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Pio-Lopez L, Levin M. Aging as a loss of morphostatic information: A developmental bioelectricity perspective. Ageing Res Rev 2024; 97:102310. [PMID: 38636560 DOI: 10.1016/j.arr.2024.102310] [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: 11/05/2023] [Revised: 02/21/2024] [Accepted: 04/12/2024] [Indexed: 04/20/2024]
Abstract
Maintaining order at the tissue level is crucial throughout the lifespan, as failure can lead to cancer and an accumulation of molecular and cellular disorders. Perhaps, the most consistent and pervasive result of these failures is aging, which is characterized by the progressive loss of function and decline in the ability to maintain anatomical homeostasis and reproduce. This leads to organ malfunction, diseases, and ultimately death. The traditional understanding of aging is that it is caused by the accumulation of molecular and cellular damage. In this article, we propose a complementary view of aging from the perspective of endogenous bioelectricity which has not yet been integrated into aging research. We propose a view of aging as a morphostasis defect, a loss of biophysical prepattern information, encoding anatomical setpoints used for dynamic tissue and organ homeostasis. We hypothesize that this is specifically driven by abrogation of the endogenous bioelectric signaling that normally harnesses individual cell behaviors toward the creation and upkeep of complex multicellular structures in vivo. Herein, we first describe bioelectricity as the physiological software of life, and then identify and discuss the links between bioelectricity and life extension strategies and age-related diseases. We develop a bridge between aging and regeneration via bioelectric signaling that suggests a research program for healthful longevity via morphoceuticals. Finally, we discuss the broader implications of the homologies between development, aging, cancer and regeneration and how morphoceuticals can be developed for aging.
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Affiliation(s)
- Léo Pio-Lopez
- Allen Discovery Center, Tufts University, Medford, MA 02155, USA
| | - Michael Levin
- Allen Discovery Center, Tufts University, Medford, MA 02155, USA; Wyss Institute for Biologically Inspired Engineering, Boston, MA 02115, USA.
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2
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Ohmori H, Hirai Y, Matsui R, Watanabe D. High resolution recording of local field currents simultaneously with sound-evoked calcium signals by a photometric patch electrode in the auditory cortex field L of the chick. J Neurosci Methods 2023; 392:109863. [PMID: 37075913 DOI: 10.1016/j.jneumeth.2023.109863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 03/06/2023] [Accepted: 04/15/2023] [Indexed: 04/21/2023]
Abstract
BACKGROUND Functioning of the brain is based on both electrical and metabolic activity of neural ensembles. Accordingly, it would be useful to measure intracellular metabolic signaling simultaneously with electrical activity in the brain in vivo. NEW METHOD We innovated a PhotoMetric-patch-Electrode (PME) recording system that has a high temporal resolution incorporating a photomultiplier tube as a light detector. The PME is fabricated from a quartz glass capillary to transmit light as a light guide, and it can detect electrical signals as a patch electrode simultaneously with a fluorescence signal. RESULTS We measured the sound-evoked Local Field Current (LFC) and fluorescence Ca2+ signal from neurons labeled with Ca2+-sensitive dye Oregon Green BAPTA1 in field L, the avian auditory cortex. Sound stimulation evoked multi-unit spike bursts and Ca2+ signals, and enhanced the fluctuation of LFC. After a brief sound stimulation, the cross-correlation between LFC and Ca2+ signal was prolonged. D-AP5 (antagonist for NMDA receptors) suppressed the sound-evoked Ca2+ signal when applied locally by pressure from the tip of PME. COMPARISON WITH EXISTING METHODS In contrast to existing multiphoton imaging or optical fiber recording methods, the PME is a patch electrode pulled simply from a quartz glass capillary and can measure fluorescence signals at the tip simultaneously with electrical signal at any depth of the brain structure. CONCLUSION The PME is devised to record electrical and optical signals simultaneously with high temporal resolution. Moreover, it can inject chemical agents dissolved in the tip-filling medium locally by pressure, allowing manipulation of neural activity pharmacologically.
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Affiliation(s)
- Harunori Ohmori
- Department of Physiology & Neurobiology, Faculty of Medicine, Kyoto University, Kyoto, Japan.
| | - Yasuharu Hirai
- Department of Physiology & Neurobiology, Faculty of Medicine, Kyoto University, Kyoto, Japan
| | - Ryosuke Matsui
- Department of Biological Sciences, Faculty of Medicine, Kyoto University, Kyoto, Japan
| | - Dai Watanabe
- Department of Biological Sciences, Faculty of Medicine, Kyoto University, Kyoto, Japan
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3
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Ma Y, Shu WC, Lin L, Cao XJ, Oertel D, Smith PH, Jackson MB. Imaging Voltage Globally and in Isofrequency Lamina in Slices of Mouse Ventral Cochlear Nucleus. eNeuro 2023; 10:ENEURO.0465-22.2023. [PMID: 36792362 PMCID: PMC9997695 DOI: 10.1523/eneuro.0465-22.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 02/02/2023] [Accepted: 02/06/2023] [Indexed: 02/17/2023] Open
Abstract
The cochlear nuclei (CNs) receive sensory information from the ear and perform fundamental computations before relaying this information to higher processing centers. These computations are performed by distinct types of neurons interconnected in circuits dedicated to the specialized roles of the auditory system. In the present study, we explored the use of voltage imaging to investigate CN circuitry. We tested two approaches based on fundamentally different voltage sensing technologies. Using a voltage-sensitive dye we recorded glutamate receptor-independent signals arising predominantly from axons. The mean conduction velocity of these fibers of 0.27 m/s was rapid but in range with other unmyelinated axons. We then used a genetically-encoded hybrid voltage sensor (hVOS) to image voltage from a specific population of neurons. Probe expression was controlled using Cre recombinase linked to c-fos activation. This activity-induced gene enabled targeting of neurons that are activated when a mouse hears a pure 15-kHz tone. In CN slices from these animals auditory nerve fiber stimulation elicited a glutamate receptor-dependent depolarization in hVOS probe-labeled neurons. These cells resided within a band corresponding to an isofrequency lamina, and responded with a high degree of synchrony. In contrast to the axonal origin of voltage-sensitive dye signals, hVOS signals represent predominantly postsynaptic responses. The introduction of voltage imaging to the CN creates the opportunity to investigate auditory processing circuitry in populations of neurons targeted on the basis of their genetic identity and their roles in sensory processing.
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Affiliation(s)
- Yihe Ma
- Department of Neuroscience, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705
| | - Wen-Chi Shu
- Department of Neuroscience, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705
| | - Lin Lin
- Department of Neuroscience, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705
| | - Xiao-Jie Cao
- Department of Neuroscience, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705
| | - Donata Oertel
- Department of Neuroscience, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705
| | - Philip H Smith
- Department of Neuroscience, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705
| | - Meyer B Jackson
- Department of Neuroscience, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705
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4
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Pedraza-González L, Barneschi L, Marszałek M, Padula D, De Vico L, Olivucci M. Automated QM/MM Screening of Rhodopsin Variants with Enhanced Fluorescence. J Chem Theory Comput 2023; 19:293-310. [PMID: 36516450 DOI: 10.1021/acs.jctc.2c00928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
We present a computational protocol for the fast and automated screening of excited-state hybrid quantum mechanics/molecular mechanics (QM/MM) models of rhodopsins to be used as fluorescent probes based on the automatic rhodopsin modeling protocol (a-ARM). Such "a-ARM fluorescence screening protocol" is implemented through a general Python-based driver, PyARM, that is also proposed here. The implementation and performance of the protocol are benchmarked using different sets of rhodopsin variants whose absorption and, more relevantly, emission spectra have been experimentally measured. We show that, despite important limitations that make unsafe to use it as a black-box tool, the protocol reproduces the observed trends in fluorescence and it is capable of selecting novel potentially fluorescent rhodopsins. We also show that the protocol can be used in mechanistic investigations to discern fluorescence enhancement effects associated with a near degeneracy of the S1/S2 states or, alternatively, with a barrier generated via coupling of the S0/S1 wave functions.
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Affiliation(s)
- Laura Pedraza-González
- Department of Biotechnology, Chemistry and Pharmacy, Università degli Studi di Siena, Via A. Moro 2, I-53100 Siena, Italy
| | - Leonardo Barneschi
- Department of Biotechnology, Chemistry and Pharmacy, Università degli Studi di Siena, Via A. Moro 2, I-53100 Siena, Italy
| | - Michał Marszałek
- Department of Biotechnology, Chemistry and Pharmacy, Università degli Studi di Siena, Via A. Moro 2, I-53100 Siena, Italy.,Faculty of Chemistry, Wrocław University of Science and Technology, Wybrzeże Wyspiaǹskiego 27, 50-370 Wrocław, Poland
| | - Daniele Padula
- Department of Biotechnology, Chemistry and Pharmacy, Università degli Studi di Siena, Via A. Moro 2, I-53100 Siena, Italy
| | - Luca De Vico
- Department of Biotechnology, Chemistry and Pharmacy, Università degli Studi di Siena, Via A. Moro 2, I-53100 Siena, Italy
| | - Massimo Olivucci
- Department of Biotechnology, Chemistry and Pharmacy, Università degli Studi di Siena, Via A. Moro 2, I-53100 Siena, Italy.,Department of Chemistry, Bowling Green State University, Bowling Green, Ohio 43403, United States
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5
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Chiang CC, Durand DM. Subthreshold Oscillating Waves in Neural Tissue Propagate by Volume Conduction and Generate Interference. Brain Sci 2022; 13:74. [PMID: 36672054 PMCID: PMC9856930 DOI: 10.3390/brainsci13010074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 12/21/2022] [Accepted: 12/28/2022] [Indexed: 12/31/2022] Open
Abstract
Subthreshold neural oscillations have been observed in several brain regions and can influence the timing of neural spikes. However, the spatial extent and function of these spontaneous oscillations remain unclear. To study the mechanisms underlying these oscillations, we use optogenetic stimulation to generate oscillating waves in the longitudinal hippocampal slice expressing optopatch proteins. We found that optogenetic stimulation can generate two types of neural activity: suprathreshold neural spikes and subthreshold oscillating waves. Both waves could propagate bidirectionally at similar speeds and go through a transection of the tissue. The propagating speed is independent of the oscillating frequency but increases with increasing amplitudes of the waves. The endogenous electric fields generated by oscillating waves are about 0.6 mV/mm along the dendrites and about 0.3 mV/mm along the cell layer. We also observed that these oscillating waves could interfere with each other. Optical stimulation applied simultaneously at each slice end generated a larger wave in the middle of the tissue (constructive interference) or destructive interference with laser signals in opposite phase. However, the suprathreshold neural spikes were annihilated when they collided. Finally, the waves were not affected by the NMDA blocker (APV) and still propagated in the presence of tetrodotoxin (TTX) but at a significantly lower amplitude. The role of these subthreshold waves in neural function is unknown, but the results show that at low amplitude, the subthreshold propagating waves lack a refractory period allowing a novel analog form of preprocessing of neural activity by interference independent of synaptic transmission.
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Affiliation(s)
| | - Dominique M. Durand
- Neural Engineering Center, Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA
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6
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Balood M, Ahmadi M, Eichwald T, Ahmadi A, Majdoubi A, Roversi K, Roversi K, Lucido CT, Restaino AC, Huang S, Ji L, Huang KC, Semerena E, Thomas SC, Trevino AE, Merrison H, Parrin A, Doyle B, Vermeer DW, Spanos WC, Williamson CS, Seehus CR, Foster SL, Dai H, Shu CJ, Rangachari M, Thibodeau J, V Del Rincon S, Drapkin R, Rafei M, Ghasemlou N, Vermeer PD, Woolf CJ, Talbot S. Nociceptor neurons affect cancer immunosurveillance. Nature 2022; 611:405-412. [PMID: 36323780 PMCID: PMC9646485 DOI: 10.1038/s41586-022-05374-w] [Citation(s) in RCA: 61] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 09/21/2022] [Indexed: 11/07/2022]
Abstract
Solid tumours are innervated by nerve fibres that arise from the autonomic and sensory peripheral nervous systems1-5. Whether the neo-innervation of tumours by pain-initiating sensory neurons affects cancer immunosurveillance remains unclear. Here we show that melanoma cells interact with nociceptor neurons, leading to increases in their neurite outgrowth, responsiveness to noxious ligands and neuropeptide release. Calcitonin gene-related peptide (CGRP)-one such nociceptor-produced neuropeptide-directly increases the exhaustion of cytotoxic CD8+ T cells, which limits their capacity to eliminate melanoma. Genetic ablation of the TRPV1 lineage, local pharmacological silencing of nociceptors and antagonism of the CGRP receptor RAMP1 all reduced the exhaustion of tumour-infiltrating leukocytes and decreased the growth of tumours, nearly tripling the survival rate of mice that were inoculated with B16F10 melanoma cells. Conversely, CD8+ T cell exhaustion was rescued in sensory-neuron-depleted mice that were treated with local recombinant CGRP. As compared with wild-type CD8+ T cells, Ramp1-/- CD8+ T cells were protected against exhaustion when co-transplanted into tumour-bearing Rag1-deficient mice. Single-cell RNA sequencing of biopsies from patients with melanoma revealed that intratumoral RAMP1-expressing CD8+ T cells were more exhausted than their RAMP1-negative counterparts, whereas overexpression of RAMP1 correlated with a poorer clinical prognosis. Overall, our results suggest that reducing the release of CGRP from tumour-innervating nociceptors could be a strategy to improve anti-tumour immunity by eliminating the immunomodulatory effects of CGRP on cytotoxic CD8+ T cells.
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Affiliation(s)
- Mohammad Balood
- Département de Pharmacologie et Physiologie, Université de Montréal, Montréal, Quebec, Canada
- Département de Médecine Moléculaire, Faculté de Médecine, Université Laval, Québec, Quebec, Canada
| | - Maryam Ahmadi
- Département de Pharmacologie et Physiologie, Université de Montréal, Montréal, Quebec, Canada
| | - Tuany Eichwald
- Département de Pharmacologie et Physiologie, Université de Montréal, Montréal, Quebec, Canada
- Departamento de Bioquímica, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - Ali Ahmadi
- Département de Pharmacologie et Physiologie, Université de Montréal, Montréal, Quebec, Canada
| | - Abdelilah Majdoubi
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montréal, Quebec, Canada
| | - Karine Roversi
- Département de Pharmacologie et Physiologie, Université de Montréal, Montréal, Quebec, Canada
| | - Katiane Roversi
- Département de Pharmacologie et Physiologie, Université de Montréal, Montréal, Quebec, Canada
| | | | - Anthony C Restaino
- Cancer Biology and Immunotherapies, Sanford Research, Sioux Falls, SD, USA
| | | | | | | | - Elise Semerena
- Département de Pharmacologie et Physiologie, Université de Montréal, Montréal, Quebec, Canada
| | - Sini C Thomas
- Département de Pharmacologie et Physiologie, Université de Montréal, Montréal, Quebec, Canada
| | - Alexandro E Trevino
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Hannah Merrison
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Alexandre Parrin
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Benjamin Doyle
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Daniel W Vermeer
- Cancer Biology and Immunotherapies, Sanford Research, Sioux Falls, SD, USA
| | - William C Spanos
- Cancer Biology and Immunotherapies, Sanford Research, Sioux Falls, SD, USA
| | | | - Corey R Seehus
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Simmie L Foster
- Depression Clinical Research Program, Massachusetts General Hospital, Boston, MA, USA
| | | | | | - Manu Rangachari
- Département de Médecine Moléculaire, Faculté de Médecine, Université Laval, Québec, Quebec, Canada
| | - Jacques Thibodeau
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montréal, Quebec, Canada
| | | | - Ronny Drapkin
- Penn Ovarian Cancer Research Center, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Moutih Rafei
- Département de Pharmacologie et Physiologie, Université de Montréal, Montréal, Quebec, Canada
| | - Nader Ghasemlou
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada
| | - Paola D Vermeer
- Cancer Biology and Immunotherapies, Sanford Research, Sioux Falls, SD, USA
| | - Clifford J Woolf
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Sebastien Talbot
- Département de Pharmacologie et Physiologie, Université de Montréal, Montréal, Quebec, Canada.
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada.
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7
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Barneschi L, Marsili E, Pedraza-González L, Padula D, De Vico L, Kaliakin D, Blanco-González A, Ferré N, Huix-Rotllant M, Filatov M, Olivucci M. On the fluorescence enhancement of arch neuronal optogenetic reporters. Nat Commun 2022; 13:6432. [PMID: 36307417 PMCID: PMC9616920 DOI: 10.1038/s41467-022-33993-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Accepted: 10/07/2022] [Indexed: 12/25/2022] Open
Abstract
The lack of a theory capable of connecting the amino acid sequence of a light-absorbing protein with its fluorescence brightness is hampering the development of tools for understanding neuronal communications. Here we demonstrate that a theory can be established by constructing quantum chemical models of a set of Archaerhodopsin reporters in their electronically excited state. We found that the experimentally observed increase in fluorescence quantum yield is proportional to the computed decrease in energy difference between the fluorescent state and a nearby photoisomerization channel leading to an exotic diradical of the protein chromophore. This finding will ultimately support the development of technologies for searching novel fluorescent rhodopsin variants and unveil electrostatic changes that make light emission brighter and brighter.
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Affiliation(s)
- Leonardo Barneschi
- grid.9024.f0000 0004 1757 4641Dipartimento di Biotecnologie, Chimica e Farmacia, Università di Siena, via A. Moro 2, I-53100 Siena, Italy
| | - Emanuele Marsili
- grid.9024.f0000 0004 1757 4641Dipartimento di Biotecnologie, Chimica e Farmacia, Università di Siena, via A. Moro 2, I-53100 Siena, Italy ,grid.8250.f0000 0000 8700 0572University of Durham, Department of Chemistry, South Road, Durham, DH1 3LE United Kingdom ,grid.5337.20000 0004 1936 7603Present Address: Centre for Computational Chemistry, School of Chemistry, University of Bristol, Bristol, BS8 1TS, United Kingdom
| | - Laura Pedraza-González
- grid.9024.f0000 0004 1757 4641Dipartimento di Biotecnologie, Chimica e Farmacia, Università di Siena, via A. Moro 2, I-53100 Siena, Italy ,grid.5395.a0000 0004 1757 3729Present Address: Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via Giuseppe Moruzzi, 13, I-56124 Pisa, Italy
| | - Daniele Padula
- grid.9024.f0000 0004 1757 4641Dipartimento di Biotecnologie, Chimica e Farmacia, Università di Siena, via A. Moro 2, I-53100 Siena, Italy
| | - Luca De Vico
- grid.9024.f0000 0004 1757 4641Dipartimento di Biotecnologie, Chimica e Farmacia, Università di Siena, via A. Moro 2, I-53100 Siena, Italy
| | - Danil Kaliakin
- grid.253248.a0000 0001 0661 0035Department of Chemistry, Bowling Green State University, Bowling Green, OH 43403 USA
| | - Alejandro Blanco-González
- grid.253248.a0000 0001 0661 0035Department of Chemistry, Bowling Green State University, Bowling Green, OH 43403 USA
| | - Nicolas Ferré
- grid.462456.70000 0004 4902 8637Institut de Chimie Radicalaire (UMR-7273), Aix-Marseille Université, CNRS, 13397 Marseille, Cedex 20 France
| | - Miquel Huix-Rotllant
- grid.462456.70000 0004 4902 8637Institut de Chimie Radicalaire (UMR-7273), Aix-Marseille Université, CNRS, 13397 Marseille, Cedex 20 France
| | - Michael Filatov
- grid.258803.40000 0001 0661 1556Department of Chemistry, Kyungpook National University, Daegu, 702-701 South Korea
| | - Massimo Olivucci
- grid.9024.f0000 0004 1757 4641Dipartimento di Biotecnologie, Chimica e Farmacia, Università di Siena, via A. Moro 2, I-53100 Siena, Italy ,grid.253248.a0000 0001 0661 0035Department of Chemistry, Bowling Green State University, Bowling Green, OH 43403 USA ,grid.11843.3f0000 0001 2157 9291University of Strasbourg Institute for Advanced Studies, 5, alleé duGeń eŕ al Rouvillois, F-67083 Strasbourg, France
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8
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Penzkofer A, Silapetere A, Hegemann P. Theoretical Investigation of the Photocycle Dynamics of the Archaerhodopsin 3 Based Fluorescent Voltage Sensor Archon2. J Photochem Photobiol A Chem 2022. [DOI: 10.1016/j.jphotochem.2022.114366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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9
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All-optical interrogation of neural circuits in behaving mice. Nat Protoc 2022; 17:1579-1620. [PMID: 35478249 DOI: 10.1038/s41596-022-00691-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 02/09/2022] [Indexed: 12/22/2022]
Abstract
Recent advances combining two-photon calcium imaging and two-photon optogenetics with computer-generated holography now allow us to read and write the activity of large populations of neurons in vivo at cellular resolution and with high temporal resolution. Such 'all-optical' techniques enable experimenters to probe the effects of functionally defined neurons on neural circuit function and behavioral output with new levels of precision. This greatly increases flexibility, resolution, targeting specificity and throughput compared with alternative approaches based on electrophysiology and/or one-photon optogenetics and can interrogate larger and more densely labeled populations of neurons than current voltage imaging-based implementations. This protocol describes the experimental workflow for all-optical interrogation experiments in awake, behaving head-fixed mice. We describe modular procedures for the setup and calibration of an all-optical system (~3 h), the preparation of an indicator and opsin-expressing and task-performing animal (~3-6 weeks), the characterization of functional and photostimulation responses (~2 h per field of view) and the design and implementation of an all-optical experiment (achievable within the timescale of a normal behavioral experiment; ~3-5 h per field of view). We discuss optimizations for efficiently selecting and targeting neuronal ensembles for photostimulation sequences, as well as generating photostimulation response maps from the imaging data that can be used to examine the impact of photostimulation on the local circuit. We demonstrate the utility of this strategy in three brain areas by using different experimental setups. This approach can in principle be adapted to any brain area to probe functional connectivity in neural circuits and investigate the relationship between neural circuit activity and behavior.
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10
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Sepehri Rad M, Cohen LB, Baker BJ. Conserved Amino Acids Residing Outside the Voltage Field Can Shift the Voltage Sensitivity and Increase the Signal Speed and Size of Ciona Based GEVIs. Front Cell Dev Biol 2022; 10:868143. [PMID: 35784472 PMCID: PMC9243531 DOI: 10.3389/fcell.2022.868143] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 05/13/2022] [Indexed: 11/19/2022] Open
Abstract
To identify potential regions of the voltage-sensing domain that could shift the voltage sensitivity of Ciona intestinalis based Genetically Encoded Voltage Indicators (GEVIs), we aligned the amino acid sequences of voltage-gated sodium channels from different organisms. Conserved polar residues were identified at multiple transmembrane/loop junctions in the voltage sensing domain. Similar conservation of polar amino acids was found in the voltage-sensing domain of the voltage-sensing phosphatase gene family. These conserved residues were mutated to nonpolar or oppositely charged amino acids in a GEVI that utilizes the voltage sensing domain of the voltage sensing phosphatase from Ciona fused to the fluorescent protein, super ecliptic pHluorin (A227D). Different mutations shifted the voltage sensitivity to more positive or more negative membrane potentials. Double mutants were then created by selecting constructs that shifted the optical signal to a more physiologically relevant voltage range. Introduction of these mutations into previously developed GEVIs resulted in Plos6-v2 which improved the dynamic range to 40% ΔF/F/100 mV, a 25% increase over the parent, ArcLight. The onset time constant of Plos6-v2 is also 50% faster than ArcLight. Thus, Plos6-v2 appears to be the GEVI of choice.
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Affiliation(s)
- Masoud Sepehri Rad
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, South Korea
- Department of Neuroscience, University of Wisconsin, Madison, WI, United States
| | - Lawrence B. Cohen
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, South Korea
- Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT, United States
- *Correspondence: Lawrence B. Cohen, ; Bradley J. Baker,
| | - Bradley J. Baker
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, South Korea
- Division of Bio-Medical Science and Technology, KIST School, Korea University of Science and Technology (UST), Seoul, South Korea
- *Correspondence: Lawrence B. Cohen, ; Bradley J. Baker,
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11
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Kasatkina LA, Verkhusha VV. Transgenic mice encoding modern imaging probes: Properties and applications. Cell Rep 2022; 39:110845. [PMID: 35613592 PMCID: PMC9183799 DOI: 10.1016/j.celrep.2022.110845] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 03/31/2022] [Accepted: 04/28/2022] [Indexed: 12/04/2022] Open
Abstract
Modern biology is increasingly reliant on optical technologies, including visualization and longitudinal monitoring of cellular processes. The major limitation here is the availability of animal models to track the molecules and cells in their natural environment in vivo. Owing to the integrity of the studied tissue and the high stability of transgene expression throughout life, transgenic mice encoding fluorescent proteins and biosensors represent unique tools for in vivo studies in norm and pathology. We review the strategies for targeting probe expression in specific tissues, cell subtypes, or cellular compartments. We describe the application of transgenic mice expressing fluorescent proteins for tracking protein expression patterns, apoptotic events, tissue differentiation and regeneration, neurogenesis, tumorigenesis, and cell fate mapping. We overview the possibilities of functional imaging of secondary messengers, neurotransmitters, and ion fluxes. Finally, we provide the rationale and perspectives for the use of transgenic imaging probes in translational research and drug discovery.
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Affiliation(s)
- Ludmila A Kasatkina
- Department of Genetics and Gruss-Lipper Biophotonics Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Vladislav V Verkhusha
- Department of Genetics and Gruss-Lipper Biophotonics Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Medicum, Faculty of Medicine, University of Helsinki, Helsinki 00290, Finland.
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12
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Roversi K, Tabatabaei M, Desjardins-Lecavalier N, Balood M, Crosson T, Costantino S, Griffith M, Talbot S, Boutopoulos C. Nanophotonics Enable Targeted Photothermal Silencing of Nociceptor Neurons. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2103364. [PMID: 35195345 DOI: 10.1002/smll.202103364] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 12/28/2021] [Indexed: 06/14/2023]
Abstract
The sensory nervous and immune systems work in concert to preserve homeostasis. While this endogenous interplay protects from danger, it may drive chronic pathologies. Currently, genetic engineering of neurons remains the primary approach to interfere selectively with this potentially deleterious interplay. However, such manipulations are not feasible in a clinical setting. Here, this work reports a nanotechnology-enabled concept to silence subsets of unmodified nociceptor neurons that exploits their ability to respond to heat via the transient receptor potential vanilloid type 1 (TRPV1) channel. This strategy uses laser stimulation of antibody-coated gold nanoparticles to heat-activate TRPV1, turning this channel into a cell-specific drug-entry port. This delivery method allows transport of a charged cationic derivative of an N-type calcium channel blocker (CNCB-2) into targeted sensory fibers. CNCB-2 delivery blocks neuronal calcium currents and neuropeptides release, resulting in targeted silencing of nociceptors. Finally, this work demonstrates the ability of the approach to probe neuro-immune crosstalk by targeting cytokine-responsive nociceptors and by successfully preventing nociceptor-induced CD8+ T-cells polarization. Overall, this work constitutes the first demonstration of targeted silencing of nociceptor neuron subsets without requiring genetic modification, establishing a strategy for interfering with deleterious neuro-immune interplays.
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Affiliation(s)
- Katiane Roversi
- Département de Pharmacologie et Physiologie, Université de Montréal, Montréal, QC, H3C 3J7, Canada
- Centre de Recherche Hôpital Maisonneuve-Rosemont, Montréal, QC, H1T 2M4, Canada
- Département d'ophtalmologie, Université de Montréal, Montréal, QC, H3C 3J7, Canada
| | - Maryam Tabatabaei
- Département de Pharmacologie et Physiologie, Université de Montréal, Montréal, QC, H3C 3J7, Canada
- Centre de Recherche Hôpital Maisonneuve-Rosemont, Montréal, QC, H1T 2M4, Canada
| | - Nicolas Desjardins-Lecavalier
- Centre de Recherche Hôpital Maisonneuve-Rosemont, Montréal, QC, H1T 2M4, Canada
- Institut de Génie Biomédical, Université de Montréal, Montréal, QC, H3C 3J7, Canada
| | - Mohammad Balood
- Département de Pharmacologie et Physiologie, Université de Montréal, Montréal, QC, H3C 3J7, Canada
| | - Theo Crosson
- Département de Pharmacologie et Physiologie, Université de Montréal, Montréal, QC, H3C 3J7, Canada
| | - Santiago Costantino
- Centre de Recherche Hôpital Maisonneuve-Rosemont, Montréal, QC, H1T 2M4, Canada
- Département d'ophtalmologie, Université de Montréal, Montréal, QC, H3C 3J7, Canada
- Institut de Génie Biomédical, Université de Montréal, Montréal, QC, H3C 3J7, Canada
| | - May Griffith
- Centre de Recherche Hôpital Maisonneuve-Rosemont, Montréal, QC, H1T 2M4, Canada
- Département d'ophtalmologie, Université de Montréal, Montréal, QC, H3C 3J7, Canada
- Institut de Génie Biomédical, Université de Montréal, Montréal, QC, H3C 3J7, Canada
| | - Sebastien Talbot
- Département de Pharmacologie et Physiologie, Université de Montréal, Montréal, QC, H3C 3J7, Canada
| | - Christos Boutopoulos
- Centre de Recherche Hôpital Maisonneuve-Rosemont, Montréal, QC, H1T 2M4, Canada
- Département d'ophtalmologie, Université de Montréal, Montréal, QC, H3C 3J7, Canada
- Institut de Génie Biomédical, Université de Montréal, Montréal, QC, H3C 3J7, Canada
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13
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Voltage imaging in the olfactory bulb using transgenic mouse lines expressing the genetically encoded voltage indicator ArcLight. Sci Rep 2022; 12:1875. [PMID: 35115567 PMCID: PMC8813909 DOI: 10.1038/s41598-021-04482-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 12/09/2021] [Indexed: 01/06/2023] Open
Abstract
Genetically encoded voltage indicators (GEVIs) allow optical recordings of membrane potential changes in defined cell populations. Transgenic reporter animals that facilitate precise and repeatable targeting with high expression levels would further the use of GEVIs in the in vivo mammalian brain. However, the literature on developing and applying transgenic mouse lines as vehicles for GEVI expression is limited. Here we report the first in vivo experiments using a transgenic reporter mouse for the GEVI ArcLight, which utilizes a Cre/tTA dependent expression system (TIGRE 1.0). We developed two mouse lines with ArcLight expression restricted to either olfactory receptor neurons, or a subpopulation of interneurons located in the granule and glomerular layers in the olfactory bulb. The ArcLight expression in these lines was sufficient for in vivo imaging of odorant responses in single trials using epifluorescence and 2-photon imaging. The voltage responses were odor-specific and concentration-dependent, which supported earlier studies about perceptual transformations carried out by the bulb that used calcium sensors of neural activity. This study demonstrates that the ArcLight transgenic line is a flexible genetic tool that can be used to record the neuronal electrical activity of different cell types with a signal-to-noise ratio that is comparable to previous reports using viral transduction.
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14
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Iseppon F, Linley JE, Wood JN. Calcium imaging for analgesic drug discovery. NEUROBIOLOGY OF PAIN 2022; 11:100083. [PMID: 35079661 PMCID: PMC8777277 DOI: 10.1016/j.ynpai.2021.100083] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 12/17/2021] [Accepted: 12/27/2021] [Indexed: 11/24/2022]
Abstract
Calcium imaging is an efficient way to dissect the activity of neurons in vivo. GCaMP indicators can be expressed in specific cell populations for in vivo imaging. Pain research have benefitted greatly from these features in the recent decade. Preclinical research is shifting towards the analysis of pain models and mechanisms. In vivo calcium imaging is the ideal tool for an efficient drug discovery paradigm.
Somatosensation and pain are complex phenomena involving a rangeofspecialised cell types forming different circuits within the peripheral and central nervous systems. In recent decades, advances in the investigation of these networks, as well as their function in sensation, resulted from the constant evolution of electrophysiology and imaging techniques to allow the observation of cellular activity at the population level both in vitro and in vivo. Genetically encoded indicators of neuronal activity, combined with recent advances in DNA engineering and modern microscopy, offer powerful tools to dissect and visualise the activity of specific neuronal subpopulations with high spatial and temporal resolution. In recent years various groups developed in vivo imaging techniques to image calcium transients in the dorsal root ganglia, the spinal cord and the brain of anesthetised and awake, behaving animals to address fundamental questions in both the physiology and pathophysiology of somatosensation and pain. This approach, besides giving unprecedented details on the circuitry of innocuous and painful sensation, can be a very powerful tool for pharmacological research, from the characterisation of new potential drugs to the discovery of new, druggable targets within specific neuronal subpopulations. Here we summarise recent developments in calcium imaging for pain research, discuss technical challenges and advances, and examine the potential positive impact of this technique in early preclinical phases of the analgesic drug discovery process.
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15
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Penzkofer A, Silapetere A, Hegemann P. Photocycle dynamics of the Archaerhodopsin 3 based fluorescent voltage sensor Archon2. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2021; 225:112331. [PMID: 34688164 DOI: 10.1016/j.jphotobiol.2021.112331] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Revised: 09/21/2021] [Accepted: 10/05/2021] [Indexed: 11/28/2022]
Abstract
The retinal photocycle dynamics of the fluorescent voltage sensor Archon2 in pH 8 Tris buffer was studied. Archon2 is a mutant of Archaerhodopsin 3 (Arch) from Halorubrum sodomense obtained by a robotic multidimensional directed evolution approach (Archon2 = Arch T56P-P60S-T80P-D95H-T99S-T116I-F161V-T183I-L197I-A225C). The samples were photo-excited to the first absorption band of the protonated retinal Schiff base (PRSB) Ret_586 (absorption maximum at λmax = 586 nm, excitation wavelengths λexc = 590 nm and 632.8 nm). The photocycle dynamics were studied by recording absorption spectra during light exposure and after light exposure. Ret_586 photoisomerized to Ret_535 (main component) and Ret_485 (minor component). Ret_535 backward photoisomerized to Ret_586 in light-adapted state (named Ret_586la) and partly deprotonated to neutral retinal Schiff base (RSB) Ret_372 in light adapted state (named Ret_372la, same isomer form as Ret_535). After excitation light switch-off Ret_372la recovered to Ret_372 in dark-adapted state (Ret_372da) which slowly re-protonated to Ret_535, and Ret_535 slowly isomerized back to Ret_586 in dark-adapted state (Ret_586da). Photocycle schemes and reaction coordinate diagrams are developed and photocycle parameters are determined.
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Affiliation(s)
- Alfons Penzkofer
- Fakultät für Physik, Universität Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany.
| | - Arita Silapetere
- Experimentelle Biophysik, Institut für Biologie, Humboldt Universität zu Berlin, Invalidenstraße 42, D-10115 Berlin, Germany
| | - Peter Hegemann
- Experimentelle Biophysik, Institut für Biologie, Humboldt Universität zu Berlin, Invalidenstraße 42, D-10115 Berlin, Germany
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16
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Zhang XM, Yokoyama T, Sakamoto M. Imaging Voltage with Microbial Rhodopsins. Front Mol Biosci 2021; 8:738829. [PMID: 34513932 PMCID: PMC8423911 DOI: 10.3389/fmolb.2021.738829] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 08/11/2021] [Indexed: 12/15/2022] Open
Abstract
Membrane potential is the critical parameter that reflects the excitability of a neuron, and it is usually measured by electrophysiological recordings with electrodes. However, this is an invasive approach that is constrained by the problems of lacking spatial resolution and genetic specificity. Recently, the development of a variety of fluorescent probes has made it possible to measure the activity of individual cells with high spatiotemporal resolution. The adaptation of this technique to image electrical activity in neurons has become an informative method to study neural circuits. Genetically encoded voltage indicators (GEVIs) can be used with superior performance to accurately target specific genetic populations and reveal neuronal dynamics on a millisecond scale. Microbial rhodopsins are commonly used as optogenetic actuators to manipulate neuronal activities and to explore the circuit mechanisms of brain function, but they also can be used as fluorescent voltage indicators. In this review, we summarize recent advances in the design and the application of rhodopsin-based GEVIs.
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Affiliation(s)
- Xiao Min Zhang
- Department of Pathophysiology, Guangdong Provincial Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Tatsushi Yokoyama
- Department of Optical Neural and Molecular Physiology, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Masayuki Sakamoto
- Department of Optical Neural and Molecular Physiology, Graduate School of Biostudies, Kyoto University, Kyoto, Japan.,Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency, Kyoto, Japan
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17
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Kaberniuk AA, Baloban M, Monakhov MV, Shcherbakova DM, Verkhusha VV. Single-component near-infrared optogenetic systems for gene transcription regulation. Nat Commun 2021; 12:3859. [PMID: 34162879 PMCID: PMC8222386 DOI: 10.1038/s41467-021-24212-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2019] [Accepted: 06/03/2021] [Indexed: 11/09/2022] Open
Abstract
Near-infrared (NIR) optogenetic systems for transcription regulation are in high demand because NIR light exhibits low phototoxicity, low scattering, and allows combining with probes of visible range. However, available NIR optogenetic systems consist of several protein components of large size and multidomain structure. Here, we engineer single-component NIR systems consisting of evolved photosensory core module of Idiomarina sp. bacterial phytochrome, named iLight, which are smaller and packable in adeno-associated virus. We characterize iLight in vitro and in gene transcription repression in bacterial and gene transcription activation in mammalian cells. Bacterial iLight system shows 115-fold repression of protein production. Comparing to multi-component NIR systems, mammalian iLight system exhibits higher activation of 65-fold in cells and faster 6-fold activation in deep tissues of mice. Neurons transduced with viral-encoded iLight system exhibit 50-fold induction of fluorescent reporter. NIR light-induced neuronal expression of green-light-activatable CheRiff channelrhodopsin causes 20-fold increase of photocurrent and demonstrates efficient spectral multiplexing. Current near-IR optogenetic systems to regulate transcription consist of a number of large protein components. Here the authors report a smaller single-component near-IR system, iLight, developed from a bacterial phytochrome that they use to control gene transcription in bacterial and mammalian cells.
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Affiliation(s)
- Andrii A Kaberniuk
- Department of Anatomy and Structural Biology, and Gruss-Lipper Biophotonics Center, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Mikhail Baloban
- Department of Anatomy and Structural Biology, and Gruss-Lipper Biophotonics Center, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Mikhail V Monakhov
- Department of Anatomy and Structural Biology, and Gruss-Lipper Biophotonics Center, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Daria M Shcherbakova
- Department of Anatomy and Structural Biology, and Gruss-Lipper Biophotonics Center, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Vladislav V Verkhusha
- Department of Anatomy and Structural Biology, and Gruss-Lipper Biophotonics Center, Albert Einstein College of Medicine, Bronx, NY, USA. .,Medicum, Faculty of Medicine, University of Helsinki, Helsinki, Finland. .,Science Center for Genetics and Life Sciences, Sirius University of Science and Technology, Sochi, Russia.
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18
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Leng S, Carlone DL, Guagliardo NA, Barrett PQ, Breault DT. Rosette morphology in zona glomerulosa formation and function. Mol Cell Endocrinol 2021; 530:111287. [PMID: 33891993 PMCID: PMC8159910 DOI: 10.1016/j.mce.2021.111287] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 03/29/2021] [Accepted: 04/13/2021] [Indexed: 12/18/2022]
Abstract
How morphology informs function is a fundamental biological question. Here, we review the morphological features of the adrenal zona glomerulosa (zG), highlighting recent cellular and molecular discoveries that govern its formation. The zG consists of glomeruli enwrapped in a Laminin-β1-enriched basement membrane (BM). Within each glomerulus, zG cells are organized as rosettes, a multicellular structure widely used throughout development to mediate epithelial remodeling, but not often found in healthy adult tissues. Rosettes arise by constriction at a common cellular contact point mediated/facilitated by adherens junctions (AJs). In mice, small, dispersed AJs first appear postnatally and enrich along the entire cell-cell contact around 10 days after birth. Subsequently, these AJ-rich contacts contract, allowing rosettes to form. Concurrently, flat sheet-like domains in the nascent zG, undergo invagination and folding, gradually giving rise to the compact round glomeruli that comprise the adult zG. How these structures impact adrenal function is discussed.
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Affiliation(s)
- Sining Leng
- Division of Endocrinology, Boston Children's Hospital, Boston, MA, 02115, USA.
| | - Diana L Carlone
- Division of Endocrinology, Boston Children's Hospital, Boston, MA, 02115, USA.
| | - Nick A Guagliardo
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA, USA.
| | - Paula Q Barrett
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA, USA.
| | - David T Breault
- Division of Endocrinology, Boston Children's Hospital, Boston, MA, 02115, USA.
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19
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Spool JA, Macedo-Lima M, Scarpa G, Morohashi Y, Yazaki-Sugiyama Y, Remage-Healey L. Genetically identified neurons in avian auditory pallium mirror core principles of their mammalian counterparts. Curr Biol 2021; 31:2831-2843.e6. [PMID: 33989528 DOI: 10.1016/j.cub.2021.04.039] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 02/12/2021] [Accepted: 04/15/2021] [Indexed: 12/21/2022]
Abstract
In vertebrates, advanced cognitive abilities are typically associated with the telencephalic pallium. In mammals, the pallium is a layered mixture of excitatory and inhibitory neuronal populations with distinct molecular, physiological, and network phenotypes. This cortical architecture is proposed to support efficient, high-level information processing. Comparative perspectives across vertebrates provide a lens to understand the common features of pallium that are important for advanced cognition. Studies in songbirds have established strikingly parallel features of neuronal types between mammalian and avian pallium. However, lack of genetic access to defined pallial cell types in non-mammalian vertebrates has hindered progress in resolving connections between molecular and physiological phenotypes. A definitive mapping of the physiology of pallial cells onto their molecular identities in birds is critical for understanding how synaptic and computational properties depend on underlying molecular phenotypes. Using viral tools to target excitatory versus inhibitory neurons in the zebra finch auditory association pallium (calmodulin-dependent kinase alpha [CaMKIIα] and glutamate decarboxylase 1 [GAD1] promoters, respectively), we systematically tested predictions derived from mammalian pallium. We identified two genetically distinct neuronal populations that exhibit profound physiological and computational similarities with mammalian excitatory and inhibitory pallial cells, definitively aligning putative cell types in avian caudal nidopallium with these molecular identities. Specifically, genetically identified CaMKIIα and GAD1 cell types in avian auditory association pallium exhibit distinct intrinsic physiological parameters, distinct auditory coding principles, and inhibitory-dependent pallial synchrony, gamma oscillations, and local suppression. The retention, or convergence, of these molecular and physiological features in both birds and mammals clarifies the characteristics of pallial circuits for advanced cognitive abilities.
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Affiliation(s)
- Jeremy A Spool
- Neuroscience and Behavior, Center for Neuroendocrine Studies, University of Massachusetts, Amherst, MA 01003, USA
| | - Matheus Macedo-Lima
- Neuroscience and Behavior, Center for Neuroendocrine Studies, University of Massachusetts, Amherst, MA 01003, USA; CAPES Foundation, Ministry of Education of Brazil, Brasília 70040-020, Brazil
| | - Garrett Scarpa
- Neuroscience and Behavior, Center for Neuroendocrine Studies, University of Massachusetts, Amherst, MA 01003, USA
| | - Yuichi Morohashi
- Okinawa Institute of Science and Technology (OIST) Graduate University, Okinawa, Japan
| | - Yoko Yazaki-Sugiyama
- Okinawa Institute of Science and Technology (OIST) Graduate University, Okinawa, Japan
| | - Luke Remage-Healey
- Neuroscience and Behavior, Center for Neuroendocrine Studies, University of Massachusetts, Amherst, MA 01003, USA.
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20
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Bioelectric signaling: Reprogrammable circuits underlying embryogenesis, regeneration, and cancer. Cell 2021; 184:1971-1989. [PMID: 33826908 DOI: 10.1016/j.cell.2021.02.034] [Citation(s) in RCA: 117] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 01/08/2021] [Accepted: 02/16/2021] [Indexed: 12/16/2022]
Abstract
How are individual cell behaviors coordinated toward invariant large-scale anatomical outcomes in development and regeneration despite unpredictable perturbations? Endogenous distributions of membrane potentials, produced by ion channels and gap junctions, are present across all tissues. These bioelectrical networks process morphogenetic information that controls gene expression, enabling cell collectives to make decisions about large-scale growth and form. Recent progress in the analysis and computational modeling of developmental bioelectric circuits and channelopathies reveals how cellular collectives cooperate toward organ-level structural order. These advances suggest a roadmap for exploiting bioelectric signaling for interventions addressing developmental disorders, regenerative medicine, cancer reprogramming, and synthetic bioengineering.
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21
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Leong LM, Kang BE, Baker BJ. Improving the flexibility of genetically encoded voltage indicators via intermolecular FRET. Biophys J 2021; 120:1927-1941. [PMID: 33744262 PMCID: PMC8204331 DOI: 10.1016/j.bpj.2021.03.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 02/25/2021] [Accepted: 03/10/2021] [Indexed: 11/16/2022] Open
Abstract
A new family of genetically encoded voltage indicators (GEVIs) has been developed based on intermolecular Förster resonance energy transfer (FRET). To test the hypothesis that the GEVI ArcLight functions via interactions between the fluorescent protein (FP) domains of neighboring probes, the FP of ArcLight was replaced with either a FRET donor or acceptor FP. We discovered relatively large FRET signals only when cells were cotransfected with both the FRET donor and acceptor GEVIs. Using a cyan fluorescent protein donor and an RFP acceptor, we were able to observe a voltage-dependent signal with an emission peak separated by over 200 nm from the excitation wavelength. The intermolecular FRET strategy also works for rhodopsin-based probes, potentially improving their flexibility as well. Separating the FRET pair into two distinct proteins has important advantages over intramolecular FRET constructs. The signals are larger because the voltage-induced conformational change moves two FPs independently. The expression of the FRET donor and acceptor can also be restricted independently, enabling greater cell type specificity as well as refined subcellular voltage reporting.
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Affiliation(s)
- Lee Min Leong
- Brain Science Institute, Korea Institute of Science and Technology, Seongbuk-gu, Seoul, Republic of Korea; Division of Bio-Medical Science and Technology, KIST School, Korea University of Science and Technology (UST), Seoul, Republic of Korea
| | - Bok Eum Kang
- Brain Science Institute, Korea Institute of Science and Technology, Seongbuk-gu, Seoul, Republic of Korea
| | - Bradley J Baker
- Brain Science Institute, Korea Institute of Science and Technology, Seongbuk-gu, Seoul, Republic of Korea; Division of Bio-Medical Science and Technology, KIST School, Korea University of Science and Technology (UST), Seoul, Republic of Korea.
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22
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Noguchi A, Ikegaya Y, Matsumoto N. In Vivo Whole-Cell Patch-Clamp Methods: Recent Technical Progress and Future Perspectives. SENSORS (BASEL, SWITZERLAND) 2021; 21:1448. [PMID: 33669656 PMCID: PMC7922023 DOI: 10.3390/s21041448] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 02/12/2021] [Accepted: 02/16/2021] [Indexed: 02/01/2023]
Abstract
Brain functions are fundamental for the survival of organisms, and they are supported by neural circuits consisting of a variety of neurons. To investigate the function of neurons at the single-cell level, researchers often use whole-cell patch-clamp recording techniques. These techniques enable us to record membrane potentials (including action potentials) of individual neurons of not only anesthetized but also actively behaving animals. This whole-cell recording method enables us to reveal how neuronal activities support brain function at the single-cell level. In this review, we introduce previous studies using in vivo patch-clamp recording techniques and recent findings primarily regarding neuronal activities in the hippocampus for behavioral function. We further discuss how we can bridge the gap between electrophysiology and biochemistry.
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Affiliation(s)
- Asako Noguchi
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan; (A.N.); (Y.I.)
| | - Yuji Ikegaya
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan; (A.N.); (Y.I.)
- Institute for AI and Beyond, The University of Tokyo, Tokyo 113-0033, Japan
- Center for Information and Neural Networks, National Institute of Information and Communications Technology, Suita City, Osaka 565-0871, Japan
| | - Nobuyoshi Matsumoto
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan; (A.N.); (Y.I.)
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23
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Adam Y. All-optical electrophysiology in behaving animals. J Neurosci Methods 2021; 353:109101. [PMID: 33600851 DOI: 10.1016/j.jneumeth.2021.109101] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 01/13/2021] [Accepted: 02/09/2021] [Indexed: 12/28/2022]
Abstract
Technology for simultaneous control and readout of the membrane potential of multiple neurons in behaving animals at high spatio-temporal resolution will have a high impact on neuroscience research. Significant progress in the development of Genetically Encoded Voltage Indicators (GEVIs) now enables to optically record subthreshold and spiking activity from ensembles of cells in behaving animals. In some cases, the GEVIs were also combined with optogenetic actuators to enable 'all-optical' control and readout of membrane potential at cellular resolution. Here I describe the recent progress in GEVI development and discuss the various aspects necessary to perform a successful 'all-optical' electrophysiology experiment in behaving, head-fixed animals. These aspects include the voltage indicators, the optogenetic actuators, strategies for protein expression, optical hardware, and image processing software. Furthermore, I discuss various applications of the technology, highlighting its advantages over classic electrode-based techniques. I argue that GEVIs now transformed from a 'promising' technology to a practical tool that can be used to tackle fundamental questions in neuroscience.
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Affiliation(s)
- Yoav Adam
- Edmond and Lily Safra Center for Brain Science, The Hebrew University of Jerusalem, Jerusalem, Israel.
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24
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Monakhov MV, Matlashov ME, Colavita M, Song C, Shcherbakova DM, Antic SD, Verkhusha VV, Knöpfel T. Screening and Cellular Characterization of Genetically Encoded Voltage Indicators Based on Near-Infrared Fluorescent Proteins. ACS Chem Neurosci 2020; 11:3523-3531. [PMID: 33063984 DOI: 10.1021/acschemneuro.0c00046] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
We developed genetically encoded voltage indicators using a transmembrane voltage-sensing domain and bright near-infrared fluorescent proteins derived from bacterial phytochromes. These new voltage indicators are excited by 640 nm light and emission is measured at 670 nm, allowing imaging in the near-infrared tissue transparency window. The spectral properties of our new indicators permit seamless voltage imaging with simultaneous blue-green light optogenetic actuator activation as well as simultaneous voltage-calcium imaging when paired with green calcium indicators. Iterative optimizations led to a fluorescent probe, here termed nirButterfly, which reliably reports neuronal activities including subthreshold membrane potential depolarization and hyperpolarization as well as spontaneous spiking or electrically- and optogenetically evoked action potentials. This enables largely improved all-optical causal interrogations of physiology.
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Affiliation(s)
- Mikhail V Monakhov
- Institute for Systems Genomics, Stem Cell Institute, Department of Neuroscience, UConn Health, Farmington, Connecticut 06030, United States
- Department of Anatomy and Structural Biology and Gruss-Lipper Biophotonics Center, Albert Einstein College of Medicine, Bronx, New York 10461, United States
| | - Mikhail E Matlashov
- Department of Anatomy and Structural Biology and Gruss-Lipper Biophotonics Center, Albert Einstein College of Medicine, Bronx, New York 10461, United States
| | - Michelangelo Colavita
- Laboratory for Neuronal Circuit Dynamics, Imperial College London, London W12 0NN, U.K
| | - Chenchen Song
- Laboratory for Neuronal Circuit Dynamics, Imperial College London, London W12 0NN, U.K
| | - Daria M Shcherbakova
- Department of Anatomy and Structural Biology and Gruss-Lipper Biophotonics Center, Albert Einstein College of Medicine, Bronx, New York 10461, United States
| | - Srdjan D Antic
- Institute for Systems Genomics, Stem Cell Institute, Department of Neuroscience, UConn Health, Farmington, Connecticut 06030, United States
| | - Vladislav V Verkhusha
- Department of Anatomy and Structural Biology and Gruss-Lipper Biophotonics Center, Albert Einstein College of Medicine, Bronx, New York 10461, United States
| | - Thomas Knöpfel
- Laboratory for Neuronal Circuit Dynamics, Imperial College London, London W12 0NN, U.K
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25
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Penzkofer A, Silapetere A, Hegemann P. Absorption and Emission Spectroscopic Investigation of the Thermal Dynamics of the Archaerhodopsin 3 Based Fluorescent Voltage Sensor Archon2. Int J Mol Sci 2020; 21:ijms21186576. [PMID: 32911811 PMCID: PMC7555599 DOI: 10.3390/ijms21186576] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 08/28/2020] [Accepted: 09/01/2020] [Indexed: 01/12/2023] Open
Abstract
Archon2 is a fluorescent voltage sensor derived from Archaerhodopsin 3 (Arch) of Halorubrum sodomense using robotic multidimensional directed evolution approach. Here we report absorption and emission spectroscopic studies of Archon2 in Tris buffer at pH 8. Absorption cross-section spectra, fluorescence quantum distributions, fluorescence quantum yields, and fluorescence excitation spectra were determined. The thermal stability of Archon2 was studied by long-time attenuation coefficient measurements at room temperature (21 ± 1 °C) and at refrigerator temperature (3 ± 1 °C). The apparent melting temperature was determined by stepwise sample heating up and cooling down (obtained apparent melting temperature: 63 ± 3 °C). In the protein melting process protonated retinal Schiff base (PRSB) with absorption maximum at 586 nm converted to de-protonated retinal Schiff base (RSB) with absorption maximum at 380 nm. Storage of Archon2 at room temperature and refrigerator temperature caused absorption coefficient decrease because of partial protein clustering to aggregates at condensation nuclei and sedimentation. At room temperature an onset of light scattering was observed after two days because of the beginning of protein unfolding. During the period of observation (18 days at 21 °C, 22 days at 3 °C) no change of retinal isomer composition was observed indicating a high potential energy barrier of S0 ground-state isomerization.
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Affiliation(s)
- Alfons Penzkofer
- Fakultät für Physik, Universität Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
- Correspondence: ; Tel.: +49-941-943-2107
| | - Arita Silapetere
- Experimentelle Biophysik, Institut für Biologie, Humboldt Universität zu Berlin, Invalidenstraße 42, D-10115 Berlin, Germany; (A.S.); (P.H.)
| | - Peter Hegemann
- Experimentelle Biophysik, Institut für Biologie, Humboldt Universität zu Berlin, Invalidenstraße 42, D-10115 Berlin, Germany; (A.S.); (P.H.)
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26
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Rhee JK, Leong LM, Mukim MSI, Kang BE, Lee S, Bilbao-Broch L, Baker BJ. Biophysical Parameters of GEVIs: Considerations for Imaging Voltage. Biophys J 2020; 119:1-8. [PMID: 32521239 PMCID: PMC7335909 DOI: 10.1016/j.bpj.2020.05.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 04/17/2020] [Accepted: 05/20/2020] [Indexed: 11/29/2022] Open
Abstract
Genetically encoded voltage indicators (GEVIs) continue to evolve, resulting in many different probes with varying strengths and weaknesses. Developers of new GEVIs tend to highlight their positive features. A recent article from an independent laboratory has compared the signal/noise ratios of a number of GEVIs. Such a comparison can be helpful to investigators eager to try to image the voltage of excitable cells. In this perspective, we will present examples of how the biophysical features of GEVIs affect the imaging of excitable cells in an effort to assist researchers when considering probes for their specific needs.
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Affiliation(s)
- Jun Kyu Rhee
- Center for Functional Connectomics, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea; Division of Bio-Medical Science and Technology, KIST School, Korea University of Science and Technology (UST), Seoul, Republic of Korea
| | - Lee Min Leong
- Center for Functional Connectomics, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea; Division of Bio-Medical Science and Technology, KIST School, Korea University of Science and Technology (UST), Seoul, Republic of Korea
| | - Md Sofequl Islam Mukim
- Center for Functional Connectomics, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea; Division of Bio-Medical Science and Technology, KIST School, Korea University of Science and Technology (UST), Seoul, Republic of Korea
| | - Bok Eum Kang
- Center for Functional Connectomics, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea
| | - Sungmoo Lee
- Center for Functional Connectomics, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea
| | - Laura Bilbao-Broch
- Center for Functional Connectomics, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea; Division of Bio-Medical Science and Technology, KIST School, Korea University of Science and Technology (UST), Seoul, Republic of Korea
| | - Bradley J Baker
- Center for Functional Connectomics, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea; Division of Bio-Medical Science and Technology, KIST School, Korea University of Science and Technology (UST), Seoul, Republic of Korea.
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27
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Harding EK, Fung SW, Bonin RP. Insights Into Spinal Dorsal Horn Circuit Function and Dysfunction Using Optical Approaches. Front Neural Circuits 2020; 14:31. [PMID: 32595458 PMCID: PMC7303281 DOI: 10.3389/fncir.2020.00031] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Accepted: 05/01/2020] [Indexed: 12/13/2022] Open
Abstract
Somatosensation encompasses a variety of essential modalities including touch, pressure, proprioception, temperature, pain, and itch. These peripheral sensations are crucial for all types of behaviors, ranging from social interaction to danger avoidance. Somatosensory information is transmitted from primary afferent fibers in the periphery into the central nervous system via the dorsal horn of the spinal cord. The dorsal horn functions as an intermediary processing center for this information, comprising a complex network of excitatory and inhibitory interneurons as well as projection neurons that transmit the processed somatosensory information from the spinal cord to the brain. It is now known that there can be dysfunction within this spinal cord circuitry in pathological pain conditions and that these perturbations contribute to the development and maintenance of pathological pain. However, the complex and heterogeneous network of the spinal dorsal horn has hampered efforts to further elucidate its role in somatosensory processing. Emerging optical techniques promise to illuminate the underlying organization and function of the dorsal horn and provide insights into the role of spinal cord sensory processing in shaping the behavioral response to somatosensory input that we ultimately observe. This review article will focus on recent advances in optogenetics and fluorescence imaging techniques in the spinal cord, encompassing findings from both in vivo and in vitro preparations. We will also discuss the current limitations and difficulties of employing these techniques to interrogate the spinal cord and current practices and approaches to overcome these challenges.
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Affiliation(s)
- Erika K Harding
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, ON, Canada.,Department of Comparative Biology and Experimental Medicine, University of Calgary, Calgary, AB, Canada
| | - Samuel Wanchi Fung
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, ON, Canada
| | - Robert P Bonin
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, ON, Canada.,University of Toronto Centre for the Study of Pain, University of Toronto, Toronto, ON, Canada
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28
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Kostyuk AI, Kokova AD, Podgorny OV, Kelmanson IV, Fetisova ES, Belousov VV, Bilan DS. Genetically Encoded Tools for Research of Cell Signaling and Metabolism under Brain Hypoxia. Antioxidants (Basel) 2020; 9:E516. [PMID: 32545356 PMCID: PMC7346190 DOI: 10.3390/antiox9060516] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 06/04/2020] [Accepted: 06/06/2020] [Indexed: 02/08/2023] Open
Abstract
Hypoxia is characterized by low oxygen content in the tissues. The central nervous system (CNS) is highly vulnerable to a lack of oxygen. Prolonged hypoxia leads to the death of brain cells, which underlies the development of many pathological conditions. Despite the relevance of the topic, different approaches used to study the molecular mechanisms of hypoxia have many limitations. One promising lead is the use of various genetically encoded tools that allow for the observation of intracellular parameters in living systems. In the first part of this review, we provide the classification of oxygen/hypoxia reporters as well as describe other genetically encoded reporters for various metabolic and redox parameters that could be implemented in hypoxia studies. In the second part, we discuss the advantages and disadvantages of the primary hypoxia model systems and highlight inspiring examples of research in which these experimental settings were combined with genetically encoded reporters.
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Affiliation(s)
- Alexander I. Kostyuk
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.D.K.); (O.V.P.); (I.V.K.); (E.S.F.); (V.V.B.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
| | - Aleksandra D. Kokova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.D.K.); (O.V.P.); (I.V.K.); (E.S.F.); (V.V.B.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
| | - Oleg V. Podgorny
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.D.K.); (O.V.P.); (I.V.K.); (E.S.F.); (V.V.B.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
- Koltzov Institute of Developmental Biology, 119334 Moscow, Russia
| | - Ilya V. Kelmanson
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.D.K.); (O.V.P.); (I.V.K.); (E.S.F.); (V.V.B.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
| | - Elena S. Fetisova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.D.K.); (O.V.P.); (I.V.K.); (E.S.F.); (V.V.B.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
- Faculty of Biology, Lomonosov Moscow State University, 119992 Moscow, Russia
| | - Vsevolod V. Belousov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.D.K.); (O.V.P.); (I.V.K.); (E.S.F.); (V.V.B.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
- Institute for Cardiovascular Physiology, Georg August University Göttingen, D-37073 Göttingen, Germany
- Federal Center for Cerebrovascular Pathology and Stroke, 117997 Moscow, Russia
| | - Dmitry S. Bilan
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.D.K.); (O.V.P.); (I.V.K.); (E.S.F.); (V.V.B.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
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29
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Villette V, Chavarha M, Dimov IK, Bradley J, Pradhan L, Mathieu B, Evans SW, Chamberland S, Shi D, Yang R, Kim BB, Ayon A, Jalil A, St-Pierre F, Schnitzer MJ, Bi G, Toth K, Ding J, Dieudonné S, Lin MZ. Ultrafast Two-Photon Imaging of a High-Gain Voltage Indicator in Awake Behaving Mice. Cell 2020; 179:1590-1608.e23. [PMID: 31835034 DOI: 10.1016/j.cell.2019.11.004] [Citation(s) in RCA: 188] [Impact Index Per Article: 47.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 07/08/2019] [Accepted: 10/31/2019] [Indexed: 10/25/2022]
Abstract
Optical interrogation of voltage in deep brain locations with cellular resolution would be immensely useful for understanding how neuronal circuits process information. Here, we report ASAP3, a genetically encoded voltage indicator with 51% fluorescence modulation by physiological voltages, submillisecond activation kinetics, and full responsivity under two-photon excitation. We also introduce an ultrafast local volume excitation (ULoVE) method for kilohertz-rate two-photon sampling in vivo with increased stability and sensitivity. Combining a soma-targeted ASAP3 variant and ULoVE, we show single-trial tracking of spikes and subthreshold events for minutes in deep locations, with subcellular resolution and with repeated sampling over days. In the visual cortex, we use soma-targeted ASAP3 to illustrate cell-type-dependent subthreshold modulation by locomotion. Thus, ASAP3 and ULoVE enable high-speed optical recording of electrical activity in genetically defined neurons at deep locations during awake behavior.
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Affiliation(s)
- Vincent Villette
- Institut de Biologie de l'École Normale Supérieure (IBENS), École Normale Supérieure, CNRS, INSERM, PSL Research University, Paris 75005, France
| | - Mariya Chavarha
- Department of Neurobiology, Stanford University, Stanford, CA 94305, USA; Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Ivan K Dimov
- Department of Neurobiology, Stanford University, Stanford, CA 94305, USA; CNC Program, Stanford University, Stanford, CA 94305, USA
| | - Jonathan Bradley
- Institut de Biologie de l'École Normale Supérieure (IBENS), École Normale Supérieure, CNRS, INSERM, PSL Research University, Paris 75005, France
| | - Lagnajeet Pradhan
- Department of Neurobiology, Stanford University, Stanford, CA 94305, USA; CNC Program, Stanford University, Stanford, CA 94305, USA
| | - Benjamin Mathieu
- Institut de Biologie de l'École Normale Supérieure (IBENS), École Normale Supérieure, CNRS, INSERM, PSL Research University, Paris 75005, France
| | - Stephen W Evans
- Department of Neurobiology, Stanford University, Stanford, CA 94305, USA
| | - Simon Chamberland
- Department of Psychiatry and Neuroscience, CERVO Brain Research Centre, Université Laval, Quebec City, QC G1J 2G3, Canada
| | - Dongqing Shi
- Department of Neurobiology, Stanford University, Stanford, CA 94305, USA; School of Life Sciences, University of Science and Technology of China, Hefei 230026, China
| | - Renzhi Yang
- Department of Neurosurgery, Stanford University, Stanford, CA 94305, USA; Biology PhD Program, Stanford University, Stanford, CA 94305, USA
| | - Benjamin B Kim
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Annick Ayon
- Institut de Biologie de l'École Normale Supérieure (IBENS), École Normale Supérieure, CNRS, INSERM, PSL Research University, Paris 75005, France
| | - Abdelali Jalil
- Université de Paris, SPPIN - Saints-Pères Paris Institute for the Neurosciences, CNRS, Paris F-75006, France
| | - François St-Pierre
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
| | - Mark J Schnitzer
- CNC Program, Stanford University, Stanford, CA 94305, USA; Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA
| | - Guoqiang Bi
- School of Life Sciences, University of Science and Technology of China, Hefei 230026, China; CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai 20031, China
| | - Katalin Toth
- Department of Psychiatry and Neuroscience, CERVO Brain Research Centre, Université Laval, Quebec City, QC G1J 2G3, Canada
| | - Jun Ding
- Department of Neurosurgery, Stanford University, Stanford, CA 94305, USA
| | - Stéphane Dieudonné
- Institut de Biologie de l'École Normale Supérieure (IBENS), École Normale Supérieure, CNRS, INSERM, PSL Research University, Paris 75005, France.
| | - Michael Z Lin
- Department of Neurobiology, Stanford University, Stanford, CA 94305, USA; Department of Bioengineering, Stanford University, Stanford, CA 94305, USA.
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30
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Shroff SN, Das SL, Tseng HA, Noueihed J, Fernandez F, White JA, Chen CS, Han X. Voltage Imaging of Cardiac Cells and Tissue Using the Genetically Encoded Voltage Sensor Archon1. iScience 2020; 23:100974. [PMID: 32299055 PMCID: PMC7160579 DOI: 10.1016/j.isci.2020.100974] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2019] [Revised: 02/21/2020] [Accepted: 03/05/2020] [Indexed: 01/19/2023] Open
Abstract
Precise measurement of action potentials (APs) is needed to observe electrical activity and cellular communication within cardiac tissue. Voltage-sensitive dyes (VSDs) are traditionally used to measure cardiac APs; however, they require acute chemical addition that prevents chronic imaging. Genetically encoded voltage indicators (GEVIs) enable long-term studies of APs without the need of chemical additions, but current GEVIs used in cardiac tissue exhibit poor kinetics and/or low signal to noise (SNR). Here, we demonstrate the use of Archon1, a recently developed GEVI, in hiPSC-derived cardiomyocytes (CMs). When expressed in CMs, Archon1 demonstrated fast kinetics comparable with patch-clamp electrophysiology and high SNR significantly greater than the VSD Di-8-ANEPPS. Additionally, Archon1 enabled monitoring of APs across multiple cells simultaneously in 3D cardiac tissues. These results highlight Archon1's capability to investigate the electrical activity of CMs in a variety of applications and its potential to probe functionally complex in vitro models, as well as in vivo systems. Genetic sensor Archon1 reports membrane voltage in hiPSC-derived cardiomyocytes Archon1 monitors action potentials in 2D and 3D cardiac tissue with high sensitivity Archon1 repeatedly monitored voltage in the same cells and over extended time periods Voltage dynamics of multiple cells were recorded simultaneously with Archon1
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Affiliation(s)
- Sanaya N Shroff
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
| | - Shoshana L Das
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA; Harvard-MIT Program in Health Sciences and Technology, Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115, USA
| | - Hua-An Tseng
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
| | - Jad Noueihed
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
| | - Fernando Fernandez
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
| | - John A White
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
| | - Christopher S Chen
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA; Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115, USA.
| | - Xue Han
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA.
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31
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Fan LZ, Kheifets S, Böhm UL, Wu H, Piatkevich KD, Xie ME, Parot V, Ha Y, Evans KE, Boyden ES, Takesian AE, Cohen AE. All-Optical Electrophysiology Reveals the Role of Lateral Inhibition in Sensory Processing in Cortical Layer 1. Cell 2020; 180:521-535.e18. [PMID: 31978320 PMCID: PMC7259440 DOI: 10.1016/j.cell.2020.01.001] [Citation(s) in RCA: 91] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 11/06/2019] [Accepted: 01/03/2020] [Indexed: 11/22/2022]
Abstract
Cortical layer 1 (L1) interneurons have been proposed as a hub for attentional modulation of underlying cortex, but the transformations that this circuit implements are not known. We combined genetically targeted voltage imaging with optogenetic activation and silencing to study the mechanisms underlying sensory processing in mouse barrel cortex L1. Whisker stimuli evoked precisely timed single spikes in L1 interneurons, followed by strong lateral inhibition. A mild aversive stimulus activated cholinergic inputs and evoked a bimodal distribution of spiking responses in L1. A simple conductance-based model that only contained lateral inhibition within L1 recapitulated the sensory responses and the winner-takes-all cholinergic responses, and the model correctly predicted that the network would function as a spatial and temporal high-pass filter for excitatory inputs. Our results demonstrate that all-optical electrophysiology can reveal basic principles of neural circuit function in vivo and suggest an intuitive picture for how L1 transforms sensory and modulatory inputs. VIDEO ABSTRACT.
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Affiliation(s)
- Linlin Z Fan
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Simon Kheifets
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Urs L Böhm
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Hao Wu
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Kiryl D Piatkevich
- Media Lab and McGovern Institute for Brain Research, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA
| | - Michael E Xie
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Vicente Parot
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Yooree Ha
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | | | - Edward S Boyden
- Media Lab and McGovern Institute for Brain Research, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA
| | - Anne E Takesian
- Harvard Medical School, Boston, MA, USA; Massachusetts Eye and Ear Infirmary, Boston, MA, USA
| | - Adam E Cohen
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA; Department of Physics, Harvard University, Cambridge, MA, USA; Howard Hughes Medical Institute, Chevy Chase, MD, USA.
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32
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Penzkofer A, Silapetere A, Hegemann P. Photocycle Dynamics of the Archaerhodopsin 3 Based Fluorescent Voltage Sensor QuasAr1. Int J Mol Sci 2019; 21:ijms21010160. [PMID: 31881701 PMCID: PMC6982170 DOI: 10.3390/ijms21010160] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 12/18/2019] [Accepted: 12/19/2019] [Indexed: 11/16/2022] Open
Abstract
The retinal photocycle dynamics of the fluorescent voltage sensor QuasAr1 (Archaerhodopsin 3 P60S-T80S-D95H-D106H-F161V mutant from Halorubrum sodomense) in pH 8 Tris buffer was studied. The samples were photoexcited to the first absorption band of the protonated retinal Schiff base (PRSB) Ret_580 (absorption maximum at λmax ≈ 580 nm), and the retinal Schiff base photoisomerization and protonation state changes were followed by absorption spectra recordings during light exposure and after light exposure. Ret_580 turned out to be composed of two protonated retinal Schiff base isomers, namely Ret_580I and Ret_580II. Photoexcitation of Ret_580I resulted in barrier-involved isomerization to Ret_540 (quantum yield ≈ 0.056) and subsequent retinal proton release leading to Ret_410 deprotonated retinal Schiff base (RSB). In the dark, Ret_410 partially recovered to Ret_580I and partially stabilized to irreversible Ret_400 due to apoprotein restructuring (Ret_410 lifetime ≈ 2 h). Photoexcitation of Ret_580II resulted in barrier-involved isomerization to Ret_640 (quantum yield ≈ 0.00135) and subsequent deprotonation to Ret_370 (RSB). In the dark, Ret_370 partially recovered to Ret_580II and partially stabilized to irreversible Ret_350 due to apoprotein restructuring (Ret_370 lifetime ≈ 10 h). Photocycle schemes and reaction coordinate diagrams for Ret_580I and Ret_580II were developed and photocyle parameters were determined.
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Affiliation(s)
- Alfons Penzkofer
- Fakultät für Physik, Universität Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
- Correspondence: ; Tel.: +49-941-943-2107
| | - Arita Silapetere
- Experimentelle Biophysik, Institut für Biologie, Humboldt Universität zu Berlin, Invalidenstraße 42, D-10115 Berlin, Germany; (A.S.); (P.H.)
| | - Peter Hegemann
- Experimentelle Biophysik, Institut für Biologie, Humboldt Universität zu Berlin, Invalidenstraße 42, D-10115 Berlin, Germany; (A.S.); (P.H.)
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33
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Lee S, Song YK, Baker BJ. Engineering Photoactivatability in Genetically Encoded Voltage and pH Indicators. Front Cell Neurosci 2019; 13:482. [PMID: 31736711 PMCID: PMC6828978 DOI: 10.3389/fncel.2019.00482] [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: 08/14/2019] [Accepted: 10/10/2019] [Indexed: 11/13/2022] Open
Abstract
Genetically-encoded indicators of neuronal activity enable the labeling of a genetically defined population of neurons to optically monitor their activities. However, researchers often find difficulties in identifying relevant signals from excessive background fluorescence. A photoactivatable version of a genetically encoded calcium indicator, sPA-GCaMP6f is a good example of circumventing such an obstacle by limiting the fluorescence to a region of interest defined by the user. Here, we apply this strategy to genetically encoded voltage (GEVI) and pH (GEPI) indicators. Three photoactivatable GEVI candidates were considered. The first one used a circularly-permuted fluorescent protein, the second design involved a Förster resonance energy transfer (FRET) pair, and the third approach employed a pH-sensitive variant of GFP, ecliptic pHluorin. The candidate with a variant of ecliptic pHluorin exhibited photoactivation and a voltage-dependent fluorescence change. This effort also yielded a pH-sensitive photoactivatable GFP that varies its brightness in response to intracellular pH changes.
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Affiliation(s)
- Sungmoo Lee
- Center for Functional Connectomics, Brain Science Institute, Korea Institute of Science and Technology, Seoul, South Korea
| | - Yoon-Kyu Song
- Program in Nano Science and Technology, Graduate School of Convergence Science and Technology, Seoul National University, Seoul, South Korea.,Advanced Institutes of Convergence Technology, Suwon, South Korea
| | - Bradley J Baker
- Center for Functional Connectomics, Brain Science Institute, Korea Institute of Science and Technology, Seoul, South Korea.,Division of Bio-Medical Science and Technology, KIST School, University of Science and Technology (UST), Seoul, South Korea
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34
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Piatkevich KD, Bensussen S, Tseng HA, Shroff SN, Lopez-Huerta VG, Park D, Jung EE, Shemesh OA, Straub C, Gritton HJ, Romano MF, Costa E, Sabatini BL, Fu Z, Boyden ES, Han X. Population imaging of neural activity in awake behaving mice. Nature 2019; 574:413-417. [PMID: 31597963 PMCID: PMC6858559 DOI: 10.1038/s41586-019-1641-1] [Citation(s) in RCA: 133] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Accepted: 08/28/2019] [Indexed: 12/21/2022]
Abstract
A longstanding goal in neuroscience has been to image membrane voltage across a population of individual neurons in an awake, behaving mammal. Here we describe a genetically encoded fluorescent voltage indicator, SomArchon, which exhibits millisecond response times and is compatible with optogenetic control, and which increases the sensitivity, signal-to-noise ratio, and number of neurons observable several-fold over previously published fully genetically encoded reagents1-8. Under conventional one-photon microscopy, SomArchon enables the routine population analysis of around 13 neurons at once, in multiple brain regions (cortex, hippocampus, and striatum) of head-fixed, awake, behaving mice. Using SomArchon, we detected both positive and negative responses of striatal neurons during movement, as previously reported by electrophysiology but not easily detected using modern calcium imaging techniques9-11, highlighting the power of voltage imaging to reveal bidirectional modulation. We also examined how spikes relate to the subthreshold theta oscillations of individual hippocampal neurons, with SomArchon showing that the spikes of individual neurons are more phase-locked to their own subthreshold theta oscillations than to local field potential theta oscillations. Thus, SomArchon reports both spikes and subthreshold voltage dynamics in awake, behaving mice.
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Affiliation(s)
- Kiryl D Piatkevich
- Media Lab, MIT, Cambridge, MA, USA
- MIT McGovern Institute for Brain Research, MIT, Cambridge, MA, USA
| | - Seth Bensussen
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Hua-An Tseng
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Sanaya N Shroff
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | | | - Demian Park
- Media Lab, MIT, Cambridge, MA, USA
- MIT McGovern Institute for Brain Research, MIT, Cambridge, MA, USA
| | - Erica E Jung
- Media Lab, MIT, Cambridge, MA, USA
- Department of Mechanical and Industrial Engineering, University of Illinois, Chicago, IL, USA
| | - Or A Shemesh
- Media Lab, MIT, Cambridge, MA, USA
- MIT McGovern Institute for Brain Research, MIT, Cambridge, MA, USA
| | - Christoph Straub
- Howard Hughes Medical Institute, Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Howard J Gritton
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Michael F Romano
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | | | - Bernardo L Sabatini
- Howard Hughes Medical Institute, Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Zhanyan Fu
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Edward S Boyden
- Media Lab, MIT, Cambridge, MA, USA.
- MIT McGovern Institute for Brain Research, MIT, Cambridge, MA, USA.
- Department of Biological Engineering, MIT, Cambridge, MA, USA.
- MIT Center for Neurobiological Engineering, MIT, Cambridge, MA, USA.
- Department of Brain and Cognitive Sciences, MIT, Cambridge, MA, USA.
- Koch Institute, MIT, Cambridge, MA, USA.
| | - Xue Han
- Department of Biomedical Engineering, Boston University, Boston, MA, USA.
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35
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Ma Y, Bayguinov PO, Jackson MB. Optical Studies of Action Potential Dynamics with hVOS probes. CURRENT OPINION IN BIOMEDICAL ENGINEERING 2019; 12:51-58. [PMID: 32864524 DOI: 10.1016/j.cobme.2019.09.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The detection of action potentials and the characterization of their waveform represent basic benchmarks for evaluating optical sensors of voltage. The effectiveness of a voltage sensor in reporting action potentials will determine its usefulness in voltage imaging experiments designed for the study of neural circuitry. The hybrid voltage sensor (hVOS) technique is based on a sensing mechanism with a rapid response to voltage changes. hVOS imaging is thus well suited for optical studies of action potentials. This technique detects action potentials in intact brain slices with an excellent signal-to-noise ratio. These optical action potentials recapitulate voltage recordings with high temporal fidelity. In different genetically-defined types of neurons targeted by cre-lox technology, hVOS recordings of action potentials recapitulate the expected differences in duration. Furthermore, by targeting an hVOS probe to axons, imaging experiments can follow action potential propagation and document dynamic changes in waveform resulting from use-dependent plasticity.
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Affiliation(s)
- Yihe Ma
- Department of Neuroscience, University of Wisconsin - Madison
| | | | - Meyer B Jackson
- Department of Neuroscience, University of Wisconsin - Madison
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36
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A nanoelectrode array for obtaining intracellular recordings from thousands of connected neurons. Nat Biomed Eng 2019; 4:232-241. [PMID: 31548592 PMCID: PMC7035150 DOI: 10.1038/s41551-019-0455-7] [Citation(s) in RCA: 116] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 08/15/2019] [Indexed: 12/20/2022]
Abstract
Current electrophysiological or optical techniques cannot reliably perform simultaneous intracellular recordings from more than a few tens of neurons. Here we report a nanoelectrode array that can simultaneously obtain intracellular recordings from thousands of connected mammalian neurons in vitro. The array consists of 4,096 platinum-black electrodes with nanoscale roughness fabricated on top of a silicon chip that monolithically integrates 4,096 microscale amplifiers, configurable into pseudocurrent-clamp mode (for concurrent current injection and voltage recording) or into pseudovoltage-clamp mode (for concurrent voltage application and current recording). We used the array in pseudovoltage-clamp mode to measure the effects of drugs on ion-channel currents. In pseudocurrent-clamp mode, the array intracellularly recorded action potentials and postsynaptic potentials from thousands of neurons. In addition, we mapped over 300 excitatory and inhibitory synaptic connections from more than 1,700 neurons that were intracellularly recorded for 19 min. This high-throughput intracellular-recording technology could benefit functional connectome mapping, electrophysiological screening and other functional interrogations of neuronal networks.
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37
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Frank JA, Antonini MJ, Anikeeva P. Next-generation interfaces for studying neural function. Nat Biotechnol 2019; 37:1013-1023. [PMID: 31406326 PMCID: PMC7243676 DOI: 10.1038/s41587-019-0198-8] [Citation(s) in RCA: 113] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 06/26/2019] [Indexed: 01/06/2023]
Abstract
Monitoring and modulating the diversity of signals used by neurons and glia in a closed-loop fashion is necessary to establish causative links between biochemical processes within the nervous system and observed behaviors. As developments in neural-interface hardware strive to keep pace with rapid progress in genetically encoded and synthetic reporters and modulators of neural activity, the integration of multiple functional features becomes a key requirement and a pressing challenge in the field of neural engineering. Electrical, optical and chemical approaches have been used to manipulate and record neuronal activity in vivo, with a recent focus on technologies that both integrate multiple modes of interaction with neurons into a single device and enable bidirectional communication with neural circuits with enhanced spatiotemporal precision. These technologies not only are facilitating a greater understanding of the brain, spinal cord and peripheral circuits in the context of health and disease, but also are informing the development of future closed-loop therapies for neurological, neuro-immune and neuroendocrine conditions.
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Affiliation(s)
- James A Frank
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
- McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Marc-Joseph Antonini
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
- McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA, USA
- Harvard/MIT Health Science & Technology Graduate Program, Cambridge, MA, USA
| | - Polina Anikeeva
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA.
- McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA, USA.
- Department of Material Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.
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38
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Storace DA, Cohen LB, Choi Y. Using Genetically Encoded Voltage Indicators (GEVIs) to Study the Input-Output Transformation of the Mammalian Olfactory Bulb. Front Cell Neurosci 2019; 13:342. [PMID: 31417362 PMCID: PMC6684792 DOI: 10.3389/fncel.2019.00342] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 07/11/2019] [Indexed: 12/19/2022] Open
Abstract
Genetically encoded voltage indicators (GEVIs) are fluorescent protein reporters of membrane potential. These tools can, in principle, be used to monitor the neural activity of genetically distinct cell types in the brain. Although introduced in 1997, they have been a challenge to use to study intact neural circuits due to a combination of small signal-to-noise ratio, slow kinetics, and poor membrane expression. New strategies have yielded novel GEVIs such as ArcLight, which have improved properties. Here, we compare the in vivo properties of ArcLight with Genetically Encoded Calcium Indicators (GECIs) in the mouse olfactory bulb. We show how voltage imaging can be combined with organic calcium sensitive dyes to measure the input-output transformation of the olfactory bulb. Finally, we demonstrate that ArcLight can be targeted to olfactory bulb interneurons. The olfactory bulb contributes substantially to the perception of the concentration invariance of odor recognition.
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Affiliation(s)
- Douglas A Storace
- Department of Biological Science, Florida State University, Tallahassee, FL, United States.,Department of Cellular and Molecular Physiology, Yale School of Medicine, Yale University, New Haven, CT, United States
| | - Lawrence B Cohen
- Department of Cellular and Molecular Physiology, Yale School of Medicine, Yale University, New Haven, CT, United States.,Center for Functional Connectomics, Korea Institute of Science and Technology, Seoul, South Korea
| | - Yunsook Choi
- Department of Cellular and Molecular Physiology, Yale School of Medicine, Yale University, New Haven, CT, United States.,Center for Functional Connectomics, Korea Institute of Science and Technology, Seoul, South Korea
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39
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Voltage imaging and optogenetics reveal behaviour-dependent changes in hippocampal dynamics. Nature 2019; 569:413-417. [PMID: 31043747 PMCID: PMC6613938 DOI: 10.1038/s41586-019-1166-7] [Citation(s) in RCA: 185] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 02/13/2019] [Indexed: 12/19/2022]
Abstract
A technology to record membrane potential from multiple neurons, simultaneously, in behaving animals will have a transformative impact on neuroscience research1, 2. Genetically encoded voltage indicators are a promising tool for these purposes, but were so far limited to single-cell recordings with marginal signal to noise ratio (SNR) in vivo3-5. We developed improved near infrared voltage indicators, high speed microscopes and targeted gene expression schemes which enabled recordings of supra- and subthreshold voltage dynamics from multiple neurons simultaneously in mouse hippocampus, in vivo. The reporters revealed sub-cellular details of back-propagating action potentials and correlations in sub-threshold voltage between multiple cells. In combination with optogenetic stimulation, the reporters revealed brain state-dependent changes in neuronal excitability, reflecting the interplay of excitatory and inhibitory synaptic inputs. These tools open the possibility for detailed explorations of network dynamics in the context of behavior.
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40
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Advances in Engineering and Application of Optogenetic Indicators for Neuroscience. APPLIED SCIENCES-BASEL 2019. [DOI: 10.3390/app9030562] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Our ability to investigate the brain is limited by available technologies that can record biological processes in vivo with suitable spatiotemporal resolution. Advances in optogenetics now enable optical recording and perturbation of central physiological processes within the intact brains of model organisms. By monitoring key signaling molecules noninvasively, we can better appreciate how information is processed and integrated within intact circuits. In this review, we describe recent efforts engineering genetically-encoded fluorescence indicators to monitor neuronal activity. We summarize recent advances of sensors for calcium, potassium, voltage, and select neurotransmitters, focusing on their molecular design, properties, and current limitations. We also highlight impressive applications of these sensors in neuroscience research. We adopt the view that advances in sensor engineering will yield enduring insights on systems neuroscience. Neuroscientists are eager to adopt suitable tools for imaging neural activity in vivo, making this a golden age for engineering optogenetic indicators.
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41
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Nakajima R, Baker BJ. Mapping of excitatory and inhibitory postsynaptic potentials of neuronal populations in hippocampal slices using the GEVI, ArcLight. JOURNAL OF PHYSICS D: APPLIED PHYSICS 2018; 51:504003. [PMID: 30739956 PMCID: PMC6366634 DOI: 10.1088/1361-6463/aae2e3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
To understand the circuitry of the brain, it is essential to clarify the functional connectivity among distinct neuronal populations. For this purpose, neuronal activity imaging using genetically-encoded calcium sensors such as GCaMP has been a powerful approach due to its cell-type specificity. However, calcium (Ca2+) is an indirect measure of neuronal activity. A more direct approach would be to use genetically encoded voltage indicators (GEVIs) to observe subthreshold, synaptic activities. The GEVI, ArcLight, which exhibits large fluorescence transients in response to voltage, was expressed in excitatory neurons of the mouse CA1 hippocampus. Fluorescent signals in response to the electrical stimulation of the Schaffer collateral axons were observed in brain slice preparations. ArcLight was able to map both excitatory and inhibitory inputs projected to excitatory neurons. In contrast, the Ca2+ signal detected by GCaMP6f, was only associated with excitatory inputs. ArcLight and similar voltage sensing probes are also becoming powerful paradigms for functional connectivity mapping of brain circuitry.
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Affiliation(s)
- Ryuichi Nakajima
- Center for Functional Connectomics, Korea Institute of Science and Technology, Seongbuk-gu, Seoul, 136-791, Republic of Korea
| | - Bradley J. Baker
- Center for Functional Connectomics, Korea Institute of Science and Technology, Seongbuk-gu, Seoul, 136-791, Republic of Korea
- Department of Neuroscience, University of Science and Technology, Daejeon, Republic of Korea
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42
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Koide M, Moshkforoush A, Tsoukias NM, Hill-Eubanks DC, Wellman GC, Nelson MT, Dabertrand F. The yin and yang of K V channels in cerebral small vessel pathologies. Microcirculation 2018; 25. [PMID: 29247493 DOI: 10.1111/micc.12436] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 12/08/2017] [Indexed: 12/14/2022]
Abstract
Cerebral SVDs encompass a group of genetic and sporadic pathological processes leading to brain lesions, cognitive decline, and stroke. There is no specific treatment for SVDs, which progress silently for years before becoming clinically symptomatic. Here, we examine parallels in the functional defects of PAs in CADASIL, a monogenic form of SVD, and in response to SAH, a common type of hemorrhagic stroke that also targets the brain microvasculature. Both animal models exhibit dysregulation of the voltage-gated potassium channel, KV 1, in arteriolar myocytes, an impairment that compromises responses to vasoactive stimuli and impacts CBF autoregulation and local dilatory responses to neuronal activity (NVC). However, the extent to which this channelopathy-like defect ultimately contributes to these pathologies is unknown. Combining experimental data with computational modeling, we describe the role of KV 1 channels in the regulation of myocyte membrane potential at rest and during the modest increase in extracellular potassium associated with NVC. We conclude that PA resting membrane potential and myogenic tone depend strongly on KV 1.2/1.5 channel density, and that reciprocal changes in KV channel density in CADASIL and SAH produce opposite effects on extracellular potassium-mediated dilation during NVC.
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Affiliation(s)
- Masayo Koide
- Department of Pharmacology, University of Vermont, Burlington, VT, USA
| | - Arash Moshkforoush
- Department of Biomedical Engineering, Florida International University, Miami, FL, USA
| | - Nikolaos M Tsoukias
- Department of Biomedical Engineering, Florida International University, Miami, FL, USA
| | | | - George C Wellman
- Department of Pharmacology, University of Vermont, Burlington, VT, USA
| | - Mark T Nelson
- Department of Pharmacology, University of Vermont, Burlington, VT, USA.,Institute of Cardiovascular Sciences, University of Manchester, Manchester, UK
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43
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Kang BE, Lee S, Baker BJ. Optical consequences of a genetically-encoded voltage indicator with a pH sensitive fluorescent protein. Neurosci Res 2018; 146:13-21. [PMID: 30342069 DOI: 10.1016/j.neures.2018.10.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 09/20/2018] [Accepted: 10/16/2018] [Indexed: 12/31/2022]
Abstract
Genetically-Encoded Voltage Indicators (GEVIs) are capable of converting changes in membrane potential into an optical signal. Here, we focus on recent insights into the mechanism of ArcLight-type probes and the consequences of utilizing a pH-dependent Fluorescent Protein (FP). A negative charge on the exterior of the β-can of the FP combined with a pH-sensitive FP enables voltage-dependent conformational changes to affect the fluorescence of the probe. This hypothesis implies that interaction/dimerization of the FP creates a microenvironment for the probe that is altered via conformational changes. This mechanism explains why a pH sensitive FP with a negative charge on the outside of the β-can is needed, but also suggests that pH could affect the optical signal as well. To better understand the effects of pH on the voltage-dependent signal of ArcLight, the intracellular pH (pHi) was tested at pH 6.8, 7.2, or 7.8. The resting fluorescence of ArcLight gets brighter as the pHi increases, yet only pH 7.8 significantly affected the ΔF/F. ArcLight could also simultaneously report voltage and pH changes during the acidification of a neuron firing multiple action potentials revealing different buffering capacities of the soma versus the processes of the cell.
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Affiliation(s)
- Bok Eum Kang
- Center for Functional Connectomics, Korea Institute of Science and Technology, Seoul, Republic of Korea; Division of Bio-Medical Science & Technology, KIST School, Korea University of Science and Technology, Seoul 02792, Republic of Korea
| | - Sungmoo Lee
- Center for Functional Connectomics, Korea Institute of Science and Technology, Seoul, Republic of Korea; Program in Nanoscience and Technology, Department of Transdisciplinary Studies, Graduate School of Convergence Science and Technology, Seoul National University. Suwon, Republic of Korea
| | - Bradley J Baker
- Center for Functional Connectomics, Korea Institute of Science and Technology, Seoul, Republic of Korea; Division of Bio-Medical Science & Technology, KIST School, Korea University of Science and Technology, Seoul 02792, Republic of Korea.
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44
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Yi B, Kang BE, Lee S, Braubach S, Baker BJ. A dimeric fluorescent protein yields a bright, red-shifted GEVI capable of population signals in brain slice. Sci Rep 2018; 8:15199. [PMID: 30315245 PMCID: PMC6185910 DOI: 10.1038/s41598-018-33297-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Accepted: 09/24/2018] [Indexed: 12/21/2022] Open
Abstract
A bright, red-shifted Genetically Encoded Voltage Indicator (GEVI) was developed using a modified version of the fluorescent protein, tdTomato. Dimerization of the fluorescent domain for ArcLight-type GEVIs has been shown to affect the signal size of the voltage-dependent optical signal. For red-shifted GEVI development, tdTomato was split fusing a single dTomato chromophore to the voltage sensing domain. Optimization of the amino acid length and charge composition of the linker region between the voltage sensing domain and the fluorescent protein resulted in a probe that is an order of magnitude brighter than FlicR1 at a resting potential of -70 mV and exhibits a ten-fold larger change in fluorescence (ΔF) upon 100 mV depolarization of the plasma membrane in HEK 293 cells. Unlike ArcLight, the introduction of charged residues to the exterior of dTomato did not substantially improve the dynamic range of the optical signal. As a result, this new GEVI, Ilmol, yields a 3-fold improvement in the signal-to-noise ratio compared to FlicR1 despite a smaller fractional change in fluorescence of 4% per 100 mV depolarization of the plasma membrane. Ilmol expresses well in neurons resolving action potentials in neuronal cultures and reporting population signals in mouse hippocampal acute brain slice recordings. Ilmol is the brightest red-shifted GEVI to date enabling imaging with 160-fold less light than Archon1 for primary neuron recordings (50 mW/cm2 versus 8 W/cm2) and 600-fold less light than QuasAr2 for mouse brain slice recordings (500 mW/cm2 versus 300 W/cm2). This new GEVI uses a distinct mechanism from other approaches, opening an alternate engineering path to improve sensitivity and speed.
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Affiliation(s)
- Bumjun Yi
- The Center for Functional Connectomics, Korea Institute of Science and Technology, Seoul, Republic of Korea.,Division of Bio-Medical Science and Technology, KIST School, Korea University of Science and Technology (UST), Seoul, Republic of Korea
| | - Bok Eum Kang
- The Center for Functional Connectomics, Korea Institute of Science and Technology, Seoul, Republic of Korea.,Division of Bio-Medical Science and Technology, KIST School, Korea University of Science and Technology (UST), Seoul, Republic of Korea
| | - Sungmoo Lee
- The Center for Functional Connectomics, Korea Institute of Science and Technology, Seoul, Republic of Korea.,Department of Transdisciplinary Studies, Graduate school of Convergence Science and Technology, Seoul National University, Suwon, Republic of Korea
| | - Sophie Braubach
- The Center for Functional Connectomics, Korea Institute of Science and Technology, Seoul, Republic of Korea
| | - Bradley J Baker
- The Center for Functional Connectomics, Korea Institute of Science and Technology, Seoul, Republic of Korea. .,Division of Bio-Medical Science and Technology, KIST School, Korea University of Science and Technology (UST), Seoul, Republic of Korea.
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45
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Fan LZ, Nehme R, Adam Y, Jung ES, Wu H, Eggan K, Arnold DB, Cohen AE. All-optical synaptic electrophysiology probes mechanism of ketamine-induced disinhibition. Nat Methods 2018; 15:823-831. [PMID: 30275587 PMCID: PMC6204345 DOI: 10.1038/s41592-018-0142-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 07/15/2018] [Indexed: 02/02/2023]
Abstract
Optical assays of synaptic strength could facilitate studies of neuronal transmission and its dysregulation in disease. Here we introduce a genetic toolbox for all-optical interrogation of synaptic electrophysiology (synOptopatch) via mutually exclusive expression of a channelrhodopsin actuator and an archaerhodopsin-derived voltage indicator. Optically induced activity in the channelrhodopsin-expressing neurons generated excitatory and inhibitory postsynaptic potentials that we optically resolved in reporter-expressing neurons. We further developed a yellow spine-targeted Ca2+ indicator to localize optogenetically triggered synaptic inputs. We demonstrated synOptopatch recordings in cultured rodent neurons and in acute rodent brain slice. In synOptopatch measurements of primary rodent cultures, acute ketamine administration suppressed disynaptic inhibitory feedbacks, mimicking the effect of this drug on network function in both rodents and humans. We localized this action of ketamine to excitatory synapses onto interneurons. These results establish an in vitro all-optical model of disynaptic disinhibition, a synaptic defect hypothesized in schizophrenia-associated psychosis.
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Affiliation(s)
- Linlin Z Fan
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Ralda Nehme
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, USA
- Stanley Center for Psychiatric Research, The Broad Institute of Harvard and MIT, Cambridge, MA, USA
| | - Yoav Adam
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Eun Sun Jung
- Department of Biology, Section of Molecular and Computational Biology, University of Southern California, Los Angeles, CA, USA
| | - Hao Wu
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Kevin Eggan
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, USA
- Stanley Center for Psychiatric Research, The Broad Institute of Harvard and MIT, Cambridge, MA, USA
| | - Don B Arnold
- Department of Biology, Section of Molecular and Computational Biology, University of Southern California, Los Angeles, CA, USA
| | - Adam E Cohen
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA.
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA, USA.
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46
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Severi KE, Böhm UL, Wyart C. Investigation of hindbrain activity during active locomotion reveals inhibitory neurons involved in sensorimotor processing. Sci Rep 2018; 8:13615. [PMID: 30206288 PMCID: PMC6134141 DOI: 10.1038/s41598-018-31968-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 08/30/2018] [Indexed: 11/14/2022] Open
Abstract
Locomotion in vertebrates relies on motor circuits in the spinal cord receiving inputs from the hindbrain to execute motor commands while dynamically integrating proprioceptive sensory feedback. The spatial organization of the neuronal networks driving locomotion in the hindbrain and role of inhibition has not been extensively investigated. Here, we mapped neuronal activity with single-cell resolution in the hindbrain of restrained transgenic Tg(HuC:GCaMP5G) zebrafish larvae swimming in response to whole-field visual motion. We combined large-scale population calcium imaging in the hindbrain with simultaneous high-speed recording of the moving tail in animals where specific markers label glycinergic inhibitory neurons. We identified cells whose activity preferentially correlates with the visual stimulus or motor activity and used brain registration to compare data across individual larvae. We then morphed calcium imaging data onto the zebrafish brain atlas to compare with known transgenic markers. We report cells localized in the cerebellum whose activity is shut off by the onset of the visual stimulus, suggesting these cells may be constitutively active and silenced during sensorimotor processing. Finally, we discover that the activity of a medial stripe of glycinergic neurons in the domain of expression of the transcription factor engrailed1b is highly correlated with the onset of locomotion. Our efforts provide a high-resolution, open-access dataset for the community by comparing our functional map of the hindbrain to existing open-access atlases and enabling further investigation of this population's role in locomotion.
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Affiliation(s)
- Kristen E Severi
- Institut du Cerveau et de la Moelle épinière, ICM, Sorbonne Université, Inserm, CNRS, AP-HP, F-75013, Paris, France
- Federated Department of Biological Sciences, New Jersey Institute of Technology, University Heights, Newark, NJ, 07102, USA
| | - Urs L Böhm
- Institut du Cerveau et de la Moelle épinière, ICM, Sorbonne Université, Inserm, CNRS, AP-HP, F-75013, Paris, France
- Dept. of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Claire Wyart
- Institut du Cerveau et de la Moelle épinière, ICM, Sorbonne Université, Inserm, CNRS, AP-HP, F-75013, Paris, France.
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47
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Lossi L, Merighi A. The Use of ex Vivo Rodent Platforms in Neuroscience Translational Research With Attention to the 3Rs Philosophy. Front Vet Sci 2018; 5:164. [PMID: 30073174 PMCID: PMC6060265 DOI: 10.3389/fvets.2018.00164] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 06/29/2018] [Indexed: 01/08/2023] Open
Abstract
The principles of the 3Rs—Replacement, Reduction, and Refinement—are at the basis of most advanced national and supranational (EU) regulations on animal experimentation and welfare. In the perspective to reduce and refine the use of these animals in translational research, we here discuss the use of rodent acute and organotypically cultured central nervous system slices. We describe novel applications of these ex vivo platforms in medium-throughput screening of neuroactive molecules of potential pharmacological interest, with particular attention to more recent developments that permit to fully exploit the potential of direct genetic engineering of organotypic cultures using transfection techniques. We then describe the perspectives for expanding the use ex vivo platforms in neuroscience studies under the 3Rs philosophy using the following approaches: (1) Use of co-cultures of two brain regions physiologically connected to each other (source-target) to analyze axon regeneration and reconstruction of circuitries; (2) Microinjection or co-cultures of primary cells and/or cell lines releasing one or more neuroactive molecules to screen their physiological and/or pharmacological effects onto neuronal survival and slice circuitry. Microinjected or co-cultured cells are ideally made fluorescent after transfection with a plasmid construct encoding green or red fluorescent protein under the control of a general promoter such as hCMV; (3) Use of “sniffer” cells sensing the release of biologically active molecules from organotypic cultures by means of fluorescent probes. These cells can be prepared with activatable green fluorescent protein, a unique chromophore that remains in a “dark” state because its maturation is inhibited, and can be made fluorescent (de-quenched) if specific cellular enzymes, such as proteases or kinases, are activated.
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Affiliation(s)
- Laura Lossi
- Laboratory of Neurobiology, Department of Veterinary Sciences, University of Turin, Turin, Italy
| | - Adalberto Merighi
- Laboratory of Neurobiology, Department of Veterinary Sciences, University of Turin, Turin, Italy
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48
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Verstraelen P, Van Dyck M, Verschuuren M, Kashikar ND, Nuydens R, Timmermans JP, De Vos WH. Image-Based Profiling of Synaptic Connectivity in Primary Neuronal Cell Culture. Front Neurosci 2018; 12:389. [PMID: 29997468 PMCID: PMC6028601 DOI: 10.3389/fnins.2018.00389] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 05/22/2018] [Indexed: 12/04/2022] Open
Abstract
Neurological disorders display a broad spectrum of clinical manifestations. Yet, at the cellular level, virtually all these diseases converge into a common phenotype of dysregulated synaptic connectivity. In dementia, synapse dysfunction precedes neurodegeneration and cognitive impairment by several years, making the synapse a crucial entry point for the development of diagnostic and therapeutic strategies. Whereas high-resolution imaging and biochemical fractionations yield detailed insight into the molecular composition of the synapse, standardized assays are required to quickly gauge synaptic connectivity across large populations of cells under a variety of experimental conditions. Such screening capabilities have now become widely accessible with the advent of high-throughput, high-content microscopy. In this review, we discuss how microscopy-based approaches can be used to extract quantitative information about synaptic connectivity in primary neurons with deep coverage. We elaborate on microscopic readouts that may serve as a proxy for morphofunctional connectivity and we critically analyze their merits and limitations. Finally, we allude to the potential of alternative culture paradigms and integrative approaches to enable comprehensive profiling of synaptic connectivity.
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Affiliation(s)
- Peter Verstraelen
- Laboratory of Cell Biology and Histology, Department of Veterinary Sciences, University of Antwerp, Antwerp, Belgium
| | - Michiel Van Dyck
- Laboratory of Cell Biology and Histology, Department of Veterinary Sciences, University of Antwerp, Antwerp, Belgium
| | - Marlies Verschuuren
- Laboratory of Cell Biology and Histology, Department of Veterinary Sciences, University of Antwerp, Antwerp, Belgium
| | | | - Rony Nuydens
- Janssen Research and Development, Janssen Pharmaceutica N.V., Beerse, Belgium
| | - Jean-Pierre Timmermans
- Laboratory of Cell Biology and Histology, Department of Veterinary Sciences, University of Antwerp, Antwerp, Belgium
| | - Winnok H. De Vos
- Laboratory of Cell Biology and Histology, Department of Veterinary Sciences, University of Antwerp, Antwerp, Belgium
- Cell Systems and Imaging, Department of Molecular Biotechnology, Ghent University, Ghent, Belgium
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49
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Boesmans W, Hao MM, Vanden Berghe P. Optogenetic and chemogenetic techniques for neurogastroenterology. Nat Rev Gastroenterol Hepatol 2018; 15:21-38. [PMID: 29184183 DOI: 10.1038/nrgastro.2017.151] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Optogenetics and chemogenetics comprise a wide variety of applications in which genetically encoded actuators and indicators are used to modulate and monitor activity with high cellular specificity. Over the past 10 years, development of these genetically encoded tools has contributed tremendously to our understanding of integrated physiology. In concert with the continued refinement of probes, strategies to target transgene expression to specific cell types have also made much progress in the past 20 years. In addition, the successful implementation of optogenetic and chemogenetic techniques thrives thanks to ongoing advances in live imaging microscopy and optical technology. Although innovation of optogenetic and chemogenetic methods has been primarily driven by researchers studying the central nervous system, these techniques also hold great promise to boost research in neurogastroenterology. In this Review, we describe the different classes of tools that are currently available and give an overview of the strategies to target them to specific cell types in the gut wall. We discuss the possibilities and limitations of optogenetic and chemogenetic technology in the gut and provide an overview of their current use, with a focus on the enteric nervous system. Furthermore, we suggest some experiments that can advance our understanding of how the intrinsic and extrinsic neural networks of the gut control gastrointestinal function.
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Affiliation(s)
- Werend Boesmans
- Laboratory for Enteric Neuroscience (LENS), Translational Research Center for Gastrointestinal Disorders (TARGID), University of Leuven, Herestraat 49, O&N 1 Box 701, 3000 Leuven, Belgium.,Department of Pathology, Maastricht University Medical Center, P. Debeijelaan 25, 6229 HX, Maastricht, The Netherlands
| | - Marlene M Hao
- Laboratory for Enteric Neuroscience (LENS), Translational Research Center for Gastrointestinal Disorders (TARGID), University of Leuven, Herestraat 49, O&N 1 Box 701, 3000 Leuven, Belgium.,Department of Anatomy and Neuroscience, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Pieter Vanden Berghe
- Laboratory for Enteric Neuroscience (LENS), Translational Research Center for Gastrointestinal Disorders (TARGID), University of Leuven, Herestraat 49, O&N 1 Box 701, 3000 Leuven, Belgium
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50
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Voltage and Calcium Imaging of Brain Activity. Biophys J 2017; 113:2160-2167. [PMID: 29102396 DOI: 10.1016/j.bpj.2017.09.040] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Revised: 09/14/2017] [Accepted: 09/21/2017] [Indexed: 01/02/2023] Open
Abstract
Sensors for imaging brain activity have been under development for almost 50 years. The development of some of these tools is relatively mature, whereas qualitative improvements of others are needed and are actively pursued. In particular, genetically encoded voltage indicators are just now starting to be used to answer neurobiological questions and, at the same time, more than 10 laboratories are working to improve them. In this Biophysical Perspective, we attempt to discuss the present state of the art and indicate areas of active development.
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