. [PMID: 26207299 DOI: 10.1167/iovs.14-16011] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
PURPOSE Development of nongenetic animal models of local retinal degeneration is essential for studies of retinal pathologies, such as chronic retinal detachment or age-related macular degeneration. We present two different methods to induce a highly localized retinal degeneration with precise onset time, that can be applied to a broad range of species in laboratory use. METHODS A 30-μm thin polymer sheet was implanted subretinally in wild-type (WT) rats. The effects of chronic retinal separation from the RPE were studied using histology and immunohistochemistry. Another approach is applicable to species with avascular retina, such as rabbits, where the photoreceptors and RPE were thermally ablated over large areas, using a high power scanning laser. RESULTS Photoreceptors above the subretinal implant in rats degenerated over time, with 80% of the outer nuclear layer disappearing within a month, and the rest by 3 months. Similar loss was obtained by selective photocoagulation with a scanning laser. Cells in the inner nuclear layer and ganglion cell layer were preserved in both cases. However, there were signs of rewiring and decrease in the size of the bipolar cell terminals in the damaged areas. CONCLUSIONS Both methods induce highly reproducible degeneration of photoreceptors over a defined area, with complete preservation of the inner retinal neurons during the 3-month follow-up. They provide a reliable platform for studies of local retinal degeneration and development of therapeutic strategies in a wide variety of species.
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Affiliation(s)
- Henri Lorach
- Hansen Experimental Physics Laboratory, Stanford University, Stanford, California, United States 2Department of Ophthalmology, Stanford University, Stanford, California, United States 3Institut de la Vision, Paris, France
| | - Jennifer Kung
- Department of Ophthalmology, Stanford University, Stanford, California, United States
| | - Corinne Beier
- Santa Cruz Institute for Particle Physics, University of California, Santa Cruz, California, United States
| | - Yossi Mandel
- Hansen Experimental Physics Laboratory, Stanford University, Stanford, California, United States 5Faculty of Life Sciences, Bar Ilan University, Ramat Gan, Israel
| | - Roopa Dalal
- Department of Ophthalmology, Stanford University, Stanford, California, United States
| | - Philip Huie
- Hansen Experimental Physics Laboratory, Stanford University, Stanford, California, United States 2Department of Ophthalmology, Stanford University, Stanford, California, United States
| | - Jenny Wang
- Hansen Experimental Physics Laboratory, Stanford University, Stanford, California, United States 2Department of Ophthalmology, Stanford University, Stanford, California, United States
| | - Seungjun Lee
- Department of Ophthalmology, Stanford University, Stanford, California, United States
| | - Alexander Sher
- Santa Cruz Institute for Particle Physics, University of California, Santa Cruz, California, United States
| | - Bryan William Jones
- Ophthalmology and Visual Sciences, Moran Eye Center, University of Utah, Salt Lake City, Utah, United States
| | - Daniel Palanker
- Hansen Experimental Physics Laboratory, Stanford University, Stanford, California, United States 2Department of Ophthalmology, Stanford University, Stanford, California, United States
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33
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Kirpichnikov MP, Ostrovskiy MA. [Optogenetics and prosthetic treatment of retinal degeneration]. Vestn Oftalmol 2015; 131:99-111. [PMID: 26310015 DOI: 10.17116/oftalma2015131399-111] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
This is a review of the current state of optogenetics-based research in the field of ophthalmology and physiology of vision. Optogenetics employs an interdisciplinary approach that amalgamates gene engineering, optics, and physiology. It involves exogenous expression of a light-activated protein in a very particular retinal cell enabling regulation (stimulation vs. inhibition) of its physiological activity. The experience with gene therapy came in very useful for optogenetics. However, unlike gene therapy, which is aimed at repairing damaged genes or replacing them with healthy ones, optogenetics is focused on protein genes delivery for further molecular control of the cell. In retina, the loss of photoreceptors is not necessarily followed by neuronal loss (at least ganglion cells remain intact), which determines the practicability of prosthetic treatment. Clinical trials can now be considered, owing to the first successful conversion of ganglion cells of mouse degenerative retinas into artificial photoreceptive cells with ON and OFF receptive fields, which is crucial for spatial vision. The following issues are reviewed here in detail: 1. Choice of cell targets within the degenerative retina. 2. Strategy of utilizing the existing light-sensitive agents and development of new optogenetic tools. 3. Gene delivery and expression in retinal cells. 4. Methods of evaluating the treatment success. 5. Selection criteria for optogenetic prosthetics. The conclusion discusses currently unsolved problems and prospects for optogenetic approaches to retinal prosthetics.
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Affiliation(s)
- M P Kirpichnikov
- Lomonosov Moscow State University, Faculty of Biology, 1 str. 12 Leninskie Gory, Moscow, Russian Federation, 119234; Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 16/10 Miklukho-Maklaya St., Moscow, Russian Federation, 117997
| | - M A Ostrovskiy
- Lomonosov Moscow State University, Faculty of Biology, 1 str. 12 Leninskie Gory, Moscow, Russian Federation, 119234; Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, 4 Kosygina St., Moscow, Russian Federation, 119334
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34
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Barrett JM, Degenaar P, Sernagor E. Blockade of pathological retinal ganglion cell hyperactivity improves optogenetically evoked light responses in rd1 mice. Front Cell Neurosci 2015; 9:330. [PMID: 26379501 PMCID: PMC4548307 DOI: 10.3389/fncel.2015.00330] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 08/10/2015] [Indexed: 12/17/2022] Open
Abstract
Retinitis pigmentosa (RP) is a progressive retinal dystrophy that causes visual impairment and eventual blindness. Retinal prostheses are the best currently available vision-restoring treatment for RP, but only restore crude vision. One possible contributing factor to the poor quality of vision achieved with prosthetic devices is the pathological retinal ganglion cell (RGC) hyperactivity that occurs in photoreceptor dystrophic disorders. Gap junction blockade with meclofenamic acid (MFA) was recently shown to diminish RGC hyperactivity and improve the signal-to-noise ratio (SNR) of RGC responses to light flashes and electrical stimulation in the rd10 mouse model of RP. We sought to extend these results to spatiotemporally patterned optogenetic stimulation in the faster-degenerating rd1 model and compare the effectiveness of a number of drugs known to disrupt rd1 hyperactivity. We crossed rd1 mice with a transgenic mouse line expressing the light-sensitive cation channel channelrhodopsin2 (ChR2) in RGCs, allowing them to be stimulated directly using high-intensity blue light. We used 60-channel ITO multielectrode arrays to record ChR2-mediated RGC responses from wholemount, ex-vivo retinas to full-field and patterned stimuli before and after application of MFA, 18-β-glycyrrhetinic acid (18BGA, another gap junction blocker) or flupirtine (Flu, a Kv7 potassium channel opener). All three drugs decreased spontaneous RGC firing, but 18BGA and Flu also decreased the sensitivity of RGCs to optogenetic stimulation. Nevertheless, all three drugs improved the SNR of ChR2-mediated responses. MFA also made it easier to discern motion direction of a moving bar from RGC population responses. Our results support the hypothesis that reduction of pathological RGC spontaneous activity characteristic in retinal degenerative disorders may improve the quality of visual responses in retinal prostheses and they provide insights into how best to achieve this for optogenetic prostheses.
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Affiliation(s)
- John M Barrett
- Faculty of Medical Sciences, Institute of Neuroscience, Newcastle University Newcastle-upon-Tyne, UK
| | - Patrick Degenaar
- Faculty of Science, Agriculture and Engineering, School of Electrical and Electronic Engineering, Newcastle University Newcastle-upon-Tyne, UK
| | - Evelyne Sernagor
- Faculty of Medical Sciences, Institute of Neuroscience, Newcastle University Newcastle-upon-Tyne, UK
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35
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Ghezzi D. Retinal prostheses: progress toward the next generation implants. Front Neurosci 2015; 9:290. [PMID: 26347602 PMCID: PMC4542462 DOI: 10.3389/fnins.2015.00290] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 07/30/2015] [Indexed: 12/18/2022] Open
Abstract
In the last decade, various clinical trials proved the capability of visual prostheses, in particular retinal implants, to restore a useful form of vision. These encouraging results promoted the emerging of several strategies for neuronal stimulation aiming at the restoration of sight. Besides the traditional approach based on electrical stimulation through metal electrodes in the different areas of the visual path (e.g., the visual cortex, the lateral geniculate nucleus, the optic nerve, and the retina), novel concepts for neuronal stimulation have been mostly exploited as building blocks of the next generation of retinal implants. This review is focused on critically discussing recent major advancements in the field of retinal stimulation with particular attention to the findings in the application of novel concepts and materials. Last, the major challenges in the field and their clinical implications will be outlined.
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Affiliation(s)
- Diego Ghezzi
- Medtronic Chair in Neuroengineering, Center for Neuroprosthetics, Interfaculty Institute of Bioengineering, School of Engineering, École Polytechnique Fédérale de Lausanne Lausanne, Switzerland
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36
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Optogenetic Vision Restoration Using Rhodopsin for Enhanced Sensitivity. Mol Ther 2015; 23:1562-71. [PMID: 26137852 PMCID: PMC4817926 DOI: 10.1038/mt.2015.121] [Citation(s) in RCA: 92] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Accepted: 06/22/2015] [Indexed: 12/26/2022] Open
Abstract
Retinal disease is one of the most active areas of gene therapy, with clinical trials ongoing in the United States for five diseases. There are currently no treatments for patients with late-stage disease in which photoreceptors have been lost. Optogenetic gene therapies are in development, but, to date, have suffered from the low light sensitivity of microbial opsins, such as channelrhodopsin and halorhodopsin, and azobenzene-based photoswitches. Several groups have shown that photoreceptive G-protein-coupled receptors (GPCRs) can be expressed heterologously, and photoactivate endogenous Gi/o signaling. We hypothesized such a GPCR could increase sensitivity due to endogenous signal amplification. We targeted vertebrate rhodopsin to retinal ON-bipolar cells of blind rd1 mice and observed restoration of: (i) light responses in retinal explants, (ii) visually-evoked potentials in visual cortex in vivo, and (iii) two forms of visually-guided behavior: innate light avoidance and discrimination of temporal light patterns in the context of fear conditioning. Importantly, both the light responses of the retinal explants and the visually-guided behavior occurred reliably at light levels that were two to three orders of magnitude dimmer than required for channelrhodopsin. Thus, gene therapy with native light-gated GPCRs presents a novel approach to impart light sensitivity for visual restoration in a useful range of illumination.
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37
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Tochitsky I, Kramer RH. Optopharmacological tools for restoring visual function in degenerative retinal diseases. Curr Opin Neurobiol 2015; 34:74-8. [PMID: 25706312 DOI: 10.1016/j.conb.2015.01.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Revised: 01/26/2015] [Accepted: 01/28/2015] [Indexed: 11/17/2022]
Abstract
Retinitis pigmentosa (RP) and age-related macular degeneration (AMD) are progressive retinal diseases that result from the death of rod and cone photoreceptors, ultimately leading to blindness. The only currently approved vision restoration treatment employs an implanted retinal 'chip' as a prosthetic device to electrically stimulate retinal neurons that survive after the photoreceptors are gone, thereby restoring light-driven neural signaling to the brain. Alternative strategies have been proposed, which would utilize optogenetic or optopharmacological tools to enable direct optical stimulation of surviving retinal neurons. Here, we review the latest studies evaluating the feasibility of these molecular tools as potential therapeutics for restoring visual function in human blinding disease.
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Affiliation(s)
- Ivan Tochitsky
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
| | - Richard H Kramer
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA.
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38
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Restoration of visual function by expression of a light-gated mammalian ion channel in retinal ganglion cells or ON-bipolar cells. Proc Natl Acad Sci U S A 2014; 111:E5574-83. [PMID: 25489083 DOI: 10.1073/pnas.1414162111] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Most inherited forms of blindness are caused by mutations that lead to photoreceptor cell death but spare second- and third-order retinal neurons. Expression of the light-gated excitatory mammalian ion channel light-gated ionotropic glutamate receptor (LiGluR) in retinal ganglion cells (RGCs) of the retina degeneration (rd1) mouse model of blindness was previously shown to restore some visual functions when stimulated by UV light. Here, we report restored retinal function in visible light in rodent and canine models of blindness through the use of a second-generation photoswitch for LiGluR, maleimide-azobenzene-glutamate 0 with peak efficiency at 460 nm (MAG0(460)). In the blind rd1 mouse, multielectrode array recordings of retinal explants revealed robust and uniform light-evoked firing when LiGluR-MAG0(460) was targeted to RGCs and robust but diverse activity patterns in RGCs when LiGluR-MAG0(460) was targeted to ON-bipolar cells (ON-BCs). LiGluR-MAG0(460) in either RGCs or ON-BCs of the rd1 mouse reinstated innate light-avoidance behavior and enabled mice to distinguish between different temporal patterns of light in an associative learning task. In the rod-cone dystrophy dog model of blindness, LiGluR-MAG0(460) in RGCs restored robust light responses to retinal explants and intravitreal delivery of LiGluR and MAG0(460) was well tolerated in vivo. The results in both large and small animal models of photoreceptor degeneration provide a path to clinical translation.
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39
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Abstract
In this issue of Neuron, Jepson et al. (2014) demonstrate that electric stimulation of primate ON parasol ganglion cells evokes spiking patterns similar to those elicited by visual motion. This work represents progress in the development of cell-type-specific retinal prosthetics for vision restoration.
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Affiliation(s)
- Stuart Trenholm
- Neural Circuit Laboratories, Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland
| | - Botond Roska
- Neural Circuit Laboratories, Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland.
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40
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Macé E, Caplette R, Marre O, Sengupta A, Chaffiol A, Barbe P, Desrosiers M, Bamberg E, Sahel JA, Picaud S, Duebel J, Dalkara D. Targeting channelrhodopsin-2 to ON-bipolar cells with vitreally administered AAV Restores ON and OFF visual responses in blind mice. Mol Ther 2014; 23:7-16. [PMID: 25095892 DOI: 10.1038/mt.2014.154] [Citation(s) in RCA: 130] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Accepted: 07/29/2014] [Indexed: 12/12/2022] Open
Abstract
Most inherited retinal dystrophies display progressive photoreceptor cell degeneration leading to severe visual impairment. Optogenetic reactivation of retinal neurons mediated by adeno-associated virus (AAV) gene therapy has the potential to restore vision regardless of patient-specific mutations. The challenge for clinical translatability is to restore a vision as close to natural vision as possible, while using a surgically safe delivery route for the fragile degenerated retina. To preserve the visual processing of the inner retina, we targeted ON bipolar cells, which are still present at late stages of disease. For safe gene delivery, we used a recently engineered AAV variant that can transduce the bipolar cells after injection into the eye's easily accessible vitreous humor. We show that AAV encoding channelrhodopsin under the ON bipolar cell-specific promoter mediates long-term gene delivery restricted to ON-bipolar cells after intravitreal administration. Channelrhodopsin expression in ON bipolar cells leads to restoration of ON and OFF responses at the retinal and cortical levels. Moreover, light-induced locomotory behavior is restored in treated blind mice. Our results support the clinical relevance of a minimally invasive AAV-mediated optogenetic therapy for visual restoration.
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Affiliation(s)
- Emilie Macé
- 1] INSERM, U968, Paris, France [2] Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, Institut de la Vision, Paris, France [3] CNRS, UMR_7210, Paris, France
| | - Romain Caplette
- 1] INSERM, U968, Paris, France [2] Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, Institut de la Vision, Paris, France [3] CNRS, UMR_7210, Paris, France
| | - Olivier Marre
- 1] INSERM, U968, Paris, France [2] Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, Institut de la Vision, Paris, France [3] CNRS, UMR_7210, Paris, France
| | - Abhishek Sengupta
- 1] INSERM, U968, Paris, France [2] Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, Institut de la Vision, Paris, France [3] CNRS, UMR_7210, Paris, France
| | - Antoine Chaffiol
- 1] INSERM, U968, Paris, France [2] Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, Institut de la Vision, Paris, France [3] CNRS, UMR_7210, Paris, France
| | - Peggy Barbe
- 1] INSERM, U968, Paris, France [2] Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, Institut de la Vision, Paris, France [3] CNRS, UMR_7210, Paris, France
| | - Mélissa Desrosiers
- 1] INSERM, U968, Paris, France [2] Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, Institut de la Vision, Paris, France [3] CNRS, UMR_7210, Paris, France
| | - Ernst Bamberg
- Department of Biophysical Chemistry, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Jose-Alain Sahel
- 1] INSERM, U968, Paris, France [2] Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, Institut de la Vision, Paris, France [3] CNRS, UMR_7210, Paris, France [4] Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, INSERM-DHOS CIC 503, Paris, France [5] Fondation Ophtalmologique Adolphe de Rothschild, Paris, France
| | - Serge Picaud
- 1] INSERM, U968, Paris, France [2] Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, Institut de la Vision, Paris, France [3] CNRS, UMR_7210, Paris, France
| | - Jens Duebel
- 1] INSERM, U968, Paris, France [2] Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, Institut de la Vision, Paris, France [3] CNRS, UMR_7210, Paris, France
| | - Deniz Dalkara
- 1] INSERM, U968, Paris, France [2] Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, Institut de la Vision, Paris, France [3] CNRS, UMR_7210, Paris, France
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41
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Chuong AS, Miri ML, Busskamp V, Matthews GAC, Acker LC, Sørensen AT, Young A, Klapoetke NC, Henninger MA, Kodandaramaiah SB, Ogawa M, Ramanlal SB, Bandler RC, Allen BD, Forest CR, Chow BY, Han X, Lin Y, Tye KM, Roska B, Cardin JA, Boyden ES. Noninvasive optical inhibition with a red-shifted microbial rhodopsin. Nat Neurosci 2014; 17:1123-9. [PMID: 24997763 PMCID: PMC4184214 DOI: 10.1038/nn.3752] [Citation(s) in RCA: 353] [Impact Index Per Article: 35.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Accepted: 06/01/2014] [Indexed: 12/11/2022]
Abstract
Optogenetic inhibition of the electrical activity of neurons enables the causal assessment of their contributions to brain functions. Red light penetrates deeper into tissue than other visible wavelengths. We present a red-shifted cruxhalorhodopsin, Jaws, derived from Haloarcula (Halobacterium) salinarum (strain Shark) and engineered to result in red light-induced photocurrents three times those of earlier silencers. Jaws exhibits robust inhibition of sensory-evoked neural activity in the cortex and results in strong light responses when used in retinas of retinitis pigmentosa model mice. We also demonstrate that Jaws can noninvasively mediate transcranial optical inhibition of neurons deep in the brains of awake mice. The noninvasive optogenetic inhibition opened up by Jaws enables a variety of important neuroscience experiments and offers a powerful general-use chloride pump for basic and applied neuroscience.
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Affiliation(s)
- Amy S Chuong
- 1] Media Lab, Department of Media Arts and Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA. [2] McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA. [3] Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Mitra L Miri
- 1] Department of Neurobiology, Yale School of Medicine, Yale University, New Haven, Connecticut, USA. [2]
| | - Volker Busskamp
- 1] Neural Circuit Laboratories, Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland. [2] Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA. [3]
| | - Gillian A C Matthews
- 1] Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA. [2]
| | - Leah C Acker
- 1] Media Lab, Department of Media Arts and Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA. [2] McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA. [3] Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA. [4]
| | - Andreas T Sørensen
- McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Andrew Young
- McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Nathan C Klapoetke
- 1] Media Lab, Department of Media Arts and Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA. [2] McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA. [3] Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Mike A Henninger
- 1] Media Lab, Department of Media Arts and Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA. [2] McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA. [3] Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Suhasa B Kodandaramaiah
- 1] Media Lab, Department of Media Arts and Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA. [2] McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA. [3] Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA. [4] George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Masaaki Ogawa
- 1] Media Lab, Department of Media Arts and Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA. [2] McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA. [3] Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Shreshtha B Ramanlal
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts, USA
| | - Rachel C Bandler
- Media Lab, Department of Media Arts and Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Brian D Allen
- Media Lab, Department of Media Arts and Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Craig R Forest
- George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Brian Y Chow
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Xue Han
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts, USA
| | - Yingxi Lin
- McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Kay M Tye
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Botond Roska
- Neural Circuit Laboratories, Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Jessica A Cardin
- 1] Department of Neurobiology, Yale School of Medicine, Yale University, New Haven, Connecticut, USA. [2] Kavli Institute for Neuroscience, Yale University, New Haven, Connecticut, USA
| | - Edward S Boyden
- 1] Media Lab, Department of Media Arts and Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA. [2] McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA. [3] Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
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Grosse W, Psakis G, Mertins B, Reiss P, Windisch D, Brademann F, Bürck J, Ulrich A, Koert U, Essen LO. Structure-based engineering of a minimal porin reveals loop-independent channel closure. Biochemistry 2014; 53:4826-38. [PMID: 24988371 DOI: 10.1021/bi500660q] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Porins, like outer membrane protein G (OmpG) of Escherichia coli, are ideal templates among ion channels for protein and chemical engineering because of their robustness and simple architecture. OmpG shows fast transitions between open and closed states, which were attributed to loop 6 (L6). As flickering limits single-channel-based applications, we pruned L6 by either 8 or 12 amino acids. While the open probabilities of both L6 variants resemble that of native OmpG, their gating frequencies were reduced by 63 and 81%, respectively. Using the 3.2 Å structure of the shorter L6 variant in the open state, we engineered a minimal porin (220 amino acids), where all remaining extramembranous loops were truncated. Unexpectedly, this minimized porin still exhibited gating, but it was 5-fold less frequent than in OmpG. The residual gating of the minimal pore is hence independent of L6 rearrangements and involves narrowing of the ion conductance pathway most probably driven by global stretching-flexing deformations of the membrane-embedded β-barrel.
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Affiliation(s)
- Wolfgang Grosse
- Department of Chemistry, Philipps-University Marburg , Hans-Meerwein-Straße, 35032 Marburg, Germany
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Luan S, Williams I, Nikolic K, Constandinou TG. Neuromodulation: present and emerging methods. FRONTIERS IN NEUROENGINEERING 2014; 7:27. [PMID: 25076887 PMCID: PMC4097946 DOI: 10.3389/fneng.2014.00027] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Accepted: 06/24/2014] [Indexed: 12/21/2022]
Abstract
Neuromodulation has wide ranging potential applications in replacing impaired neural function (prosthetics), as a novel form of medical treatment (therapy), and as a tool for investigating neurons and neural function (research). Voltage and current controlled electrical neural stimulation (ENS) are methods that have already been widely applied in both neuroscience and clinical practice for neuroprosthetics. However, there are numerous alternative methods of stimulating or inhibiting neurons. This paper reviews the state-of-the-art in ENS as well as alternative neuromodulation techniques-presenting the operational concepts, technical implementation and limitations-in order to inform system design choices.
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Affiliation(s)
- Song Luan
- Department of Electrical and Electronic Engineering, Imperial College LondonLondon, UK
- Center for Bio-Inspired Technology, Institute of Biomedical Engineering, Imperial College LondonLondon, UK
| | - Ian Williams
- Department of Electrical and Electronic Engineering, Imperial College LondonLondon, UK
- Center for Bio-Inspired Technology, Institute of Biomedical Engineering, Imperial College LondonLondon, UK
| | - Konstantin Nikolic
- Department of Electrical and Electronic Engineering, Imperial College LondonLondon, UK
- Center for Bio-Inspired Technology, Institute of Biomedical Engineering, Imperial College LondonLondon, UK
| | - Timothy G. Constandinou
- Department of Electrical and Electronic Engineering, Imperial College LondonLondon, UK
- Center for Bio-Inspired Technology, Institute of Biomedical Engineering, Imperial College LondonLondon, UK
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Derivation of traceable and transplantable photoreceptors from mouse embryonic stem cells. Stem Cell Reports 2014; 2:853-65. [PMID: 24936471 PMCID: PMC4050344 DOI: 10.1016/j.stemcr.2014.04.010] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Revised: 04/15/2014] [Accepted: 04/16/2014] [Indexed: 01/12/2023] Open
Abstract
Retinal degenerative diseases resulting in the loss of photoreceptors are one of the major causes of blindness. Photoreceptor replacement therapy is a promising treatment because the transplantation of retina-derived photoreceptors can be applied now to different murine retinopathies to restore visual function. To have an unlimited source of photoreceptors, we derived a transgenic embryonic stem cell (ESC) line in which the Crx-GFP transgene is expressed in photoreceptors and assessed the capacity of a 3D culture protocol to produce integration-competent photoreceptors. This culture system allows the production of a large number of photoreceptors recapitulating the in vivo development. After transplantation, integrated cells showed the typical morphology of mature rods bearing external segments and ribbon synapses. We conclude that a 3D protocol coupled with ESCs provides a safe and renewable source of photoreceptors displaying a development and transplantation competence comparable to photoreceptors from age-matched retinas. De novo isolation of Crx-GFP embryonic stem cell lines to trace photoreceptors 3D culture system fine-tuning to generate many integration-competent photoreceptors Revealing in-vitro- and in-vivo-developing retina similarities Characterization of the most appropriate stage to transplant photoreceptors
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Affiliation(s)
- Shrivats M Iyer
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
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46
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Boinagrov D, Pangratz-Fuehrer S, Goetz G, Palanker D. Selectivity of direct and network-mediated stimulation of the retinal ganglion cells with epi-, sub- and intraretinal electrodes. J Neural Eng 2014; 11:026008. [PMID: 24608166 DOI: 10.1088/1741-2560/11/2/026008] [Citation(s) in RCA: 111] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
OBJECTIVE Intra-retinal placement of stimulating electrodes can provide close and stable proximity to target neurons. We assessed improvement in stimulation thresholds and selectivity of the direct and network-mediated retinal stimulation with intraretinal electrodes, compared to epiretinal and subretinal placements. APPROACH Stimulation thresholds of the retinal ganglion cells (RGCs) in wild-type rat retina were measured using the patch-clamp technique. Direct and network-mediated responses were discriminated using various synaptic blockers. MAIN RESULTS Three types of RGC responses were identified: short latency (SL, τ < 5 ms) originating in RGCs, medium latency (ML, 3 < τ < 70 ms) originating in the inner nuclear layer and long latency (LL, τ > 40 ms) originating in photoreceptors. Cathodic epiretinal stimulation exhibited the lowest threshold for direct RGC response and the highest direct selectivity (network/direct thresholds ratio), exceeding a factor of 3 with pulse durations below 0.5 ms. For network-mediated stimulation, the lowest threshold was obtained with anodic pulses in OPL position, and its network selectivity (direct/network thresholds ratio) increased with pulse duration, exceeding a factor of 4 at 10 ms. Latency of all three types of responses decreased with increasing strength of the stimulus. SIGNIFICANCE These results define the optimal range of pulse durations, pulse polarities and electrode placement for the retinal prostheses aiming at direct or network-mediated stimulation of RGCs.
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Affiliation(s)
- David Boinagrov
- Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305, USA. Department of Physics, Stanford University, Stanford, CA 94305, USA
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Twyford P, Cai C, Fried S. Differential responses to high-frequency electrical stimulation in ON and OFF retinal ganglion cells. J Neural Eng 2014; 11:025001. [PMID: 24556536 DOI: 10.1088/1741-2560/11/2/025001] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
OBJECTIVE The field of retinal prosthetics for artificial vision has advanced considerably in recent years, however clinical outcomes remain inconsistent. The performance of retinal prostheses is likely limited by the inability of electrical stimuli to preferentially activate different types of retinal ganglion cell (RGC). APPROACH Here we examine the response of rabbit RGCs to high-frequency stimulation, using biphasic pulses applied at 2000 pulses per second. Responses were recorded using cell-attached patch clamp methods, and stimulation was applied epiretinally via a small cone electrode. MAIN RESULTS When prolonged stimulus trains were applied to OFF-brisk transient (BT) RGCs, the cells exhibited a non-monotonic relationship between response strength and stimulus amplitude; this response pattern was different from those elicited previously by other electrical stimuli. When the amplitude of the stimulus was modulated transiently from a non-zero baseline amplitude, ON-BT and OFF-BT cells exhibited different activity patterns: ON cells showed an increase in activity while OFF cells exhibited a decrease in activity. Using a different envelope to modulate the amplitude of the stimulus, we observed the opposite effect: ON cells exhibited a decrease in activity while OFF cells show an increase in activity. SIGNIFICANCE As ON and OFF RGCs often exhibit opposing activity patterns in response to light stimulation, this work suggests that high-frequency electrical stimulation of RGCs may be able to elicit responses that are more physiological than traditional pulsatile stimuli. Additionally, the prospect of an electrical stimulus capable of cell-type specific selective activation has broad applications throughout the fields of neural stimulation and neuroprostheses.
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Affiliation(s)
- Perry Twyford
- VA Boston Healthcare System, Boston, MA, USA. Department of Neurosurgery, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
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48
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Strategies for expanding the operational range of channelrhodopsin in optogenetic vision. PLoS One 2013; 8:e81278. [PMID: 24312285 PMCID: PMC3842264 DOI: 10.1371/journal.pone.0081278] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Accepted: 10/11/2013] [Indexed: 01/22/2023] Open
Abstract
Some hereditary diseases, such as retinitis pigmentosa, lead to blindness due to the death of photoreceptors, though the rest of the visual system might be only slightly affected. Optogenetics is a promising tool for restoring vision after retinal degeneration. In optogenetics, light-sensitive ion channels ("channelrhodopsins") are expressed in neurons so that the neurons can be activated by light. Currently existing variants of channelrhodopsin – engineered for use in neurophysiological research – do not necessarily support the goal of vision restoration optimally, due to two factors: First, the nature of the light stimulus is fundamentally different in "optogenetic vision" compared to "optogenetic neuroscience". Second, the retinal target neurons have specific properties that need to be accounted for, e.g. most retinal neurons are non-spiking. In this study, by using a computational model, we investigate properties of channelrhodopsin that might improve successful vision restoration. We pay particular attention to the operational brightness range and suggest strategies that would allow optogenetic vision over a wider intensity range than currently possible, spanning the brightest 5 orders of naturally occurring luminance. We also discuss the biophysical limitations of channelrhodopsin, and of the expressing cells, that prevent further expansion of this operational range, and we suggest design strategies for optogenetic tools which might help overcoming these limitations. Furthermore, the computational model used for this study is provided as an interactive tool for the research community.
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Francis PJ, Mansfield B, Rose S. Proceedings of the First International Optogenetic Therapies for Vision Symposium. Transl Vis Sci Technol 2013; 2:4. [PMID: 24349882 DOI: 10.1167/tvst.2.7.4] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Accepted: 10/17/2013] [Indexed: 11/24/2022] Open
Abstract
Optogenetics is a research field that uses gene therapy to deliver a gene encoding a light-activated protein to cells providing light-regulated control of targeted cell pathways. The technology is a popular tool in many fields of neuroscience, used to transiently switch cells on and off, for example, to map neural circuits. In inherited retinal degenerative diseases, where loss of vision results from the loss of photoreceptors, optogenetics can be applied to either augment the function of surviving photoreceptors or confer light sensitivity to naturally nonlight sensitive retinal cells, such as a bipolar cells. This can be achieved either by the light sensitive protein integrating with native internal signaling pathways, or by using a dual function membrane protein that integrates light signaling with an ion channel or pump activity. Exposing treated cells to light of the correct wavelength activates the protein, resulting in cellular depolarization or hyperpolarization that triggers neurological signaling to the visual cortex. While there is a lot of interest in optogenetics as a pan-disease clinical treatment for end-stage application in the inherited degenerative diseases of the retina, research to date has been limited to nonhuman clinical studies. To address the clinical translational needs of this technology, the Foundation Fighting Blindness and Massachusetts Eye and Ear Infirmary cohosted an International Optogenetic Therapies for Vision Workshop, which was held at Massachusetts Eye and Ear Infirmary, Boston, Massachusetts on June 1, 2012.
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Abstract
Optogenetic tools enable light-mediated control of cellular excitability and signaling in vivo. By manipulating biological processes, scientists can determine the roles played by these processes in intact biological systems, such as the brain. Such cellular-level control has greatly affected basic science. Here, we discuss how optogenetic tools might be translated into clinical impact through identification of new molecular and circuit-level targets and provide temporally precise interventions for defined biochemical or cellular events.
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Affiliation(s)
- Brian Y Chow
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA.
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