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Almasri RM, Ladouceur F, Mawad D, Esrafilzadeh D, Firth J, Lehmann T, Poole-Warren LA, Lovell NH, Al Abed A. Emerging trends in the development of flexible optrode arrays for electrophysiology. APL Bioeng 2023; 7:031503. [PMID: 37692375 PMCID: PMC10491464 DOI: 10.1063/5.0153753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 08/08/2023] [Indexed: 09/12/2023] Open
Abstract
Optical-electrode (optrode) arrays use light to modulate excitable biological tissues and/or transduce bioelectrical signals into the optical domain. Light offers several advantages over electrical wiring, including the ability to encode multiple data channels within a single beam. This approach is at the forefront of innovation aimed at increasing spatial resolution and channel count in multichannel electrophysiology systems. This review presents an overview of devices and material systems that utilize light for electrophysiology recording and stimulation. The work focuses on the current and emerging methods and their applications, and provides a detailed discussion of the design and fabrication of flexible arrayed devices. Optrode arrays feature components non-existent in conventional multi-electrode arrays, such as waveguides, optical circuitry, light-emitting diodes, and optoelectronic and light-sensitive functional materials, packaged in planar, penetrating, or endoscopic forms. Often these are combined with dielectric and conductive structures and, less frequently, with multi-functional sensors. While creating flexible optrode arrays is feasible and necessary to minimize tissue-device mechanical mismatch, key factors must be considered for regulatory approval and clinical use. These include the biocompatibility of optical and photonic components. Additionally, material selection should match the operating wavelength of the specific electrophysiology application, minimizing light scattering and optical losses under physiologically induced stresses and strains. Flexible and soft variants of traditionally rigid photonic circuitry for passive optical multiplexing should be developed to advance the field. We evaluate fabrication techniques against these requirements. We foresee a future whereby established telecommunications techniques are engineered into flexible optrode arrays to enable unprecedented large-scale high-resolution electrophysiology systems.
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Affiliation(s)
- Reem M. Almasri
- Graduate School of Biomedical Engineering, UNSW, Sydney, NSW 2052, Australia
| | | | - Damia Mawad
- School of Materials Science and Engineering, UNSW, Sydney, NSW 2052, Australia
| | - Dorna Esrafilzadeh
- Graduate School of Biomedical Engineering, UNSW, Sydney, NSW 2052, Australia
| | - Josiah Firth
- Australian National Fabrication Facility, UNSW, Sydney, NSW 2052, Australia
| | - Torsten Lehmann
- School of Electrical Engineering and Telecommunications, UNSW, Sydney, NSW 2052, Australia
| | | | | | - Amr Al Abed
- Graduate School of Biomedical Engineering, UNSW, Sydney, NSW 2052, Australia
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Aseyev N, Ivanova V, Balaban P, Nikitin E. Current Practice in Using Voltage Imaging to Record Fast Neuronal Activity: Successful Examples from Invertebrate to Mammalian Studies. BIOSENSORS 2023; 13:648. [PMID: 37367013 DOI: 10.3390/bios13060648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 06/09/2023] [Accepted: 06/12/2023] [Indexed: 06/28/2023]
Abstract
The optical imaging of neuronal activity with potentiometric probes has been credited with being able to address key questions in neuroscience via the simultaneous recording of many neurons. This technique, which was pioneered 50 years ago, has allowed researchers to study the dynamics of neural activity, from tiny subthreshold synaptic events in the axon and dendrites at the subcellular level to the fluctuation of field potentials and how they spread across large areas of the brain. Initially, synthetic voltage-sensitive dyes (VSDs) were applied directly to brain tissue via staining, but recent advances in transgenic methods now allow the expression of genetically encoded voltage indicators (GEVIs), specifically in selected neuron types. However, voltage imaging is technically difficult and limited by several methodological constraints that determine its applicability in a given type of experiment. The prevalence of this method is far from being comparable to patch clamp voltage recording or similar routine methods in neuroscience research. There are more than twice as many studies on VSDs as there are on GEVIs. As can be seen from the majority of the papers, most of them are either methodological ones or reviews. However, potentiometric imaging is able to address key questions in neuroscience by recording most or many neurons simultaneously, thus providing unique information that cannot be obtained via other methods. Different types of optical voltage indicators have their advantages and limitations, which we focus on in detail. Here, we summarize the experience of the scientific community in the application of voltage imaging and try to evaluate the contribution of this method to neuroscience research.
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Affiliation(s)
- Nikolay Aseyev
- Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Butlerova 5A, Moscow 117485, Russia
| | - Violetta Ivanova
- Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Butlerova 5A, Moscow 117485, Russia
| | - Pavel Balaban
- Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Butlerova 5A, Moscow 117485, Russia
| | - Evgeny Nikitin
- Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Butlerova 5A, Moscow 117485, Russia
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3
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Voltage-Sensitive Dye versus Intrinsic Signal Optical Imaging: Comparison of Tactile Responses in Primary and Secondary Somatosensory Cortices of Rats. Brain Sci 2021; 11:brainsci11101294. [PMID: 34679359 PMCID: PMC8533871 DOI: 10.3390/brainsci11101294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2021] [Revised: 09/24/2021] [Accepted: 09/27/2021] [Indexed: 11/21/2022] Open
Abstract
Studies using functional magnetic resonance imaging assume that hemodynamic responses have roughly linear relationships with underlying neural activity. However, to accurately investigate the neurovascular transfer function and compare its variability across brain regions, it is necessary to obtain full-field imaging of both electrophysiological and hemodynamic responses under various stimulus conditions with superior spatiotemporal resolution. Optical imaging combined with voltage-sensitive dye (VSD) and intrinsic signals (IS) is a powerful tool to address this issue. We performed VSD and IS imaging in the primary (S1) and secondary (S2) somatosensory cortices of rats to obtain optical maps of whisker-evoked responses. There were characteristic differences in sensory responses between the S1 and S2 cortices: VSD imaging revealed more localized excitatory and stronger inhibitory neural activity in S1 than in S2. IS imaging revealed stronger metabolic responses in S1 than in S2. We calculated the degree of response to compare the sensory responses between cortical regions and found that the ratio of the degree of response of S2 to S1 was similar, irrespective of whether the ratio was determined by VSD or IS imaging. These results suggest that neurovascular coupling does not vary between the S1 and S2 cortices.
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Sieliwonczyk E, Matchkov VV, Vandendriessche B, Alaerts M, Bakkers J, Loeys B, Schepers D. Inherited Ventricular Arrhythmia in Zebrafish: Genetic Models and Phenotyping Tools. Rev Physiol Biochem Pharmacol 2021; 184:33-68. [PMID: 34533615 DOI: 10.1007/112_2021_65] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
In the last years, the field of inheritable ventricular arrhythmia disease modelling has changed significantly with a push towards the use of novel cellular cardiomyocyte based models. However, there is a growing need for new in vivo models to study the disease pathology at the tissue and organ level. Zebrafish provide an excellent opportunity for in vivo modelling of inheritable ventricular arrhythmia syndromes due to the remarkable similarity between their cardiac electrophysiology and that of humans. Additionally, many state-of-the-art methods in gene editing and electrophysiological phenotyping are available for zebrafish research. In this review, we give a comprehensive overview of the published zebrafish genetic models for primary electrical disorders and arrhythmogenic cardiomyopathy. We summarise and discuss the strengths and weaknesses of the different technical approaches for the generation of genetically modified zebrafish disease models, as well as the electrophysiological approaches in zebrafish phenotyping. By providing this detailed overview, we aim to draw attention to the potential of the zebrafish model for studying arrhythmia syndromes at the organ level and as a platform for personalised medicine and drug testing.
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Affiliation(s)
- Ewa Sieliwonczyk
- Center of Medical Genetics, Faculty of Medicine and Health Sciences, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium.
| | - Vladimir V Matchkov
- Department of Biomedicine, Pulmonary and Cardiovascular Pharmacology, Aarhus University, Aarhus, Denmark
| | - Bert Vandendriessche
- Center of Medical Genetics, Faculty of Medicine and Health Sciences, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium
| | - Maaike Alaerts
- Center of Medical Genetics, Faculty of Medicine and Health Sciences, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium
| | - Jeroen Bakkers
- Hubrecht Institute for Developmental and Stem Cell Biology, Utrecht, The Netherlands
| | - Bart Loeys
- Center of Medical Genetics, Faculty of Medicine and Health Sciences, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium
| | - Dorien Schepers
- Center of Medical Genetics, Faculty of Medicine and Health Sciences, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium.,Laboratory for Molecular, Cellular and Network Excitability, Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium
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5
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Fung C, Vanden Berghe P. Functional circuits and signal processing in the enteric nervous system. Cell Mol Life Sci 2020; 77:4505-4522. [PMID: 32424438 PMCID: PMC7599184 DOI: 10.1007/s00018-020-03543-6] [Citation(s) in RCA: 89] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 04/13/2020] [Accepted: 04/27/2020] [Indexed: 02/06/2023]
Abstract
The enteric nervous system (ENS) is an extensive network comprising millions of neurons and glial cells contained within the wall of the gastrointestinal tract. The major functions of the ENS that have been most studied include the regulation of local gut motility, secretion, and blood flow. Other areas that have been gaining increased attention include its interaction with the immune system, with the gut microbiota and its involvement in the gut-brain axis, and neuro-epithelial interactions. Thus, the enteric circuitry plays a central role in intestinal homeostasis, and this becomes particularly evident when there are faults in its wiring such as in neurodevelopmental or neurodegenerative disorders. In this review, we first focus on the current knowledge on the cellular composition of enteric circuits. We then further discuss how enteric circuits detect and process external information, how these signals may be modulated by physiological and pathophysiological factors, and finally, how outputs are generated for integrated gut function.
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Affiliation(s)
- Candice Fung
- Laboratory for Enteric NeuroScience (LENS), Translational Research Center for Gastrointestinal Disorders (TARGID), University of Leuven, Leuven, Belgium
| | - Pieter Vanden Berghe
- Laboratory for Enteric NeuroScience (LENS), Translational Research Center for Gastrointestinal Disorders (TARGID), University of Leuven, Leuven, Belgium.
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Tang Q, Tsytsarev V, Yan F, Wang C, Erzurumlu RS, Chen Y. In vivo voltage-sensitive dye imaging of mouse cortical activity with mesoscopic optical tomography. NEUROPHOTONICS 2020; 7:041402. [PMID: 33274250 PMCID: PMC7708784 DOI: 10.1117/1.nph.7.4.041402] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Accepted: 11/11/2020] [Indexed: 05/11/2023]
Abstract
Significance: Cellular layering is a hallmark of the mammalian neocortex with layer and cell type-specific connections within the cortical mantle and subcortical connections. A key challenge in studying circuit function within the neocortex is to understand the spatial and temporal patterns of information flow between different columns and layers. Aim: We aimed to investigate the three-dimensional (3D) layer- and area-specific interactions in mouse cortex in vivo. Approach: We applied a new promising neuroimaging method-fluorescence laminar optical tomography in combination with voltage-sensitive dye imaging (VSDi). VSDi is a powerful technique for interrogating membrane potential dynamics in assemblies of cortical neurons, but it is traditionally used for two-dimensional (2D) imaging. Our mesoscopic technique allows visualization of neuronal activity in a 3D manner with high temporal resolution. Results: We first demonstrated the depth-resolved capability of 3D mesoscopic imaging technology in Thy1-ChR2-YFP transgenic mice. Next, we recorded the long-range functional projections between sensory cortex (S1) and motor cortex (M1) in mice, in vivo, following single whisker deflection. Conclusions: The results show that mesoscopic imaging technique has the potential to investigate the layer-specific neural connectivity in the mouse cortex in vivo. Combination of mesoscopic imaging technique with optogenetic control strategy is a promising platform for determining depth-resolved interactions between cortical circuit elements.
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Affiliation(s)
- Qinggong Tang
- University of Oklahoma, Stephenson School of Biomedical Engineering, Norman, Oklahoma, United States
- University of Maryland, Fischell Department of Bioengineering, College Park, Maryland, United States
- Address all correspondence to Qinggong Tang, ; Reha S. Erzurumlu, ; Yu Chen,
| | - Vassiliy Tsytsarev
- University of Maryland School of Medicine, Department of Anatomy and Neurobiology, Baltimore, Maryland, United States
| | - Feng Yan
- University of Oklahoma, Stephenson School of Biomedical Engineering, Norman, Oklahoma, United States
| | - Chen Wang
- University of Oklahoma, Stephenson School of Biomedical Engineering, Norman, Oklahoma, United States
| | - Reha S. Erzurumlu
- University of Maryland School of Medicine, Department of Anatomy and Neurobiology, Baltimore, Maryland, United States
- Address all correspondence to Qinggong Tang, ; Reha S. Erzurumlu, ; Yu Chen,
| | - Yu Chen
- University of Maryland, Fischell Department of Bioengineering, College Park, Maryland, United States
- University of Massachusetts, Department of Biomedical Engineering, Amherst, Massachusetts, United States
- Address all correspondence to Qinggong Tang, ; Reha S. Erzurumlu, ; Yu Chen,
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Song C, Piscopo DM, Niell CM, Knöpfel T. Cortical signatures of wakeful somatosensory processing. Sci Rep 2018; 8:11977. [PMID: 30097603 PMCID: PMC6086870 DOI: 10.1038/s41598-018-30422-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 07/24/2018] [Indexed: 12/13/2022] Open
Abstract
Sensory inputs carry critical information for the survival of an organism. In mice, tactile information conveyed by the whiskers is of high behavioural relevance, and is broadcasted across cortical areas beyond the primary somatosensory cortex. Mesoscopic voltage sensitive dye imaging (VSDI) of cortical population response to whisker stimulations has shown that seemingly 'simple' sensory stimuli can have extended impact on cortical circuit dynamics. Here we took advantage of genetically encoded voltage indicators (GEVIs) that allow for cell type-specific monitoring of population voltage dynamics in a chronic dual-hemisphere transcranial windowed mouse preparation to directly compare the cortex-wide broadcasting of sensory information in wakening (lightly anesthetized to sedated) and awake mice. Somatosensory-evoked cortex-wide dynamics is altered across brain states, with anatomically sequential hyperpolarising activity observed in the awake cortex. GEVI imaging revealed cortical activity maps with increased specificity, high spatial coverage, and at the timescale of cortical information processing.
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Affiliation(s)
- Chenchen Song
- Laboratory for Neuronal Circuit Dynamics, Imperial College London, W12 0NN, London, UK
| | - Denise M Piscopo
- Institute of Neuroscience, University of Oregon, Eugene, Oregon, 97403, USA
| | - Cristopher M Niell
- Institute of Neuroscience, University of Oregon, Eugene, Oregon, 97403, USA
| | - Thomas Knöpfel
- Laboratory for Neuronal Circuit Dynamics, Imperial College London, W12 0NN, London, UK. .,Centre for Neurotechnology, Institute of Biomedical Engineering, Imperial College London, SW7 2AZ, London, UK.
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8
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Kibat C, Krishnan S, Ramaswamy M, Baker BJ, Jesuthasan S. Imaging voltage in zebrafish as a route to characterizing a vertebrate functional connectome: promises and pitfalls of genetically encoded indicators. J Neurogenet 2017; 30:80-8. [PMID: 27328843 DOI: 10.1080/01677063.2016.1180384] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Neural circuits are non-linear dynamical systems that transform information based on the pattern of input, current state and functional connectivity. To understand how a given stimulus is processed, one would ideally record neural activity across the entire brain of a behaving animal, at cellular or even subcellular resolution, in addition to characterizing anatomical connectivity. Given their transparency and relatively small size, larval zebrafish provide a powerful system for brain-wide monitoring of neural activity. Genetically encoded calcium indicators have been used for this purpose, but cannot directly report hyperpolarization or sub-threshold activity. Voltage indicators, in contrast, have this capability. Here, we test whether two different genetically encoded voltage reporters, ASAP1 and Bongwoori, can be expressed and report activity in the zebrafish brain, using widefield, two-photon and light sheet microscopy. We were unable to express ASAP1 in neurons. Bongwoori, in contrast expressed well, and because of its membrane localization, allowed visualization of axon trajectories in 3D. Bongwoori displayed stimulus-evoked changes in fluorescence, which could be detected in single trials. However, under high laser illumination, puncta on neural membranes underwent spontaneous fluctuations in intensity, suggesting that the probe is susceptible to blinking artefacts. These data indicate that larval zebrafish can be used to image electrical activity in the brain of an intact vertebrate at high resolution, although care is needed in imaging and analysis. Recording activity across the whole brain will benefit from further developments in imaging hardware and indicators.
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Affiliation(s)
- Caroline Kibat
- a Neural Circuitry and Behaviour Lab , Institute of Molecular and Cell Biology , Singapore , Singapore
| | - Seetha Krishnan
- b NUS Graduate School for Integrative Sciences and Engineering , Singapore , Singapore
| | - Mahathi Ramaswamy
- b NUS Graduate School for Integrative Sciences and Engineering , Singapore , Singapore
| | - Bradley J Baker
- c Center for Functional Connectomics , Korea Institute of Science and Technology , Seoul , South Korea
| | - Suresh Jesuthasan
- a Neural Circuitry and Behaviour Lab , Institute of Molecular and Cell Biology , Singapore , Singapore ;,d Program in Neuroscience and Behavioural Disorders , Duke-NUS Graduate School of Medicine , Singapore , Singapore ;,e Department of Physiology , National University of Singapore , Singapore , Singapore
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9
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Chamberland S, Yang HH, Pan MM, Evans SW, Guan S, Chavarha M, Yang Y, Salesse C, Wu H, Wu JC, Clandinin TR, Toth K, Lin MZ, St-Pierre F. Fast two-photon imaging of subcellular voltage dynamics in neuronal tissue with genetically encoded indicators. eLife 2017; 6. [PMID: 28749338 PMCID: PMC5584994 DOI: 10.7554/elife.25690] [Citation(s) in RCA: 120] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 07/21/2017] [Indexed: 12/22/2022] Open
Abstract
Monitoring voltage dynamics in defined neurons deep in the brain is critical for unraveling the function of neuronal circuits but is challenging due to the limited performance of existing tools. In particular, while genetically encoded voltage indicators have shown promise for optical detection of voltage transients, many indicators exhibit low sensitivity when imaged under two-photon illumination. Previous studies thus fell short of visualizing voltage dynamics in individual neurons in single trials. Here, we report ASAP2s, a novel voltage indicator with improved sensitivity. By imaging ASAP2s using random-access multi-photon microscopy, we demonstrate robust single-trial detection of action potentials in organotypic slice cultures. We also show that ASAP2s enables two-photon imaging of graded potentials in organotypic slice cultures and in Drosophila. These results demonstrate that the combination of ASAP2s and fast two-photon imaging methods enables detection of neural electrical activity with subcellular spatial resolution and millisecond-timescale precision. DOI:http://dx.doi.org/10.7554/eLife.25690.001
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Affiliation(s)
- Simon Chamberland
- Department of Psychiatry and Neuroscience, Quebec Mental Health Institute, Université Laval, Québec, Canada
| | - Helen H Yang
- Department of Neurobiology, Stanford University, Stanford, United States
| | - Michael M Pan
- Department of Bioengineering, Stanford University, Stanford, United States.,Department of Pediatrics, Stanford University, Stanford, United States
| | - Stephen W Evans
- Department of Neurobiology, Stanford University, Stanford, United States.,Department of Bioengineering, Stanford University, Stanford, United States.,Department of Pediatrics, Stanford University, Stanford, United States
| | - Sihui Guan
- Department of Neuroscience, Baylor College of Medicine, Houston, United States
| | - Mariya Chavarha
- Department of Neurobiology, Stanford University, Stanford, United States.,Department of Bioengineering, Stanford University, Stanford, United States.,Department of Pediatrics, Stanford University, Stanford, United States
| | - Ying Yang
- Department of Neurobiology, Stanford University, Stanford, United States.,Department of Bioengineering, Stanford University, Stanford, United States.,Department of Pediatrics, Stanford University, Stanford, United States
| | - Charleen Salesse
- Department of Psychiatry and Neuroscience, Quebec Mental Health Institute, Université Laval, Québec, Canada
| | - Haodi Wu
- Stanford Cardiovascular Institute, Stanford University, Stanford, United States
| | - Joseph C Wu
- Stanford Cardiovascular Institute, Stanford University, Stanford, United States
| | - Thomas R Clandinin
- Department of Neurobiology, Stanford University, Stanford, United States
| | - Katalin Toth
- Department of Psychiatry and Neuroscience, Quebec Mental Health Institute, Université Laval, Québec, Canada
| | - Michael Z Lin
- Department of Neurobiology, Stanford University, Stanford, United States.,Department of Bioengineering, Stanford University, Stanford, United States.,Department of Pediatrics, Stanford University, Stanford, United States
| | - François St-Pierre
- Department of Bioengineering, Stanford University, Stanford, United States.,Department of Pediatrics, Stanford University, Stanford, United States.,Department of Neuroscience, Baylor College of Medicine, Houston, United States
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Borden PY, Ortiz AD, Waiblinger C, Sederberg AJ, Morrissette AE, Forest CR, Jaeger D, Stanley GB. Genetically expressed voltage sensor ArcLight for imaging large scale cortical activity in the anesthetized and awake mouse. NEUROPHOTONICS 2017; 4:031212. [PMID: 28491905 PMCID: PMC5416966 DOI: 10.1117/1.nph.4.3.031212] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 04/10/2017] [Indexed: 06/07/2023]
Abstract
With the recent breakthrough in genetically expressed voltage indicators (GEVIs), there has been a tremendous demand to determine the capabilities of these sensors in vivo. Novel voltage sensitive fluorescent proteins allow for direct measurement of neuron membrane potential changes through changes in fluorescence. Here, we utilized ArcLight, a recently developed GEVI, and examined the functional characteristics in the widely used mouse somatosensory whisker pathway. We measured the resulting evoked fluorescence using a wide-field microscope and a CCD camera at 200 Hz, which enabled voltage recordings over the entire cortical region with high temporal resolution. We found that ArcLight produced a fluorescent response in the S1 barrel cortex during sensory stimulation at single whisker resolution. During wide-field cortical imaging, we encountered substantial hemodynamic noise that required additional post hoc processing through noise subtraction techniques. Over a period of 28 days, we found clear and consistent ArcLight fluorescence responses to a simple sensory input. Finally, we demonstrated the use of ArcLight to resolve cortical S1 sensory responses in the awake mouse. Taken together, our results demonstrate the feasibility of ArcLight as a measurement tool for mesoscopic, chronic imaging.
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Affiliation(s)
- Peter Y. Borden
- Georgia Institute of Technology and Emory University, Wallace H. Coulter Department of Biomedical Engineering, Atlanta, Georgia, United States
| | - Alex D. Ortiz
- Georgia Institute of Technology and Emory University, Wallace H. Coulter Department of Biomedical Engineering, Atlanta, Georgia, United States
| | - Christian Waiblinger
- Georgia Institute of Technology and Emory University, Wallace H. Coulter Department of Biomedical Engineering, Atlanta, Georgia, United States
| | - Audrey J. Sederberg
- Georgia Institute of Technology and Emory University, Wallace H. Coulter Department of Biomedical Engineering, Atlanta, Georgia, United States
| | - Arthur E. Morrissette
- Emory University, Neuroscience Program, Department of Biology, Atlanta, Georgia, United States
| | - Craig R. Forest
- Georgia Institute of Technology and Emory University, School of Mechanical Engineering, Atlanta, Georgia, United States
| | - Dieter Jaeger
- Emory University, Neuroscience Program, Department of Biology, Atlanta, Georgia, United States
| | - Garrett B. Stanley
- Georgia Institute of Technology and Emory University, Wallace H. Coulter Department of Biomedical Engineering, Atlanta, Georgia, United States
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Song C, Barnes S, Knöpfel T. Mammalian cortical voltage imaging using genetically encoded voltage indicators: a review honoring professor Amiram Grinvald. NEUROPHOTONICS 2017; 4:031214. [PMID: 28491906 PMCID: PMC5416838 DOI: 10.1117/1.nph.4.3.031214] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 04/05/2017] [Indexed: 06/07/2023]
Abstract
The pioneering work of Amiram Grinvald established voltage-sensitive dye imaging (VSDI) in the mammalian cortex in the 1980s and inspired decades of cortical voltage imaging and the associated technological developments. The recent conception and development of genetically encoded voltage indicators (GEVIs) overcome many of the limitations of classical VSDI, and open experimental approaches that provide accruing support for orchestrated neuronal circuit dynamics of spatially distributed neuronal circuit underlying behaviors. We will review recent achievements using GEVIs to optically monitor the cortical activity in mammalian brains in vivo and provide a perspective for potential future directions.
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Affiliation(s)
- Chenchen Song
- Imperial College London, Laboratory for Neuronal Circuit Dynamics, London, United Kingdom
| | - Samuel Barnes
- Imperial College London, Laboratory for Neuronal Circuit Dynamics, London, United Kingdom
- Imperial College London, Division of Brain Sciences, London, United Kingdom
| | - Thomas Knöpfel
- Imperial College London, Laboratory for Neuronal Circuit Dynamics, London, United Kingdom
- Imperial College London, Division of Brain Sciences, London, United Kingdom
- Institute of Biomedical Engineering, Imperial College London, Centre for Neurotechnology, South Kensington, London, United Kingdom
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12
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Tsytsarev V, Akkentli F, Pumbo E, Tang Q, Chen Y, Erzurumlu RS, Papkovsky DB. Planar implantable sensor for in vivo measurement of cellular oxygen metabolism in brain tissue. J Neurosci Methods 2017; 281:1-6. [PMID: 28219725 DOI: 10.1016/j.jneumeth.2017.02.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 01/13/2017] [Accepted: 02/15/2017] [Indexed: 10/20/2022]
Abstract
BACKGROUND Brain imaging methods are continually improving. Imaging of the cerebral cortex is widely used in both animal experiments and charting human brain function in health and disease. Among the animal models, the rodent cerebral cortex has been widely used because of patterned neural representation of the whiskers on the snout and relative ease of activating cortical tissue with whisker stimulation. NEW METHOD We tested a new planar solid-state oxygen sensor comprising a polymeric film with a phosphorescent oxygen-sensitive coating on the working side, to monitor dynamics of oxygen metabolism in the cerebral cortex following sensory stimulation. RESULTS Sensory stimulation led to changes in oxygenation and deoxygenation processes of activated areas in the barrel cortex. We demonstrate the possibility of dynamic mapping of relative changes in oxygenation in live mouse brain tissue with such a sensor. COMPARISON WITH EXISTING METHOD Oxygenation-based functional magnetic resonance imaging (fMRI) is very effective method for functional brain mapping but have high costs and limited spatial resolution. Optical imaging of intrinsic signal (IOS) does not provide the required sensitivity, and voltage-sensitive dye optical imaging (VSDi) has limited applicability due to significant toxicity of the voltage-sensitive dye. Our planar solid-state oxygen sensor imaging approach circumvents these limitations, providing a simple optical contrast agent with low toxicity and rapid application. CONCLUSIONS The planar solid-state oxygen sensor described here can be used as a tool in visualization and real-time analysis of sensory-evoked neural activity in vivo. Further, this approach allows visualization of local neural activity with high temporal and spatial resolution.
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Affiliation(s)
- Vassiliy Tsytsarev
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, 20 Penn Street, HSF-2, 21201 MD, Baltimore, USA.
| | - Fatih Akkentli
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, 20 Penn Street, HSF-2, 21201 MD, Baltimore, USA.
| | - Elena Pumbo
- Center for Genetic Medicine, Children's National Medical Center, Washington DC, 111 Michigan Avenue, NW Washington, DC 20010, USA.
| | - Qinggong Tang
- Fischell Department of Bioengineering, University of Maryland, College Park, Kim Engineering Building, College Park, MD 20740, USA.
| | - Yu Chen
- Fischell Department of Bioengineering, University of Maryland, College Park, Kim Engineering Building, College Park, MD 20740, USA.
| | - Reha S Erzurumlu
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, 20 Penn Street, HSF-2, 21201 MD, Baltimore, USA.
| | - Dmitri B Papkovsky
- School of Biochemistry and Cell Biology, University College Cork, Cavanagh Pharmacy Building 1.28, College Road, Cork, Ireland.
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Nakajima R, Jung A, Yoon BJ, Baker BJ. Optogenetic Monitoring of Synaptic Activity with Genetically Encoded Voltage Indicators. Front Synaptic Neurosci 2016; 8:22. [PMID: 27547183 PMCID: PMC4974255 DOI: 10.3389/fnsyn.2016.00022] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Accepted: 07/25/2016] [Indexed: 11/13/2022] Open
Abstract
The age of genetically encoded voltage indicators (GEVIs) has matured to the point that changes in membrane potential can now be observed optically in vivo. Improving the signal size and speed of these voltage sensors has been the primary driving forces during this maturation process. As a result, there is a wide range of probes using different voltage detecting mechanisms and fluorescent reporters. As the use of these probes transitions from optically reporting membrane potential in single, cultured cells to imaging populations of cells in slice and/or in vivo, a new challenge emerges—optically resolving the different types of neuronal activity. While improvements in speed and signal size are still needed, optimizing the voltage range and the subcellular expression (i.e., soma only) of the probe are becoming more important. In this review, we will examine the ability of recently developed probes to report synaptic activity in slice and in vivo. The voltage-sensing fluorescent protein (VSFP) family of voltage sensors, ArcLight, ASAP-1, and the rhodopsin family of probes are all good at reporting changes in membrane potential, but all have difficulty distinguishing subthreshold depolarizations from action potentials and detecting neuronal inhibition when imaging populations of cells. Finally, we will offer a few possible ways to improve the optical resolution of the various types of neuronal activities.
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Affiliation(s)
- Ryuichi Nakajima
- Center for Functional Connectomics, Korea Institute of Science and Technology Seongbuk-gu, Seoul, South Korea
| | - Arong Jung
- Center for Functional Connectomics, Korea Institute of Science and TechnologySeongbuk-gu, Seoul, South Korea; College of Life Sciences and Biotechnology, Korea UniversitySeongbuk-gu, Seoul, South Korea
| | - Bong-June Yoon
- College of Life Sciences and Biotechnology, Korea University Seongbuk-gu, Seoul, South Korea
| | - Bradley J Baker
- Center for Functional Connectomics, Korea Institute of Science and TechnologySeongbuk-gu, Seoul, South Korea; Department of Neuroscience, Korea University of Science and TechnologyDaejeon, South Korea
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Antic SD, Empson RM, Knöpfel T. Voltage imaging to understand connections and functions of neuronal circuits. J Neurophysiol 2016; 116:135-52. [PMID: 27075539 DOI: 10.1152/jn.00226.2016] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 04/11/2016] [Indexed: 12/30/2022] Open
Abstract
Understanding of the cellular mechanisms underlying brain functions such as cognition and emotions requires monitoring of membrane voltage at the cellular, circuit, and system levels. Seminal voltage-sensitive dye and calcium-sensitive dye imaging studies have demonstrated parallel detection of electrical activity across populations of interconnected neurons in a variety of preparations. A game-changing advance made in recent years has been the conceptualization and development of optogenetic tools, including genetically encoded indicators of voltage (GEVIs) or calcium (GECIs) and genetically encoded light-gated ion channels (actuators, e.g., channelrhodopsin2). Compared with low-molecular-weight calcium and voltage indicators (dyes), the optogenetic imaging approaches are 1) cell type specific, 2) less invasive, 3) able to relate activity and anatomy, and 4) facilitate long-term recordings of individual cells' activities over weeks, thereby allowing direct monitoring of the emergence of learned behaviors and underlying circuit mechanisms. We highlight the potential of novel approaches based on GEVIs and compare those to calcium imaging approaches. We also discuss how novel approaches based on GEVIs (and GECIs) coupled with genetically encoded actuators will promote progress in our knowledge of brain circuits and systems.
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Affiliation(s)
- Srdjan D Antic
- Stem Cell Institute, Institute for Systems Genomics, UConn Health, Farmington, Connecticut
| | - Ruth M Empson
- Department of Physiology, Brain Research New Zealand, Otago School of Medical Sciences, University of Otago, Dunedin, New Zealand; and
| | - Thomas Knöpfel
- Division of Brain Sciences, Department of Medicine and Centre for Neurotechnology, Institute of Biomedical Engineering, Imperial College London, London, United Kingdom
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Boesmans W, Hao MM, Vanden Berghe P. Optical Tools to Investigate Cellular Activity in the Intestinal Wall. J Neurogastroenterol Motil 2015; 21:337-51. [PMID: 26130630 PMCID: PMC4496899 DOI: 10.5056/jnm15096] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Accepted: 06/10/2015] [Indexed: 12/13/2022] Open
Abstract
Live imaging has become an essential tool to investigate the coordinated activity and output of cellular networks. Within the last decade, 2 Nobel prizes have been awarded to recognize innovations in the field of imaging: one for the discovery, use, and optimization of the green fluorescent protein (2008) and the second for the development of super-resolved fluorescence microscopy (2014). New advances in both optogenetics and microscopy now enable researchers to record and manipulate activity from specific populations of cells with better contrast and resolution, at higher speeds, and deeper into live tissues. In this review, we will discuss some of the recent developments in microscope technology and in the synthesis of fluorescent probes, both synthetic and genetically encoded. We focus on how live imaging of cellular physiology has progressed our understanding of the control of gastrointestinal motility, and we discuss the hurdles to overcome in order to apply the novel tools in the field of neurogastroenterology and motility.
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Affiliation(s)
- Werend Boesmans
- Laboratory for Enteric NeuroScience (LENS), Translational Research Center for GastroIntestinal Disorders (TARGID), Department of Clinical and Experimental Medicine, University of Leuven, Leuven, Belgium
| | - Marlene M Hao
- Laboratory for Enteric NeuroScience (LENS), Translational Research Center for GastroIntestinal Disorders (TARGID), Department of Clinical and Experimental Medicine, University of Leuven, Leuven, Belgium
| | - Pieter Vanden Berghe
- Laboratory for Enteric NeuroScience (LENS), Translational Research Center for GastroIntestinal Disorders (TARGID), Department of Clinical and Experimental Medicine, University of Leuven, Leuven, Belgium
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Knöpfel T, Gallero-Salas Y, Song C. Genetically encoded voltage indicators for large scale cortical imaging come of age. Curr Opin Chem Biol 2015; 27:75-83. [PMID: 26115448 DOI: 10.1016/j.cbpa.2015.06.006] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2015] [Revised: 05/22/2015] [Accepted: 06/05/2015] [Indexed: 11/19/2022]
Abstract
Electrical signals are fundamental to cellular sensing, communication and motility. In the nervous system, information is represented as receptor, synaptic and action potentials. Understanding how brain functions emerge from these electrical signals is one of the ultimate challenges in neuroscience and requires a methodology to monitor membrane voltage transients from large numbers of cells at high spatio-temporal resolution. Optical voltage imaging holds longstanding promises to achieve this, and has gained a fresh powerful momentum with the development of genetically encoded voltage indicators (GEVIs). With a focus on neuroimaging studies on intact mouse brains, we highlight recent advances in this field.
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Affiliation(s)
- Thomas Knöpfel
- Department of Medicine, Imperial College London, London W12 0NN, United Kingdom.
| | - Yasir Gallero-Salas
- Department of Medicine, Imperial College London, London W12 0NN, United Kingdom
| | - Chenchen Song
- Department of Medicine, Imperial College London, London W12 0NN, United Kingdom
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