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Cho YU, Lee JY, Yu KJ. Integration of in vivo electrophysiology and optogenetics in rodents with PEDOT:PSS neural electrode array. STAR Protoc 2024; 5:102909. [PMID: 38427565 PMCID: PMC10918330 DOI: 10.1016/j.xpro.2024.102909] [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] [Received: 11/23/2023] [Revised: 12/27/2023] [Accepted: 02/07/2024] [Indexed: 03/03/2024] Open
Abstract
Here, we present a protocol for the fabrication of transparent implantable electrode arrays for integrating optogenetics and electrophysiology. We describe steps for fabricating microelectrodes using the conductive polymer poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate). We then detail procedures for analyzing performance of the electrodes and recording light-evoked neural activities from the transgenic mouse. This protocol utilizes photolithography rather than conventional electrodeposition. For complete details on the use and execution of this protocol, please refer to Cho et al. (2022).1.
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Affiliation(s)
- Young Uk Cho
- School of Electrical and Electronic Engineering, Yonsei University, 50 Yonsei-ro, Seodaemungu, Seoul 03722, Republic of Korea
| | - Ju Young Lee
- School of Electrical and Electronic Engineering, Yonsei University, 50 Yonsei-ro, Seodaemungu, Seoul 03722, Republic of Korea
| | - Ki Jun Yu
- School of Electrical and Electronic Engineering, Yonsei University, 50 Yonsei-ro, Seodaemungu, Seoul 03722, Republic of Korea; School of Electrical and Electronic Engineering, YU-KIST Institute, Yonsei University, 50 Yonsei-ro, Seodaemungu, Seoul 03722, Republic of Korea.
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2
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de Melo MB, Daldegan-Bueno D, Favaro VM, Oliveira MGM. The subiculum role on learning and memory tasks using rats and mice: A scoping review. Neurosci Biobehav Rev 2023; 155:105460. [PMID: 37939978 DOI: 10.1016/j.neubiorev.2023.105460] [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] [Received: 07/13/2023] [Revised: 10/24/2023] [Accepted: 11/03/2023] [Indexed: 11/10/2023]
Abstract
This scoping review aimed to systematically identify and summarize data related to subiculum involvement in learning and memory behavioral tasks in rats and mice. Following a systematic strategy based on PICO and PRISMA guidelines, we searched five indexed databases (PubMed, Web of Science, EMBASE, Scopus, and PsycInfo) using a standardized search strategy to identify peer-reviewed articles published in English (pre-registration: osf.io/hm5ea). We identified 31 articles investigating the role of the subiculum in spatial, working, and recognition memories (n = 11), memories related to addiction models (n = 9), aversive memories (n = 7), and memories related to appetitive learning (n = 5). We highlight a dissociation in the dorsoventral axis of the subiculum with many studies exploring the ventral subiculum (n = 21) but only a few exploring the dorsal one (n = 10). We also observe the necessity of more data including mice, female animals, genetic tools, and better statistical approaches for replication purposes and research refinement. These findings provide a broad framework of the subiculum involvement in learning and memory, showing essential questions that can be explored by further studies.
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Affiliation(s)
- Márcio Braga de Melo
- Departamento de Psicobiologia, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Dimitri Daldegan-Bueno
- School of Pharmacy, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Vanessa Manchim Favaro
- Setor de Investigação de Doenças Neuromusculares, Departamento de Neurologia e Neurocirurgia, Universidade Federal de São Paulo, São Paulo, SP, Brazil
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3
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Fanni AM, Okoye D, Monge FA, Hammond J, Maghsoodi F, Martin TD, Brinkley G, Phipps ML, Evans DG, Martinez JS, Whitten DG, Chi EY. Controlled and Selective Photo-oxidation of Amyloid-β Fibrils by Oligomeric p-Phenylene Ethynylenes. ACS APPLIED MATERIALS & INTERFACES 2022; 14:14871-14886. [PMID: 35344326 PMCID: PMC10452927 DOI: 10.1021/acsami.1c22869] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Photodynamic therapy (PDT) has been explored as a therapeutic strategy to clear toxic amyloid aggregates involved in neurodegenerative disorders such as Alzheimer's disease. A major limitation of PDT is off-target oxidation, which can be lethal for the surrounding cells. We have shown that a novel class of oligo-p-phenylene ethynylenes (OPEs) exhibit selective binding and fluorescence turn-on in the presence of prefibrillar and fibrillar aggregates of disease-relevant proteins such as amyloid-β (Aβ) and α-synuclein. Concomitant with fluorescence turn-on, OPE also photosensitizes singlet oxygen under illumination through the generation of a triplet state, pointing to the potential application of OPEs as photosensitizers in PDT. Herein, we investigated the photosensitizing activity of an anionic OPE for the photo-oxidation of Aβ fibrils and compared its efficacy to the well-known but nonselective photosensitizer methylene blue (MB). Our results show that, while MB photo-oxidized both monomeric and fibrillar conformers of Aβ40, OPE oxidized only Aβ40 fibrils, targeting two histidine residues on the fibril surface and a methionine residue located in the fibril core. Oxidized fibrils were shorter and more dispersed but retained the characteristic β-sheet rich fibrillar structure and the ability to seed further fibril growth. Importantly, the oxidized fibrils displayed low toxicity. We have thus discovered a class of novel theranostics for the simultaneous detection and oxidization of amyloid aggregates. Importantly, the selectivity of OPE's photosensitizing activity overcomes the limitation of off-target oxidation of traditional photosensitizers and represents an advancement of PDT as a viable strategy to treat neurodegenerative disorders.
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Affiliation(s)
- Adeline M. Fanni
- Center for Biomedical Engineering, University of New Mexico, Albuquerque, NM 87131
- Biomedical Engineering Graduate Program, University of New Mexico, Albuquerque, NM. 87131
| | - Daniel Okoye
- Center for Biomedical Engineering, University of New Mexico, Albuquerque, NM 87131
| | - Florencia A. Monge
- Center for Biomedical Engineering, University of New Mexico, Albuquerque, NM 87131
- Biomedical Engineering Graduate Program, University of New Mexico, Albuquerque, NM. 87131
| | - Julia Hammond
- Department of Chemical and Biological Engineering, University of New Mexico, Albuquerque, NM. 87131
- Rose-Hulman Institute of Technology, Terre Haute, IN 47803
| | - Fahimeh Maghsoodi
- Nanoscience and Microsystems Engineering Graduate Program, University of New Mexico, Albuquerque, NM 87131
| | - Tye D. Martin
- Center for Biomedical Engineering, University of New Mexico, Albuquerque, NM 87131
- Biomedical Engineering Graduate Program, University of New Mexico, Albuquerque, NM. 87131
| | - Gabriella Brinkley
- Department of Chemical and Biological Engineering, University of New Mexico, Albuquerque, NM. 87131
- Chemical Engineering Department, University of Minnesota, Duluth, MN 55812
| | - M. Lisa Phipps
- Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, NM 87545
| | - Deborah G. Evans
- Department of Chemistry and Chemical Biology, University of New Mexico, NM 87131
| | - Jennifer S. Martinez
- Center for Materials Interfaces in Research and Applications, Northern Arizona University, Flagstaff, AZ 86011
- Department of Applied Physics and Materials Science, Northern Arizona University, Flagstaff, AZ 86011
| | - David G. Whitten
- Center for Biomedical Engineering, University of New Mexico, Albuquerque, NM 87131
- Department of Chemical and Biological Engineering, University of New Mexico, Albuquerque, NM. 87131
| | - Eva Y. Chi
- Center for Biomedical Engineering, University of New Mexico, Albuquerque, NM 87131
- Department of Chemical and Biological Engineering, University of New Mexico, Albuquerque, NM. 87131
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Li J, Yang L, Guo Q, Du P, Wang L, Zhao X, Liu N, Yang X, Luo J, Tang J. All-vacuum fabrication of yellow perovskite light-emitting diodes. Sci Bull (Beijing) 2022; 67:178-185. [DOI: 10.1016/j.scib.2021.09.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Revised: 07/15/2021] [Accepted: 08/13/2021] [Indexed: 11/30/2022]
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Current Review of Optical Neural Interfaces for Clinical Applications. MICROMACHINES 2021; 12:mi12080925. [PMID: 34442547 PMCID: PMC8400671 DOI: 10.3390/mi12080925] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 07/20/2021] [Accepted: 07/29/2021] [Indexed: 11/16/2022]
Abstract
Neural interfaces, which enable the recording and stimulation of living neurons, have emerged as valuable tools in understanding the brain in health and disease, as well as serving as neural prostheses. While neural interfaces are typically based on electrical transduction, alternative energy modalities have been explored to create safe and effective approaches. Among these approaches, optical methods of linking neurons to the outside world have gained attention because light offers high spatial selectivity and decreased invasiveness. Here, we review the current state-of-art of optical neural interfaces and their clinical applications. Optical neural interfaces can be categorized into optical control and optical readout, each of which can be divided into intrinsic and extrinsic approaches. We discuss the advantages and disadvantages of each of these methods and offer a comparison of relative performance. Future directions, including their clinical opportunities, are discussed with regard to the optical properties of biological tissue.
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Gheorghiu M, Polonschii C, Popescu O, Gheorghiu E. Advanced Optogenetic-Based Biosensing and Related Biomaterials. MATERIALS 2021; 14:ma14154151. [PMID: 34361345 PMCID: PMC8347019 DOI: 10.3390/ma14154151] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 07/12/2021] [Accepted: 07/20/2021] [Indexed: 02/07/2023]
Abstract
The ability to stimulate mammalian cells with light, brought along by optogenetic control, has significantly broadened our understanding of electrically excitable tissues. Backed by advanced (bio)materials, it has recently paved the way towards novel biosensing concepts supporting bio-analytics applications transversal to the main biomedical stream. The advancements concerning enabling biomaterials and related novel biosensing concepts involving optogenetics are reviewed with particular focus on the use of engineered cells for cell-based sensing platforms and the available toolbox (from mere actuators and reporters to novel multifunctional opto-chemogenetic tools) for optogenetic-enabled real-time cellular diagnostics and biosensor development. The key advantages of these modified cell-based biosensors concern both significantly faster (minutes instead of hours) and higher sensitivity detection of low concentrations of bioactive/toxic analytes (below the threshold concentrations in classical cellular sensors) as well as improved standardization as warranted by unified analytic platforms. These novel multimodal functional electro-optical label-free assays are reviewed among the key elements for optogenetic-based biosensing standardization. This focused review is a potential guide for materials researchers interested in biosensing based on light-responsive biomaterials and related analytic tools.
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Affiliation(s)
- Mihaela Gheorghiu
- International Centre of Biodynamics, 1B Intrarea Portocalelor, 060101 Bucharest, Romania;
- Correspondence: (M.G.); (E.G.)
| | - Cristina Polonschii
- International Centre of Biodynamics, 1B Intrarea Portocalelor, 060101 Bucharest, Romania;
| | - Octavian Popescu
- Molecular Biology Center, Institute for Interdisciplinary Research in Bio-Nano-Sciences, Babes-Bolyai-University, 400084 Cluj-Napoca, Romania;
- Institute of Biology Bucharest, Romanian Academy, 296 Splaiul Independentei, 060031 Bucharest, Romania
| | - Eugen Gheorghiu
- International Centre of Biodynamics, 1B Intrarea Portocalelor, 060101 Bucharest, Romania;
- Correspondence: (M.G.); (E.G.)
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Jeong J, Jung J, Jung D, Kim J, Ju H, Kim T, Lee J. An implantable optogenetic stimulator wirelessly powered by flexible photovoltaics with near-infrared (NIR) light. Biosens Bioelectron 2021; 180:113139. [PMID: 33714161 DOI: 10.1016/j.bios.2021.113139] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 02/17/2021] [Accepted: 02/28/2021] [Indexed: 12/11/2022]
Abstract
Optogenetics is a cutting-edge tool in neuroscience that employs light-sensitive proteins and controlled illumination for neuromodulation. Its main advantage is the ability to demonstrate causal relationships by manipulating the activity of specific neuronal populations and observing behavioral phenotypes. However, the tethering system used to deliver light to optogenetic tools can constrain both natural animal behaviors and experimental design. Here, we present an optically powered and controlled wireless optogenetic system using near-infrared (NIR) light for high transmittance through live tissues. In vivo optogenetic stimulations using this system induced whisker movement in channelrhodopsin-expressing mice, confirming the photovoltaics-generated electrical power was sufficient, and the remote controlling system operated successfully. The proposed optogenetic system provides improved optogenetic applications in freely moving animals.
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Affiliation(s)
- Jinmo Jeong
- School of Mechanical Engineering, Gwangju Institute of Science and Technology (GIST), 123 Cheomdangwagi-ro, Buk-gu, Gwangju, 61005, Republic of Korea
| | - Jieun Jung
- Department of Biomedical Science and Engineering, Gwangju Institute of Science and Technology (GIST), 123 Cheomdangwagi-ro, Buk-gu, Gwangju, 61005, Republic of Korea
| | - Dongwuk Jung
- School of Mechanical Engineering, Gwangju Institute of Science and Technology (GIST), 123 Cheomdangwagi-ro, Buk-gu, Gwangju, 61005, Republic of Korea
| | - Juho Kim
- Department of Applied Nano-Mechanics, Nano-Convergence Manufacturing Systems Research Division, Korea Institute of Machinery & Materials (KIMM), 156 Gajeongbuk-Ro, Yuseong-Gu, Daejeon, 34103, Republic of Korea
| | - Hunpyo Ju
- School of Mechanical Engineering, Gwangju Institute of Science and Technology (GIST), 123 Cheomdangwagi-ro, Buk-gu, Gwangju, 61005, Republic of Korea
| | - Tae Kim
- Department of Biomedical Science and Engineering, Gwangju Institute of Science and Technology (GIST), 123 Cheomdangwagi-ro, Buk-gu, Gwangju, 61005, Republic of Korea.
| | - Jongho Lee
- School of Mechanical Engineering, Gwangju Institute of Science and Technology (GIST), 123 Cheomdangwagi-ro, Buk-gu, Gwangju, 61005, Republic of Korea.
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Mocanu VM, Shmuel A. Optical Imaging-Based Guidance of Viral Microinjections and Insertion of a Laminar Electrophysiology Probe Into a Predetermined Barrel in Mouse Area S1BF. Front Neural Circuits 2021; 15:541676. [PMID: 34054436 PMCID: PMC8158817 DOI: 10.3389/fncir.2021.541676] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 03/31/2021] [Indexed: 12/04/2022] Open
Abstract
Wide-field Optical Imaging of Intrinsic Signals (OI-IS; Grinvald et al., 1986) is a method for imaging functional brain hemodynamic responses, mainly used to image activity from the surface of the cerebral cortex. It localizes small functional modules – such as cortical columns – with great spatial resolution and spatial specificity relative to the site of increases in neuronal activity. OI-IS is capable of imaging responses either through an intact or thinned skull or following a craniotomy. Therefore, it is minimally invasive, which makes it ideal for survival experiments. Here we describe OI-IS-based methods for guiding microinjections of optogenetics viral vectors in proximity to small functional modules (S1 barrels) of the cerebral cortex and for guiding the insertion of electrodes for electrophysiological recording into such modules. We validate our proposed methods by tissue processing of the cerebral barrel field area, revealing the track of the electrode in a predetermined barrel. In addition, we demonstrate the use of optical imaging to visualize the spatial extent of the optogenetics photostimulation, making it possible to estimate one of the two variables that conjointly determine which region of the brain is stimulated. Lastly, we demonstrate the use of OI-IS at high-magnification for imaging the upper recording contacts of a laminar probe, making it possible to estimate the insertion depth of all contacts relative to the surface of the cortex. These methods support the precise positioning of microinjections and recording electrodes, thus overcoming the variability in the spatial position of fine-scale functional modules.
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Affiliation(s)
- Victor M Mocanu
- McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, QC, Canada.,Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
| | - Amir Shmuel
- McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, QC, Canada.,Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada.,Department of Physiology, McGill University, Montreal, QC, Canada.,Department of Biomedical Engineering, McGill University, Montreal, QC, Canada
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Neural substrates involved in the cognitive information processing in teleost fish. Anim Cogn 2021; 24:923-946. [PMID: 33907938 PMCID: PMC8360893 DOI: 10.1007/s10071-021-01514-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Revised: 02/25/2021] [Accepted: 03/06/2021] [Indexed: 02/04/2023]
Abstract
Over the last few decades, it has been shown that fish, comprising the largest group of vertebrates and in many respects one of the least well studied, possess many cognitive abilities comparable to those of birds and mammals. Despite a plethora of behavioural studies assessing cognition abilities and an abundance of neuroanatomical studies, only few studies have aimed to or in fact identified the neural substrates involved in the processing of cognitive information. In this review, an overview of the currently available studies addressing the joint research topics of cognitive behaviour and neuroscience in teleosts (and elasmobranchs wherever possible) is provided, primarily focusing on two fundamentally different but complementary approaches, i.e. ablation studies and Immediate Early Gene (IEG) analyses. More recently, the latter technique has become one of the most promising methods to visualize neuronal populations activated in specific brain areas, both during a variety of cognitive as well as non-cognition-related tasks. While IEG studies may be more elegant and potentially easier to conduct, only lesion studies can help researchers find out what information animals can learn or recall prior to and following ablation of a particular brain area.
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A Novel Research Technology to Explore the Mystery of Traditional Chinese Medicine: Optogenetics. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2021. [DOI: 10.1155/2021/6613368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Traditional Chinese medicine (TCM) is gaining increasing popularity worldwide for the function of health promotion and adjuvant therapy. However, the world's understanding of TCM is far from enough, which seriously limits the modernization and internationalization of TCM. Therefore, modern and efficient analytical methods are urgently needed to understand the mechanism of TCM. Optogenetics is one of the most prevalent technologies in the 21st century and has been used to explore life science, especially neuroscience. It already has had great influences in the study of neural circuits and animal models of mental diseases and was named “Method of the Year” by the Nature Methods journal in 2010. Increased interests occurred in the applications of optogenetics to explore a myriad of medical and mental health disorders. However, it has not so far been noticed by TCM researchers. We elaborated on an idea that introducing this technique into the field of TCM research to improve diagnosis, treatments, and evaluating the therapeutic effects. In this review, we made a systematic prospect in the theory, feasibility, and application of TCM optogenetics. We mainly focused on applying optogenetic methodologies to make a more comprehensive understanding of TCM.
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Abstract
The electromechanical function of the heart involves complex, coordinated activity over time and space. Life-threatening cardiac arrhythmias arise from asynchrony in these space-time events; therefore, therapies for prevention and treatment require fundamental understanding and the ability to visualize, perturb and control cardiac activity. Optogenetics combines optical and molecular biology (genetic) approaches for light-enabled sensing and actuation of electrical activity with unprecedented spatiotemporal resolution and parallelism. The year 2020 marks a decade of developments in cardiac optogenetics since this technology was adopted from neuroscience and applied to the heart. In this Review, we appraise a decade of advances that define near-term (immediate) translation based on all-optical electrophysiology, including high-throughput screening, cardiotoxicity testing and personalized medicine assays, and long-term (aspirational) prospects for clinical translation of cardiac optogenetics, including new optical therapies for rhythm control. The main translational opportunities and challenges for optogenetics to be fully embraced in cardiology are also discussed.
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Alzheimer's Disease as a Result of Stimulus Reduction in a GABA-A-Deficient Brain: A Neurocomputational Model. Neural Plast 2020; 2020:8895369. [PMID: 33123190 PMCID: PMC7582082 DOI: 10.1155/2020/8895369] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 08/17/2020] [Accepted: 09/09/2020] [Indexed: 02/07/2023] Open
Abstract
Several research studies point to the fact that sensory and cognitive reductions like cataracts, deafness, macular degeneration, or even lack of activity after job retirement, precede the onset of Alzheimer's disease. To simulate Alzheimer's disease earlier stages, which manifest in sensory cortices, we used a computational model of the koniocortex that is the first cortical stage processing sensory information. The architecture and physiology of the modeled koniocortex resemble those of its cerebral counterpart being capable of continuous learning. This model allows one to analyze the initial phases of Alzheimer's disease by “aging” the artificial koniocortex through synaptic pruning, by the modification of acetylcholine and GABA-A signaling, and by reducing sensory stimuli, among other processes. The computational model shows that during aging, a GABA-A deficit followed by a reduction in sensory stimuli leads to a dysregulation of neural excitability, which in the biological brain is associated with hypermetabolism, one of the earliest symptoms of Alzheimer's disease.
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Cardiac Optogenetics in Atrial Fibrillation: Current Challenges and Future Opportunities. BIOMED RESEARCH INTERNATIONAL 2020; 2020:8814092. [PMID: 33195698 PMCID: PMC7641281 DOI: 10.1155/2020/8814092] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 10/07/2020] [Indexed: 12/23/2022]
Abstract
Although rarely life-threatening on short term, atrial fibrillation leads to increased mortality and decreased quality of life through its complications, including heart failure and stroke. Recent studies highlight the benefits of maintaining sinus rhythm. However, pharmacological long-term rhythm control strategies may be shadowed by associated proarrhythmic effects. At the same time, electrical cardioversion is limited to hospitals, while catheter ablation therapy, although effective, is invasive and is dedicated to specific patients, usually with low amounts of atrial fibrosis (preferably Utah I-II). Cardiac optogenetics allows influencing the heart's electrical activity by applying specific wavelength light pulses to previously engineered cardiomyocytes into expressing microbial derived light-sensitive proteins called opsins. The resulting ion influx may give rise to either hyperpolarizing or depolarizing currents, thus offering a therapeutic potential in cardiac electrophysiology, including pacing, resynchronization, and arrhythmia termination. Optogenetic atrial fibrillation cardioversion might be achieved by inducing a conduction block or filling of the excitable gap. The authors agree that transmural opsin expression and appropriate illumination with an exposure time longer than the arrhythmia cycle length are necessary to achieve successful arrhythmia termination. However, the efficiency and safety of biological cardioversion in humans remain to be seen, as well as side effects such as immune reactions and loss of opsin expression. The possibility of delivering pain-free shocks with out-of-hospital biological cardioversion is tempting; however, there are several issues that need to be addressed first: applicability and safety in humans, long-term behaviour, anticoagulation requirements, and fibrosis interactions.
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Lu X, Shen Y, Campbell RE. Engineering Photosensory Modules of Non-Opsin-Based Optogenetic Actuators. Int J Mol Sci 2020; 21:E6522. [PMID: 32906617 PMCID: PMC7555876 DOI: 10.3390/ijms21186522] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 09/03/2020] [Accepted: 09/04/2020] [Indexed: 11/17/2022] Open
Abstract
Optogenetic (photo-responsive) actuators engineered from photoreceptors are widely used in various applications to study cell biology and tissue physiology. In the toolkit of optogenetic actuators, the key building blocks are genetically encodable light-sensitive proteins. Currently, most optogenetic photosensory modules are engineered from naturally-occurring photoreceptor proteins from bacteria, fungi, and plants. There is a growing demand for novel photosensory domains with improved optical properties and light-induced responses to satisfy the needs of a wider variety of studies in biological sciences. In this review, we focus on progress towards engineering of non-opsin-based photosensory domains, and their representative applications in cell biology and physiology. We summarize current knowledge of engineering of light-sensitive proteins including light-oxygen-voltage-sensing domain (LOV), cryptochrome (CRY2), phytochrome (PhyB and BphP), and fluorescent protein (FP)-based photosensitive domains (Dronpa and PhoCl).
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Affiliation(s)
- Xiaocen Lu
- Department of Chemistry, University of Alberta, Edmonton, AB T6G 2G2, Canada; (X.L.); (Y.S.)
| | - Yi Shen
- Department of Chemistry, University of Alberta, Edmonton, AB T6G 2G2, Canada; (X.L.); (Y.S.)
| | - Robert E. Campbell
- Department of Chemistry, University of Alberta, Edmonton, AB T6G 2G2, Canada; (X.L.); (Y.S.)
- Department of Chemistry, The University of Tokyo, Tokyo 113-0033, Japan
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Li C, Wang J, Liu L. Alzheimer's Therapeutic Strategy: Photoactive Platforms for Suppressing the Aggregation of Amyloid β Protein. Front Chem 2020; 8:509. [PMID: 32793545 PMCID: PMC7385073 DOI: 10.3389/fchem.2020.00509] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 05/18/2020] [Indexed: 01/09/2023] Open
Abstract
Neurodegenerative diseases such as Alzheimer's disease (AD) have become a public health problem. Progressive cerebral accumulation of amyloid protein (Aβ) was widely considered as the cause of AD. One promising strategy for AD preclinical study is to degrade and clear the deposited amyloid aggregates with β-sheet-rich secondary structure in the brain. Based on the requirement, photo-active materials with the specific excitation and the standardization of the photosensitizer preparation and application in clinics, have attracted increased attention in the study and treatment of neurodegenerative disease as a novel method termed as photodynamic therapy (PDT). This review will focus on the new photosensitizing materials and discuss the trend of PDT techniques for the possible application in the treatment strategy of amyloid-related diseases.
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Affiliation(s)
- Chenglong Li
- School of Material Science and Engineering, Institute for Advanced Materials, Jiangsu University, Zhenjiang, China
| | - Jie Wang
- School of Material Science and Engineering, Institute for Advanced Materials, Jiangsu University, Zhenjiang, China
| | - Lei Liu
- School of Material Science and Engineering, Institute for Advanced Materials, Jiangsu University, Zhenjiang, China
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Wang H, Zhou X, Cui D, Liu R, Tan R, Wang X, Liu Z, Yin T. Comparative Study of Transcranial Magneto-Acoustic Stimulation and Transcranial Ultrasound Stimulation of Motor Cortex. Front Behav Neurosci 2019; 13:241. [PMID: 31680896 PMCID: PMC6798265 DOI: 10.3389/fnbeh.2019.00241] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Accepted: 09/24/2019] [Indexed: 11/13/2022] Open
Abstract
Transcranial ultrasound stimulation (TUS; f < 1 MHz) is a promising approach to non-invasive brain stimulation. Transcranial magneto-acoustic stimulation (TMAS) is a technique of neuromodulation for regulating neuroelectric-activity utilizing a magnetic-acoustic coupling electric field generated by low-intensity ultrasound and magnetic fields. However, both techniques use the physical means of low-intensity ultrasound and can induce the response of the motor cortex. Therefore, it is necessary to distinguish the difference between the two techniques in the regulation of neural activity. This study is the first to quantify the amplitude and response latency of motor cortical electromyography (EMG) in mice induced by TMAS and TUS. The amplitude of EMG (2.73 ± 0.32 mV) induced by TMAS was significantly greater than that induced by TUS (2.22 ± 0.33 mV), and the EMG response latency induced by TMAS (101.25 ± 88.4 ms) was significantly lower than that induced by TUS (181.25 ± 158.4 ms). This shows that TMAS can shorten the response time of nerve activity and enhance the neuromodulation effect of TUS on the motor cortex. This provides a theoretical basis for revealing the physiological mechanisms of TMAS and the treatment of neuropsychiatric diseases using it.
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Affiliation(s)
| | | | | | | | | | | | - Zhipeng Liu
- Peking Union Medical College, Institute of Biomedical Engineering, Chinese Academy of Medical Sciences, Tianjin, China
| | - Tao Yin
- Peking Union Medical College, Institute of Biomedical Engineering, Chinese Academy of Medical Sciences, Tianjin, China
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17
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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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18
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Chidambaram SB, Rathipriya AG, Bolla SR, Bhat A, Ray B, Mahalakshmi AM, Manivasagam T, Thenmozhi AJ, Essa MM, Guillemin GJ, Chandra R, Sakharkar MK. Dendritic spines: Revisiting the physiological role. Prog Neuropsychopharmacol Biol Psychiatry 2019; 92:161-193. [PMID: 30654089 DOI: 10.1016/j.pnpbp.2019.01.005] [Citation(s) in RCA: 150] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2018] [Revised: 01/04/2019] [Accepted: 01/12/2019] [Indexed: 12/11/2022]
Abstract
Dendritic spines are small, thin, specialized protrusions from neuronal dendrites, primarily localized in the excitatory synapses. Sophisticated imaging techniques revealed that dendritic spines are complex structures consisting of a dense network of cytoskeletal, transmembrane and scaffolding molecules, and numerous surface receptors. Molecular signaling pathways, mainly Rho and Ras family small GTPases pathways that converge on actin cytoskeleton, regulate the spine morphology and dynamics bi-directionally during synaptic activity. During synaptic plasticity the number and shapes of dendritic spines undergo radical reorganizations. Long-term potentiation (LTP) induction promote spine head enlargement and the formation and stabilization of new spines. Long-term depression (LTD) results in their shrinkage and retraction. Reports indicate increased spine density in the pyramidal neurons of autism and Fragile X syndrome patients and reduced density in the temporal gyrus loci of schizophrenic patients. Post-mortem reports of Alzheimer's brains showed reduced spine number in the hippocampus and cortex. This review highlights the spine morphogenesis process, the activity-dependent structural plasticity and mechanisms by which synaptic activity sculpts the dendritic spines, the structural and functional changes in spines during learning and memory using LTP and LTD processes. It also discusses on spine status in neurodegenerative diseases and the impact of nootropics and neuroprotective agents on the functional restoration of dendritic spines.
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Affiliation(s)
- Saravana Babu Chidambaram
- Department of Pharmacology, JSS College of Pharmacy, JSS Academy of Higher Education & Research (JSSAHER), Mysuru, Karnataka 570015, India.
| | - A G Rathipriya
- Food and Brain Research Foundation, Chennai, Tamil Nadu, India
| | - Srinivasa Rao Bolla
- Department of Anatomy, College of Medicine, Imam Abdulrahman Bin Faisal University, Damam, Saudi Arabia
| | - Abid Bhat
- Department of Pharmacology, JSS College of Pharmacy, JSS Academy of Higher Education & Research (JSSAHER), Mysuru, Karnataka 570015, India
| | - Bipul Ray
- Department of Pharmacology, JSS College of Pharmacy, JSS Academy of Higher Education & Research (JSSAHER), Mysuru, Karnataka 570015, India
| | - Arehally Marappa Mahalakshmi
- Department of Pharmacology, JSS College of Pharmacy, JSS Academy of Higher Education & Research (JSSAHER), Mysuru, Karnataka 570015, India
| | - Thamilarasan Manivasagam
- Department of Biochemistry and Biotechnology, Faculty of Science, Annamalai University, Annamalainagar, Tamilnadu, India
| | - Arokiasamy Justin Thenmozhi
- Department of Biochemistry and Biotechnology, Faculty of Science, Annamalai University, Annamalainagar, Tamilnadu, India
| | - Musthafa Mohamed Essa
- Department of Food Science and Nutrition, CAMS, Sultan Qaboos University, Muscat, Oman
| | - Gilles J Guillemin
- Neuropharmacology Group, Faculty of Medicine and Health Sciences, Deb Bailey MND Research Laboratory, Macquarie University, Sydney, NSW 2109, Australia
| | - Ramesh Chandra
- Department of Chemistry, Ambedkar Centre for BioMedical Research, Delhi University, Delhi 110007, India
| | - Meena Kishore Sakharkar
- College of Pharmacy and Nutrition, University of Saskatchewan, 107, Wiggins Road, Saskatoon, SK S7N 5C9, Canada.
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19
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Antognazza MR, Abdel Aziz I, Lodola F. Use of Exogenous and Endogenous Photomediators as Efficient ROS Modulation Tools: Results and Perspectives for Therapeutic Purposes. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:2867516. [PMID: 31049131 PMCID: PMC6462332 DOI: 10.1155/2019/2867516] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 01/15/2019] [Indexed: 01/09/2023]
Abstract
Reactive Oxygen Species (ROS) play an essential dual role in living systems. Healthy levels of ROS modulate several signaling pathways, but at the same time, when they exceed normal physiological amounts, they work in the opposite direction, playing pivotal functions in the pathophysiology of multiple severe medical conditions (i.e., cancer, diabetes, neurodegenerative and cardiovascular diseases, and aging). Therefore, the research for methods to detect their levels via light-sensitive fluorescent probes has been extensively studied over the years. However, this is not the only link between light and ROS. In fact, the modulation of ROS mediated by light has been exploited already for a long time. In this review, we report the state of the art, as well as recent developments, in the field of photostimulation of oxidative stress, from photobiomodulation (PBM) mediated by naturally expressed light-sensitive proteins to the most recent optogenetic approaches, and finally, we describe the main methods of exogenous stimulation, in particular highlighting the new insights based on optically driven ROS modulation mediated by polymeric materials.
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Affiliation(s)
- Maria Rosa Antognazza
- Center for Nano Science and Technology, Istituto Italiano di Tecnologia, Via Pascoli 70/3, 20133 Milano, Italy
| | - Ilaria Abdel Aziz
- Center for Nano Science and Technology, Istituto Italiano di Tecnologia, Via Pascoli 70/3, 20133 Milano, Italy
- Politecnico di Milano, Dipartimento di Fisica, Piazza L. Da Vinci 32, 20133 Milano, Italy
| | - Francesco Lodola
- Center for Nano Science and Technology, Istituto Italiano di Tecnologia, Via Pascoli 70/3, 20133 Milano, Italy
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20
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Dokukina I, Nenov A, Garavelli M, Marian CM, Weingart O. QM/MM Photodynamics of Retinal in the Channelrhodopsin Chimera C1C2 with OM3/MRCI. CHEMPHOTOCHEM 2019. [DOI: 10.1002/cptc.201800185] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Irina Dokukina
- Institut für Theoretische Chemie und ComputerchemieHeinrich-Heine-Universität Düsseldorf Universitätsstr. 1 40225 Düsseldorf Germany
| | - Artur Nenov
- Dipartimento di Chimica Industriale “Toso Montanari”Universitá degli Studi di Bologna Viale del Risorgimento, 4 40136 Bologna Italia
| | - Marco Garavelli
- Dipartimento di Chimica Industriale “Toso Montanari”Universitá degli Studi di Bologna Viale del Risorgimento, 4 40136 Bologna Italia
| | - Christel M. Marian
- Institut für Theoretische Chemie und ComputerchemieHeinrich-Heine-Universität Düsseldorf Universitätsstr. 1 40225 Düsseldorf Germany
| | - Oliver Weingart
- Institut für Theoretische Chemie und ComputerchemieHeinrich-Heine-Universität Düsseldorf Universitätsstr. 1 40225 Düsseldorf Germany
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21
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Milas A, Jagrić M, Martinčić J, Tolić IM. Optogenetic reversible knocksideways, laser ablation, and photoactivation on the mitotic spindle in human cells. Methods Cell Biol 2018; 145:191-215. [DOI: 10.1016/bs.mcb.2018.03.024] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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22
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Optogenetic Tools for Subcellular Applications in Neuroscience. Neuron 2017; 96:572-603. [PMID: 29096074 DOI: 10.1016/j.neuron.2017.09.047] [Citation(s) in RCA: 216] [Impact Index Per Article: 30.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 03/30/2017] [Accepted: 09/26/2017] [Indexed: 12/21/2022]
Abstract
The ability to study cellular physiology using photosensitive, genetically encoded molecules has profoundly transformed neuroscience. The modern optogenetic toolbox includes fluorescent sensors to visualize signaling events in living cells and optogenetic actuators enabling manipulation of numerous cellular activities. Most optogenetic tools are not targeted to specific subcellular compartments but are localized with limited discrimination throughout the cell. Therefore, optogenetic activation often does not reflect context-dependent effects of highly localized intracellular signaling events. Subcellular targeting is required to achieve more specific optogenetic readouts and photomanipulation. Here we first provide a detailed overview of the available optogenetic tools with a focus on optogenetic actuators. Second, we review established strategies for targeting these tools to specific subcellular compartments. Finally, we discuss useful tools and targeting strategies that are currently missing from the optogenetics repertoire and provide suggestions for novel subcellular optogenetic applications.
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23
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Shedding Light on Alzheimer's β-Amyloidosis: Photosensitized Methylene Blue Inhibits Self-Assembly of β-Amyloid Peptides and Disintegrates Their Aggregates. Sci Rep 2017; 7:7523. [PMID: 28790398 PMCID: PMC5548810 DOI: 10.1038/s41598-017-07581-2] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 06/27/2017] [Indexed: 02/06/2023] Open
Abstract
Abnormal aggregation of β-amyloid (Aβ) peptides is a major hallmark of Alzheimer’s disease (AD). In spite of numerous attempts to prevent the β-amyloidosis, no effective drugs for treating AD have been developed to date. Among many candidate chemicals, methylene blue (MB) has proved its therapeutic potential for AD in a number of in vitro and in vivo studies; but the result of recent clinical trials performed with MB and its derivative was negative. Here, with the aid of multiple photochemical analyses, we first report that photoexcited MB molecules can block Aβ42 aggregation in vitro. Furthermore, our in vivo study using Drosophila AD model demonstrates that photoexcited MB is highly effective in suppressing synaptic toxicity, resulting in a reduced damage to the neuromuscular junction (NMJ), an enhanced locomotion, and decreased vacuole in the brain. The hindrance effect is attributed to Aβ42 oxidation by singlet oxygen (1O2) generated from photoexcited MB. Finally, we show that photoexcited MB possess a capability to disaggregate the pre-existing Aβ42 aggregates and reduce Aβ-induced cytotoxicity. Our work suggests that light illumination can provide an opportunity to boost the efficacies of MB toward photodynamic therapy of AD in future.
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24
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Berlin S, Isacoff EY. Synapses in the spotlight with synthetic optogenetics. EMBO Rep 2017; 18:677-692. [PMID: 28396573 DOI: 10.15252/embr.201744010] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 03/02/2017] [Accepted: 03/09/2017] [Indexed: 12/15/2022] Open
Abstract
Membrane receptors and ion channels respond to various stimuli and relay that information across the plasma membrane by triggering specific and timed processes. These include activation of second messengers, allowing ion permeation, and changing cellular excitability, to name a few. Gaining control over equivalent processes is essential to understand neuronal physiology and pathophysiology. Recently, new optical techniques have emerged proffering new remote means to control various functions of defined neuronal populations by light, dubbed optogenetics. Still, optogenetic tools do not typically address the activity of receptors and channels native to neurons (or of neuronal origin), nor gain access to their signaling mechanisms. A related method-synthetic optogenetics-bridges this gap by endowing light sensitivity to endogenous neuronal receptors and channels by the appending of synthetic, light-receptive molecules, or photoswitches. This provides the means to photoregulate neuronal receptors and channels and tap into their native signaling mechanisms in select regions of the neurons, such as the synapse. This review discusses the development of synthetic optogenetics as a means to study neuronal receptors and channels remotely, in their natural environment, with unprecedented spatial and temporal precision, and provides an overview of tool design, mode of action, potential clinical applications and insights and achievements gained.
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Affiliation(s)
- Shai Berlin
- The Ruth and Bruce Rappaport Faculty of Medicine, Technion- Israel Institute of Technology, Haifa, Israel
| | - Ehud Y Isacoff
- Helen Wills Neuroscience Institute, University of California, Berkeley, CA, USA.,Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA.,Physical Bioscience Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
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25
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Yoshida K, Tsunoda SP, Brown LS, Kandori H. A unique choanoflagellate enzyme rhodopsin exhibits light-dependent cyclic nucleotide phosphodiesterase activity. J Biol Chem 2017; 292:7531-7541. [PMID: 28302718 DOI: 10.1074/jbc.m117.775569] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Revised: 03/13/2017] [Indexed: 12/28/2022] Open
Abstract
Photoactivated adenylyl cyclase (PAC) and guanylyl cyclase rhodopsin increase the concentrations of intracellular cyclic nucleotides upon illumination, serving as promising second-generation tools in optogenetics. To broaden the arsenal of such tools, it is desirable to have light-activatable enzymes that can decrease cyclic nucleotide concentrations in cells. Here, we report on an unusual microbial rhodopsin that may be able to meet the demand. It is found in the choanoflagellate Salpingoeca rosetta and contains a C-terminal cyclic nucleotide phosphodiesterase (PDE) domain. We examined the enzymatic activity of the protein (named Rh-PDE) both in HEK293 membranes and whole cells. Although Rh-PDE was constitutively active in the dark, illumination increased its hydrolytic activity 1.4-fold toward cGMP and 1.6-fold toward cAMP, as measured in isolated crude membranes. Purified full-length Rh-PDE displayed maximal light absorption at 492 nm and formed the M intermediate with the deprotonated Schiff base upon illumination. The M state decayed to the parent spectral state in 7 s, producing long-lasting activation of the enzyme domain with increased activity. We discuss a possible mechanism of the Rh-PDE activation by light. Furthermore, Rh-PDE decreased cAMP concentration in HEK293 cells in a light-dependent manner and could do so repeatedly without losing activity. Thus, Rh-PDE may hold promise as a potential optogenetic tool for light control of intracellular cyclic nucleotides (e.g. to study cyclic nucleotide-associated signal transduction cascades).
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Affiliation(s)
- Kazuho Yoshida
- From the Department of Life Science and Applied Chemistry and
| | - Satoshi P Tsunoda
- From the Department of Life Science and Applied Chemistry and .,JST PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012, Japan, and.,the OptoBioTechnology Research Center, Nagoya Institute of Technology, Showa-ku, Nagoya 466-8555, Japan
| | - Leonid S Brown
- the Department of Physics, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - Hideki Kandori
- From the Department of Life Science and Applied Chemistry and .,the OptoBioTechnology Research Center, Nagoya Institute of Technology, Showa-ku, Nagoya 466-8555, Japan
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26
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Brenker K, Osthof K, Yang J, Reth M. LED Thermo Flow - Combining Optogenetics with Flow Cytometry. J Vis Exp 2016. [PMID: 28060327 DOI: 10.3791/54707] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Optogenetic tools allow isolated, functional investigations of almost any signaling molecule within complex signaling pathways. A major obstacle is the controlled delivery of light to the cell sample and hence the most popular tools for optogenetic studies are microscopy-based cell analyses and in vitro experiments. The flow cytometer has major advantages over a microscope, including the ability to rapidly measure thousands of cells at single cell resolution. However, it is not yet widely used in optogenetics. Here, we present a device that combines the power of optogenetics and flow cytometry: the LED Thermo Flow. This device illuminates cells at specific wavelengths, light intensities and temperatures during flow cytometric measurements. It can be built at low cost and be used with most common flow cytometers. To demonstrate its utility, we characterized the photoswitching kinetics of Dronpa proteins in vivo and in real time. This protocol can be adapted to almost all optically controlled substances and substantially expands the set of possible experiments. More importantly, it will greatly simplify the discovery and development of new optogenetic tools.
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Affiliation(s)
- Kathrin Brenker
- Max-Planck Institute for Immunobiology und Epigenetics; Spemann Graduate School of Biology and Medicine (SGBM), University of Freiburg; Centre for Biological Signaling Studies, BIOSS, University of Freiburg;
| | - Kerstin Osthof
- Max-Planck Institute for Immunobiology und Epigenetics; Albert-Ludwigs-Universität
| | - Jianying Yang
- Max-Planck Institute for Immunobiology und Epigenetics; Centre for Biological Signaling Studies, BIOSS, University of Freiburg
| | - Michael Reth
- Max-Planck Institute for Immunobiology und Epigenetics; Centre for Biological Signaling Studies, BIOSS, University of Freiburg; Institute for Biology III (Mol. Immunology), Albert-Ludwigs-Universität
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27
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Vassanelli S, Mahmud M. Trends and Challenges in Neuroengineering: Toward "Intelligent" Neuroprostheses through Brain-"Brain Inspired Systems" Communication. Front Neurosci 2016; 10:438. [PMID: 27721741 PMCID: PMC5034009 DOI: 10.3389/fnins.2016.00438] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 09/09/2016] [Indexed: 11/30/2022] Open
Abstract
Future technologies aiming at restoring and enhancing organs function will intimately rely on near-physiological and energy-efficient communication between living and artificial biomimetic systems. Interfacing brain-inspired devices with the real brain is at the forefront of such emerging field, with the term "neurobiohybrids" indicating all those systems where such interaction is established. We argue that achieving a "high-level" communication and functional synergy between natural and artificial neuronal networks in vivo, will allow the development of a heterogeneous world of neurobiohybrids, which will include "living robots" but will also embrace "intelligent" neuroprostheses for augmentation of brain function. The societal and economical impact of intelligent neuroprostheses is likely to be potentially strong, as they will offer novel therapeutic perspectives for a number of diseases, and going beyond classical pharmaceutical schemes. However, they will unavoidably raise fundamental ethical questions on the intermingling between man and machine and more specifically, on how deeply it should be allowed that brain processing is affected by implanted "intelligent" artificial systems. Following this perspective, we provide the reader with insights on ongoing developments and trends in the field of neurobiohybrids. We address the topic also from a "community building" perspective, showing through a quantitative bibliographic analysis, how scientists working on the engineering of brain-inspired devices and brain-machine interfaces are increasing their interactions. We foresee that such trend preludes to a formidable technological and scientific revolution in brain-machine communication and to the opening of new avenues for restoring or even augmenting brain function for therapeutic purposes.
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Affiliation(s)
- Stefano Vassanelli
- NeuroChip Laboratory, Department of Biomedical Sciences, University of PadovaPadova, Italy
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28
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Klimas A, Ambrosi CM, Yu J, Williams JC, Bien H, Entcheva E. OptoDyCE as an automated system for high-throughput all-optical dynamic cardiac electrophysiology. Nat Commun 2016; 7:11542. [PMID: 27161419 PMCID: PMC4866323 DOI: 10.1038/ncomms11542] [Citation(s) in RCA: 107] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2015] [Accepted: 04/05/2016] [Indexed: 01/11/2023] Open
Abstract
The improvement of preclinical cardiotoxicity testing, discovery of new ion-channel-targeted drugs, and phenotyping and use of stem cell-derived cardiomyocytes and other biologics all necessitate high-throughput (HT), cellular-level electrophysiological interrogation tools. Optical techniques for actuation and sensing provide instant parallelism, enabling contactless dynamic HT testing of cells and small-tissue constructs, not affordable by other means. Here we show, computationally and experimentally, the limits of all-optical electrophysiology when applied to drug testing, then implement and validate OptoDyCE, a fully automated system for all-optical cardiac electrophysiology. We validate optical actuation by virally introducing optogenetic drivers in rat and human cardiomyocytes or through the modular use of dedicated light-sensitive somatic ‘spark' cells. We show that this automated all-optical approach provides HT means of cellular interrogation, that is, allows for dynamic testing of >600 multicellular samples or compounds per hour, and yields high-content information about the action of a drug over time, space and doses. The efficiency of preclinical drug testing and characterization of cellular function can be improved through the use of optogenetic tools. Here Klimas et al. present and validate OptoDyCE, a fully automated system for all-optical high-throughput cardiac electrophysiology.
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Affiliation(s)
- Aleksandra Klimas
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York, USA
| | - Christina M Ambrosi
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York, USA
| | - Jinzhu Yu
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York, USA
| | - John C Williams
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York, USA
| | - Harold Bien
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York, USA
| | - Emilia Entcheva
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York, USA
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29
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Entcheva E, Bub G. All-optical control of cardiac excitation: combined high-resolution optogenetic actuation and optical mapping. J Physiol 2016; 594:2503-10. [PMID: 26857427 PMCID: PMC4850200 DOI: 10.1113/jp271559] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 12/28/2015] [Indexed: 11/21/2022] Open
Abstract
Cardiac tissue is an excitable system that can support complex spatiotemporal dynamics, including instabilities (arrhythmias) with lethal consequences. While over the last two decades optical mapping of excitation (voltage and calcium dynamics) has facilitated the detailed characterization of such arrhythmia events, until recently, no precise tools existed to actively interrogate cardiac dynamics in space and time. In this work, we discuss the combined use of new methods for space- and time-resolved optogenetic actuation and simultaneous fast, high resolution optical imaging of cardiac excitation waves. First, the mechanisms, limitations and unique features of optically induced responses in cardiomyocytes are outlined. These include the ability to bidirectionally control the membrane potential using depolarizing and hyperpolarizing opsins; the ability to induce prolonged sustained voltage changes; and the ability to control refractoriness and the shape of the cardiac action potential. At the syncytial tissue level, we discuss optogenetically enabled experimentation on cell-cell coupling, alteration of conduction properties and termination of propagating waves by light. Specific attention is given to space- and time-resolved application of optical stimulation using dynamic light patterns to perturb ongoing activation and to probe electrophysiological properties at desired tissue locations. The combined use of optical methods to perturb and to observe the system can offer new tools for precise feedback control of cardiac electrical activity, not available previously with pharmacological and electrical stimulation. These new experimental tools for all-optical electrophysiology allow for a level of precise manipulation and quantification of cardiac dynamics comparable in robustness to the computational setting, and can provide new insights into pacemaking, arrhythmogenesis and suppression or cardioversion.
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Affiliation(s)
- Emilia Entcheva
- Department of Biomedical EngineeringGeorge Washington UniversityWashingtonDCUSA
| | - Gil Bub
- Department of Physiology, Anatomy and GeneticsUniversity of OxfordOxfordUK
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30
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Sanchez-Rodriguez SP, Sauer JP, Stanley SA, Qian X, Gottesdiener A, Friedman JM, Dordick JS. Plasmonic activation of gold nanorods for remote stimulation of calcium signaling and protein expression in HEK 293T cells. Biotechnol Bioeng 2016; 113:2228-40. [PMID: 27563853 DOI: 10.1002/bit.25984] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2015] [Revised: 02/17/2016] [Accepted: 03/21/2016] [Indexed: 02/03/2023]
Abstract
Remote activation of specific cells of a heterogeneous population can provide a useful research tool for clinical and therapeutic applications. Here, we demonstrate that photostimulation of gold nanorods (AuNRs) using a tunable near-infrared (NIR) laser at specific longitudinal surface plasmon resonance wavelengths can induce the selective and temporal internalization of calcium in HEK 293T cells. Biotin-PEG-Au nanorods coated with streptavidin Alexa Fluor-633 and biotinylated anti-His antibodies were used to decorate cells genetically modified with His-tagged TRPV1 temperature-sensitive ion channel and AuNRs conjugated to biotinylated RGD peptide were used to decorate integrins in unmodified cells. Plasmonic activation can be stimulated at weak laser power (0.7-4.0 W/cm(2) ) without causing cell damage. Selective activation of TRPV1 channels could be controlled by laser power between 1.0 and 1.5 W/cm(2) . Integrin targeting robustly stimulated calcium signaling due to a dense cellular distribution of nanoparticles. Such an approach represents a functional tool for combinatorial activation of cell signaling in heterogeneous cell populations. Our results suggest that it is possible to induce cell activation via NIR-induced gold nanorod heating through the selective targeting of membrane proteins in unmodified cells to produce calcium signaling and downstream expression of specific genes with significant relevance for both in vitro and therapeutic applications. Biotechnol. Bioeng. 2016;113: 2228-2240. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Sandra P Sanchez-Rodriguez
- Department of Chemical and Biological Engineering, and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York, 12180
| | - Jeremy P Sauer
- Department of Chemical and Biological Engineering, and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York, 12180
| | - Sarah A Stanley
- Laboratory of Molecular Genetics, Rockefeller University, 1230 York Ave, New York, New York, 10065
| | - Xi Qian
- Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, New York, 12180
| | - Andrew Gottesdiener
- Laboratory of Molecular Genetics, Rockefeller University, 1230 York Ave, New York, New York, 10065.,Weill Cornell Medical College, New York, New York
| | - Jeffrey M Friedman
- Laboratory of Molecular Genetics, Rockefeller University, 1230 York Ave, New York, New York, 10065.
| | - Jonathan S Dordick
- Department of Chemical and Biological Engineering, and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York, 12180. .,Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, New York, 12180. .,Departments of Biomedical Engineering and Biological Sciences, Rensselaer Polytechnic Institute, Troy, New York, 12180.
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Williams JC, Entcheva E. Optogenetic versus Electrical Stimulation of Human Cardiomyocytes: Modeling Insights. Biophys J 2016; 108:1934-45. [PMID: 25902433 DOI: 10.1016/j.bpj.2015.03.032] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Revised: 02/25/2015] [Accepted: 03/18/2015] [Indexed: 11/15/2022] Open
Abstract
Optogenetics provides an alternative to electrical stimulation to manipulate membrane voltage, and trigger or modify action potentials (APs) in excitable cells. We compare biophysically and energetically the cellular responses to direct electrical current injection versus optical stimulation mediated by genetically expressed light-sensitive ion channels, e.g., Channelrhodopsin-2 (ChR2). Using a computational model of ChR2(H134R mutant), we show that both stimulation modalities produce similar-in-morphology APs in human cardiomyocytes, and that electrical and optical excitability vary with cell type in a similar fashion. However, whereas the strength-duration curves for electrical excitation in ventricular and atrial cardiomyocytes closely follow the theoretical exponential relationship for an equivalent RC circuit, the respective optical strength-duration curves significantly deviate, exhibiting higher nonlinearity. We trace the origin of this deviation to the waveform of the excitatory current-a nonrectangular self-terminating inward current produced in optical stimulation due to ChR2 kinetics and voltage-dependent rectification. Using a unifying charge measure to compare energy needed for electrical and optical stimulation, we reveal that direct electrical current injection (rectangular pulse) is more efficient at short pulses, whereas voltage-mediated negative feedback leads to self-termination of ChR2 current and renders optical stimulation more efficient for long low-intensity pulses. This applies to cardiomyocytes but not to neuronal cells (with much shorter APs). Furthermore, we demonstrate the cell-specific use of ChR2 current as a unique modulator of intrinsic activity, allowing for optical control of AP duration in atrial and, to a lesser degree, in ventricular myocytes. For self-oscillatory cells, such as Purkinje, constant light at extremely low irradiance can be used for fine control of oscillatory frequency, whereas constant electrical stimulation is not feasible due to electrochemical limitations. Our analysis offers insights for designing future new energy-efficient stimulation strategies in heart or brain.
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Affiliation(s)
- John C Williams
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York; Department of Electrical and Computer Engineering, Stony Brook University, Stony Brook, New York
| | - Emilia Entcheva
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York; Institute for Molecular Cardiology, Stony Brook University, Stony Brook, New York.
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Inscribing Optical Excitability to Non-Excitable Cardiac Cells: Viral Delivery of Optogenetic Tools in Primary Cardiac Fibroblasts. Methods Mol Biol 2016; 1408:303-17. [PMID: 26965132 DOI: 10.1007/978-1-4939-3512-3_21] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
We describe in detail a method to introduce optogenetic actuation tools, a mutant version of channelrhodopsin-2, ChR2(H134R), and archaerhodopsin (ArchT), into primary cardiac fibroblasts (cFB) in vitro by adenoviral infection to yield quick, robust, and consistent expression. Instructions on adjusting infection parameters such as the multiplicity of infection and virus incubation duration are provided to generalize the method for different lab settings or cell types. Specific conditions are discussed to create hybrid co-cultures of the optogenetically modified cFB and non-transformed cardiomyocytes to obtain light-sensitive excitable cardiac syncytium, including stencil-patterned cell growth. We also describe an all-optical framework for the functional testing of responsiveness of these opsins in cFB. The presented methodology provides cell-specific tools for the mechanistic investigation of the functional bioelectric contribution of different non-excitable cells in the heart and their electrical coupling to cardiomyocytes under different conditions.
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Song C, Knöpfel T. Optogenetics enlightens neuroscience drug discovery. Nat Rev Drug Discov 2015; 15:97-109. [DOI: 10.1038/nrd.2015.15] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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Cardiac Optogenetics: Enhancement by All-trans-Retinal. Sci Rep 2015; 5:16542. [PMID: 26568132 PMCID: PMC4644984 DOI: 10.1038/srep16542] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2015] [Accepted: 10/15/2015] [Indexed: 11/30/2022] Open
Abstract
All-trans-Retinal (ATR) is a photosensitizer, serving as the chromophore for depolarizing and hyperpolarizing light-sensitive ion channels and pumps (opsins), recently employed as fast optical actuators. In mammalian optogenetic applications (in brain and heart), endogenous ATR availability is not considered a limiting factor, yet it is unclear how ATR modulation may affect the response to optical stimulation. We hypothesized that exogenous ATR may improve light responsiveness of cardiac cells modified by Channelrhodopsin2 (ChR2), hence lowering the optical pacing energy. In virally-transduced (Ad-ChR2(H134R)-eYFP) light-sensitive cardiac syncytium in vitro, ATR supplements ≤2 μM improved cardiomyocyte viability and augmented ChR2 membrane expression several-fold, while >4 μM was toxic. Employing integrated optical actuation (470 nm) and optical mapping, we found that 1–2 μM ATR dramatically reduced optical pacing energy (over 30 times) to several μW/mm2, lowest values reported to date, but also caused action potential prolongation, minor changes in calcium transients and no change in conduction. Theoretical analysis helped explain ATR-caused reduction of optical excitation threshold in cardiomyocytes. We conclude that cardiomyocytes operate at non-saturating retinal levels, and carefully-dosed exogenous ATR can enhance the performance of ChR2 in cardiac cells and yield energy benefits over orders of magnitude for optogenetic stimulation.
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Sonogenetics is a non-invasive approach to activating neurons in Caenorhabditis elegans. Nat Commun 2015; 6:8264. [PMID: 26372413 PMCID: PMC4571289 DOI: 10.1038/ncomms9264] [Citation(s) in RCA: 206] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Accepted: 08/04/2015] [Indexed: 12/30/2022] Open
Abstract
A major challenge in neuroscience is to reliably activate individual neurons, particularly those in deeper brain regions. Current optogenetic approaches require invasive surgical procedures to deliver light of specific wavelengths to target cells to activate or silence them. Here, we demonstrate the use of low-pressure ultrasound as a non-invasive trigger to activate specific ultrasonically sensitized neurons in the nematode, Caenorhabditis elegans. We first show that wild-type animals are insensitive to low-pressure ultrasound and require gas-filled microbubbles to transduce the ultrasound wave. We find that neuron-specific misexpression of TRP-4, the pore-forming subunit of a mechanotransduction channel, sensitizes neurons to ultrasound stimulus, resulting in behavioural outputs. Furthermore, we use this approach to manipulate the function of sensory neurons and interneurons and identify a role for PVD sensory neurons in modifying locomotory behaviours. We suggest that this method can be broadly applied to manipulate cellular functions in vivo. Common optogenetic approaches require surgical procedures to deliver light of specific wavelengths to the target cells. Here the authors demonstrate the use of low-pressure ultrasound as a non-invasive trigger to activate specific neurons in Caenorhabditis elegans and find that the mechanotransduction channel TRP-4 sensitizes cells to the ultrasound stimulus.
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Gao S, Nagpal J, Schneider MW, Kozjak-Pavlovic V, Nagel G, Gottschalk A. Optogenetic manipulation of cGMP in cells and animals by the tightly light-regulated guanylyl-cyclase opsin CyclOp. Nat Commun 2015; 6:8046. [PMID: 26345128 PMCID: PMC4569695 DOI: 10.1038/ncomms9046] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2015] [Accepted: 07/11/2015] [Indexed: 12/28/2022] Open
Abstract
Cyclic GMP (cGMP) signalling regulates multiple biological functions through activation of protein kinase G and cyclic nucleotide-gated (CNG) channels. In sensory neurons, cGMP permits signal modulation, amplification and encoding, before depolarization. Here we implement a guanylyl cyclase rhodopsin from Blastocladiella emersonii as a new optogenetic tool (BeCyclOp), enabling rapid light-triggered cGMP increase in heterologous cells (Xenopus oocytes, HEK293T cells) and in Caenorhabditis elegans. Among five different fungal CyclOps, exhibiting unusual eight transmembrane topologies and cytosolic N-termini, BeCyclOp is the superior optogenetic tool (light/dark activity ratio: 5,000; no cAMP production; turnover (20 °C) ∼17 cGMP s−1). Via co-expressed CNG channels (OLF in oocytes, TAX-2/4 in C. elegans muscle), BeCyclOp photoactivation induces a rapid conductance increase and depolarization at very low light intensities. In O2/CO2 sensory neurons of C. elegans, BeCyclOp activation evokes behavioural responses consistent with their normal sensory function. BeCyclOp therefore enables precise and rapid optogenetic manipulation of cGMP levels in cells and animals. Cyclic guanosine monophosphate (cGMP) is a cellular second messenger involved in many processes including regulation of neuronal excitability and vascular tone. Gao, Nagpal et al., employ a fungal rhodopsin to optogenetically control cGMP levels in multiple systems including C. elegans sensory neurons.
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Affiliation(s)
- Shiqiang Gao
- Department of Biology, Institute for Molecular Plant Physiology and Biophysics, Biocenter, Julius-Maximilians-University of Würzburg, Julius-von-Sachs-Platz 2, D-97082 Würzburg, Germany
| | - Jatin Nagpal
- Buchmann Institute for Molecular Life Sciences, Goethe University, Max von Laue Strasse 15, D-60438 Frankfurt, Germany.,Department for Biochemistry, Chemistry and Pharmacy, Institute of Biochemistry, Goethe University, Max von Laue Strasse 9, D-60438 Frankfurt, Germany
| | - Martin W Schneider
- Buchmann Institute for Molecular Life Sciences, Goethe University, Max von Laue Strasse 15, D-60438 Frankfurt, Germany.,Department for Biochemistry, Chemistry and Pharmacy, Institute of Biochemistry, Goethe University, Max von Laue Strasse 9, D-60438 Frankfurt, Germany
| | - Vera Kozjak-Pavlovic
- Department of Microbiology, Biocenter, Julius-Maximilians-University of Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Georg Nagel
- Department of Biology, Institute for Molecular Plant Physiology and Biophysics, Biocenter, Julius-Maximilians-University of Würzburg, Julius-von-Sachs-Platz 2, D-97082 Würzburg, Germany
| | - Alexander Gottschalk
- Buchmann Institute for Molecular Life Sciences, Goethe University, Max von Laue Strasse 15, D-60438 Frankfurt, Germany.,Department for Biochemistry, Chemistry and Pharmacy, Institute of Biochemistry, Goethe University, Max von Laue Strasse 9, D-60438 Frankfurt, Germany.,Cluster of Excellence Frankfurt-Macromolecular Complexes (CEF-MC), Goethe University, Max von Laue Strasse 15, D-60438 Frankfurt, Germany
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Penzkofer A, Tanwar M, Veetil SK, Kateriya S. Photo-dynamics of photoactivated adenylyl cyclase TpPAC from the spirochete bacterium Turneriella parva strain H(T). JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2015; 153:90-102. [PMID: 26398816 DOI: 10.1016/j.jphotobiol.2015.08.027] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Revised: 08/26/2015] [Accepted: 08/31/2015] [Indexed: 11/26/2022]
Abstract
The photoactivated adenylyl cyclase TpPAC from the spirochete bacterium Turneriella parva was synthesized and the purified recombinant protein was characterized by biochemical and optical spectroscopic methods. TpPAC consists of a BLUF domain (BLUF = Blue Light sensor Using Flavin) and an adenylyl cyclase homology domain (CHD). A light induced cAMP cyclase activity of ≈ 53.3 nmolmg(-1)min(-1) was measured while in the dark the cyclase activity was approximately a factor of 240 lower. The photo-cycling dynamics of the BLUF domain of TpPAC was studied by absorption spectra, fluorescence quantum distribution, and fluorescence lifetime measurements. The quantum efficiency of BLUF domain signaling state formation was found to be ϕs ≈ 0.59. A three-component exponential recovery of the signaling state to the receptor state was observed with the time constants τrec,1 = 4.8s, τrec,2 = 34.2s, and τrec,3 = 293s at 21.3 °C. The protein thermal stability was studied by stepwise sample heating and cooling. An apparent TpPAC melting temperature of ϑm ≈ 46 °C was determined. The photo-degradation of TpPAC in the signaling state was studied by prolonged intense light exposure at 455 nm. An irreversible flavin photo-degradation was observed with quantum yield ϕD ≈ 8.7 × 10(-6).
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Affiliation(s)
- Alfons Penzkofer
- Fakultät für Physik, Universität Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany.
| | - Meenakshi Tanwar
- Department of Biochemistry, University of Delhi South Campus, Benito Juarez Road, New Delhi 110021, India
| | - Sindhu Kandoth Veetil
- Department of Biochemistry, University of Delhi South Campus, Benito Juarez Road, New Delhi 110021, India
| | - Suneel Kateriya
- School of Biotechnology, Jawaharlal Nehru University, New Delhi 110067, India
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38
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Vandecasteele M, Senova YS, Palfi S, Dugué GP. Potentiel thérapeutique de la neuromodulation optogénétique. Med Sci (Paris) 2015; 31:404-16. [DOI: 10.1051/medsci/20153104015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
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39
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Dugué GP, Tricoire L. [Principles and applications of optogenetics in neuroscience]. Med Sci (Paris) 2015; 31:291-303. [PMID: 25855283 DOI: 10.1051/medsci/20153103015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Numerous achievements in biology have resulted from the evolution of biophotonics, a general term describing the use of light in the study of living systems. Over the last fifteen years, biophotonics has progressively blended with molecular genetics to give rise to optogenetics, a set of techniques enabling the functional study of genetically-defined cellular populations, compartments or processes with optical methods. In neuroscience, optogenetics allows real-time monitoring and control of the activity of specific neuronal populations in a wide range of animal models. This technical breakthrough provides a new level of sophistication in experimental approaches in the field of fundamental neuroscience, significantly enhancing our ability to understand the complexity of neuronal circuits.
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Affiliation(s)
- Guillaume P Dugué
- CNRS UMR 8197, Inserm U1024, IBENS S4.9, 46, rue d'Ulm, 75005 Paris, France
| | - Ludovic Tricoire
- CNRS UMR 8246, Inserm U1130, université Pierre et Marie Curie UM CR119, 9, quai Saint Bernard, 75005 Paris, France
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40
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Abstract
Genetically encoded optical actuators and indicators have changed the landscape of neuroscience, enabling targetable control and readout of specific components of intact neural circuits in behaving animals. Here, we review the development of optical neural interfaces, focusing on hardware designed for optical control of neural activity, integrated optical control and electrical readout, and optical readout of population and single-cell neural activity in freely moving mammals.
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Affiliation(s)
- Melissa R Warden
- Department of Neurobiology and Behavior, Cornell University, Ithaca, New York 14853;
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41
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42
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Entcheva E. Fiat lux in understanding cardiac pacing, resynchronization and signalling by way of optogenetics. Cardiovasc Res 2014; 102:342-3. [PMID: 24760549 DOI: 10.1093/cvr/cvu109] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Emilia Entcheva
- Department of Biomedical Engineering, Stony Brook University, Stony Brook 11790, NY, USA
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43
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Optobiology: optical control of biological processes via protein engineering. Biochem Soc Trans 2014; 41:1183-8. [PMID: 24059506 DOI: 10.1042/bst20130150] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Enabling optical control over biological processes is a defining goal of the new field of optogenetics. Control of membrane voltage by natural rhodopsin family ion channels has found widespread acceptance in neuroscience, due to the fact that these natural proteins control membrane voltage without further engineering. In contrast, optical control of intracellular biological processes has been a fragmented effort, with various laboratories engineering light-responsive properties into proteins in different manners. In the present article, we review the various systems that have been developed for controlling protein functions with light based on vertebrate rhodopsins, plant photoregulatory proteins and, most recently, the photoswitchable fluorescent protein Dronpa. By allowing biology to be controlled with spatiotemporal specificity and tunable dynamics, light-controllable proteins will find applications in the understanding of cellular and organismal biology and in synthetic biology.
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44
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Two-photon voltage imaging using a genetically encoded voltage indicator. Sci Rep 2014; 3:2231. [PMID: 23868559 PMCID: PMC3715760 DOI: 10.1038/srep02231] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Accepted: 06/21/2013] [Indexed: 11/09/2022] Open
Abstract
Voltage-sensitive fluorescent proteins (VSFPs) are a family of genetically-encoded voltage indicators (GEVIs) reporting membrane voltage fluctuation from genetically-targeted cells in cell cultures to whole brains in awake mice as demonstrated earlier using 1-photon (1P) fluorescence excitation imaging. However, in-vivo 1P imaging captures optical signals only from superficial layers and does not optically resolve single neurons. Two-photon excitation (2P) imaging, on the other hand, has not yet been convincingly applied to GEVI experiments. Here we show that 2P imaging of VSFP Butterfly 1.2 expresssing pyramidal neurons in layer 2/3 reports optical membrane voltage in brain slices consistent with 1P imaging but with a 2-3 larger ΔR/R value. 2P imaging of mouse cortex in-vivo achieved cellular resolution throughout layer 2/3. In somatosensory cortex we recorded sensory responses to single whisker deflections in anesthetized mice at full frame video rate. Our results demonstrate the feasibility of GEVI-based functional 2P imaging in mouse cortex.
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45
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Pama EAC, Colzato LS, Hommel B. Optogenetics as a neuromodulation tool in cognitive neuroscience. Front Psychol 2013; 4:610. [PMID: 24046763 PMCID: PMC3764402 DOI: 10.3389/fpsyg.2013.00610] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Accepted: 08/21/2013] [Indexed: 01/20/2023] Open
Affiliation(s)
- E A Claudia Pama
- Cognitive Psychology Unit, Psychology, Leiden Institute for Brain and Cognition, Leiden University Leiden, Netherlands
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46
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Smedemark-Margulies N, Trapani JG. Tools, methods, and applications for optophysiology in neuroscience. Front Mol Neurosci 2013; 6:18. [PMID: 23882179 PMCID: PMC3713398 DOI: 10.3389/fnmol.2013.00018] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2013] [Accepted: 06/27/2013] [Indexed: 11/13/2022] Open
Abstract
The advent of optogenetics and genetically encoded photosensors has provided neuroscience researchers with a wealth of new tools and methods for examining and manipulating neuronal function in vivo. There exists now a wide range of experimentally validated protein tools capable of modifying cellular function, including light-gated ion channels, recombinant light-gated G protein-coupled receptors, and even neurotransmitter receptors modified with tethered photo-switchable ligands. A large number of genetically encoded protein sensors have also been developed to optically track cellular activity in real time, including membrane-voltage-sensitive fluorophores and fluorescent calcium and pH indicators. The development of techniques for controlled expression of these proteins has also increased their utility by allowing the study of specific populations of cells. Additionally, recent advances in optics technology have enabled both activation and observation of target proteins with high spatiotemporal fidelity. In combination, these methods have great potential in the study of neural circuits and networks, behavior, animal models of disease, as well as in high-throughput ex vivo studies. This review collects some of these new tools and methods and surveys several current and future applications of the evolving field of optophysiology.
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G N, Tan A, Farhatnia Y, Rajadas J, Hamblin MR, Khaw PT, Seifalian AM. Channelrhodopsins: visual regeneration and neural activation by a light switch. N Biotechnol 2013; 30:461-74. [PMID: 23664865 DOI: 10.1016/j.nbt.2013.04.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Revised: 03/28/2013] [Accepted: 04/16/2013] [Indexed: 01/09/2023]
Abstract
The advent of optogenetics provides a new direction for the field of neuroscience and biotechnology, serving both as a refined investigative tool and as potential cure for many medical conditions via genetic manipulation. Although still in its infancy, recent advances in optogenetics has made it possible to remotely manipulate in vivo cellular functions using light. Coined Nature Methods' 'Method of the Year' in 2010, the optogenetic toolbox has the potential to control cell, tissue and even animal behaviour. This optogenetic toolbox consists of light-sensitive proteins that are able to modulate membrane potential in response to light. Channelrhodopsins (ChR) are light-gated microbial ion channels, which were first described in green algae. ChR2 (a subset of ChR) is a seven transmembrane α helix protein, which evokes membrane depolarization and mediates an action potential upon photostimulation with blue (470 nm) light. By contrast to other seven-transmembrane proteins that require second messengers to open ion channels, ChR2 form ion channels themselves, allowing ultrafast depolarization (within 50 milliseconds of illumination). It has been shown that integration of ChR2 into various tissues of mice can activate neural circuits, control heart muscle contractions, and even restore breathing after spinal cord injury. More compellingly, a plethora of evidence has indicated that artificial expression of ChR2 in retinal ganglion cells can reinstate visual perception in mice with retinal degeneration.
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Affiliation(s)
- Natasha G
- Centre for Nanotechnology & Regenerative Medicine, UCL Division of Surgery & Interventional Science, University College London, London, UK
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Mourot A, Tochitsky I, Kramer RH. Light at the end of the channel: optical manipulation of intrinsic neuronal excitability with chemical photoswitches. Front Mol Neurosci 2013; 6:5. [PMID: 23518818 PMCID: PMC3604625 DOI: 10.3389/fnmol.2013.00005] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Accepted: 03/06/2013] [Indexed: 11/15/2022] Open
Abstract
Ion channels are transmembrane proteins that control the movement of ions across the cell membrane. They are the molecular machines that make neurons excitable by enabling the initiation and propagation of action potentials (APs). Rapid signaling within and between neurons requires complex molecular processes that couple the sensing of membrane voltage or neurotransmitter release to the fast opening and closing of the ion channel gate. Malfunction of an ion channel's sensing or gating module can have disastrous pathological consequences. However, linking molecular changes to the modulation of neural circuits and ultimately to a physiological or pathological state is not a straightforward task. It requires precise and sophisticated methods of controlling the function of ion channels in their native environment. To address this issue we have developed new photochemical tools that enable the remote control of neuronal ion channels with light. Due to its optical nature, our approach permits the manipulation of the nervous system with high spatial, temporal and molecular precision that will help us understand the link between ion channel function and physiology. In addition, this strategy may also be used in the clinic for the direct treatment of some neuronal disorders.
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Affiliation(s)
- Alexandre Mourot
- Department of Molecular and Cell Biology, University of California Berkeley, CA, USA ; Department of Neurobiology of Adaptive Processes, UMR7102 CNRS, Université Pierre et Marie Curie Paris, France
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Abstract
Optogenetics is an emerging technology for optical interrogation and control of biological function with high specificity and high spatiotemporal resolution. Mammalian cells and tissues can be sensitized to respond to light by a relatively simple and well-tolerated genetic modification using microbial opsins (light-gated ion channels and pumps). These can achieve fast and specific excitatory or inhibitory response, offering distinct advantages over traditional pharmacological or electrical means of perturbation. Since the first demonstrations of utility in mammalian cells (neurons) in 2005, optogenetics has spurred immense research activity and has inspired numerous applications for dissection of neural circuitry and understanding of brain function in health and disease, applications ranging from in vitro to work in behaving animals. Only recently (since 2010), the field has extended to cardiac applications with less than a dozen publications to date. In consideration of the early phase of work on cardiac optogenetics and the impact of the technique in understanding another excitable tissue, the brain, this review is largely a perspective of possibilities in the heart. It covers the basic principles of operation of light-sensitive ion channels and pumps, the available tools and ongoing efforts in optimizing them, overview of neuroscience use, as well as cardiac-specific questions of implementation and ideas for best use of this emerging technology in the heart.
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Affiliation(s)
- Emilia Entcheva
- Department of Biomedical Engineering, Department of Physiology and Biophysics, and Institute for Molecular Cardiology, Stony Brook University, Stony Brook, New York, USA
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Pathak GP, Vrana JD, Tucker CL. Optogenetic control of cell function using engineered photoreceptors. Biol Cell 2012; 105:59-72. [PMID: 23157573 DOI: 10.1111/boc.201200056] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Accepted: 11/12/2012] [Indexed: 11/29/2022]
Abstract
Over the past decades, there has been growing recognition that light can provide a powerful stimulus for biological interrogation. Light-actuated tools allow manipulation of molecular events with ultra-fine spatial and fast temporal resolution, as light can be rapidly delivered and focused with sub-micrometre precision within cells. While light-actuated chemicals such as photolabile 'caged' compounds have been in existence for decades, the use of genetically encoded natural photoreceptors for optical control of biological processes has recently emerged as a powerful new approach with several advantages over traditional methods. Here, we review recent advances using light to control basic cellular functions and discuss the engineering challenges that lie ahead for improving and expanding the ever-growing optogenetic toolkit.
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Affiliation(s)
- Gopal P Pathak
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 90045, USA
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