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Hososhima S, Shigemura S, Kandori H, Tsunoda SP. Novel optogenetics tool: Gt_CCR4, a light-gated cation channel with high reactivity to weak light. Biophys Rev 2020; 12:453-459. [PMID: 32166612 DOI: 10.1007/s12551-020-00676-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 03/02/2020] [Indexed: 12/12/2022] Open
Abstract
Optogenetics is a growing technique which allows manipulation of biological events simply by illumination. The technique is appreciated especially in the neuroscience field because of its availability in controlling neuronal functions. A light-gated cation channel, Cr_ChR2 from Chlamydomonas reinhardtii, is the first and mostly applied to optogenetics for activating neuronal excitability. In addition, the molecular mechanism of Cr_ChR2 has been intensively studied by electrophysiology, spectroscopy, X-ray structural studies, etc. Novel cation channelrhodopsins from Guillardia theta, namely, Gt_CCR1-4, were discovered in 2016 and 2017. These channelrhodopsins are more homologous to haloarchaeal rhodopsins, particularly the proton pumps. Thus these cryptophyte-type light-gated cation channels are structurally and mechanistically distinct from chlorophyte channelrhodopsin such as Cr_ChR2. We here compared the photocurrent properties, cation selectivity, and kinetics between well-known Cr_ChR2 and Gt_CCR4. The light sensitivity of Gt_CCR4 is significantly higher than that of Cr_ChR2, while the channel open lifetime is in the same range as that of Cr_ChR2. Gt_CCR4 shows high Na+ selectivity in which the selectivity ratio for Na+ was 37-fold larger than that for Cr_ChR2, which primarily conducts H+. On the other hand, Gt_CCR4 conducted almost no H+ and no Ca2+ under physiological conditions. Other unique features and the applicability of Gt_CCR4 for optogenetics were discussed.
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Affiliation(s)
- Shoko Hososhima
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Showa-ku, Nagoya, 466-8555, Japan
| | - Shunta Shigemura
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Showa-ku, Nagoya, 466-8555, Japan
| | - Hideki Kandori
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Showa-ku, Nagoya, 466-8555, Japan.,OptoBio Technology Research Center, Nagoya Institute of Technology, Showa-ku, Nagoya, 466-8555, Japan
| | - Satoshi P Tsunoda
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Showa-ku, Nagoya, 466-8555, Japan. .,PRESTO, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012, Japan.
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102
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Kandori H. Biophysics of rhodopsins and optogenetics. Biophys Rev 2020; 12:355-361. [PMID: 32065378 DOI: 10.1007/s12551-020-00645-0] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 02/10/2020] [Indexed: 01/19/2023] Open
Abstract
Rhodopsins are photoreceptive proteins and key tools in optogenetics. Although rhodopsin was originally named as a red-colored pigment for vision, the modern meaning of rhodopsin encompasses photoactive proteins containing a retinal chromophore in animals and microbes. Animal and microbial rhodopsins respectively possess 11-cis and all-trans retinal, respectively. As cofactors bound with their animal and microbial rhodopsin (seven transmembrane α-helices) environments, 11-cis and all-trans retinal undergo photoisomerization into all-trans and 13-cis retinal forms as part of their functional cycle. While animal rhodopsins are G protein coupled receptors, the function of microbial rhodopsins is highly divergent. Many of the microbial rhodopsins are able to transport ions in a passive or an active manner. These light-gated channels or light-driven pumps represent the main tools for respectively effecting neural excitation and silencing in the emerging field of optogenetics. In this article, the biophysics of rhodopsins and their relationship to optogenetics are reviewed. As history has proven, understanding the molecular mechanism of microbial rhodopsins is a prerequisite for their rational exploitation as the optogenetics tools of the future.
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103
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Luo JW, Nikolic K, Degenaar P. Modelling Optogenetic Subthreshold Effects. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2020; 2019:6136-6140. [PMID: 31947244 DOI: 10.1109/embc.2019.8856664] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We develop a system-level approach to modelling optogenetic-neurons firing behaviour in in-vivo conditions. This approach contains three sub-modules: 1) a Mie/Rayleigh scattering mode of light penetration in tissue; 2) a classic likelihood Poisson spiking train model; 3) a 4-state model of the Channelrhodopsin-2 (ChR2) channel added to a CA3 neuron Hodgkin-Huxley model. We first investigate opto-neurons lightto-spike mechanisms in an in-vivo model: the background noise (synaptic currents) play a dominant role in generating spikes rather than light intensities as for in-vitro conditions (Typically the required light intensity is less than 0.3 mW/mm2 for in-vivo). Then the spiking fidelity is analyzed for different background noise levels. Next, by combining light penetration profiles, we show how neuron firing rates decay as tissue distance increases, for a 2D dimensional cross-section. This preliminary data clearly demonstrate that at given light stimulation protocol, the maximum effected distance in-vivo is 250 μm with small frequency decay rates, while for in-vitro is 50μm with considerable frequency decay rates. Therefore, the developed model can be used for designing sensible light stimulation strategies in-vivo and opto-electronics systems.
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104
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Kandori H. Retinal Proteins: Photochemistry and Optogenetics. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2020. [DOI: 10.1246/bcsj.20190292] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Hideki Kandori
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Showa-ku, Nagoya, Aichi 466-8555, Japan
- OptoBioTechnology Research Center, Nagoya Institute of Technology, Showa-ku, Nagoya, Aichi 466-8555, Japan
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105
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Islam J, Kc E, Oh BH, Moon HC, Park YS. Pain modulation effect on motor cortex after optogenetic stimulation in shPKCγ knockdown dorsal root ganglion-compressed Sprague-Dawley rat model. Mol Pain 2020; 16:1744806920943685. [PMID: 32865105 PMCID: PMC7466896 DOI: 10.1177/1744806920943685] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 06/03/2020] [Accepted: 06/08/2020] [Indexed: 12/14/2022] Open
Abstract
Neuropathic pain can be generated by chronic compression of dorsal root ganglion (CCD). Stimulation of primary motor cortex can disrupt the nociceptive sensory signal at dorsal root ganglion level and reduce pain behaviors. But the mechanism behind it is still implicit. Protein kinase C gamma is known as an essential enzyme for the development of neuropathic pain, and specific inhibitor of protein kinase C gamma can disrupt the sensory signal and reduce pain behaviors. Optogenetic stimulation has been emerged as a new and promising conducive method for refractory neuropathic pain. The aim of this study was to provide evidence whether optical stimulation of primary motor cortex can modulate chronic neuropathic pain in CCD rat model. Animals were randomly divided into CCD group, sham group, and control group. Dorsal root ganglion-compressed neuropathic pain model was established in animals, and knocking down of protein kinase C gamma was also accomplished. Pain behavioral scores were significantly improved in the short hairpin Protein Kinase C gamma knockdown CCD animals during optic stimulation. Ventral posterolateral thalamic firing inhibition was also observed during light stimulation on motor cortex in CCD animal. We assessed alteration of pain behaviors in pre-light off, stimulation-light on, and post-light off state. In vivo extracellular recording of the ventral posterolateral thalamus, viral expression in the primary motor cortex, and protein kinase C gamma expression in dorsal root ganglion were investigated. So, optical cortico-thalamic inhibition by motor cortex stimulation can improve neuropathic pain behaviors in CCD animal, and knocking down of protein kinase C gamma plays a conducive role in the process. This study provides feasibility for in vivo optogenetic stimulation on primary motor cortex of dorsal root ganglion-initiated neuropathic pain.
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Affiliation(s)
- Jaisan Islam
- Department of Neuroscience, College of Medicine, Chungbuk National University, Republic of Korea
| | - Elina Kc
- Department of Neuroscience, College of Medicine, Chungbuk National University, Republic of Korea
| | - Byeong Ho Oh
- Department of Neurosurgery, College of Medicine, Chungbuk National University, Chungbuk National University Hospital, Republic of Korea
| | - Hyeong Cheol Moon
- Department of Neuroscience, College of Medicine, Chungbuk National University, Republic of Korea
- Department of Neurosurgery, Gamma Knife Icon Center, Chungbuk National University Hospital, Republic of Korea
| | - Young Seok Park
- Department of Neuroscience, College of Medicine, Chungbuk National University, Republic of Korea
- Department of Neurosurgery, College of Medicine, Chungbuk National University, Chungbuk National University Hospital, Republic of Korea
- Department of Neurosurgery, Gamma Knife Icon Center, Chungbuk National University Hospital, Republic of Korea
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106
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Kojima K, Shibukawa A, Sudo Y. The Unlimited Potential of Microbial Rhodopsins as Optical Tools. Biochemistry 2019; 59:218-229. [PMID: 31815443 DOI: 10.1021/acs.biochem.9b00768] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Microbial rhodopsins, a photoactive membrane protein family, serve as fundamental tools for optogenetics, an innovative technology for controlling biological activities with light. Microbial rhodopsins are widely distributed in nature and have a wide variety of biological functions. Regardless of the many different known types of microbial rhodopsins, only a few of them have been used in optogenetics to control neural activity to understand neural networks. The efforts of our group have been aimed at identifying and characterizing novel rhodopsins from nature and also at engineering novel variant rhodopsins by rational design. On the basis of the molecular and functional characteristics of those novel rhodopsins, we have proposed new rhodopsin-based optogenetics tools to control not only neural activities but also "non-neural" activities. In this Perspective, we introduce the achievements and summarize future challenges in creating optogenetics tools using rhodopsins. The implementation of optogenetics deep inside an in vivo brain is the well-known challenge for existing rhodopsins. As a perspective to address this challenge, we introduce innovative optical illumination techniques using wavefront shaping that can reinforce the low light sensitivity of the rhodopsins and realize deep-brain optogenetics. The applications of our optogenetics tools could be extended to manipulate non-neural biological activities such as gene expression, apoptosis, energy production, and muscle contraction. We also discuss the potentially unlimited biotechnological applications of microbial rhodopsins in the future such as in photovoltaic devices and in drug delivery systems. We believe that advances in the field will greatly expand the potential uses of microbial rhodopsins as optical tools.
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Affiliation(s)
- Keiichi Kojima
- Graduate School of Medicine, Dentistry and Pharmaceutical Sciences , Okayama University , Okayama 700-8530 , Japan
| | - Atsushi Shibukawa
- Graduate School of Medicine, Dentistry and Pharmaceutical Sciences , Okayama University , Okayama 700-8530 , Japan
| | - Yuki Sudo
- Graduate School of Medicine, Dentistry and Pharmaceutical Sciences , Okayama University , Okayama 700-8530 , Japan
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107
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Montazeri L, El Zarif N, Trenholm S, Sawan M. Optogenetic Stimulation for Restoring Vision to Patients Suffering From Retinal Degenerative Diseases: Current Strategies and Future Directions. IEEE TRANSACTIONS ON BIOMEDICAL CIRCUITS AND SYSTEMS 2019; 13:1792-1807. [PMID: 31689206 DOI: 10.1109/tbcas.2019.2951298] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Optogenetic strategies for vision restoration involve photosensitizing surviving retinal neurons following retinal degeneration, using emerging optogenetic techniques. This approach opens the door to a minimally-invasive retinal vision restoration approach. Moreover, light stimulation has the potential to offer better spatial and temporal resolution than conventional retinal electrical prosthetics. Although proof-of-concept studies in animal models have demonstrated the possibility of restoring vision using optogenetic techniques, and initial clinical trials are underway, there are still hurdles to pass before such an approach restores naturalistic vision in humans. One limitation is the development of light stimulation devices to activate optogenetic channels in the retina. Here we review recent progress in the design and implementation of optogenetic stimulation devices and outline the corresponding technological challenges. Finally, while most work to date has focused on providing therapy to patients suffering from retinitis pigmentosa, we provide additional insights into strategies for applying optogenetic vision restoration to patients suffering from age-related macular degeneration.
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108
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Perez-Medina AL, Galligan JJ. Optogenetic analysis of neuromuscular transmission in the colon of ChAT-ChR2-YFP BAC transgenic mice. Am J Physiol Gastrointest Liver Physiol 2019; 317:G569-G579. [PMID: 31411893 PMCID: PMC6879885 DOI: 10.1152/ajpgi.00089.2019] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Propulsion of luminal content along the gut requires coordinated contractions and relaxations of gastrointestinal smooth muscles controlled by the enteric nervous system. Activation of excitatory motor neurons (EMNs) causes muscle contractions, whereas inhibitory motor neuron (IMN) activation causes muscle relaxation. EMNs release acetylcholine (ACh), which acts at muscarinic receptors on smooth muscle cells and adjacent interstitial cells of Cajal, causing excitatory junction potentials (EJPs). IMNs release ATP (or another purine) and nitric oxide to cause inhibitory junction potentials (IJPs) and muscle relaxation. We used commercially available choline acetyltransferase (ChAT)-channelrhodopsin-2 (ChR2)-yellow fluorescent protein (YFP) bacterial artificial chromosome (BAC) transgenic mice, which express ChR2 in cholinergic neurons, to study cholinergic neuromuscular transmission in the colon. Intracellular microelectrodes were used to record IJPs and EJPs from circular muscle cells. We used blue light stimulation (BLS, 470 nm, 20 mW/mm2) and electrical field stimulation (EFS) to activate myenteric neurons. EFS evoked IJPs only, whereas BLS evoked EJPs and IJPs. Mecamylamine (10 µM, nicotinic cholinergic receptor antagonist) reduced BLS-evoked IJPs by 50% but had no effect on electrically evoked IJPs. MRS 2179 (10 µM, a P2Y1 receptor antagonist) blocked BLS-evoked IJPs. MRS 2179 and Nω-nitro-l-arginine (100 µM, nitric oxide synthase inhibitor) isolated the EJP, which was blocked by scopolamine (1 µM, muscarinic ACh receptor antagonist). Immunohistochemistry revealed ChAT expression in ~88% of enhanced YFP (eYFP)-expressing neurons, whereas 12% of eYFP neurons expressed nitric oxide synthase. These data show that cholinergic interneurons synapse with EMNs and IMNs to cause contraction and relaxation of colonic smooth muscle.NEW & NOTEWORTHY Electrical stimulation of interganglionic connectives has been used widely to study synaptic transmission in the enteric nervous system. However, electrical stimulation will activate many types of neurons and nerve fibers, which complicates data interpretation. Optogenetic activation of enteric neurons using genetically modified mice expressing channelrhodopsin-2 in cholinergic neurons offers a new approach that provides more specificity for nerve stimulation when studying myenteric plexus nerve circuitry.
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Affiliation(s)
| | - James J. Galligan
- 1Department of Pharmacology & Toxicology, Michigan State University, East Lansing, Michigan,2Neuroscience Program, Michigan State University, East Lansing, Michigan
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109
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Albers F, Wachsmuth L, Schache D, Lambers H, Faber C. Functional MRI Readouts From BOLD and Diffusion Measurements Differentially Respond to Optogenetic Activation and Tissue Heating. Front Neurosci 2019; 13:1104. [PMID: 31708721 PMCID: PMC6821691 DOI: 10.3389/fnins.2019.01104] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Accepted: 10/01/2019] [Indexed: 12/12/2022] Open
Abstract
Functional blood-oxygenation-level-dependent (BOLD) MRI provides a brain-wide readout that depends on the hemodynamic response to neuronal activity. Diffusion fMRI has been proposed as an alternative to BOLD fMRI and has been postulated to directly rely on neuronal activity. These complementary functional readouts are versatile tools to be combined with optogenetic stimulation to investigate networks of the brain. The cell-specificity and temporal precision of optogenetic manipulations promise to enable further investigation of the origin of fMRI signals. The signal characteristics of the diffusion fMRI readout vice versa may better resolve network effects of optogenetic stimulation. However, the light application needed for optogenetic stimulation is accompanied by heat deposition within the tissue. As both diffusion and BOLD are sensitive to temperature changes, light application can lead to apparent activations confounding the interpretation of fMRI data. The degree of tissue heating, the appearance of apparent activation in different fMRI sequences and the origin of these phenomena are not well understood. Here, we disentangled apparent activations in BOLD and diffusion measurements in rats from physiological activation upon sensory or optogenetic stimulation. Both, BOLD and diffusion fMRI revealed similar signal shapes upon sensory stimulation that differed clearly from those upon heating. Apparent activations induced by high-intensity light application were dominated by T2∗-effects and resulted in mainly negative signal changes. We estimated that even low-intensity light application used for optogenetic stimulation reduces the BOLD response close to the fiber by up to 0.4%. The diffusion fMRI signal contained T2, T2∗ and diffusion components. The apparent diffusion coefficient, which reflects the isolated diffusion component, showed negative changes upon both optogenetic and electric forepaw stimulation. In contrast, positive changes were detected upon high-intensity light application and thus ruled out heating as a major contributor to the diffusion fMRI signal.
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Affiliation(s)
- Franziska Albers
- Translational Research Imaging Center, Department of Clinical Radiology, University Hospital Münster, Münster, Germany
| | - Lydia Wachsmuth
- Translational Research Imaging Center, Department of Clinical Radiology, University Hospital Münster, Münster, Germany
| | - Daniel Schache
- Translational Research Imaging Center, Department of Clinical Radiology, University Hospital Münster, Münster, Germany
| | - Henriette Lambers
- Translational Research Imaging Center, Department of Clinical Radiology, University Hospital Münster, Münster, Germany
| | - Cornelius Faber
- Translational Research Imaging Center, Department of Clinical Radiology, University Hospital Münster, Münster, Germany
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110
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A customizable microfluidic platform for medium-throughput modeling of neuromuscular circuits. Biomaterials 2019; 225:119537. [PMID: 31614290 PMCID: PMC7294901 DOI: 10.1016/j.biomaterials.2019.119537] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 10/02/2019] [Accepted: 10/07/2019] [Indexed: 01/27/2023]
Abstract
Neuromuscular circuits (NMCs) are vital for voluntary movement, and effective models of NMCs are needed to understand the pathogenesis of, as well as to identify effective treatments for, multiple diseases, including Duchenne’s muscular dystrophy and amyotrophic lateral sclerosis. Microfluidics are ideal for recapitulating the central and peripheral compartments of NMCs, but myotubes often detach before functional NMCs are formed. In addition, microfluidic systems are often limited to a single experimental unit, which significantly limits their application in disease modeling and drug discovery. Here, we developed a microfluidic platform (MFP) containing over 100 experimental units, making it suitable for medium-throughput applications. To overcome detachment, we incorporated a reactive polymer surface allowing customization of the environment to culture different cell types. Using this approach, we identified conditions that enable long-term co-culture of human motor neurons and myotubes differentiated from human induced pluripotent stem cells inside our MFP. Optogenetics demonstrated the formation of functional NMCs. Furthermore, we developed a novel application of the rabies tracing assay to efficiently identify NMCs in our MFP. Therefore, our MFP enables large-scale generation and quantification of functional NMCs for disease modeling and pharmacological drug targeting.
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111
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Wrobel C, Dieter A, Huet A, Keppeler D, Duque-Afonso CJ, Vogl C, Hoch G, Jeschke M, Moser T. Optogenetic stimulation of cochlear neurons activates the auditory pathway and restores auditory-driven behavior in deaf adult gerbils. Sci Transl Med 2019; 10:10/449/eaao0540. [PMID: 29997248 DOI: 10.1126/scitranslmed.aao0540] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 11/17/2017] [Accepted: 06/19/2018] [Indexed: 12/26/2022]
Abstract
Cochlear implants partially restore hearing via direct electrical stimulation of spiral ganglion neurons (SGNs). However, spread of excitation from each electrode limits spectral coding. We explored the use of optogenetics to deliver spatially restricted and cell-specific excitation in the cochlea of adult Mongolian gerbils. Adeno-associated virus carrying the gene encoding the light-sensitive calcium translocating channelrhodopsin (CatCh) was injected into the cochlea of adult gerbils. SGNs in all cochlea turns showed stable and long-lasting CatCh expression, and electrophysiological recording from single SGNs showed that light stimulation up to few hundred Hertz induced neuronal firing. We characterized the light-induced activity in the auditory pathway by electrophysiological and behavioral analysis. Light- and sound-induced auditory brainstem responses showed similar kinetics and amplitude. In normal hearing adult gerbils, optical cochlear implants elicited stable optical auditory brainstem responses over a period of weeks. In normal hearing animals, light stimulation cued avoidance behavior that could be reproduced by subsequent acoustic stimulation, suggesting similar perception of light and acoustic stimuli. Neurons of the primary auditory cortex of normal hearing adult gerbils responded with changes in firing rates with increasing light intensity. In deaf adult gerbils, light stimulation generated auditory responses and cued avoidance behavior indicating partial restoration of auditory function. Our data show that optogenetic cochlear stimulation achieved good temporal fidelity with low light intensities in an adult rodent model, suggesting that optogenetics might be used to develop cochlear implants with improved restorative capabilities.
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Affiliation(s)
- Christian Wrobel
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, 37075 Göttingen, Germany.,Collaborative Research Center 889, University of Göttingen, 37075 Göttingen, Germany.,Department of Otorhinolaryngology, Head and Neck Surgery, Ruhr University Bochum, St. Elisabeth Hospital, 44787 Bochum, Germany
| | - Alexander Dieter
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, 37075 Göttingen, Germany.,Göttingen Graduate School for Neurosciences and Molecular Biosciences, University of Göttingen, 37075 Göttingen, Germany.,Auditory Neuroscience and Optogenetics Group, German Primate Center, 37077 Göttingen, Germany
| | - Antoine Huet
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, 37075 Göttingen, Germany.,Auditory Neuroscience and Optogenetics Group, German Primate Center, 37077 Göttingen, Germany
| | - Daniel Keppeler
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, 37075 Göttingen, Germany.,Göttingen Graduate School for Neurosciences and Molecular Biosciences, University of Göttingen, 37075 Göttingen, Germany
| | - Carlos J Duque-Afonso
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, 37075 Göttingen, Germany.,Göttingen Graduate School for Neurosciences and Molecular Biosciences, University of Göttingen, 37075 Göttingen, Germany
| | - Christian Vogl
- Collaborative Research Center 889, University of Göttingen, 37075 Göttingen, Germany.,Presynaptogenesis and Intracellular Transport in Hair Cells Group, Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, 37075 Göttingen, Germany
| | - Gerhard Hoch
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, 37075 Göttingen, Germany.,Collaborative Research Center 889, University of Göttingen, 37075 Göttingen, Germany.,Auditory Neuroscience and Optogenetics Group, German Primate Center, 37077 Göttingen, Germany
| | - Marcus Jeschke
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, 37075 Göttingen, Germany. .,Auditory Neuroscience and Optogenetics Group, German Primate Center, 37077 Göttingen, Germany
| | - Tobias Moser
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, 37075 Göttingen, Germany. .,Collaborative Research Center 889, University of Göttingen, 37075 Göttingen, Germany.,Göttingen Graduate School for Neurosciences and Molecular Biosciences, University of Göttingen, 37075 Göttingen, Germany.,Auditory Neuroscience and Optogenetics Group, German Primate Center, 37077 Göttingen, Germany.,Bernstein Center for Computational Neuroscience, University of Göttingen, 37077 Göttingen, Germany.,Center for Nanoscale Microscopy and Molecular Physiology of the Brain, University of Göttingen, 37075 Göttingen, Germany
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112
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Ferenczi EA, Tan X, Huang CLH. Principles of Optogenetic Methods and Their Application to Cardiac Experimental Systems. Front Physiol 2019; 10:1096. [PMID: 31572204 PMCID: PMC6749684 DOI: 10.3389/fphys.2019.01096] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Accepted: 08/08/2019] [Indexed: 12/12/2022] Open
Abstract
Optogenetic techniques permit studies of excitable tissue through genetically expressed light-gated microbial channels or pumps permitting transmembrane ion movement. Light activation of these proteins modulates cellular excitability with millisecond precision. This review summarizes optogenetic approaches, using examples from neurobiological applications, and then explores their application in cardiac electrophysiology. We review the available opsins, including depolarizing and hyperpolarizing variants, as well as modulators of G-protein coupled intracellular signaling. We discuss the biophysical properties that determine the ability of microbial opsins to evoke reliable, precise stimulation or silencing of electrophysiological activity. We also review spectrally shifted variants offering possibilities for enhanced depth of tissue penetration, combinatorial stimulation for targeting different cell subpopulations, or all-optical read-in and read-out studies. Expression of the chosen optogenetic tool in the cardiac cell of interest then requires, at the single-cell level, introduction of opsin-encoding genes by viral transduction, or coupling "spark cells" to primary cardiomyocytes or a stem-cell derived counterpart. At the system-level, this requires construction of transgenic mice expressing ChR2 in their cardiomyocytes, or in vivo injection (myocardial or systemic) of adenoviral expression systems. Light delivery, by laser or LED, with widespread or multipoint illumination, although relatively straightforward in vitro may be technically challenged by cardiac motion and light-scattering in biological tissue. Physiological read outs from cardiac optogenetic stimulation include single cell patch clamp recordings, multi-unit microarray recordings from cell monolayers or slices, and electrical recordings from isolated Langendorff perfused hearts. Optical readouts of specific cellular events, including ion transients, voltage changes or activity in biochemical signaling cascades, using small detecting molecules or genetically encoded sensors now offer powerful opportunities for all-optical control and monitoring of cellular activity. Use of optogenetics has expanded in cardiac physiology, mainly using optically controlled depolarizing ion channels to control heart rate and for optogenetic defibrillation. ChR2-expressing cardiomyocytes show normal baseline and active excitable membrane and Ca2+ signaling properties and are sensitive even to ~1 ms light pulses. They have been employed in studies of the intrinsic cardiac adrenergic system and of cardiac arrhythmic properties.
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Affiliation(s)
- Emily A. Ferenczi
- Department of Neurology, Massachusetts General Hospital and Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States
| | - Xiaoqiu Tan
- Key Laboratory of Medical Electrophysiology, Ministry of Education and Medical Electrophysiological Key Laboratory of Sichuan Province, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, China
| | - Christopher L.-H. Huang
- Physiological Laboratory, University of Cambridge, Cambridge, United Kingdom
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
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113
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Abstract
We previously reported a cation channelrhodopsin, Gt_CCR4, which is one of the 44 types of microbial rhodopsins from a cryptophyte flagellate, Guillardia theta. Due to the modest homology of amino acid sequences with a chlorophyte channelrhodopsin such as Cr_ChR2 from Chlamydomonas reinhardtii, it has been proposed that a family of cryptophyte channelrhodopsin, including Gt_CCR4, has a distinct molecular mechanism for channel gating and ion permeation. In this study, we compared the photocurrent properties, cation selectivity and kinetics between well-known Cr_ChR2 and Gt_CCR4 by a conventional path clamp method. Large and stable light-induced cation conduction by Gt_CCR4 at the maximum absorbing wavelength (530 nm) was observed with only small inactivation (15%), whereas the photocurrent of Cr_ChR2 exhibited significant inactivation (50%) and desensitization. The light sensitivity of Gt_CCR4 was higher (EC50 = 0.13 mW/mm2) than that of Cr_ChR2 (EC50 = 0.80 mW/mm2) while the channel open life time (photocycle speed) was in the same range as that of Cr_ChR2 (25~30 ms for Gt_CCR4 and 10~15 ms for Cr_ChR2). This observation implies that Gt_CCR4 enables optical neuronal spiking with weak light in high temporal resolution when applied in neuroscience. Furthermore, we demonstrated high Na+ selectivity of Gt_CCR4 in which the selectivity ratio for Na+ was 37-fold larger than that for Cr_ChR2, which primarily conducts H+. On the other hand, Gt_CCR4 conducted almost no H+ and no Ca2+ under physiological conditions. These results suggest that ion selectivity in Gt_CCR4 is distinct from that in Cr_ChR2. In addition, a unique red-absorbing and stable intermediate in the photocycle was observed, indicating a photochromic property of Gt_CCR4.
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114
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Jüttner J, Szabo A, Gross-Scherf B, Morikawa RK, Rompani SB, Hantz P, Szikra T, Esposti F, Cowan CS, Bharioke A, Patino-Alvarez CP, Keles Ö, Kusnyerik A, Azoulay T, Hartl D, Krebs AR, Schübeler D, Hajdu RI, Lukats A, Nemeth J, Nagy ZZ, Wu KC, Wu RH, Xiang L, Fang XL, Jin ZB, Goldblum D, Hasler PW, Scholl HPN, Krol J, Roska B. Targeting neuronal and glial cell types with synthetic promoter AAVs in mice, non-human primates and humans. Nat Neurosci 2019; 22:1345-1356. [PMID: 31285614 DOI: 10.1038/s41593-019-0431-2] [Citation(s) in RCA: 111] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 05/17/2019] [Indexed: 01/20/2023]
Abstract
Targeting genes to specific neuronal or glial cell types is valuable for both understanding and repairing brain circuits. Adeno-associated viruses (AAVs) are frequently used for gene delivery, but targeting expression to specific cell types is an unsolved problem. We created a library of 230 AAVs, each with a different synthetic promoter designed using four independent strategies. We show that a number of these AAVs specifically target expression to neuronal and glial cell types in the mouse and non-human primate retina in vivo and in the human retina in vitro. We demonstrate applications for recording and stimulation, as well as the intersectional and combinatorial labeling of cell types. These resources and approaches allow economic, fast and efficient cell-type targeting in a variety of species, both for fundamental science and for gene therapy.
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Affiliation(s)
- Josephine Jüttner
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Arnold Szabo
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, Hungary
| | - Brigitte Gross-Scherf
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Rei K Morikawa
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Santiago B Rompani
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
- Epigenetics and Neurobiology Unit, European Molecular Biology Laboratory, Monterotondo, Italy
| | - Peter Hantz
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
- Department of Laboratory Medicine, Medical School, University of Pécs, Pécs, Hungary
| | - Tamas Szikra
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Federico Esposti
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
- Division of Neuroscience, San Raffaele Research Institute, Università Vita-Salute San Raffaele, Milan, Italy
| | - Cameron S Cowan
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Arjun Bharioke
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Claudia P Patino-Alvarez
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Özkan Keles
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Akos Kusnyerik
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | | | - Dominik Hartl
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Arnaud R Krebs
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
- Genome Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Dirk Schübeler
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
- Faculty of Science, University of Basel, Basel, Switzerland
| | - Rozina I Hajdu
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - Akos Lukats
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, Hungary
| | - Janos Nemeth
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - Zoltan Z Nagy
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - Kun-Chao Wu
- Laboratory for Stem Cell and Retinal Regeneration, Institute of Stem Cell Research, Division of Ophthalmic Genetics, The Eye Hospital, Wenzhou Medical University, State Key Laboratory of Ophthalmology, Optometry and Visual Science, National International Joint Research Center for Regenerative Medicine and Neurogenetics, Wenzhou, China
| | - Rong-Han Wu
- Laboratory for Stem Cell and Retinal Regeneration, Institute of Stem Cell Research, Division of Ophthalmic Genetics, The Eye Hospital, Wenzhou Medical University, State Key Laboratory of Ophthalmology, Optometry and Visual Science, National International Joint Research Center for Regenerative Medicine and Neurogenetics, Wenzhou, China
| | - Lue Xiang
- Laboratory for Stem Cell and Retinal Regeneration, Institute of Stem Cell Research, Division of Ophthalmic Genetics, The Eye Hospital, Wenzhou Medical University, State Key Laboratory of Ophthalmology, Optometry and Visual Science, National International Joint Research Center for Regenerative Medicine and Neurogenetics, Wenzhou, China
| | - Xiao-Long Fang
- Laboratory for Stem Cell and Retinal Regeneration, Institute of Stem Cell Research, Division of Ophthalmic Genetics, The Eye Hospital, Wenzhou Medical University, State Key Laboratory of Ophthalmology, Optometry and Visual Science, National International Joint Research Center for Regenerative Medicine and Neurogenetics, Wenzhou, China
| | - Zi-Bing Jin
- Laboratory for Stem Cell and Retinal Regeneration, Institute of Stem Cell Research, Division of Ophthalmic Genetics, The Eye Hospital, Wenzhou Medical University, State Key Laboratory of Ophthalmology, Optometry and Visual Science, National International Joint Research Center for Regenerative Medicine and Neurogenetics, Wenzhou, China
| | - David Goldblum
- Department of Ophthalmology, University Hospital Basel, Basel, Switzerland
| | - Pascal W Hasler
- Department of Ophthalmology, University Hospital Basel, Basel, Switzerland
| | - Hendrik P N Scholl
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland
- Department of Ophthalmology, University Hospital Basel, Basel, Switzerland
- Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USA
| | - Jacek Krol
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland.
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland.
| | - Botond Roska
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland.
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland.
- Department of Ophthalmology, University Hospital Basel, Basel, Switzerland.
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115
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Dombrowski T, Rankovic V, Moser T. Toward the Optical Cochlear Implant. Cold Spring Harb Perspect Med 2019; 9:cshperspect.a033225. [PMID: 30323016 DOI: 10.1101/cshperspect.a033225] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
When hearing fails, cochlear implants (CIs) provide open speech perception to most of the currently half a million CI users. CIs bypass the defective sensory organ and stimulate the auditory nerve electrically. The major bottleneck of current CIs is the poor coding of spectral information, which results from wide current spread from each electrode contact. As light can be more conveniently confined, optical stimulation of the auditory nerve presents a promising perspective for a fundamental advance of CIs. Moreover, given the improved frequency resolution of optical excitation and its versatility for arbitrary stimulation patterns the approach also bears potential for auditory research. Here, we review the current state of the art focusing on the emerging concept of optogenetic stimulation of the auditory pathway. Developing optogenetic stimulation for auditory research and future CIs requires efforts toward viral gene transfer to the neurons, design and characterization of appropriate optogenetic actuators, as well as engineering of multichannel optical implants.
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Affiliation(s)
- Tobias Dombrowski
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center, 37075 Göttingen, Germany.,Department of Otorhinolaryngology, Head and Neck Surgery, Ruhr University Bochum, St. Elisabeth Hospital, 44787 Bochum, Germany
| | - Vladan Rankovic
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center, 37075 Göttingen, Germany.,Auditory Neuroscience and Optogenetics Group, German Primate Center, 37077 Göttingen, Germany
| | - Tobias Moser
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center, 37075 Göttingen, Germany.,Auditory Neuroscience and Optogenetics Group, German Primate Center, 37077 Göttingen, Germany.,Auditory Neuroscience Group, Max-Planck-Institute for Experimental Medicine, 37075 Göttingen, Germany
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116
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Callahan RA, Roberts R, Sengupta M, Kimura Y, Higashijima SI, Bagnall MW. Spinal V2b neurons reveal a role for ipsilateral inhibition in speed control. eLife 2019; 8:e47837. [PMID: 31355747 PMCID: PMC6701946 DOI: 10.7554/elife.47837] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2019] [Accepted: 07/26/2019] [Indexed: 12/22/2022] Open
Abstract
The spinal cord contains a diverse array of interneurons that govern motor output. Traditionally, models of spinal circuits have emphasized the role of inhibition in enforcing reciprocal alternation between left and right sides or flexors and extensors. However, recent work has shown that inhibition also increases coincident with excitation during contraction. Here, using larval zebrafish, we investigate the V2b (Gata3+) class of neurons, which contribute to flexor-extensor alternation but are otherwise poorly understood. Using newly generated transgenic lines we define two stable subclasses with distinct neurotransmitter and morphological properties. These V2b subclasses synapse directly onto motor neurons with differential targeting to speed-specific circuits. In vivo, optogenetic manipulation of V2b activity modulates locomotor frequency: suppressing V2b neurons elicits faster locomotion, whereas activating V2b neurons slows locomotion. We conclude that V2b neurons serve as a brake on axial motor circuits. Together, these results indicate a role for ipsilateral inhibition in speed control.
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Affiliation(s)
- Rebecca A Callahan
- Department of NeuroscienceWashington University School of MedicineSt LouisUnited States
| | - Richard Roberts
- Department of NeuroscienceWashington University School of MedicineSt LouisUnited States
| | - Mohini Sengupta
- Department of NeuroscienceWashington University School of MedicineSt LouisUnited States
| | | | | | - Martha W Bagnall
- Department of NeuroscienceWashington University School of MedicineSt LouisUnited States
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117
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Hyung S, Lee S, Kim YJ, Bang S, Tahk D, Park J, Suh JF, Jeon NL. Optogenetic neuronal stimulation promotes axon outgrowth and myelination of motor neurons in a three‐dimensional motor neuron–Schwann cell coculture model on a microfluidic biochip. Biotechnol Bioeng 2019; 116:2425-2438. [DOI: 10.1002/bit.27083] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 05/02/2019] [Accepted: 06/06/2019] [Indexed: 12/21/2022]
Affiliation(s)
- Sujin Hyung
- Center for BionicsKorea Institute of Science and Technology Seoul South Korea
- BK21 Plus Transformative Training Program for Creative Mechanical and Aerospace EngineersSeoul National University Seoul South Korea
- Multiscale Mechanical Design School of Mechanical and Aerospace Engineering, Institute of Advanced Machinery and DesignSeoul National University Seoul South Korea
| | - Seung‐Ryeol Lee
- Multiscale Mechanical Design School of Mechanical and Aerospace Engineering, Institute of Advanced Machinery and DesignSeoul National University Seoul South Korea
| | - Yeon Jee Kim
- Center for BionicsKorea Institute of Science and Technology Seoul South Korea
| | - Seokyoung Bang
- Multiscale Mechanical Design School of Mechanical and Aerospace Engineering, Institute of Advanced Machinery and DesignSeoul National University Seoul South Korea
| | - Dongha Tahk
- Multiscale Mechanical Design School of Mechanical and Aerospace Engineering, Institute of Advanced Machinery and DesignSeoul National University Seoul South Korea
| | - Jong‐Chul Park
- Department of Medical Engineering and Brain Korea 21 PLUS Project for Medical ScienceYonsei University College of Medicine Seoul South Korea
| | - Jun‐Kyo Francis Suh
- Center for BionicsKorea Institute of Science and Technology Seoul South Korea
| | - Noo Li Jeon
- Multiscale Mechanical Design School of Mechanical and Aerospace Engineering, Institute of Advanced Machinery and DesignSeoul National University Seoul South Korea
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118
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Jiang C, Li HT, Zhou YM, Wang X, Wang L, Liu ZQ. Cardiac optogenetics: a novel approach to cardiovascular disease therapy. Europace 2019; 20:1741-1749. [PMID: 29253159 DOI: 10.1093/europace/eux345] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Accepted: 10/24/2017] [Indexed: 12/13/2022] Open
Abstract
Optogenetics is a cell-type specific and high spatial-temporal resolution method that combines genetic encoding of light-sensitive proteins and optical manipulation techniques. Optogenetics technology provides a novel approach for research on cardiac arrhythmia treatment, including pacing, recovering the conduction system, and achieving cardiac resynchronization with precise and low-energy optical control. Photosensitive proteins, which usually act as ion channels, pumps, or receptors, are delivered to target cells, where they respond to light pulses of specific wavelengths, evoke transient flows of transmembrane ion currents, and induce signal transmission. With the development of gene technology, the in vivo efficiency of optogenetics in cardiology has been trialed, and in vitro experiments have been performed to test its potential in cardiac electrophysiology. Challenges for applying optogenetics in large animals and humans include the effectiveness, safety, and long-term expression of photosensitive proteins, unscattered and unattenuated exogenous light stimulation, and the need for implantable miniature light stimulators. Photosensitive proteins, genetic engineering technology, and light equipment are essential for experiments in cardiac optogenetics. Optogenetics may provide an alternative method for evaluating the mechanism of cardiac arrhythmias, testing hypotheses, and treating cardiovascular diseases.
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Affiliation(s)
- Chan Jiang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, PR China.,Cardiovascular Research Institute, Wuhan University, Wuhan, PR China.,Hubei Key Laboratory of Cardiology, Wuhan, PR China
| | - Hai Tao Li
- Department of Cardiology, Hainan General Hospital, Haikou, PR China
| | - Yong Ming Zhou
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, PR China.,Cardiovascular Research Institute, Wuhan University, Wuhan, PR China.,Hubei Key Laboratory of Cardiology, Wuhan, PR China
| | - Xi Wang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, PR China.,Cardiovascular Research Institute, Wuhan University, Wuhan, PR China.,Hubei Key Laboratory of Cardiology, Wuhan, PR China
| | - Long Wang
- Cardiovascular Research Institute, Wuhan University, Wuhan, PR China.,Hubei Key Laboratory of Cardiology, Wuhan, PR China.,Department of Anesthesiology, Renmin Hospital of Wuhan University, Wuhan, PR China
| | - Zi Qiang Liu
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, PR China.,Cardiovascular Research Institute, Wuhan University, Wuhan, PR China.,Hubei Key Laboratory of Cardiology, Wuhan, PR China
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119
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Zaglia T, Di Bona A, Mongillo M. A Light Wand to Untangle the Myocardial Cell Network. Methods Protoc 2019; 2:E34. [PMID: 31164614 PMCID: PMC6632158 DOI: 10.3390/mps2020034] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 04/24/2019] [Accepted: 04/28/2019] [Indexed: 12/30/2022] Open
Abstract
The discovery of optogenetics has revolutionized research in neuroscience by providing the tools for noninvasive, cell-type selective modulation of membrane potential and cellular function in vitro and in vivo. Rhodopsin-based optogenetics has later been introduced in experimental cardiology studies and used as a tool to photoactivate cardiac contractions or to identify the sites, timing, and location most effective for defibrillating impulses to interrupt cardiac arrhythmias. The exploitation of cell-selectivity of optogenetics, and the generation of model organisms with myocardial cell type targeted expression of opsins has started to yield novel and sometimes unexpected notions on myocardial biology. This review summarizes the main results, the different uses, and the prospective developments of cardiac optogenetics.
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Affiliation(s)
- Tania Zaglia
- Department of Cardiac, Thoracic, Vascular Sciences and Public Health, University of Padova, via Giustiniani 2, 35128 Padova, Italy.
- Department of Biomedical Sciences, University of Padova, Via Ugo Bassi 58/B, 35122 Padova, Italy.
- Veneto Institute of Molecular Medicine, Via Orus 2, 35129 Padova, Italy.
| | - Anna Di Bona
- Department of Cardiac, Thoracic, Vascular Sciences and Public Health, University of Padova, via Giustiniani 2, 35128 Padova, Italy.
- Veneto Institute of Molecular Medicine, Via Orus 2, 35129 Padova, Italy.
| | - Marco Mongillo
- Department of Cardiac, Thoracic, Vascular Sciences and Public Health, University of Padova, via Giustiniani 2, 35128 Padova, Italy.
- Department of Biomedical Sciences, University of Padova, Via Ugo Bassi 58/B, 35122 Padova, Italy.
- CNR Institute of Neuroscience, Viale G. Colombo 3, 35121 Padova, Italy.
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120
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Ganjawala TH, Lu Q, Fenner MD, Abrams GW, Pan ZH. Improved CoChR Variants Restore Visual Acuity and Contrast Sensitivity in a Mouse Model of Blindness under Ambient Light Conditions. Mol Ther 2019; 27:1195-1205. [PMID: 31010741 DOI: 10.1016/j.ymthe.2019.04.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 04/03/2019] [Accepted: 04/03/2019] [Indexed: 11/15/2022] Open
Abstract
Severe photoreceptor cell death in retinal degenerative diseases leads to partial or complete blindness. Optogenetics is a promising strategy to treat blindness. The feasibility of this strategy has been demonstrated through the ectopic expression of microbial channelrhodopsins (ChRs) and other genetically encoded light sensors in surviving retinal neurons in animal models. A major drawback for ChR-based visual restoration is low light sensitivity. Here, we report the development of highly operational light-sensitive ChRs by optimizing the kinetics of a recently reported ChR variant, Chloromonas oogama (CoChR). In particular, we identified two CoChR mutants, CoChR-L112C and CoChR-H94E/L112C/K264T, with markedly enhanced light sensitivity. The improved light sensitivity of the CoChR mutants was confirmed by ex vivo electrophysiological recordings in the retina. Furthermore, the CoChR mutants restored the vision of a blind mouse model under ambient light conditions with remarkably good contrast sensitivity and visual acuity, as evidenced by the results of behavioral assays. The ability to restore functional vision under normal light conditions with the improved CoChR variants removed a major obstacle for ChR-based optogenetic vision restoration.
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Affiliation(s)
- Tushar H Ganjawala
- Department of Ophthalmology, Visual and Anatomical Sciences, Kresge Eye Institute, Wayne State University School of Medicine, Detroit, MI, USA
| | - Qi Lu
- Department of Ophthalmology, Visual and Anatomical Sciences, Kresge Eye Institute, Wayne State University School of Medicine, Detroit, MI, USA
| | - Mitchell D Fenner
- Department of Ophthalmology, Visual and Anatomical Sciences, Kresge Eye Institute, Wayne State University School of Medicine, Detroit, MI, USA
| | - Gary W Abrams
- Department of Ophthalmology, Visual and Anatomical Sciences, Kresge Eye Institute, Wayne State University School of Medicine, Detroit, MI, USA
| | - Zhuo-Hua Pan
- Department of Ophthalmology, Visual and Anatomical Sciences, Kresge Eye Institute, Wayne State University School of Medicine, Detroit, MI, USA.
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121
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Daigle TL, Madisen L, Hage TA, Valley MT, Knoblich U, Larsen RS, Takeno MM, Huang L, Gu H, Larsen R, Mills M, Bosma-Moody A, Siverts LA, Walker M, Graybuck LT, Yao Z, Fong O, Nguyen TN, Garren E, Lenz GH, Chavarha M, Pendergraft J, Harrington J, Hirokawa KE, Harris JA, Nicovich PR, McGraw MJ, Ollerenshaw DR, Smith KA, Baker CA, Ting JT, Sunkin SM, Lecoq J, Lin MZ, Boyden ES, Murphy GJ, da Costa NM, Waters J, Li L, Tasic B, Zeng H. A Suite of Transgenic Driver and Reporter Mouse Lines with Enhanced Brain-Cell-Type Targeting and Functionality. Cell 2019; 174:465-480.e22. [PMID: 30007418 DOI: 10.1016/j.cell.2018.06.035] [Citation(s) in RCA: 450] [Impact Index Per Article: 90.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 04/12/2018] [Accepted: 06/13/2018] [Indexed: 01/05/2023]
Abstract
Modern genetic approaches are powerful in providing access to diverse cell types in the brain and facilitating the study of their function. Here, we report a large set of driver and reporter transgenic mouse lines, including 23 new driver lines targeting a variety of cortical and subcortical cell populations and 26 new reporter lines expressing an array of molecular tools. In particular, we describe the TIGRE2.0 transgenic platform and introduce Cre-dependent reporter lines that enable optical physiology, optogenetics, and sparse labeling of genetically defined cell populations. TIGRE2.0 reporters broke the barrier in transgene expression level of single-copy targeted-insertion transgenesis in a wide range of neuronal types, along with additional advantage of a simplified breeding strategy compared to our first-generation TIGRE lines. These novel transgenic lines greatly expand the repertoire of high-precision genetic tools available to effectively identify, monitor, and manipulate distinct cell types in the mouse brain.
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Affiliation(s)
- Tanya L Daigle
- Allen Institute for Brain Science, Seattle, WA 98109, USA
| | - Linda Madisen
- Allen Institute for Brain Science, Seattle, WA 98109, USA
| | - Travis A Hage
- Allen Institute for Brain Science, Seattle, WA 98109, USA
| | | | - Ulf Knoblich
- Allen Institute for Brain Science, Seattle, WA 98109, USA
| | - Rylan S Larsen
- Allen Institute for Brain Science, Seattle, WA 98109, USA
| | - Marc M Takeno
- Allen Institute for Brain Science, Seattle, WA 98109, USA
| | - Lawrence Huang
- Allen Institute for Brain Science, Seattle, WA 98109, USA
| | - Hong Gu
- Allen Institute for Brain Science, Seattle, WA 98109, USA
| | - Rachael Larsen
- Allen Institute for Brain Science, Seattle, WA 98109, USA
| | - Maya Mills
- Allen Institute for Brain Science, Seattle, WA 98109, USA
| | | | | | - Miranda Walker
- Allen Institute for Brain Science, Seattle, WA 98109, USA
| | | | - Zizhen Yao
- Allen Institute for Brain Science, Seattle, WA 98109, USA
| | - Olivia Fong
- Allen Institute for Brain Science, Seattle, WA 98109, USA
| | | | - Emma Garren
- Allen Institute for Brain Science, Seattle, WA 98109, USA
| | - Garreck H Lenz
- Allen Institute for Brain Science, Seattle, WA 98109, USA
| | - Mariya Chavarha
- Departments of Neurobiology and Bioengineering, Stanford University School of Medicine, Stanford, CA 94305, USA
| | | | | | | | - Julie A Harris
- Allen Institute for Brain Science, Seattle, WA 98109, USA
| | | | - Medea J McGraw
- Allen Institute for Brain Science, Seattle, WA 98109, USA
| | | | | | | | | | - Susan M Sunkin
- Allen Institute for Brain Science, Seattle, WA 98109, USA
| | - Jérôme Lecoq
- Allen Institute for Brain Science, Seattle, WA 98109, USA
| | - Michael Z Lin
- Departments of Neurobiology and Bioengineering, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Edward S Boyden
- MIT Media Lab and McGovern Institute, Departments of Biological Engineering and Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Gabe J Murphy
- Allen Institute for Brain Science, Seattle, WA 98109, USA
| | | | - Jack Waters
- Allen Institute for Brain Science, Seattle, WA 98109, USA
| | - Lu Li
- Allen Institute for Brain Science, Seattle, WA 98109, USA
| | - Bosiljka Tasic
- Allen Institute for Brain Science, Seattle, WA 98109, USA
| | - Hongkui Zeng
- Allen Institute for Brain Science, Seattle, WA 98109, USA.
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122
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O’Shea C, Holmes AP, Winter J, Correia J, Ou X, Dong R, He S, Kirchhof P, Fabritz L, Rajpoot K, Pavlovic D. Cardiac Optogenetics and Optical Mapping - Overcoming Spectral Congestion in All-Optical Cardiac Electrophysiology. Front Physiol 2019; 10:182. [PMID: 30899227 PMCID: PMC6416196 DOI: 10.3389/fphys.2019.00182] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2018] [Accepted: 02/14/2019] [Indexed: 12/30/2022] Open
Abstract
Optogenetic control of the heart is an emergent technology that offers unparalleled spatio-temporal control of cardiac dynamics via light-sensitive ion pumps and channels (opsins). This fast-evolving technique holds broad scope in both clinical and basic research setting. Combination of optogenetics with optical mapping of voltage or calcium fluorescent probes facilitates 'all-optical' electrophysiology, allowing precise optogenetic actuation of cardiac tissue with high spatio-temporal resolution imaging of action potential and calcium transient morphology and conduction patterns. In this review, we provide a synopsis of optogenetics and discuss in detail its use and compatibility with optical interrogation of cardiac electrophysiology. We briefly discuss the benefits of all-optical cardiac control and electrophysiological interrogation compared to traditional techniques, and describe mechanisms, unique features and limitations of optically induced cardiac control. In particular, we focus on state-of-the-art setup design, challenges in light delivery and filtering, and compatibility of opsins with fluorescent reporters used in optical mapping. The interaction of cardiac tissue with light, and physical and computational approaches to overcome the 'spectral congestion' that arises from the combination of optogenetics and optical mapping are discussed. Finally, we summarize recent preclinical work applications of combined cardiac optogenetics and optical mapping approach.
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Affiliation(s)
- Christopher O’Shea
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, United Kingdom
- School of Computer Science, University of Birmingham, Birmingham, United Kingdom
- EPSRC Centre for Doctoral Training in Physical Sciences for Health, School of Chemistry, University of Birmingham, Birmingham, United Kingdom
| | - Andrew P. Holmes
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, United Kingdom
- Institute of Clinical Sciences, University of Birmingham, Birmingham, United Kingdom
| | - James Winter
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Joao Correia
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Xianhong Ou
- Key Laboratory of Medical Electrophysiology of Ministry of Education, Collaborative Innovation Center for Prevention and Treatment of Cardiovascular Disease/Institute of Cardiovascular Research, Southwest Medical University, Luzhou, China
| | - Ruirui Dong
- Key Laboratory of Medical Electrophysiology of Ministry of Education, Collaborative Innovation Center for Prevention and Treatment of Cardiovascular Disease/Institute of Cardiovascular Research, Southwest Medical University, Luzhou, China
| | - Shicheng He
- Key Laboratory of Medical Electrophysiology of Ministry of Education, Collaborative Innovation Center for Prevention and Treatment of Cardiovascular Disease/Institute of Cardiovascular Research, Southwest Medical University, Luzhou, China
| | - Paulus Kirchhof
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, United Kingdom
- Department of Cardiology, UHB NHS Trust, Birmingham, United Kingdom
| | - Larissa Fabritz
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, United Kingdom
- Department of Cardiology, UHB NHS Trust, Birmingham, United Kingdom
| | - Kashif Rajpoot
- School of Computer Science, University of Birmingham, Birmingham, United Kingdom
| | - Davor Pavlovic
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, United Kingdom
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123
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Jung K, Park JH, Kim SY, Jeon NL, Cho SR, Hyung S. Optogenetic stimulation promotes Schwann cell proliferation, differentiation, and myelination in vitro. Sci Rep 2019; 9:3487. [PMID: 30837563 PMCID: PMC6401157 DOI: 10.1038/s41598-019-40173-w] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 01/24/2019] [Indexed: 11/18/2022] Open
Abstract
Schwann cells (SCs) constitute a crucial element of the peripheral nervous system, by structurally supporting the formation of myelin and conveying vital trophic factors to the nervous system. However, the functions of SCs in developmental and regenerative stages remain unclear. Here, we investigated how optogenetic stimulation (OS) of SCs regulates their development. In SC monoculture, OS substantially enhanced SC proliferation and the number of BrdU+-S100ß+-SCs over time. In addition, OS also markedly promoted the expression of both Krox20 and myelin basic protein (MBP) in SC culture medium containing dBcAMP/NRG1, which induced differentiation. We found that the effects of OS are dependent on the intracellular Ca2+ level. OS induces elevated intracellular Ca2+ levels through the T-type voltage-gated calcium channel (VGCC) and mobilization of Ca2+ from both inositol 1,4,5-trisphosphate (IP3)-sensitive stores and caffeine/ryanodine-sensitive stores. Furthermore, we confirmed that OS significantly increased expression levels of both Krox20 and MBP in SC-motor neuron (MN) coculture, which was notably prevented by pharmacological intervention with Ca2+. Taken together, our results demonstrate that OS of SCs increases the intracellular Ca2+ level and can regulate proliferation, differentiation, and myelination, suggesting that OS of SCs may offer a new approach to the treatment of neurodegenerative disorders.
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Affiliation(s)
- Kyuhwan Jung
- Graduate Program of Nano Science and Technology, Graduate School of Yonsei University, Seoul, Korea
| | - Ji Hye Park
- Gradaute Program of Translational Neuroscience, Institute for Clinical Neurobiology, University of Wuerzburg, Wuerzburg, Germany
| | - Sung-Yon Kim
- Department of Biophysics and Chemical Biology, Seoul National University, Seoul, South Korea
| | - Noo Li Jeon
- Multiscale Mechanical Design School of Mechanical and Aerospace Engineering Institute of Advanced Machinery and Design, Seoul National University, Seoul, Korea. .,Institute of Bioengineering, Seoul National University, Seoul, Korea.
| | - Sung-Rae Cho
- Graduate Program of Nano Science and Technology, Graduate School of Yonsei University, Seoul, Korea. .,Department and Research Institute of Rehabilitation Medicine, Yonsei University College of Medicine, Seoul, Korea.
| | - Sujin Hyung
- Multiscale Mechanical Design School of Mechanical and Aerospace Engineering Institute of Advanced Machinery and Design, Seoul National University, Seoul, Korea. .,BK21 Plus Transformative Training Program for Creative Mechanical and Aerospace Engineers, Seoul National University, Seoul, Korea. .,Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, USA.
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124
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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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125
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Mutated Channelrhodopsins with Increased Sodium and Calcium Permeability. APPLIED SCIENCES-BASEL 2019. [DOI: 10.3390/app9040664] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
(1) Background: After the discovery and application of Chlamydomonas reinhardtii channelrhodopsins, the optogenetic toolbox has been greatly expanded with engineered and newly discovered natural channelrhodopsins. However, channelrhodopsins of higher Ca2+ conductance or more specific ion permeability are in demand. (2) Methods: In this study, we mutated the conserved aspartate of the transmembrane helix 4 (TM4) within Chronos and PsChR and compared them with published ChR2 aspartate mutants. (3) Results: We found that the ChR2 D156H mutant (XXM) showed enhanced Na+ and Ca2+ conductance, which was not noticed before, while the D156C mutation (XXL) influenced the Na+ and Ca2+ conductance only slightly. The aspartate to histidine and cysteine mutations of Chronos and PsChR also influenced their photocurrent, ion permeability, kinetics, and light sensitivity. Most interestingly, PsChR D139H showed a much-improved photocurrent, compared to wild type, and even higher Na+ selectivity to H+ than XXM. PsChR D139H also showed a strongly enhanced Ca2+ conductance, more than two-fold that of the CatCh. (4) Conclusions: We found that mutating the aspartate of the TM4 influences the ion selectivity of channelrhodopsins. With the large photocurrent and enhanced Na+ selectivity and Ca2+ conductance, XXM and PsChR D139H are promising powerful optogenetic tools, especially for Ca2+ manipulation.
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126
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Cho YK, Park D, Yang A, Chen F, Chuong AS, Klapoetke NC, Boyden ES. Multidimensional screening yields channelrhodopsin variants having improved photocurrent and order-of-magnitude reductions in calcium and proton currents. J Biol Chem 2019; 294:3806-3821. [PMID: 30610117 DOI: 10.1074/jbc.ra118.006996] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Indexed: 12/21/2022] Open
Abstract
Channelrhodopsins (ChRs) are light-gated ion channels in widespread use in neuroscience for mediating the genetically targetable optical control of neurons (optogenetics). ChRs pass multiple kinds of ions, and although nonspecific ChR-mediated conductance is not an issue in many neuroscience studies, conductance of calcium and protons, which can mediate diverse cellular signals, may be undesirable in some instances. Here, we turned our attention to the creation of ChRs that have high cation photocurrent but pass fewer calcium ions and protons. We developed an automated, time-resolved screening method capable of rapidly phenotyping channelrhodopsin-2 (ChR2) variants. We found substitution mutations throughout ChR2 that could boost current while altering ion selectivity and observed that the mutations that reduced calcium or proton conductance have additive effects. By combining four mutations, we obtained a ChR, ChromeQ, with improved photocurrent that possesses order-of-magnitude reductions in calcium and proton conductance and high fidelity in driving repetitive action potentials in neurons. The approach presented here offers a viable pathway toward customization of complex physiological properties of optogenetic tools. We propose that our screening method not only enables elucidation of new ChR variants that affect microbial opsin performance but may also reveal new principles of optogenetic protein engineering.
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Affiliation(s)
- Yong Ku Cho
- From the MIT Media Lab, McGovern Institute, and Koch Institute, Departments of Biological Engineering and Brain and Cognitive Sciences, Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts 02139
| | - Demian Park
- From the MIT Media Lab, McGovern Institute, and Koch Institute, Departments of Biological Engineering and Brain and Cognitive Sciences, Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts 02139
| | - Aimei Yang
- From the MIT Media Lab, McGovern Institute, and Koch Institute, Departments of Biological Engineering and Brain and Cognitive Sciences, Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts 02139
| | - Fei Chen
- From the MIT Media Lab, McGovern Institute, and Koch Institute, Departments of Biological Engineering and Brain and Cognitive Sciences, Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts 02139
| | - Amy S Chuong
- From the MIT Media Lab, McGovern Institute, and Koch Institute, Departments of Biological Engineering and Brain and Cognitive Sciences, Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts 02139
| | - Nathan C Klapoetke
- From the MIT Media Lab, McGovern Institute, and Koch Institute, Departments of Biological Engineering and Brain and Cognitive Sciences, Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts 02139
| | - Edward S Boyden
- From the MIT Media Lab, McGovern Institute, and Koch Institute, Departments of Biological Engineering and Brain and Cognitive Sciences, Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts 02139
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127
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Stahlberg MA, Ramakrishnan C, Willig KI, Boyden ES, Deisseroth K, Dean C. Investigating the feasibility of channelrhodopsin variants for nanoscale optogenetics. NEUROPHOTONICS 2019; 6:015007. [PMID: 30854405 PMCID: PMC6393647 DOI: 10.1117/1.nph.6.1.015007] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Accepted: 02/05/2019] [Indexed: 06/09/2023]
Abstract
Optogenetics has revolutionized the study of circuit function in the brain, by allowing activation of specific ensembles of neurons by light. However, this technique has not yet been exploited extensively at the subcellular level. Here, we test the feasibility of a focal stimulation approach using stimulated emission depletion/reversible saturable optical fluorescence transitions-like illumination, whereby switchable light-gated channels are focally activated by a laser beam of one wavelength and deactivated by an overlapping donut-shaped beam of a different wavelength, confining activation to a center focal region. This method requires that activated channelrhodopsins are inactivated by overlapping illumination of a distinct wavelength and that photocurrents are large enough to be detected at the nanoscale. In tests of current optogenetic tools, we found that ChR2 C128A/H134R/T159C and CoChR C108S and C108S/D136A-activated with 405-nm light and inactivated by coillumination with 594-nm light-and C1V1 E122T/C167S-activated by 561-nm light and inactivated by 405-nm light-were most promising in terms of highest photocurrents and efficient inactivation with coillumination. Although further engineering of step-function channelrhodopsin variants with higher photoconductances will be required to employ this approach at the nanoscale, our findings provide a framework to guide future development of this technique.
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Affiliation(s)
- Markus A. Stahlberg
- European Neuroscience Institute, Trans-Synaptic Signaling Group, Goettingen, Germany
| | - Charu Ramakrishnan
- Stanford University, Howard Hughes Medical Institute, Department of Bioengineering, Department of Psychiatry, CNC Program, Stanford, California, United States
| | - Katrin I. Willig
- University Medical Center, Center for Nanoscale Microscopy and Molecular Physiology of the Brain, Goettingen, Germany
| | - Edward S. Boyden
- MIT Media Lab and McGovern Institute, Departments of Brain and Cognitive Science and Biological Engineering, Cambridge, Massachusetts, United States
| | - Karl Deisseroth
- Stanford University, Howard Hughes Medical Institute, Department of Bioengineering, Department of Psychiatry, CNC Program, Stanford, California, United States
| | - Camin Dean
- European Neuroscience Institute, Trans-Synaptic Signaling Group, Goettingen, Germany
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128
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Huang T, Lin SH, Malewicz NM, Zhang Y, Zhang Y, Goulding M, LaMotte RH, Ma Q. Identifying the pathways required for coping behaviours associated with sustained pain. Nature 2018; 565:86-90. [PMID: 30532001 PMCID: PMC6461409 DOI: 10.1038/s41586-018-0793-8] [Citation(s) in RCA: 146] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Accepted: 11/05/2018] [Indexed: 01/17/2023]
Abstract
Animals and humans display two types of responses to noxious stimuli. The first includes reflexive-defensive responses to prevent or limit injury. A well-known example is the quick withdrawal of one’s hand touching a hot object. When the first-line response fails to prevent tissue damage (e.g., a finger is burnt), the resulting pain invokes a second-line coping response, such as licking the injured area to soothe suffering. However, the underlying neural circuits driving these two strings of behaviors remain poorly understood. Here we show that in mice, spinal neurons marked by coexpression of TુCre and Lbx1Flpo, called Tac1Lbx1, drive pain-related coping responses. Ablation of Tac1Lbx1 neurons led to loss of persistent licking and conditioned aversion evoked by stimuli that produce sustained pain in humans, including skin pinching and burn injury, without affecting all tested reflexive-defensive reactions. This selective indifference to sustained pain resembles the phenotype seen in humans with lesions of medial thalamic nuclei1–3. Consistently, spinal Tac1 lineage neurons are connected to medial thalamic nuclei, via direct projections and indirect routes through the superior lateral parabrachial nuclei. Furthermore, the anatomical and functional segregation observed at the spinal levels is applied to primary sensory neurons. For example, in response to noxious mechanical stimuli, Mrgprd+ and TRPV1+ nociceptors are required to elicit reflexive and coping responses, respectively. Our studies therefore reveal a fundamental subdivision within the cutaneous somatosensory system. The implications for translational success from preclinical pain studies will be discussed.
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Affiliation(s)
- Tianwen Huang
- Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA.,Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Shing-Hong Lin
- Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA.,Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Nathalie M Malewicz
- Department of Anesthesiology, Yale University School of Medicine, New Haven, CT, USA
| | - Yan Zhang
- Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA.,Institute of Acupuncture and Moxibustion, Fudan Institutes of Integrative Medicine; Department of Integrative Medicine and Neurobiology, School of Basic Medical Science, Fudan University, Shanghai, China.,Cell Electrophysiology Laboratory, Wannan Medical College, Wuhu, China
| | - Ying Zhang
- Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA.,Neuroscience Research Institute and Department of Neurobiology, School of Basic Medical Sciences, Key Laboratory for Neuroscience, Ministry of Education/National Health and Family Planning Commission, Peking University, Beijing, China
| | - Martyn Goulding
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Robert H LaMotte
- Department of Anesthesiology, Yale University School of Medicine, New Haven, CT, USA
| | - Qiufu Ma
- Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA. .,Department of Neurobiology, Harvard Medical School, Boston, MA, USA.
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129
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Garita-Hernandez M, Guibbal L, Toualbi L, Routet F, Chaffiol A, Winckler C, Harinquet M, Robert C, Fouquet S, Bellow S, Sahel JA, Goureau O, Duebel J, Dalkara D. Optogenetic Light Sensors in Human Retinal Organoids. Front Neurosci 2018; 12:789. [PMID: 30450028 PMCID: PMC6224345 DOI: 10.3389/fnins.2018.00789] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 10/12/2018] [Indexed: 01/26/2023] Open
Abstract
Optogenetic technologies paved the way to dissect complex neural circuits and monitor neural activity using light in animals. In retinal disease, optogenetics has been used as a therapeutic modality to reanimate the retina after the loss of photoreceptor outer segments. However, it is not clear today which ones of the great diversity of microbial opsins are best suited for therapeutic applications in human retinas as cell lines, primary cell cultures and animal models do not predict expression patterns of microbial opsins in human retinal cells. Therefore, we sought to generate retinal organoids derived from human induced pluripotent stem cells (hiPSCs) as a screening tool to explore the membrane trafficking efficacy of some recently described microbial opsins. We tested both depolarizing and hyperpolarizing microbial opsins including CatCh, ChrimsonR, ReaChR, eNpHR 3.0, and Jaws. The membrane localization of eNpHR 3.0, ReaChR, and Jaws was the highest, likely due to their additional endoplasmic reticulum (ER) release and membrane trafficking signals. In the case of opsins that were not engineered to improve trafficking efficiency in mammalian cells such as CatCh and ChrimsonR, membrane localization was less efficient. Protein accumulation in organelles such as ER and Golgi was observed at high doses with CatCh and ER retention lead to an unfolded protein response. Also, cytoplasmic localization was observed at high doses of ChrimsonR. Our results collectively suggest that retinal organoids derived from hiPSCs can be used to predict the subcellular fate of optogenetic proteins in a human retinal context. Such organoids are also versatile tools to validate other gene therapy products and drug molecules.
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Affiliation(s)
| | - Laure Guibbal
- Institut de la Vision, Sorbonne Université, INSERM, CNRS, Paris, France
| | - Lyes Toualbi
- Institut de la Vision, Sorbonne Université, INSERM, CNRS, Paris, France
| | - Fiona Routet
- Institut de la Vision, Sorbonne Université, INSERM, CNRS, Paris, France
| | - Antoine Chaffiol
- Institut de la Vision, Sorbonne Université, INSERM, CNRS, Paris, France
| | - Celine Winckler
- Institut de la Vision, Sorbonne Université, INSERM, CNRS, Paris, France
| | - Marylin Harinquet
- Institut de la Vision, Sorbonne Université, INSERM, CNRS, Paris, France
| | - Camille Robert
- Institut de la Vision, Sorbonne Université, INSERM, CNRS, Paris, France
| | - Stephane Fouquet
- Institut de la Vision, Sorbonne Université, INSERM, CNRS, Paris, France
| | | | - José-Alain Sahel
- Institut de la Vision, Sorbonne Université, INSERM, CNRS, Paris, France
- CHNO des Quinze-Vingts, DHU Sight Restore, INSERM-DGOS CIC 1423, Paris, France
- Department of Ophthalmology, The University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
| | - Olivier Goureau
- Institut de la Vision, Sorbonne Université, INSERM, CNRS, Paris, France
| | - Jens Duebel
- Institut de la Vision, Sorbonne Université, INSERM, CNRS, Paris, France
| | - Deniz Dalkara
- Institut de la Vision, Sorbonne Université, INSERM, CNRS, Paris, France
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130
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Beck S, Yu-Strzelczyk J, Pauls D, Constantin OM, Gee CE, Ehmann N, Kittel RJ, Nagel G, Gao S. Synthetic Light-Activated Ion Channels for Optogenetic Activation and Inhibition. Front Neurosci 2018; 12:643. [PMID: 30333716 PMCID: PMC6176052 DOI: 10.3389/fnins.2018.00643] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 08/29/2018] [Indexed: 01/21/2023] Open
Abstract
Optogenetic manipulation of cells or living organisms became widely used in neuroscience following the introduction of the light-gated ion channel channelrhodopsin-2 (ChR2). ChR2 is a non-selective cation channel, ideally suited to depolarize and evoke action potentials in neurons. However, its calcium (Ca2+) permeability and single channel conductance are low and for some applications longer-lasting increases in intracellular Ca2+ might be desirable. Moreover, there is need for an efficient light-gated potassium (K+) channel that can rapidly inhibit spiking in targeted neurons. Considering the importance of Ca2+ and K+ in cell physiology, light-activated Ca2+-permeant and K+-specific channels would be welcome additions to the optogenetic toolbox. Here we describe the engineering of novel light-gated Ca2+-permeant and K+-specific channels by fusing a bacterial photoactivated adenylyl cyclase to cyclic nucleotide-gated channels with high permeability for Ca2+ or for K+, respectively. Optimized fusion constructs showed strong light-gated conductance in Xenopus laevis oocytes and in rat hippocampal neurons. These constructs could also be used to control the motility of Drosophila melanogaster larvae, when expressed in motoneurons. Illumination led to body contraction when motoneurons expressed the light-sensitive Ca2+-permeant channel, and to body extension when expressing the light-sensitive K+ channel, both effectively and reversibly paralyzing the larvae. Further optimization of these constructs will be required for application in adult flies since both constructs led to eclosion failure when expressed in motoneurons.
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Affiliation(s)
- Sebastian Beck
- Julius-von-Sachs-Institute, University of Würzburg, Würzburg, Germany
| | | | - Dennis Pauls
- Neurobiology and Genetics, Theodor-Boveri Institute, Biocenter, University of Würzburg, Würzburg, Germany
| | - Oana M Constantin
- Institute for Synaptic Physiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Christine E Gee
- Institute for Synaptic Physiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Nadine Ehmann
- Department of Neurophysiology, Institute of Physiology, University of Würzburg, Würzburg, Germany.,Department of Animal Physiology, Institute of Biology, Leipzig University, Leipzig, Germany.,Carl-Ludwig-Institute for Physiology, Leipzig University, Leipzig, Germany
| | - Robert J Kittel
- Department of Neurophysiology, Institute of Physiology, University of Würzburg, Würzburg, Germany.,Department of Animal Physiology, Institute of Biology, Leipzig University, Leipzig, Germany.,Carl-Ludwig-Institute for Physiology, Leipzig University, Leipzig, Germany
| | - Georg Nagel
- Julius-von-Sachs-Institute, University of Würzburg, Würzburg, Germany
| | - Shiqiang Gao
- Julius-von-Sachs-Institute, University of Würzburg, Würzburg, Germany
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131
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Dong N, Berlinguer-Palmini R, Soltan A, Ponon N, O'Neil A, Travelyan A, Maaskant P, Degenaar P, Sun X. Opto-electro-thermal optimization of photonic probes for optogenetic neural stimulation. JOURNAL OF BIOPHOTONICS 2018; 11:e201700358. [PMID: 29603666 DOI: 10.1002/jbio.201700358] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 03/14/2018] [Indexed: 06/08/2023]
Abstract
Implantable photonic probes are of increasing interest to the field of biophotonics and in particular, optogenetic neural stimulation. Active probes with onboard light emissive elements allow for electronic multiplexing and can be manufactured through existing microelectronics methods. However, as the optogenetics field moves towards clinical practice, an important question arises as to whether such probes will cause excessive thermal heating of the surrounding tissue. Light emitting diodes typically produce more heat than light. The resultant temperature rise of the probe surface therefore needs to be maintained under the regulatory limit of 2°C. This work combines optical and thermal modelling, which have been experimental verified. Analysis has been performed on the effect of probe/emitter geometries, emitter, and radiance requirements. Finally, the effective illumination volume has been calculated within thermal limits for different probe emitter types and required thresholds.
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Affiliation(s)
- Na Dong
- National Research Center for Optical Sensing/Communications Integrated Networking, Department of Electronics Engineering, Southeast University, Nanjing, China
| | | | - Ahmed Soltan
- School of Engineering, University of Newcastle upon Tyne, Newcastle, UK
| | - Nikhil Ponon
- School of Engineering, University of Newcastle upon Tyne, Newcastle, UK
| | - Anthony O'Neil
- School of Engineering, University of Newcastle upon Tyne, Newcastle, UK
| | - Andrew Travelyan
- Institute of Neuroscience, University of Newcastle upon Tyne, Newcastle, UK
| | - Pleun Maaskant
- Tyndall Institute, University College Cork, Cork, Ireland
| | - Patrick Degenaar
- School of Engineering, University of Newcastle upon Tyne, Newcastle, UK
| | - Xiaohan Sun
- National Research Center for Optical Sensing/Communications Integrated Networking, Department of Electronics Engineering, Southeast University, Nanjing, China
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132
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Simunovic MP, Shen W, Lin JY, Protti DA, Lisowski L, Gillies MC. Optogenetic approaches to vision restoration. Exp Eye Res 2018; 178:15-26. [PMID: 30218651 DOI: 10.1016/j.exer.2018.09.003] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 08/16/2018] [Accepted: 09/07/2018] [Indexed: 10/28/2022]
Abstract
Inherited retinal disease (IRD) affects about 1 in 3000 to 1 in 5000 individuals and is now believed to be the most common cause of blindness registration in developed countries. Until recently, the management of such conditions had been exclusively supportive. However, advances in molecular biology and medical engineering have now seen the rise of a variety of approaches to restore vision in patients with IRDs. Optogenetic approaches are primarily aimed at rendering secondary and tertiary neurons of the retina light-sensitive in order to replace degenerate or dysfunctional photoreceptors. Such approaches are attractive because they provide a "causative gene-independent" strategy, which may prove suitable for a variety of patients with IRD. We discuss theoretical and practical considerations in the selection of optogenetic molecules, vectors, surgical approaches and review previous trials of optogenetics for vision restoration. Optogenetic approaches to vision restoration have yielded promising results in pre-clinical trials and a phase I/II clinical trial is currently underway (ClinicalTrials.gov NCT02556736). Despite the significant inroads made in recent years, the ideal optogenetic molecule, vector and surgical approach have yet to be established.
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Affiliation(s)
- M P Simunovic
- Save Sight Institute, University of Sydney, 8 Macquarie St., Sydney, NSW, 2000, Australia; Retinal Unit, Sydney Eye Hospital, 8 Macquarie St., Sydney, NSW, 2000, Australia.
| | - W Shen
- Retinal Unit, Sydney Eye Hospital, 8 Macquarie St., Sydney, NSW, 2000, Australia
| | - J Y Lin
- Faculty of Health, University of Tasmania, Private Bag 23, Hobart, TAS, 7000, Australia
| | - D A Protti
- Discipline of Physiology, University of Sydney, NSW, 2006, Australia
| | - L Lisowski
- Children's Medical Research Institute, University of Sydney, NSW, 2006, Australia; Military Institute of Hygiene and Epidemiology, 24-100, Puławy, Poland
| | - M C Gillies
- Save Sight Institute, University of Sydney, 8 Macquarie St., Sydney, NSW, 2000, Australia; Retinal Unit, Sydney Eye Hospital, 8 Macquarie St., Sydney, NSW, 2000, Australia
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133
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Hernandez O, Pietrajtis K, Mathieu B, Dieudonné S. Optogenetic stimulation of complex spatio-temporal activity patterns by acousto-optic light steering probes cerebellar granular layer integrative properties. Sci Rep 2018; 8:13768. [PMID: 30213968 PMCID: PMC6137064 DOI: 10.1038/s41598-018-32017-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 08/28/2018] [Indexed: 12/11/2022] Open
Abstract
Optogenetics provides tools to control afferent activity in brain microcircuits. However, this requires optical methods that can evoke asynchronous and coordinated activity within neuronal ensembles in a spatio-temporally precise way. Here we describe a light patterning method, which combines MHz acousto-optic beam steering and adjustable low numerical aperture Gaussian beams, to achieve fast 2D targeting in scattering tissue. Using mossy fiber afferents to the cerebellar cortex as a testbed, we demonstrate single fiber optogenetic stimulation with micron-scale lateral resolution, >100 µm depth-penetration and 0.1 ms spiking precision. Protracted spatio-temporal patterns of light delivered by our illumination system evoked sustained asynchronous mossy fiber activity with excellent repeatability. Combining optical and electrical stimulations, we show that the cerebellar granular layer performs nonlinear integration, whereby sustained mossy fiber activity provides a permissive context for the transmission of salient inputs, enriching combinatorial views on mossy fiber pattern separation.
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Affiliation(s)
- Oscar Hernandez
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, PSL Université, 46 rue d'Ulm, 75005, Paris, France
- Wavefront-engineering Microscopy Group, Neurophotonics Laboratory, CNRS UMR8250, Paris Descartes University, Sorbonne Paris Cité, 45 rue des Saints-Pères, 75270, Paris Cedex 06, France
- CNC Program, Stanford University, Stanford, California, 94305, USA
| | - Katarzyna Pietrajtis
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, PSL Université, 46 rue d'Ulm, 75005, Paris, France
| | - Benjamin Mathieu
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, PSL Université, 46 rue d'Ulm, 75005, Paris, France
| | - Stéphane Dieudonné
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, PSL Université, 46 rue d'Ulm, 75005, Paris, France.
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134
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Soltan A, Barrett JM, Maaskant P, Armstrong N, Al-Atabany W, Chaudet L, Neil M, Sernagor E, Degenaar P. A head mounted device stimulator for optogenetic retinal prosthesis. J Neural Eng 2018; 15:065002. [PMID: 30156188 PMCID: PMC6372131 DOI: 10.1088/1741-2552/aadd55] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Objective. Our main objective is to demonstrate that compact high radiance gallium nitride displays can be used with conventional virtual reality optics to stimulate an optogenetic retina. Hence, we aim to introduce a non-invasive approach to restore vision for people with conditions such as retinitis pigmentosa where there is a remaining viable communication link between the retina and the visual cortex. Approach. We design and implement the headset using a high-density µLED matrix, Raspberry Pi, microcontroller from NXP and virtual reality lens. Then, a test platform is developed to evaluate the performance of the headset and the optical system. Furthermore, image simplification algorithms are used to simplify the scene to be sent to the retina. Moreover, in vivo evaluation of the genetically modified retina response at different light intensity is discussed to prove the reliability of the proposed system. Main results. We demonstrate that in keeping with regulatory guidance, the headset displays need to limit their luminance to 90 kcd m−2. We demonstrate an optical system with 5.75% efficiency which allows for 0.16 mW mm−2 irradiance on the retina within the regulatory guidance, but which is capable of an average peak irradiance of 1.35 mW mm−2. As this is lower than the commonly accepted threshold for channelrhodopsin-2, we demonstrate efficacy through an optical model of an eye onto a biological retina. Significance. We demonstrate a fully functional 8100-pixel headset system including software/hardware which can operate on a standard consumer battery for periods exceeding a 24 h recharge cycle. The headset is capable of delivering enough light to stimulate the genetically modified retina cells and also keeping the amount of light below the regulation threshold for safety.
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Affiliation(s)
- Ahmed Soltan
- School of Engineering, Newcastle University, Newcastle upon Tyne, NE1 7RU, United Kingdom
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135
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Shen YC, Sasaki T, Matsuyama T, Yamashita T, Shichida Y, Okitsu T, Yamano Y, Wada A, Ishizuka T, Yawo H, Imamoto Y. Red-Tuning of the Channelrhodopsin Spectrum Using Long Conjugated Retinal Analogues. Biochemistry 2018; 57:5544-5556. [DOI: 10.1021/acs.biochem.8b00583] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yi-Chung Shen
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Toshikazu Sasaki
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Take Matsuyama
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Takahiro Yamashita
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Yoshinori Shichida
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
- Research Organization of Science and Technology, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan
| | - Takashi Okitsu
- Laboratory of Organic Chemistry for Life Science, Kobe Pharmaceutical University, Kobe, Hyogo 658-0003, Japan
| | - Yumiko Yamano
- Laboratory of Organic Chemistry for Life Science, Kobe Pharmaceutical University, Kobe, Hyogo 658-0003, Japan
| | - Akimori Wada
- Laboratory of Organic Chemistry for Life Science, Kobe Pharmaceutical University, Kobe, Hyogo 658-0003, Japan
| | - Toru Ishizuka
- Department of Developmental Biology and Neuroscience, Graduate School of Life Science, Tohoku University, Sendai, Miyagi 980-8577, Japan
| | - Hiromu Yawo
- Department of Developmental Biology and Neuroscience, Graduate School of Life Science, Tohoku University, Sendai, Miyagi 980-8577, Japan
| | - Yasushi Imamoto
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
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136
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Lu Q, Ganjawala TH, Hattar S, Abrams GW, Pan ZH. A Robust Optomotor Assay for Assessing the Efficacy of Optogenetic Tools for Vision Restoration. Invest Ophthalmol Vis Sci 2018; 59:1288-1294. [PMID: 29625451 PMCID: PMC5839255 DOI: 10.1167/iovs.17-23278] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Purpose To develop an animal behavioral assay for the quantitative assessment of the functional efficacy of optogenetic therapies. Methods A triple-knockout (TKO) mouse line, Gnat1−/−Cnga3−/−Opn4−/−, and a double-knockout mouse line, Gnat1−/−Cnga3−/−, were employed. The expression of channelrhodopsin-2 (ChR2) and its three more light-sensitive mutants, ChR2-L132C, ChR2-L132C/T159C, and ChR2-132C/T159S, in inner retinal neurons was achieved using rAAV2 vectors via intravitreal delivery. Pupillary constriction was assessed by measuring the pupil diameter. The optomotor response (OMR) was examined using a homemade optomotor system equipped with light-emitting diodes as light stimulation. Results A robust OMR was restored in the ChR2-mutant-expressing TKO mice; however, significant pupillary constriction was observed only for the ChR2-L132C/T159S mutant. The ability to evoke an OMR was dependent on both the light intensity and grating frequency. The most light-sensitive frequency for the three ChR2 mutants was approximately 0.042 cycles per degree. Among the three ChR2 mutants, ChR2-L132C/T159S was the most light sensitive, followed by ChR2-L132C/T159C and ChR2-L132C. Melanopsin-mediated pupillary constriction resulted in a substantial reduction in the light sensitivity of the ChR2-mediated OMR. Conclusions The OMR assay using TKO mice enabled the quantitative assessment of the efficacy of different optogenetic tools and the properties of optogenetically restored vision. Thus, the assay can serve as a valuable tool for developing effective optogenetic therapies.
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Affiliation(s)
- Qi Lu
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, United States.,Department of Ophthalmology, Kresge Eye Institute, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Tushar H Ganjawala
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Samer Hattar
- National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, United States
| | - Gary W Abrams
- Department of Ophthalmology, Kresge Eye Institute, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Zhuo-Hua Pan
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, United States.,Department of Ophthalmology, Kresge Eye Institute, Wayne State University School of Medicine, Detroit, Michigan, United States
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137
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Broyles CN, Robinson P, Daniels MJ. Fluorescent, Bioluminescent, and Optogenetic Approaches to Study Excitable Physiology in the Single Cardiomyocyte. Cells 2018; 7:cells7060051. [PMID: 29857560 PMCID: PMC6028913 DOI: 10.3390/cells7060051] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 05/22/2018] [Accepted: 05/30/2018] [Indexed: 12/11/2022] Open
Abstract
This review briefly summarizes the single cell application of classical chemical dyes used to visualize cardiomyocyte physiology and their undesirable toxicities which have the potential to confound experimental observations. We will discuss, in detail, the more recent iterative development of fluorescent and bioluminescent protein-based indicators and their emerging application to cardiomyocytes. We will discuss the integration of optical control strategies (optogenetics) to augment the standard imaging approach. This will be done in the context of potential applications, and barriers, of these technologies to disease modelling, drug toxicity, and drug discovery efforts at the single-cell scale.
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Affiliation(s)
- Connor N Broyles
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, UK.
- BHF Centre of Research Excellence, University of Oxford, Oxford OX3 9DU, UK.
| | - Paul Robinson
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, UK.
- BHF Centre of Research Excellence, University of Oxford, Oxford OX3 9DU, UK.
| | - Matthew J Daniels
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, UK.
- BHF Centre of Research Excellence, University of Oxford, Oxford OX3 9DU, UK.
- Department of Cardiology, Oxford University NHS Hospitals Trust, Oxford OX3 9DU, UK.
- BHF Centre of Regenerative Medicine, University of Oxford, Oxford OX3 9DU, UK.
- Department of Biotechnology, Graduate School of Engineering, Osaka University, Mihogaoka 8-1, Ibaraki, 567-0047 Osaka, Japan.
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138
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Keplinger S, Beiderbeck B, Michalakis S, Biel M, Grothe B, Kunz L. Optogenetic Control of Neural Circuits in the Mongolian Gerbil. Front Cell Neurosci 2018; 12:111. [PMID: 29740286 PMCID: PMC5928259 DOI: 10.3389/fncel.2018.00111] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Accepted: 04/05/2018] [Indexed: 12/17/2022] Open
Abstract
The Mongolian gerbil (Meriones unguiculatus) is widely used as a model organism for the human auditory system. Its hearing range is very similar to ours and it uses the same mechanisms for sound localization. The auditory circuits underlying these functions have been characterized. However, important mechanistic details are still under debate. To elucidate these issues, precise and reversible optogenetic manipulation of neuronal activity in this complex circuitry is required. However, genetic and genomic resources for the Mongolian gerbil are poorly developed. Here, we demonstrate a reliable gene delivery system using an AAV8(Y337F)-pseudotyped recombinant adeno-associated virus (AAV) 2-based vector in which the pan-neural human synapsin (hSyn) promoter drives neuron-specific expression of CatCH (Ca2+-permeable channelrhodopsin) or NpHR3.0 (Natronomonas pharaonis halorhodopsin). After stereotactic injection into the gerbil’s auditory brainstem (medial nucleus of the trapezoid body, dorsal nucleus of the lateral lemniscus) and midbrain [inferior colliculus (IC)], we characterized CatCH- and/or NpHR3.0-transduced neurons in acute brain slices by means of whole-cell patch-clamp recordings. As the response properties of optogenetic tools strongly depend on neuronal biophysics, this parameterization is crucial for their in vivo application. In a proof-of-principle experiment in anesthetized gerbils, we observed strong suppression of sound-evoked neural responses in the dorsal nucleus of the lateral lemniscus (DNLL) and IC upon light activation of NpHR3.0. The successful validation of gene delivery and optogenetic tools in the Mongolian gerbil paves the way for future studies of the auditory circuits in this model system.
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Affiliation(s)
- Stefan Keplinger
- Division of Neurobiology, Department Biology II, Biocenter, Ludwig Maximilian University of Munich, Munich, Germany
| | - Barbara Beiderbeck
- Division of Neurobiology, Department Biology II, Biocenter, Ludwig Maximilian University of Munich, Munich, Germany.,Graduate School of Systemic Neurosciences, GSN-LMU, Ludwig Maximilian University of Munich, Munich, Germany
| | - Stylianos Michalakis
- Center for Integrated Protein Science Munich (CiPSM), Department of Pharmacy, Center for Drug Research, Ludwig Maximilian University of Munich, Munich, Germany
| | - Martin Biel
- Center for Integrated Protein Science Munich (CiPSM), Department of Pharmacy, Center for Drug Research, Ludwig Maximilian University of Munich, Munich, Germany
| | - Benedikt Grothe
- Division of Neurobiology, Department Biology II, Biocenter, Ludwig Maximilian University of Munich, Munich, Germany
| | - Lars Kunz
- Division of Neurobiology, Department Biology II, Biocenter, Ludwig Maximilian University of Munich, Munich, Germany
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139
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High frequency neural spiking and auditory signaling by ultrafast red-shifted optogenetics. Nat Commun 2018; 9:1750. [PMID: 29717130 PMCID: PMC5931537 DOI: 10.1038/s41467-018-04146-3] [Citation(s) in RCA: 92] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 04/06/2018] [Indexed: 11/29/2022] Open
Abstract
Optogenetics revolutionizes basic research in neuroscience and cell biology and bears potential for medical applications. We develop mutants leading to a unifying concept for the construction of various channelrhodopsins with fast closing kinetics. Due to different absorption maxima these channelrhodopsins allow fast neural photoactivation over the whole range of the visible spectrum. We focus our functional analysis on the fast-switching, red light-activated Chrimson variants, because red light has lower light scattering and marginal phototoxicity in tissues. We show paradigmatically for neurons of the cerebral cortex and the auditory nerve that the fast Chrimson mutants enable neural stimulation with firing frequencies of several hundred Hz. They drive spiking at high rates and temporal fidelity with low thresholds for stimulus intensity and duration. Optical cochlear implants restore auditory nerve activity in deaf mice. This demonstrates that the mutants facilitate neuroscience research and future medical applications such as hearing restoration. Optogenetic applications would benefit from channelrhodopsins (ChRs) with faster photostimulation, increased tissue transparency and lower phototoxicity. Here, the authors develop fast red-shifted ChR variants and show the abilities for temporal precise spiking of cerebral interneurons and restoring auditory activity in deaf mice.
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140
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Vann NC, Pham FD, Dorst KE, Del Negro CA. Dbx1 Pre-Bötzinger Complex Interneurons Comprise the Core Inspiratory Oscillator for Breathing in Unanesthetized Adult Mice. eNeuro 2018; 5:ENEURO.0130-18.2018. [PMID: 29845107 PMCID: PMC5971373 DOI: 10.1523/eneuro.0130-18.2018] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 04/23/2018] [Accepted: 04/25/2018] [Indexed: 01/20/2023] Open
Abstract
The brainstem pre-Bötzinger complex (preBötC) generates inspiratory breathing rhythms, but which neurons comprise its rhythmogenic core? Dbx1-derived neurons may play the preeminent role in rhythm generation, an idea well founded at perinatal stages of development but incompletely evaluated in adulthood. We expressed archaerhodopsin or channelrhodopsin in Dbx1 preBötC neurons in intact adult mice to interrogate their function. Prolonged photoinhibition slowed down or stopped breathing, whereas prolonged photostimulation sped up breathing. Brief inspiratory-phase photoinhibition evoked the next breath earlier than expected, whereas brief expiratory-phase photoinhibition delayed the subsequent breath. Conversely, brief inspiratory-phase photostimulation increased inspiratory duration and delayed the subsequent breath, whereas brief expiratory-phase photostimulation evoked the next breath earlier than expected. Because they govern the frequency and precise timing of breaths in awake adult mice with sensorimotor feedback intact, Dbx1 preBötC neurons constitute an essential core component of the inspiratory oscillator, knowledge directly relevant to human health and physiology.
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Affiliation(s)
- Nikolas C Vann
- Department of Applied Science, Integrated Science Center, William & Mary, Williamsburg, VA 23185
| | - Francis D Pham
- Department of Applied Science, Integrated Science Center, William & Mary, Williamsburg, VA 23185
| | - Kaitlyn E Dorst
- Department of Applied Science, Integrated Science Center, William & Mary, Williamsburg, VA 23185
| | - Christopher A Del Negro
- Department of Applied Science, Integrated Science Center, William & Mary, Williamsburg, VA 23185
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141
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Cardiac Optogenetics: 2018. JACC Clin Electrophysiol 2018; 4:155-167. [PMID: 29749932 DOI: 10.1016/j.jacep.2017.12.006] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 12/04/2017] [Accepted: 12/14/2017] [Indexed: 01/28/2023]
Abstract
Cardiac optogenetics is an emergent research area involving the delivery of light-sensitive proteins (opsins) to excitable heart tissue to enable optical modulation of cardiac electrical function. Optogenetic stimulation has many noteworthy advantages over conventional electrical methods, including selective electrophysiological modulation in specifically targeted cell subpopulations, high-resolution spatiotemporal control via patterned illumination, and use of different opsins to elicit inward or outward transmembrane current. This review summarizes developments achieved since the inception of cardiac optogenetics research, which has spanned nearly a decade. The authors first provide an overview of recent methodological advances in opsin engineering, light sensitization of cardiac tissue, strategies for illuminating the heart, and frameworks for simulating optogenetics in realistic computational models of patient hearts. They then review recent cardiac optogenetics applications, including: 1) all-optical, high-throughput, contactless assays for quantification of electrophysiological properties; 2) optogenetic perturbation of cardiac tissue to unveil mechanistic insights on the initiation, perpetuation, and termination of arrhythmia; and 3) disruptive translational innovations such as light-based pacemaking and defibrillation.
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142
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Bergs A, Schultheis C, Fischer E, Tsunoda SP, Erbguth K, Husson SJ, Govorunova E, Spudich JL, Nagel G, Gottschalk A, Liewald JF. Rhodopsin optogenetic toolbox v2.0 for light-sensitive excitation and inhibition in Caenorhabditis elegans. PLoS One 2018; 13:e0191802. [PMID: 29389997 PMCID: PMC5794093 DOI: 10.1371/journal.pone.0191802] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Accepted: 01/11/2018] [Indexed: 01/05/2023] Open
Abstract
In optogenetics, rhodopsins were established as light-driven tools to manipulate neuronal activity. However, during long-term photostimulation using channelrhodopsin (ChR), desensitization can reduce effects. Furthermore, requirement for continuous presence of the chromophore all-trans retinal (ATR) in model systems lacking sufficient endogenous concentrations limits its applicability. We tested known, and engineered and characterized new variants of de- and hyperpolarizing rhodopsins in Caenorhabditis elegans. ChR2 variants combined previously described point mutations that may synergize to enable prolonged stimulation. Following brief light pulses ChR2(C128S;H134R) induced muscle activation for minutes or even for hours (‘Quint’: ChR2(C128S;L132C;H134R;D156A;T159C)), thus featuring longer open state lifetime than previously described variants. Furthermore, stability after ATR removal was increased compared to the step-function opsin ChR2(C128S). The double mutants C128S;H134R and H134R;D156C enabled increased effects during repetitive stimulation. We also tested new hyperpolarizers (ACR1, ACR2, ACR1(C102A), ZipACR). Particularly ACR1 and ACR2 showed strong effects in behavioral assays and very large currents with fast kinetics. In sum, we introduce highly light-sensitive optogenetic tools, bypassing previous shortcomings, and thus constituting new tools that feature high effectiveness and fast kinetics, allowing better repetitive stimulation or investigating prolonged neuronal activity states in C. elegans and, possibly, other systems.
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Affiliation(s)
- Amelie Bergs
- Buchmann Institute for Molecular Life Sciences, Goethe-University, Frankfurt, Germany
- Department of Biochemistry, Chemistry and Pharmacy, Institute of Biophysical Chemistry, Goethe-University, Frankfurt, Germany
- International Max Planck Research School in Structure and Function of Biological Membranes, Frankfurt, Germany
| | - Christian Schultheis
- Buchmann Institute for Molecular Life Sciences, Goethe-University, Frankfurt, Germany
- Department of Biochemistry, Chemistry and Pharmacy, Institute of Biophysical Chemistry, Goethe-University, Frankfurt, Germany
| | - Elisabeth Fischer
- Buchmann Institute for Molecular Life Sciences, Goethe-University, Frankfurt, Germany
- Department of Biochemistry, Chemistry and Pharmacy, Institute of Biophysical Chemistry, Goethe-University, Frankfurt, Germany
| | - Satoshi P. Tsunoda
- Buchmann Institute for Molecular Life Sciences, Goethe-University, Frankfurt, Germany
- Department of Biochemistry, Chemistry and Pharmacy, Institute of Biophysical Chemistry, Goethe-University, Frankfurt, Germany
| | - Karen Erbguth
- Buchmann Institute for Molecular Life Sciences, Goethe-University, Frankfurt, Germany
- Department of Biochemistry, Chemistry and Pharmacy, Institute of Biophysical Chemistry, Goethe-University, Frankfurt, Germany
| | - Steven J. Husson
- Systemic Physiological & Ecotoxicological Research (SPHERE), University of Antwerp, Antwerp, Belgium
| | - Elena Govorunova
- Center for Membrane Biology, Department of Biochemistry and Molecular Biology, University of Texas Health Science Center at Houston, McGovern Medical School, Houston, Texas, United States of America
| | - John L. Spudich
- Center for Membrane Biology, Department of Biochemistry and Molecular Biology, University of Texas Health Science Center at Houston, McGovern Medical School, Houston, Texas, United States of America
| | - Georg Nagel
- Department of Biology, Institute for Molecular Plant Physiology and Biophysics, Julius-Maximilians-University of Würzburg, Würzburg, Germany
| | - Alexander Gottschalk
- Buchmann Institute for Molecular Life Sciences, Goethe-University, Frankfurt, Germany
- Department of Biochemistry, Chemistry and Pharmacy, Institute of Biophysical Chemistry, Goethe-University, Frankfurt, Germany
- Cluster of Excellence Frankfurt - Macromolecular Complexes (CEF-MC), Goethe University, Frankfurt, Germany
- * E-mail: (AG); (JFL)
| | - Jana F. Liewald
- Buchmann Institute for Molecular Life Sciences, Goethe-University, Frankfurt, Germany
- Department of Biochemistry, Chemistry and Pharmacy, Institute of Biophysical Chemistry, Goethe-University, Frankfurt, Germany
- * E-mail: (AG); (JFL)
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143
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Streit J, Kleinlogel S. Dynamic all-optical drug screening on cardiac voltage-gated ion channels. Sci Rep 2018; 8:1153. [PMID: 29348631 PMCID: PMC5773578 DOI: 10.1038/s41598-018-19412-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 12/27/2017] [Indexed: 11/09/2022] Open
Abstract
Voltage-gated ion channels (VGCs) are prime targets for the pharmaceutical industry, but drug profiling on VGCs is challenging, since drug interactions are confined to specific conformational channel states mediated by changes in transmembrane potential. Here we combined various optogenetic tools to develop dynamic, high-throughput drug profiling assays with defined light-step protocols to interrogate VGC states on a millisecond timescale. We show that such light-induced electrophysiology (LiEp) yields high-quality pharmacological data with exceptional screening windows for drugs acting on the major cardiac VGCs, including hNav1.5, hKv1.5 and hERG. LiEp-based screening remained robust when using a variety of optogenetic actuators (ChR2, ChR2(H134R), CatCh, ChR2-EYFP-βArchT) and different types of organic (RH421, Di-4-ANBDQPQ, BeRST1) or genetic voltage sensors (QuasAr1). The tractability of LiEp allows a versatile and precise alternative to state-of-the-art VGC drug screening platforms such as automated electrophysiology or FLIPR readers.
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Affiliation(s)
- Jonas Streit
- Institute of Physiology, University of Bern, Bühlplatz 5, 3012, Bern, Switzerland
| | - Sonja Kleinlogel
- Institute of Physiology, University of Bern, Bühlplatz 5, 3012, Bern, Switzerland.
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144
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Zhao X, Lenek D, Dag U, Dickson BJ, Keleman K. Persistent activity in a recurrent circuit underlies courtship memory in Drosophila. eLife 2018; 7:31425. [PMID: 29322941 PMCID: PMC5800849 DOI: 10.7554/elife.31425] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 01/09/2018] [Indexed: 11/30/2022] Open
Abstract
Recurrent connections are thought to be a common feature of the neural circuits that encode memories, but how memories are laid down in such circuits is not fully understood. Here we present evidence that courtship memory in Drosophila relies on the recurrent circuit between mushroom body gamma (MBγ), M6 output, and aSP13 dopaminergic neurons. We demonstrate persistent neuronal activity of aSP13 neurons and show that it transiently potentiates synaptic transmission from MBγ>M6 neurons. M6 neurons in turn provide input to aSP13 neurons, prolonging potentiation of MBγ>M6 synapses over time periods that match short-term memory. These data support a model in which persistent aSP13 activity within a recurrent circuit lays the foundation for a short-term memory. Memories help to shape behavior, and can last from a few seconds to an entire lifetime. Working memory, in which information is temporarily held available for use in an ongoing task, is the most fleeting form of memory. It relies on persistent activation of a network of nerve cells or neurons that represent the information in question. Strengthening the connections between those neurons may result in a longer-lasting memory. But the mechanisms that support the formation of memories of different durations are not fully understood. Zhao et al. have now explored these mechanisms in the fruit fly by studying memory for courtship behavior. Inexperienced male fruit flies will attempt to court both virgin females and females who have recently mated. But the latter reject courtship attempts, and male fruit flies therefore learn to avoid them. This is known as courtship memory, and it relies on a network of neurons within a region of the fruit fly brain called the mushroom body. Within the mushroom body, dopamine neuron sends signals to a neuron called the Kenyon cell, which in turn sends signals to a mushroom body output neuron. The latter activates circuits responsible for decision-making and movement. But it also activates the dopamine neuron, thereby forming a recurrent circuit or loop. When the courtship is rejected, the dopamine neuron becomes persistently active, which generates a working memory of the experience. If the circuit is activated again during this period of persistent firing, the working memory may be converted into a longer-lasting memory. The results of Zhao et al. provide insights into the mechanisms by which memories form and undergo strengthening. They suggest that distinct processes within a single neural circuit give rise to memories of different durations. Recurrent loops are also present within the brains of mammals. Similar processes may thus support the formation and persistence of our own memories.
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Affiliation(s)
| | - Daniela Lenek
- Research Institute of Molecular Pathology, Vienna, Austria
| | - Ugur Dag
- Janelia Research Campus, Ashburn, United States
| | - Barry J Dickson
- Janelia Research Campus, Ashburn, United States.,Queensland Brain Institute, University of Queensland, St Lucia, Australia
| | - Krystyna Keleman
- Janelia Research Campus, Ashburn, United States.,Research Institute of Molecular Pathology, Vienna, Austria
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145
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Nedrud D, Schmidt D. Combinatorial Assembly of Lumitoxins. Methods Mol Biol 2018; 1684:193-209. [PMID: 29058193 DOI: 10.1007/978-1-4939-7362-0_15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Ion channels are among the most important proteins in neuroscience and serve as drug targets for many brain disorders. During development, learning, disease progression, and other processes, the activity levels of specific ion channels are tuned in a cell-type specific manner. However, it is difficult to assess how cell-specific changes in ion channel activity alter emergent brain functions. We have developed a protein architecture for fully genetically encoded light-activated modulation of endogenous ion channel activity. Fusing a genetically encoded photoswitch and an ion channel-modulating peptide toxin in a computationally designed fashion, this reagent, which we call Lumitoxins, can mediate light-modulation of specific endogenous ion channel activities in targeted cells. The modular lumitoxin architecture may be useful in a diversity of neuroscience tools. Here, we delineate how to construct lumitoxin genes from synthesized components, and provide a general outline for how to test their function in mammalian cell culture.
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Affiliation(s)
- David Nedrud
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota-Twin Cities, Minneapolis, MN, USA
| | - Daniel Schmidt
- Department of Genetics, Cell Biology and Development, University of Minnesota-Twin Cities, 321 Church Street SE, 6-160 Jackson, Minneapolis, MN, 55455, USA.
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146
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Boesmans W, Hao MM, Vanden Berghe P. Optogenetic and chemogenetic techniques for neurogastroenterology. Nat Rev Gastroenterol Hepatol 2018; 15:21-38. [PMID: 29184183 DOI: 10.1038/nrgastro.2017.151] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Optogenetics and chemogenetics comprise a wide variety of applications in which genetically encoded actuators and indicators are used to modulate and monitor activity with high cellular specificity. Over the past 10 years, development of these genetically encoded tools has contributed tremendously to our understanding of integrated physiology. In concert with the continued refinement of probes, strategies to target transgene expression to specific cell types have also made much progress in the past 20 years. In addition, the successful implementation of optogenetic and chemogenetic techniques thrives thanks to ongoing advances in live imaging microscopy and optical technology. Although innovation of optogenetic and chemogenetic methods has been primarily driven by researchers studying the central nervous system, these techniques also hold great promise to boost research in neurogastroenterology. In this Review, we describe the different classes of tools that are currently available and give an overview of the strategies to target them to specific cell types in the gut wall. We discuss the possibilities and limitations of optogenetic and chemogenetic technology in the gut and provide an overview of their current use, with a focus on the enteric nervous system. Furthermore, we suggest some experiments that can advance our understanding of how the intrinsic and extrinsic neural networks of the gut control gastrointestinal function.
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Affiliation(s)
- Werend Boesmans
- Laboratory for Enteric Neuroscience (LENS), Translational Research Center for Gastrointestinal Disorders (TARGID), University of Leuven, Herestraat 49, O&N 1 Box 701, 3000 Leuven, Belgium.,Department of Pathology, Maastricht University Medical Center, P. Debeijelaan 25, 6229 HX, Maastricht, The Netherlands
| | - Marlene M Hao
- Laboratory for Enteric Neuroscience (LENS), Translational Research Center for Gastrointestinal Disorders (TARGID), University of Leuven, Herestraat 49, O&N 1 Box 701, 3000 Leuven, Belgium.,Department of Anatomy and Neuroscience, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Pieter Vanden Berghe
- Laboratory for Enteric Neuroscience (LENS), Translational Research Center for Gastrointestinal Disorders (TARGID), University of Leuven, Herestraat 49, O&N 1 Box 701, 3000 Leuven, Belgium
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147
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Eickelbeck D, Karapinar R, Herlitze S, Spoida K. Optogenetic Approaches for Controlling Neuronal Activity and Plasticity. HANDBOOK OF BEHAVIORAL NEUROSCIENCE 2018. [DOI: 10.1016/b978-0-12-812028-6.00016-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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148
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Abstract
Microbial rhodopsins (MRs) are a large family of photoactive membrane proteins, found in microorganisms belonging to all kingdoms of life, with new members being constantly discovered. Among the MRs are light-driven proton, cation and anion pumps, light-gated cation and anion channels, and various photoreceptors. Due to their abundance and amenability to studies, MRs served as model systems for a great variety of biophysical techniques, and recently found a great application as optogenetic tools. While the basic aspects of microbial rhodopsins functioning have been known for some time, there is still a plenty of unanswered questions. This chapter presents and summarizes the available knowledge, focusing on the functional and structural studies.
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Affiliation(s)
- Ivan Gushchin
- Moscow Institute of Physics and Technology, Dolgoprudniy, Russia.
| | - Valentin Gordeliy
- Moscow Institute of Physics and Technology, Dolgoprudniy, Russia.
- University of Grenoble Alpes, CEA, CNRS, IBS, Grenoble, France.
- Institute of Complex Systems (ICS), ICS-6: Structural Biochemistry, Research Centre Jülich, Jülich, Germany.
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149
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Scholl HPN, Strauss RW, Singh MS, Dalkara D, Roska B, Picaud S, Sahel JA. Emerging therapies for inherited retinal degeneration. Sci Transl Med 2017; 8:368rv6. [PMID: 27928030 DOI: 10.1126/scitranslmed.aaf2838] [Citation(s) in RCA: 147] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Accepted: 11/17/2016] [Indexed: 12/13/2022]
Abstract
Inherited retinal degenerative diseases, a genetically and phenotypically heterogeneous group of disorders, affect the function of photoreceptor cells and are among the leading causes of blindness. Recent advances in molecular genetics and cell biology are elucidating the pathophysiological mechanisms underlying these disorders and are helping to identify new therapeutic approaches, such as gene therapy, stem cell therapy, and optogenetics. Several of these approaches have entered the clinical phase of development. Artificial replacement of dying photoreceptor cells using retinal prostheses has received regulatory approval. Precise retinal imaging and testing of visual function are facilitating more efficient clinical trial design. In individual patients, disease stage will determine whether the therapeutic strategy should comprise photoreceptor cell rescue to delay or arrest vision loss or retinal replacement for vision restoration.
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Affiliation(s)
- Hendrik P N Scholl
- Department of Ophthalmology, University of Basel, 4056 Basel, Switzerland. .,Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD 21287, USA
| | - Rupert W Strauss
- Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD 21287, USA.,Moorfields Eye Hospital, London EC1V 2PD, U.K.,UCL Institute of Ophthalmology, University College London, London EC1V 9EL, U.K.,Department of Ophthalmology, Medical University Graz, Graz, Austria.,Department of Ophthalmology, Johannes Kepler University Linz, 4021 Linz, Austria
| | - Mandeep S Singh
- Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD 21287, USA
| | - Deniz Dalkara
- INSERM, UMR S 968, 75012 Paris, France.,Sorbonne Universités, UPMC Univ Paris 06, Institut de la Vision, Paris, France.,CNRS, UMR 7210, 75012 Paris, France
| | - Botond Roska
- Department of Ophthalmology, University of Basel, 4056 Basel, Switzerland.,Neural Circuit Laboratories, Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland
| | - Serge Picaud
- INSERM, UMR S 968, 75012 Paris, France.,Sorbonne Universités, UPMC Univ Paris 06, Institut de la Vision, Paris, France.,CNRS, UMR 7210, 75012 Paris, France
| | - José-Alain Sahel
- INSERM, UMR S 968, 75012 Paris, France.,Sorbonne Universités, UPMC Univ Paris 06, Institut de la Vision, Paris, France.,CNRS, UMR 7210, 75012 Paris, France.,Fondation Ophtalmologique Adolphe de Rothschild, 75019 Paris, France.,Centre d'Investigation Clinique 1423, INSERM-Center Hospitalier National d'Ophtalmologie des Quinze-Vingts, 75012 Paris, France.,Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
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150
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Abstract
Fluorescent protein-based biosensors are indispensable molecular tools for life science research. The invention and development of high-fidelity biosensors for a particular molecule or molecular event often catalyze important scientific breakthroughs. Understanding the structural and functional organization of brain activities remain a subject for which optical sensors are in desperate need and of growing interest. Here, we review genetically encoded fluorescent sensors for imaging neuronal activities with a focus on the design principles and optimizations of various sensors. New bioluminescent sensors useful for deep-tissue imaging are also discussed. By highlighting the protein engineering efforts and experimental applications of these sensors, we can consequently analyze factors influencing their performance. Finally, we remark on how future developments can fill technological gaps and lead to new discoveries.
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Affiliation(s)
- Zhijie Chen
- California Institute for Quantitative Biosciences, QB3, University of California, Berkeley, CA 94720, USA
| | - Tan M. Truong
- Center for Membrane and Cell Physiology, and Biomedical Sciences (BIMS) Graduate Program, University of Virginia, Charlottesville, VA 22908, USA
| | - Hui-wang Ai
- Center for Membrane and Cell Physiology, and Biomedical Sciences (BIMS) Graduate Program, University of Virginia, Charlottesville, VA 22908, USA
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA 22908, USA
- Correspondence:
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