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Menezes EC, Geiger H, Abreu FF, Rachmany L, Wilson DA, Alldred MJ, Castellanos FX, Fu R, Sargin D, Corvelo A, Teixeira CM. Early-life prefrontal cortex inhibition and early-life stress lead to long-lasting behavioral, transcriptional, and physiological impairments. Mol Psychiatry 2024; 29:2359-2371. [PMID: 38486048 PMCID: PMC11399324 DOI: 10.1038/s41380-024-02499-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 02/24/2024] [Accepted: 02/27/2024] [Indexed: 09/01/2024]
Abstract
Early-life stress has been linked to multiple neurodevelopmental and neuropsychiatric deficits. Our previous studies have linked maternal presence/absence from the nest in developing rat pups to changes in prefrontal cortex (PFC) activity. Furthermore, we have shown that these changes are modulated by serotonergic signaling. Here we test whether changes in PFC activity during early life affect the developing cortex leading to behavioral alterations in the adult. We show that inhibiting the PFC of mouse pups leads to cognitive deficits in the adult comparable to those seen following maternal separation. Moreover, we show that activating the PFC during maternal separation can prevent these behavioral deficits. To test how maternal separation affects the transcriptional profile of the PFC we performed single-nucleus RNA-sequencing. Maternal separation led to differential gene expression almost exclusively in inhibitory neurons. Among others, we found changes in GABAergic and serotonergic pathways in these interneurons. Interestingly, both maternal separation and early-life PFC inhibition led to changes in physiological responses in prefrontal activity to GABAergic and serotonergic antagonists that were similar to the responses of more immature brains. Prefrontal activation during maternal separation prevented these changes. These data point to a crucial role of PFC activity during early life in behavioral expression in adulthood.
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Affiliation(s)
- Edênia C Menezes
- Emotional Brain Institute, Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, 10962, USA
- Department of Child and Adolescent Psychiatry, New York University Grossman School of Medicine, New York, NY, 10016, USA
| | | | - Fabiula F Abreu
- Emotional Brain Institute, Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, 10962, USA
- Department of Child and Adolescent Psychiatry, New York University Grossman School of Medicine, New York, NY, 10016, USA
| | - Lital Rachmany
- Emotional Brain Institute, Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, 10962, USA
- Department of Child and Adolescent Psychiatry, New York University Grossman School of Medicine, New York, NY, 10016, USA
| | - Donald A Wilson
- Emotional Brain Institute, Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, 10962, USA
- Department of Child and Adolescent Psychiatry, New York University Grossman School of Medicine, New York, NY, 10016, USA
| | - Melissa J Alldred
- Emotional Brain Institute, Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, 10962, USA
- Department of Psychiatry, New York University Grossman School of Medicine, New York, NY, 10016, USA
| | - Francisco X Castellanos
- Emotional Brain Institute, Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, 10962, USA
- Department of Child and Adolescent Psychiatry, New York University Grossman School of Medicine, New York, NY, 10016, USA
| | - Rui Fu
- New York Genome Center, New York, NY, 10013, USA
| | - Derya Sargin
- Department of Psychology, Department of Physiology and Pharmacology, Hotchkiss Brain Institute, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, T2N 1N4, Canada
| | | | - Cátia M Teixeira
- Emotional Brain Institute, Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, 10962, USA.
- Department of Child and Adolescent Psychiatry, New York University Grossman School of Medicine, New York, NY, 10016, USA.
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Optogenetically Engineered Neurons Differentiated from Human SH-SY5Y Cells Survived and Expressed ChR2 in 3D Hydrogel. Biomedicines 2022; 10:biomedicines10071534. [PMID: 35884839 PMCID: PMC9313127 DOI: 10.3390/biomedicines10071534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 06/20/2022] [Accepted: 06/25/2022] [Indexed: 11/25/2022] Open
Abstract
The cases of brain degenerative disease will rise as the human population ages. Current treatments have a transient effect and lack an investigative system that is physiologically relevant for testing. There is evidence suggesting optogenetic stimulation is a potential strategy; however, an in vitro disease and optogenetic model requires a three-dimensional microenvironment. Alginate is a promising material for tissue and optogenetic engineering. Although it is bioinert, alginate hydrogel is transparent and therefore allows optical penetration for stimulation. In this study, alginate was functionalized with arginine-glycine-aspartate acid (RGD) to serve as a 3D platform for encapsulation of human SH-SY5Y cells, which were optogenetically modified and characterized. The RGD-alginate hydrogels were tested for swelling and degradation. Prior to encapsulation, the cells were assessed for neuronal expression and optical-stimulation response. The results showed that RGD-alginate possessed a consistent swelling ratio of 18% on day 7, and degradation remained between 3.7−5% throughout 14 days. Optogenetically modified SH-SY5Y cells were highly viable (>85%) after lentiviral transduction and neuronal differentiation. The cells demonstrated properties of functional neurons, developing beta III tubulin (TuJ1)-positive long neurites, forming neural networks, and expressing vGlut2. Action potentials were produced upon optical stimulation. The neurons derived from human SH-SY5Y cells were successfully genetically modified and encapsulated; they survived and expressed ChR2 in an RGD-alginate hydrogel system.
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Hiyoshi K, Shiraishi A, Fukuda N, Tsuda S. In vivo wide-field voltage imaging in zebrafish with voltage-sensitive dye and genetically encoded voltage indicator. Dev Growth Differ 2021; 63:417-428. [PMID: 34411280 DOI: 10.1111/dgd.12744] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 07/01/2021] [Accepted: 07/04/2021] [Indexed: 11/28/2022]
Abstract
The brain consists of neural circuits, which are assemblies of various neuron types. For understanding how the brain works, it is essential to identify the functions of each type of neuron and neuronal circuits. Recent advances in our understanding of brain function and its development have been achieved using light to detect neuronal activity. Optical measurement of membrane potentials through voltage imaging is a desirable approach, enabling fast, direct, and simultaneous detection of membrane potentials in a population of neurons. Its high speed and directness can help detect synaptic and action potentials and hyperpolarization, which encode critical information for brain function. Here, we describe in vivo voltage imaging procedures that we have recently established using zebrafish, a powerful animal model in developmental biology and neuroscience. By applying two types of voltage sensors, voltage-sensitive dyes (VSDs, Di-4-ANEPPS) and genetically encoded voltage indicators (GEVIs, ASAP1), spatiotemporal dynamics of voltage signals can be detected in the whole cerebellum and spinal cord in awake fish at single-cell and neuronal population levels. Combining this method with other approaches, such as optogenetics, behavioral analysis, and electrophysiology would facilitate a deeper understanding of the network dynamics of the brain circuitry and its development.
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Affiliation(s)
- Kanae Hiyoshi
- Division of Life Science, Graduate School of Science and Engineering, Saitama University, Saitama City, Japan
| | - Asuka Shiraishi
- Division of Life Science, Graduate School of Science and Engineering, Saitama University, Saitama City, Japan
| | - Narumi Fukuda
- Division of Life Science, Graduate School of Science and Engineering, Saitama University, Saitama City, Japan
| | - Sachiko Tsuda
- Division of Life Science, Graduate School of Science and Engineering, Saitama University, Saitama City, Japan.,Integrative Research Center for Life Sciences and Biotechnology, Saitama University, Saitama City, Japan
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Vila OF, Chavez M, Ma SP, Yeager K, Zholudeva LV, Colón-Mercado JM, Qu Y, Nash TR, Lai C, Feliciano CM, Carter M, Kamm RD, Judge LM, Conklin BR, Ward ME, McDevitt TC, Vunjak-Novakovic G. Bioengineered optogenetic model of human neuromuscular junction. Biomaterials 2021; 276:121033. [PMID: 34403849 DOI: 10.1016/j.biomaterials.2021.121033] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 07/09/2021] [Accepted: 07/15/2021] [Indexed: 12/28/2022]
Abstract
Functional human tissues engineered from patient-specific induced pluripotent stem cells (hiPSCs) hold great promise for investigating the progression, mechanisms, and treatment of musculoskeletal diseases in a controlled and systematic manner. For example, bioengineered models of innervated human skeletal muscle could be used to identify novel therapeutic targets and treatments for patients with complex central and peripheral nervous system disorders. There is a need to develop standardized and objective quantitative methods for engineering and using these complex tissues, in order increase their robustness, reproducibility, and predictiveness across users. Here we describe a standardized method for engineering an isogenic, patient specific human neuromuscular junction (NMJ) that allows for automated quantification of NMJ function to diagnose disease using a small sample of blood serum and evaluate new therapeutic modalities. By combining tissue engineering, optogenetics, microfabrication, optoelectronics and video processing, we created a novel platform for the precise investigation of the development and degeneration of human NMJ. We demonstrate the utility of this platform for the detection and diagnosis of myasthenia gravis, an antibody-mediated autoimmune disease that disrupts the NMJ function.
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Affiliation(s)
- Olaia F Vila
- Columbia University, 622 W 168th St, New York, NY, 10032, USA; Gladstone Institutes, 1650 Owens St, San Francisco, CA, 94158, USA.
| | - Miguel Chavez
- Columbia University, 622 W 168th St, New York, NY, 10032, USA
| | - Stephen P Ma
- Columbia University, 622 W 168th St, New York, NY, 10032, USA
| | - Keith Yeager
- Columbia University, 622 W 168th St, New York, NY, 10032, USA
| | | | | | - Yihuai Qu
- Columbia University, 622 W 168th St, New York, NY, 10032, USA
| | - Trevor R Nash
- Columbia University, 622 W 168th St, New York, NY, 10032, USA
| | - Carmen Lai
- Gladstone Institutes, 1650 Owens St, San Francisco, CA, 94158, USA
| | - Carissa M Feliciano
- Gladstone Institutes, 1650 Owens St, San Francisco, CA, 94158, USA; Department of Pediatrics, UCSF, 550 16th St, Floor 5, San Francisco, CA, 94143, USA
| | - Matthew Carter
- Gladstone Institutes, 1650 Owens St, San Francisco, CA, 94158, USA
| | - Roger D Kamm
- Department of Mechanical Engineering and Biological Engineering, Massachusetts Institute of Technology, Cambridge MA, 02139, USA
| | - Luke M Judge
- Gladstone Institutes, 1650 Owens St, San Francisco, CA, 94158, USA; Department of Pediatrics, UCSF, 550 16th St, Floor 5, San Francisco, CA, 94143, USA
| | - Bruce R Conklin
- Gladstone Institutes, 1650 Owens St, San Francisco, CA, 94158, USA
| | - Michael E Ward
- National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, 20892, USA
| | - Todd C McDevitt
- Gladstone Institutes, 1650 Owens St, San Francisco, CA, 94158, USA
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The Optogenetic Revolution in Cerebellar Investigations. Int J Mol Sci 2020; 21:ijms21072494. [PMID: 32260234 PMCID: PMC7212757 DOI: 10.3390/ijms21072494] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 03/30/2020] [Accepted: 04/01/2020] [Indexed: 12/13/2022] Open
Abstract
The cerebellum is most renowned for its role in sensorimotor control and coordination, but a growing number of anatomical and physiological studies are demonstrating its deep involvement in cognitive and emotional functions. Recently, the development and refinement of optogenetic techniques boosted research in the cerebellar field and, impressively, revolutionized the methodological approach and endowed the investigations with entirely new capabilities. This translated into a significant improvement in the data acquired for sensorimotor tests, allowing one to correlate single-cell activity with motor behavior to the extent of determining the role of single neuronal types and single connection pathways in controlling precise aspects of movement kinematics. These levels of specificity in correlating neuronal activity to behavior could not be achieved in the past, when electrical and pharmacological stimulations were the only available experimental tools. The application of optogenetics to the investigation of the cerebellar role in higher-order and cognitive functions, which involves a high degree of connectivity with multiple brain areas, has been even more significant. It is possible that, in this field, optogenetics has changed the game, and the number of investigations using optogenetics to study the cerebellar role in non-sensorimotor functions in awake animals is growing. The main issues addressed by these studies are the cerebellar role in epilepsy (through connections to the hippocampus and the temporal lobe), schizophrenia and cognition, working memory for decision making, and social behavior. It is also worth noting that optogenetics opened a new perspective for cerebellar neurostimulation in patients (e.g., for epilepsy treatment and stroke rehabilitation), promising unprecedented specificity in the targeted pathways that could be either activated or inhibited.
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Optical measurement of neuronal activity in the developing cerebellum of zebrafish using voltage-sensitive dye imaging. Neuroreport 2019; 29:1349-1354. [PMID: 30192301 DOI: 10.1097/wnr.0000000000001113] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Voltage-sensitive dye (VSD) imaging enables fast, direct, and simultaneous detection of membrane potentials from a population of neurons forming neuronal circuits. This enables the detection of hyperpolarization together with depolarization, whose balance plays a pivotal role in the function of many brain regions. Among these is the cerebellum, which contains a significant number of inhibitory neurons. However, the mechanism underlying the functional development remains unclear. In this study, we used a model system ideal to study neurogenesis by applying VSD imaging to the cerebellum of zebrafish larvae to analyze the neuronal activity of the developing cerebellum, focusing on both excitation and inhibition. We performed in-vivo high-speed imaging of the entire cerebellum of the zebrafish, which was stained using Di-4-ANEPPS, a widely used VSD. To examine whether neuronal activity in the zebrafish cerebellum could be detected by this VSD, we applied electrical stimulation during VSD imaging, which showed that depolarization was detected widely in the cerebellum upon stimulation. These responses mostly disappeared following treatment with tetrodotoxin, indicating that Di-4-ANEPPS enabled optical measurement of neuronal activity in the developing cerebellum of zebrafish. Moreover, hyperpolarizing signals were also detected upon stimulation, but these were significantly reduced by treatment with picrotoxin, a GABAA receptor inhibitor, indicating that these responses represent inhibitory signals. This approach will enable a detailed analysis of the spatiotemporal dynamics of the excitation and inhibition in the cerebellum along its developmental stages, leading to a deeper understanding of the functional development of the cerebellum in vertebrates.
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Soor NS, Quicke P, Howe CL, Pang KT, Neil MAA, Schultz SR, Foust AJ. All-optical crosstalk-free manipulation and readout of Chronos-expressing neurons. JOURNAL OF PHYSICS D: APPLIED PHYSICS 2019; 52:104002. [PMID: 31057183 PMCID: PMC6466639 DOI: 10.1088/1361-6463/aaf944] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 12/03/2018] [Accepted: 12/13/2018] [Indexed: 06/09/2023]
Abstract
All optical neurophysiology allows manipulation and readout of neural network activity with single-cell spatial resolution and millisecond temporal resolution. Neurons can be made to express proteins that actuate transmembrane currents upon light absorption, enabling optical control of membrane potential and action potential signalling. In addition, neurons can be genetically or synthetically labelled with fluorescent reporters of changes in intracellular calcium concentration or membrane potential. Thus, to optically manipulate and readout neural activity in parallel, two spectra are involved: the action spectrum of the actuator, and the absorption spectrum of the fluorescent reporter. Due to overlap in these spectra, previous all-optical neurophysiology paradigms have been hindered by spurious activation of neuronal activity caused by the readout light. Here, we pair the blue-green absorbing optogenetic actuator, Chronos, with a deep red-emitting fluorescent calcium reporter CaSiR-1. We show that cultured Chinese hamster ovary cells transfected with Chronos do not exhibit transmembrane currents when illuminated with wavelengths and intensities suitable for exciting one-photon CaSiR-1 fluorescence. We then demonstrate crosstalk-free, high signal-to-noise ratio CaSiR-1 red fluorescence imaging at 100 frames s-1 of Chronos-mediated calcium transients evoked in neurons with blue light pulses at rates up to 20 Hz. These results indicate that the spectral separation between red light excited fluorophores, excited efficiently at or above 640 nm, with blue-green absorbing opsins such as Chronos, is sufficient to avoid spurious opsin actuation by the imaging wavelengths and therefore enable crosstalk-free all-optical neuronal manipulation and readout.
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Affiliation(s)
- Navjeevan S Soor
- Centre for Neurotechnology, Imperial College London, London, United Kingdom
- Department of Bioengineering, Imperial College London, London, United Kingdom
| | - Peter Quicke
- Centre for Neurotechnology, Imperial College London, London, United Kingdom
- Department of Bioengineering, Imperial College London, London, United Kingdom
| | - Carmel L Howe
- Centre for Neurotechnology, Imperial College London, London, United Kingdom
- Department of Bioengineering, Imperial College London, London, United Kingdom
| | - Kuin T Pang
- Department of Bioengineering, Imperial College London, London, United Kingdom
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (ASTAR), Singapore
| | - Mark A A Neil
- Department of Physics, Blackett Laboratory, Imperial College London, London, United Kingdom
| | - Simon R Schultz
- Centre for Neurotechnology, Imperial College London, London, United Kingdom
- Department of Bioengineering, Imperial College London, London, United Kingdom
| | - Amanda J Foust
- Centre for Neurotechnology, Imperial College London, London, United Kingdom
- Department of Bioengineering, Imperial College London, London, United Kingdom
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Optical interrogation of neuronal circuitry in zebrafish using genetically encoded voltage indicators. Sci Rep 2018; 8:6048. [PMID: 29662090 PMCID: PMC5902623 DOI: 10.1038/s41598-018-23906-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 03/20/2018] [Indexed: 11/21/2022] Open
Abstract
Optical measurement of membrane potentials enables fast, direct and simultaneous detection of membrane potentials from a population of neurons, providing a desirable approach for functional analysis of neuronal circuits. Here, we applied recently developed genetically encoded voltage indicators, ASAP1 (Accelerated Sensor of Action Potentials 1) and QuasAr2 (Quality superior to Arch 2), to zebrafish, an ideal model system for studying neurogenesis. To achieve this, we established transgenic lines which express the voltage sensors, and showed that ASAP1 is expressed in zebrafish neurons. To examine whether neuronal activity could be detected by ASAP1, we performed whole-cerebellum imaging, showing that depolarization was detected widely in the cerebellum and optic tectum upon electrical stimulation. Spontaneous activity in the spinal cord was also detected by ASAP1 imaging at single-cell resolution as well as at the neuronal population level. These responses mostly disappeared following treatment with tetrodotoxin, indicating that ASAP1 enabled optical measurement of neuronal activity in the zebrafish brain. Combining this method with other approaches, such as optogenetics and behavioural analysis may facilitate a deeper understanding of the functional organization of brain circuitry and its development.
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Jung H, Kang H, Nam Y. Digital micromirror based near-infrared illumination system for plasmonic photothermal neuromodulation. BIOMEDICAL OPTICS EXPRESS 2017; 8:2866-2878. [PMID: 28663912 PMCID: PMC5480435 DOI: 10.1364/boe.8.002866] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 04/05/2017] [Accepted: 04/24/2017] [Indexed: 05/12/2023]
Abstract
Light-mediated neuromodulation techniques provide great advantages to investigate neuroscience due to its high spatial and temporal resolution. To generate a spatial pattern of neural activity, it is necessary to develop a system for patterned-light illumination to a specific area. Digital micromirror device (DMD) based patterned illumination system have been used for neuromodulation due to its simple configuration and design flexibility. In this paper, we developed a patterned near-infrared (NIR) illumination system for region specific photothermal manipulation of neural activity using NIR-sensitive plasmonic gold nanorods (GNRs). The proposed system had high power transmission efficiency for delivering power density up to 19 W/mm2. We used a GNR-coated microelectrode array (MEA) to perform biological experiments using E18 rat hippocampal neurons and showed that it was possible to inhibit neural spiking activity of specific area in neural circuits with the patterned NIR illumination. This patterned NIR illumination system can serve as a promising neuromodulation tool to investigate neuroscience in a wide range of physiological and clinical applications.
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Zhang H, Reichert E, Cohen AE. Optical electrophysiology for probing function and pharmacology of voltage-gated ion channels. eLife 2016; 5. [PMID: 27215841 PMCID: PMC4907688 DOI: 10.7554/elife.15202] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Accepted: 05/12/2016] [Indexed: 12/15/2022] Open
Abstract
Voltage-gated ion channels mediate electrical dynamics in excitable tissues and are an important class of drug targets. Channels can gate in sub-millisecond timescales, show complex manifolds of conformational states, and often show state-dependent pharmacology. Mechanistic studies of ion channels typically involve sophisticated voltage-clamp protocols applied through manual or automated electrophysiology. Here, we develop all-optical electrophysiology techniques to study activity-dependent modulation of ion channels, in a format compatible with high-throughput screening. Using optical electrophysiology, we recapitulate many voltage-clamp protocols and apply to Nav1.7, a channel implicated in pain. Optical measurements reveal that a sustained depolarization strongly potentiates the inhibitory effect of PF-04856264, a Nav1.7-specific blocker. In a pilot screen, we stratify a library of 320 FDA-approved compounds by binding mechanism and kinetics, and find close concordance with patch clamp measurements. Optical electrophysiology provides a favorable tradeoff between throughput and information content for studies of NaV channels, and possibly other voltage-gated channels. DOI:http://dx.doi.org/10.7554/eLife.15202.001 Ion channels are specialized proteins that span the cell membrane. When activated, these channels allow ions to pass through them, which can produce electrical spikes that carry information in nerve cells and regulate the beating of the heart. Researchers interested in understanding how ion channels behave often use a technique called patch clamp electrophysiology to measure the electrical current across the cell membrane. The technique can be used to probe if a specific drug can block an ion channel, but it is not well suited to screening lots of potential drugs because it is slow and expensive. A group of ion channels known as voltage-gated sodium channels play an important role in generating the electrical spikes in nerve cells. One subtype called NaV1.7 is involved in sensing pain and drugs that block NaV1.7 might be useable as painkillers, but only if they are specific to this channel. This is because there are many similar sodium channels that are important in other processes in the body. Zhang et al. have now developed a new light-based technique to measure how ion channels behave. The technique uses light to activate the channel and a fluorescent protein to report on the membrane’s voltage. Zhang et al. used the new technique to probe how sodium channels, in particular NaV1.7, interact with drugs. Mammalian cells grown in the lab were engineered to produce NaV1.7, a light-activated ion channel (called CheRiff), and a fluorescent reporter protein. A flash of blue light delivered to the cells activated CheRiff, which in turn activated NaV1.7. At the same time, the fluorescence of the reporter protein was used as a read-out of NaV1.7’s activity. Zhang et al. showed that they could reproduce many conventional electrophysiology measurements using their new light-based approach. Optical measurements were then used to screen 320 drugs to see whether they could block NaV1.7. The results of the screen corresponded closely with measurements made using conventional electrophysiology. These results demonstrate that the new optical technique is both fast and precise enough to be used in drug discovery. Further studies could now ask if this optical technique can also be used to study other ion channels, such as potassium channels and calcium channels. DOI:http://dx.doi.org/10.7554/eLife.15202.002
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Affiliation(s)
- Hongkang Zhang
- Departments of Chemistry and Chemical Biology and Physics, Harvard University, Cambridge, United States.,Howard Hughes Medical Institute, Harvard University, Cambridge, United States
| | - Elaine Reichert
- Departments of Chemistry and Chemical Biology and Physics, Harvard University, Cambridge, United States
| | - Adam E Cohen
- Departments of Chemistry and Chemical Biology and Physics, Harvard University, Cambridge, United States.,Howard Hughes Medical Institute, Harvard University, Cambridge, United States
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Favre-Bulle IA, Preece D, Nieminen TA, Heap LA, Scott EK, Rubinsztein-Dunlop H. Scattering of Sculpted Light in Intact Brain Tissue, with implications for Optogenetics. Sci Rep 2015; 5:11501. [PMID: 26108566 PMCID: PMC4480008 DOI: 10.1038/srep11501] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Accepted: 05/27/2015] [Indexed: 11/08/2022] Open
Abstract
Optogenetics uses light to control and observe the activity of neurons, often using a focused laser beam. As brain tissue is a scattering medium, beams are distorted and spread with propagation through neural tissue, and the beam's degradation has important implications in optogenetic experiments. To address this, we present an analysis of scattering and loss of intensity of focused laser beams at different depths within the brains of zebrafish larvae. Our experimental set-up uses a 488 nm laser and a spatial light modulator to focus a diffraction-limited spot of light within the brain. We use a combination of experimental measurements of back-scattered light in live larvae and computational modelling of the scattering to determine the spatial distribution of light. Modelling is performed using the Monte Carlo method, supported by generalised Lorenz-Mie theory in the single-scattering approximation. Scattering in areas rich in cell bodies is compared to that of regions of neuropil to identify the distinct and dramatic contributions that cell nuclei make to scattering. We demonstrate the feasibility of illuminating individual neurons, even in nucleus-rich areas, at depths beyond 100 μm using a spatial light modulator in combination with a standard laser and microscope optics.
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Affiliation(s)
- Itia A. Favre-Bulle
- School of Mathematics and Physics, The University of Queensland, Brisbane QLD, Australia
| | - Daryl Preece
- School of Mathematics and Physics, The University of Queensland, Brisbane QLD, Australia
| | - Timo A. Nieminen
- School of Mathematics and Physics, The University of Queensland, Brisbane QLD, Australia
| | - Lucy A. Heap
- School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia
| | - Ethan K. Scott
- School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
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Venkatachalam V, Cohen AE. Imaging GFP-based reporters in neurons with multiwavelength optogenetic control. Biophys J 2015; 107:1554-63. [PMID: 25296307 DOI: 10.1016/j.bpj.2014.08.020] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 08/02/2014] [Accepted: 08/07/2014] [Indexed: 12/20/2022] Open
Abstract
To study the impact of neural activity on cellular physiology, one would like to combine precise control of firing patterns with highly sensitive probes of cellular physiology. Light-gated ion channels, e.g., Channelrhodopsin-2, enable precise control of firing patterns; green fluorescent protein-based reporters, e.g., the GCaMP6f Ca(2+) reporter, enable highly sensitive probing of cellular physiology. However, for most actuator-reporter combinations, spectral overlap prevents straightforward combination within a single cell. Here we explore multiwavelength control of channelrhodopsins to circumvent this limitation. The "stoplight" technique described in this article uses channelrhodopsin variants that are opened by blue light and closed by orange light. Cells are illuminated with constant blue light to excite fluorescence of a green fluorescent protein-based reporter. Modulated illumination with orange light negatively regulates activation of the channelrhodopsin. We performed detailed photophysical characterization and kinetic modeling of four candidate stoplight channelrhodopsins. The variant with the highest contrast, sdChR(C138S,E154A), enabled all-optical measurements of activity-induced calcium transients in cultured rat hippocampal neurons, although cell-to-cell variation in expression levels presents a challenge for quantification.
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Affiliation(s)
- Veena Venkatachalam
- Biophysics Program, Harvard Stem Cell Institute, Harvard University, Cambridge, Massachusetts
| | - Adam E Cohen
- Departments of Chemistry and Chemical Biology and Physics, Harvard Stem Cell Institute, Harvard University, Cambridge, Massachusetts; Howard Hughes Medical Institute, Chevy Chase, Maryland.
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Lo SQ, Koh DXP, Sng JCG, Augustine GJ. All-optical mapping of barrel cortex circuits based on simultaneous voltage-sensitive dye imaging and channelrhodopsin-mediated photostimulation. NEUROPHOTONICS 2015; 2:021013. [PMID: 26158003 PMCID: PMC4478985 DOI: 10.1117/1.nph.2.2.021013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/25/2014] [Accepted: 03/04/2015] [Indexed: 05/25/2023]
Abstract
We describe an experimental approach that uses light to both control and detect neuronal activity in mouse barrel cortex slices: blue light patterned by a digital micromirror array system allowed us to photostimulate specific layers and columns, while a red-shifted voltage-sensitive dye was used to map out large-scale circuit activity. We demonstrate that such all-optical mapping can interrogate various circuits in somatosensory cortex by sequentially activating different layers and columns. Further, mapping in slices from whisker-deprived mice demonstrated that chronic sensory deprivation did not significantly alter feedforward inhibition driven by layer 5 pyramidal neurons. Further development of voltage-sensitive optical probes should allow this all-optical mapping approach to become an important and high-throughput tool for mapping circuit interactions in the brain.
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Affiliation(s)
- Shun Qiang Lo
- National University of Singapore, Yong Loo Lin School of Medicine, Department of Physiology, Singapore 117597, Singapore
- Nanyang Technological University, Lee Kong Chian School of Medicine, Proteos, Biopolis, Level 4, 61 Biopolis Drive, #04-06/07, Singapore 138673, Singapore
- Institute of Molecular and Cell Biology, A*STAR, Proteos, 61 Biopolis Drive, Proteos, Singapore 138673, Singapore
- Marine Biological Laboratory, 7 MBL Street, Woods Hole, Massachusetts 02543, United States
| | - Dawn X. P. Koh
- National University of Singapore, Graduate School of Integrative Sciences and Engineering, Singapore 117456, Singapore
- National University of Singapore, Yong Loo Lin School of Medicine, Department of Pharmacology, Singapore 117599, Singapore
- Singapore Institute of Clinical Sciences (SICS), A*STAR, Brenner Centre for Molecular Medicine, 30 Medical Drive, Singapore 117609, Singapore
| | - Judy C. G. Sng
- National University of Singapore, Yong Loo Lin School of Medicine, Department of Pharmacology, Singapore 117599, Singapore
- Singapore Institute of Clinical Sciences (SICS), A*STAR, Brenner Centre for Molecular Medicine, 30 Medical Drive, Singapore 117609, Singapore
| | - George J. Augustine
- National University of Singapore, Yong Loo Lin School of Medicine, Department of Physiology, Singapore 117597, Singapore
- Nanyang Technological University, Lee Kong Chian School of Medicine, Proteos, Biopolis, Level 4, 61 Biopolis Drive, #04-06/07, Singapore 138673, Singapore
- Institute of Molecular and Cell Biology, A*STAR, Proteos, 61 Biopolis Drive, Proteos, Singapore 138673, Singapore
- Marine Biological Laboratory, 7 MBL Street, Woods Hole, Massachusetts 02543, United States
- Korea Institute of Science and Technology, Center for Functional Connectomics, 39-1 Hawolgokdong, Seongbukgu, Seoul 136-791, Republic of Korea
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14
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Fujieda T, Koganezawa N, Ide Y, Shirao T, Sekino Y. An inhibitory pathway controlling the gating mechanism of the mouse lateral amygdala revealed by voltage-sensitive dye imaging. Neurosci Lett 2015; 590:126-31. [DOI: 10.1016/j.neulet.2015.01.079] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Revised: 01/28/2015] [Accepted: 01/29/2015] [Indexed: 01/11/2023]
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15
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Richner TJ, Baumgartner R, Brodnick SK, Azimipour M, Krugner-Higby LA, Eliceiri KW, Williams JC, Pashaie R. Patterned optogenetic modulation of neurovascular and metabolic signals. J Cereb Blood Flow Metab 2015; 35:140-7. [PMID: 25388678 PMCID: PMC4294407 DOI: 10.1038/jcbfm.2014.189] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Revised: 09/26/2014] [Accepted: 09/30/2014] [Indexed: 11/09/2022]
Abstract
The hemodynamic and metabolic response of the cortex depends spatially and temporally on the activity of multiple cell types. Optogenetics enables specific cell types to be modulated with high temporal precision and is therefore an emerging method for studying neurovascular and neurometabolic coupling. Going beyond temporal investigations, we developed a microprojection system to apply spatial photostimulus patterns in vivo. We monitored vascular and metabolic fluorescence signals after photostimulation in Thy1-channelrhodopsin-2 mice. Cerebral arteries increased in diameter rapidly after photostimulation, while nearby veins showed a slower smaller response. The amplitude of the arterial response was depended on the area of cortex stimulated. The fluorescence signal emitted at 450/100 nm and excited with ultraviolet is indicative of reduced nicotinamide adenine dinucleotide, an endogenous fluorescent enzyme involved in glycolysis and the citric acid cycle. This fluorescence signal decreased quickly and transiently after optogenetic stimulation, suggesting that glucose metabolism is tightly locked to optogenetic stimulation. To verify optogenetic stimulation of the cortex, we used a transparent substrate microelectrode array to map cortical potentials resulting from optogenetic stimulation. Spatial optogenetic stimulation is a new tool for studying neurovascular and neurometabolic coupling.
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Affiliation(s)
- Thomas J Richner
- Laboratory for Optical and Computational Instrumentation and Department of Biomedical Engineering, University of Wisconsin at Madison, Madison, Wisconsin, USA
| | - Ryan Baumgartner
- Department of Electrical Engineering and Computer Science, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, USA
| | - Sarah K Brodnick
- Laboratory for Optical and Computational Instrumentation and Department of Biomedical Engineering, University of Wisconsin at Madison, Madison, Wisconsin, USA
| | - Mehdi Azimipour
- Department of Electrical Engineering and Computer Science, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, USA
| | - Lisa A Krugner-Higby
- Laboratory for Optical and Computational Instrumentation and Department of Biomedical Engineering, University of Wisconsin at Madison, Madison, Wisconsin, USA
| | - Kevin W Eliceiri
- Laboratory for Optical and Computational Instrumentation and Department of Biomedical Engineering, University of Wisconsin at Madison, Madison, Wisconsin, USA
| | - Justin C Williams
- Laboratory for Optical and Computational Instrumentation and Department of Biomedical Engineering, University of Wisconsin at Madison, Madison, Wisconsin, USA
| | - Ramin Pashaie
- Department of Electrical Engineering and Computer Science, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, USA
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16
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Jaafari N, Vogt KE, Saggau P, Leslie LM, Zecevic D, Canepari M. Combining Membrane Potential Imaging with Other Optical Techniques. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2015; 859:103-25. [PMID: 26238050 DOI: 10.1007/978-3-319-17641-3_4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Membrane potential imaging using voltage-sensitive dyes can be combined with other optical techniques for a variety of applications. Combining voltage imaging with Ca2+ imaging allows correlating membrane potential changes with intracellular Ca2+ signals or with Ca2+ currents. Combining voltage imaging with uncaging techniques allows analyzing electrical signals elicited by photorelease of a particular molecule. This approach is also a useful tool to calibrate the change in fluorescence intensity in terms of membrane potential changes from different sites permitting spatial mapping of electrical activity. Finally, combining voltage imaging with optogenetics, in particular with channelrhodopsin stimulation, opens the gate to novel investigations of brain circuitries by allowing measurements of synaptic signals mediated by specific sets of neurons. Here we describe in detail the methods of membrane potential imaging in combination with other optical techniques and discus some important applications.
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Affiliation(s)
- Nadia Jaafari
- Inserm U836, Grenoble Institute of Neuroscience, Team 3, Grenoble Cedex 09, France
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17
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Loew LM. Design and Use of Organic Voltage Sensitive Dyes. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2015; 859:27-53. [PMID: 26238048 DOI: 10.1007/978-3-319-17641-3_2] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The chemistry and the physics of voltage sensitive dyes (VSDs) should be understood and appreciated as a prerequisite for their optimal application to problems in neuroscience cardiology. This chapter provides a basic understanding of the properties of the large variety of available organic VSDs. The mechanisms by which the dyes respond to voltage guides the best set up of the optics for recording or imaging electrophysiological activity. The physical and chemical properties of the dyes can be tuned to optimize delivery to and staining of the cells in different experimental preparations. The aim of this chapter is to arm the experimentalists who use the dyes with enough information and data to be able to intelligently choose the best dye for their specific requirements.
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Affiliation(s)
- Leslie M Loew
- Department of Cell Biology, R. D. Berlin Center for Cell Analysis and Modeling, University of Connecticut Health Center, Farmington, CT, 06030-6406, USA,
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18
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Spatially Selective Holographic Photoactivation and Functional Fluorescence Imaging in Freely Behaving Mice with a Fiberscope. Neuron 2014; 84:1157-69. [DOI: 10.1016/j.neuron.2014.11.005] [Citation(s) in RCA: 140] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/27/2014] [Indexed: 02/03/2023]
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19
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Willadt S, Canepari M, Yan P, Loew LM, Vogt KE. Combined optogenetics and voltage sensitive dye imaging at single cell resolution. Front Cell Neurosci 2014; 8:311. [PMID: 25339864 PMCID: PMC4189389 DOI: 10.3389/fncel.2014.00311] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Accepted: 09/17/2014] [Indexed: 12/30/2022] Open
Abstract
Information processing in the central nervous system makes use of densely woven networks of neurons with complex dendritic and axonal arborizations. Studying signaling in such a network requires precise control over the activity of specific neurons and an understanding how the synaptic signals are integrated. We established a system using a recently published red-shifted voltage sensitive dye in slices from mice expressing channelrhodopsin (Ch) in GABAergic neurons. Using a focused 473 nm laser for Ch activation and 635 nm laser wide field illumination for voltage sensitive dye excitation we were able to simultaneously measure dendritic voltage transients and stimulate inhibitory synaptic connections. The combination of these techniques provides excellent spatiotemporal control over neuron activation and high resolution information on dendritic signal processing.
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Affiliation(s)
- Silvia Willadt
- Neurobiology/Pharmacology, Biozentrum, University of Basel Basel, Switzerland
| | - Marco Canepari
- Laboratoire Interdisciplinare de Physique (CNRS UMR 5588) and Grenoble Institut des Neurosciences (Inserm U836) Grenoble, France
| | - Ping Yan
- R. D. Berlin Center for Cell Analysis and Modeling, University of Connecticut Health Center Farmington, CT, USA
| | - Leslie M Loew
- R. D. Berlin Center for Cell Analysis and Modeling, University of Connecticut Health Center Farmington, CT, USA
| | - Kaspar E Vogt
- Neurobiology/Pharmacology, Biozentrum, University of Basel Basel, Switzerland ; International Institute for Integrative Sleep Medicine (IIIS), University of Tsukuba Tsukuba, Japan
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20
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Bourgeois EB, Johnson BN, McCoy AJ, Trippa L, Cohen AS, Marsh ED. A toolbox for spatiotemporal analysis of voltage-sensitive dye imaging data in brain slices. PLoS One 2014; 9:e108686. [PMID: 25259520 PMCID: PMC4178182 DOI: 10.1371/journal.pone.0108686] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Accepted: 09/02/2014] [Indexed: 12/30/2022] Open
Abstract
Voltage-sensitive dye imaging (VSDI) can simultaneously monitor the spatiotemporal electrical dynamics of thousands of neurons and is often used to identify functional differences in models of neurological disease. While the chief advantage of VSDI is the ability to record spatiotemporal activity, there are no tools available to visualize and statistically compare activity across the full spatiotemporal range of the VSDI dataset. Investigators commonly analyze only a subset of the data, and a majority of the dataset is routinely excluded from analysis. We have developed a software toolbox that simplifies visual inspection of VSDI data, and permits unaided statistical comparison across spatial and temporal dimensions. First, the three-dimensional VSDI dataset (x,y,time) is geometrically transformed into a two-dimensional spatiotemporal map of activity. Second, statistical comparison between groups is performed using a non-parametric permutation test. The result is a 2D map of all significant differences in both space and time. Here, we used the toolbox to identify functional differences in activity in VSDI data from acute hippocampal slices obtained from epileptic Arx conditional knock-out and control mice. Maps of spatiotemporal activity were produced and analyzed to identify differences in the activity evoked by stimulation of each of two axonal inputs to the hippocampus: the perforant pathway and the temporoammonic pathway. In mutant hippocampal slices, the toolbox identified a widespread decrease in spatiotemporal activity evoked by the temporoammonic pathway. No significant differences were observed in the activity evoked by the perforant pathway. The VSDI toolbox permitted us to visualize and statistically compare activity across the spatiotemporal scope of the VSDI dataset. Sampling error was minimized because the representation of the data is standardized by the toolbox. Statistical comparisons were conducted quickly, across the spatiotemporal scope of the data, without a priori knowledge of the character of the responses or the likely differences between them.
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Affiliation(s)
- Elliot B. Bourgeois
- Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail:
| | - Brian N. Johnson
- Department of Pediatrics, Division of Pediatric Neurology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
| | - Almedia J. McCoy
- Department of Pediatrics, Division of Pediatric Neurology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
| | - Lorenzo Trippa
- Department of Biostatistics and Computational Biology, Dana-Farber Cancer Institute, Boston, Massachusetts, United States of America
| | - Akiva S. Cohen
- Department of Pediatrics, Division of Pediatric Neurology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
- Department of Neurology, Division of Pediatric Neurology, The Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Eric D. Marsh
- Department of Pediatrics, Division of Pediatric Neurology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
- Department of Neurology, Division of Pediatric Neurology, The Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
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21
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Hochbaum DR, Zhao Y, Farhi SL, Klapoetke N, Werley CA, Kapoor V, Zou P, Kralj JM, Maclaurin D, Smedemark-Margulies N, Saulnier JL, Boulting GL, Straub C, Cho YK, Melkonian M, Wong GKS, Harrison DJ, Murthy VN, Sabatini BL, Boyden ES, Campbell RE, Cohen AE. All-optical electrophysiology in mammalian neurons using engineered microbial rhodopsins. Nat Methods 2014; 11:825-33. [PMID: 24952910 PMCID: PMC4117813 DOI: 10.1038/nmeth.3000] [Citation(s) in RCA: 539] [Impact Index Per Article: 49.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2013] [Accepted: 05/17/2014] [Indexed: 01/27/2023]
Abstract
All-optical electrophysiology-spatially resolved simultaneous optical perturbation and measurement of membrane voltage-would open new vistas in neuroscience research. We evolved two archaerhodopsin-based voltage indicators, QuasAr1 and QuasAr2, which show improved brightness and voltage sensitivity, have microsecond response times and produce no photocurrent. We engineered a channelrhodopsin actuator, CheRiff, which shows high light sensitivity and rapid kinetics and is spectrally orthogonal to the QuasArs. A coexpression vector, Optopatch, enabled cross-talk-free genetically targeted all-optical electrophysiology. In cultured rat neurons, we combined Optopatch with patterned optical excitation to probe back-propagating action potentials (APs) in dendritic spines, synaptic transmission, subcellular microsecond-timescale details of AP propagation, and simultaneous firing of many neurons in a network. Optopatch measurements revealed homeostatic tuning of intrinsic excitability in human stem cell-derived neurons. In rat brain slices, Optopatch induced and reported APs and subthreshold events with high signal-to-noise ratios. The Optopatch platform enables high-throughput, spatially resolved electrophysiology without the use of conventional electrodes.
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Affiliation(s)
- Daniel R Hochbaum
- 1] Applied Physics Program, School of Engineering and Applied Science, Harvard University, Cambridge, Massachusetts, USA. [2]
| | - Yongxin Zhao
- 1] Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada. [2]
| | - Samouil L Farhi
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts, USA
| | - Nathan Klapoetke
- 1] The MIT Media Laboratory, Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts, USA. [2] Department of Biological Engineering, MIT, Cambridge, Massachusetts, USA. [3] Department of Brain and Cognitive Sciences, MIT, Cambridge, Massachusetts, USA. [4] McGovern Institute for Brain Research, MIT, Cambridge, Massachusetts, USA
| | - Christopher A Werley
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts, USA
| | - Vikrant Kapoor
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts, USA
| | - Peng Zou
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts, USA
| | - Joel M Kralj
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts, USA
| | - Dougal Maclaurin
- Department of Physics, Harvard University, Cambridge, Massachusetts, USA
| | | | - Jessica L Saulnier
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts, USA
| | | | - Christoph Straub
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Yong Ku Cho
- 1] The MIT Media Laboratory, Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts, USA. [2] Department of Biological Engineering, MIT, Cambridge, Massachusetts, USA. [3] Department of Brain and Cognitive Sciences, MIT, Cambridge, Massachusetts, USA. [4] McGovern Institute for Brain Research, MIT, Cambridge, Massachusetts, USA
| | - Michael Melkonian
- Institute of Botany, Cologne Biocenter, University of Cologne, Cologne, Germany
| | - Gane Ka-Shu Wong
- 1] Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada. [2] Department of Medicine, University of Alberta, Edmonton, Alberta, Canada. [3] Beijing Genomics Institute-Shenzhen, Shenzhen, China
| | - D Jed Harrison
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada
| | - Venkatesh N Murthy
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts, USA
| | - Bernardo L Sabatini
- 1] Department of Neurobiology, Harvard Medical School, Boston, Massachusetts, USA. [2] Howard Hughes Medical Institute, Harvard University, Cambridge, Massachusetts, USA
| | - Edward S Boyden
- 1] The MIT Media Laboratory, Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts, USA. [2] Department of Biological Engineering, MIT, Cambridge, Massachusetts, USA. [3] Department of Brain and Cognitive Sciences, MIT, Cambridge, Massachusetts, USA. [4] McGovern Institute for Brain Research, MIT, Cambridge, Massachusetts, USA. [5]
| | - Robert E Campbell
- 1] Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada. [2]
| | - Adam E Cohen
- 1] Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts, USA. [2] Department of Physics, Harvard University, Cambridge, Massachusetts, USA. [3] Howard Hughes Medical Institute, Harvard University, Cambridge, Massachusetts, USA
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22
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Abstract
Purkinje cells (PCs) of the cerebellar cortex are necessary for controlling movement with precision, but a mechanistic explanation of how the activity of these inhibitory neurons regulates motor output is still lacking. We used an optogenetic approach in awake mice to show for the first time that transiently suppressing spontaneous activity in a population of PCs is sufficient to cause discrete movements that can be systematically modulated in size, speed, and timing depending on how much and how long PC firing is suppressed. We further demonstrate that this fine control of movement kinematics is mediated by a graded disinhibition of target neurons in the deep cerebellar nuclei. Our results prove a long-standing model of cerebellar function and provide the first demonstration that suppression of inhibitory signals can act as a powerful mechanism for the precise control of behavior.
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23
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Govorunova EG, Sineshchekov OA, Li H, Janz R, Spudich JL. Characterization of a highly efficient blue-shifted channelrhodopsin from the marine alga Platymonas subcordiformis. J Biol Chem 2013; 288:29911-22. [PMID: 23995841 DOI: 10.1074/jbc.m113.505495] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Rhodopsin photosensors of phototactic algae act as light-gated cation channels when expressed in animal cells. These proteins (channelrhodopsins) are extensively used for millisecond scale photocontrol of cellular functions (optogenetics). We report characterization of PsChR, one of the phototaxis receptors in the alga Platymonas (Tetraselmis) subcordiformis. PsChR exhibited ∼3-fold higher unitary conductance and greater relative permeability for Na(+) ions, as compared with the most frequently used channelrhodopsin-2 from Chlamydomonas reinhardtii (CrChR2). Photocurrents generated by PsChR in HEK293 cells showed lesser inactivation and faster peak recovery than those by CrChR2. Their maximal spectral sensitivity was at 445 nm, making PsChR the most blue-shifted channelrhodopsin so far identified. The λmax of detergent-purified PsChR was 437 nm at neutral pH and exhibited red shifts (pKa values at 6.6 and 3.8) upon acidification. The purified pigment undergoes a photocycle with a prominent red-shifted intermediate whose formation and decay kinetics match the kinetics of channel opening and closing. The rise and decay of an M-like intermediate prior to formation of this putative conductive state were faster than in CrChR2. PsChR mediated sufficient light-induced membrane depolarization in cultured hippocampal neurons to trigger reliable repetitive spiking at the upper threshold frequency of the neurons. At low frequencies spiking probability decreases less with PsChR than with CrChR2 because of the faster recovery of the former. Its blue-shifted absorption enables optogenetics at wavelengths even below 400 nm. A combination of characteristics makes PsChR important for further research on structure-function relationships in ChRs and potentially useful for optogenetics, especially for combinatorial applications when short wavelength excitation is required.
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Affiliation(s)
- Elena G Govorunova
- From the Department of Biochemistry & Molecular Biology, Center for Membrane Biology and
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24
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Tsubota T, Ohashi Y, Tamura K. Optogenetics in the cerebellum: Purkinje cell-specific approaches for understanding local cerebellar functions. Behav Brain Res 2013; 255:26-34. [PMID: 23623886 DOI: 10.1016/j.bbr.2013.04.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2012] [Revised: 04/14/2013] [Accepted: 04/15/2013] [Indexed: 11/30/2022]
Abstract
The cerebellum consists of the cerebellar cortex and the cerebellar nuclei. Although the basic neuronal circuitry of the cerebellar cortex is uniform everywhere, anatomical data demonstrate that the input and output relationships of the cortex are spatially segregated between different cortical areas, which suggests that there are functional distinctions between these different areas. Perturbation of cerebellar cortical functions in a spatially restricted fashion is thus essential for investigating the distinctions among different cortical areas. In the cerebellar cortex, Purkinje cells are the sole output neurons that send information to downstream cerebellar and vestibular nuclei. Therefore, selective manipulation of Purkinje cell activities, without disturbing other neuronal types and passing fibers within the cortex, is a direct approach to spatially restrict the effects of perturbations. Although this type of approach has for many years been technically difficult, recent advances in optogenetics now enable selective activation or inhibition of Purkinje cell activities, with high temporal resolution. Here we discuss the effectiveness of using Purkinje cell-specific optogenetic approaches to elucidate the functions of local cerebellar cortex regions. We also discuss what improvements to current methods are necessary for future investigations of cerebellar functions to provide further advances.
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Affiliation(s)
- Tadashi Tsubota
- Department of Physiology, The University of Tokyo School of Medicine, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
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25
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Yawo H, Koizumi A, Hegemann P. Adventure beyond borders of scientific fields with optogenetics. Neurosci Res 2013; 75:1-2. [PMID: 23465316 DOI: 10.1016/j.neures.2013.02.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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