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Rich PD, Thiberge SY, Scott BB, Guo C, Tervo DGR, Brody CD, Karpova AY, Daw ND, Tank DW. Magnetic voluntary head-fixation in transgenic rats enables lifespan imaging of hippocampal neurons. Nat Commun 2024; 15:4154. [PMID: 38755205 PMCID: PMC11099169 DOI: 10.1038/s41467-024-48505-9] [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: 08/16/2023] [Accepted: 05/01/2024] [Indexed: 05/18/2024] Open
Abstract
The precise neural mechanisms within the brain that contribute to the remarkable lifetime persistence of memory are not fully understood. Two-photon calcium imaging allows the activity of individual cells to be followed across long periods, but conventional approaches require head-fixation, which limits the type of behavior that can be studied. We present a magnetic voluntary head-fixation system that provides stable optical access to the brain during complex behavior. Compared to previous systems that used mechanical restraint, there are no moving parts and animals can engage and disengage entirely at will. This system is failsafe, easy for animals to use and reliable enough to allow long-term experiments to be routinely performed. Animals completed hundreds of trials per session of an odor discrimination task that required 2-4 s fixations. Together with a reflectance fluorescence collection scheme that increases two-photon signal and a transgenic Thy1-GCaMP6f rat line, we are able to reliably image the cellular activity in the hippocampus during behavior over long periods (median 6 months), allowing us track the same neurons over a large fraction of animals' lives (up to 19 months).
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Affiliation(s)
- P Dylan Rich
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA.
| | | | - Benjamin B Scott
- Department of Psychological and Brain Sciences, Boston University, Boston, MA, USA
- Center for Systems Neuroscience, Boston University, Boston, MA, USA
- Neurophotonics Center, Boston University, Boston, MA, USA
| | - Caiying Guo
- Janelia Research Campus, Ashburn, VA, USA
- Howard Hughes Medical Institute, Ashburn, VA, USA
| | - D Gowanlock R Tervo
- Janelia Research Campus, Ashburn, VA, USA
- Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Carlos D Brody
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
- Howard Hughes Medical Institute, Princeton University, Princeton, NJ, USA
| | - Alla Y Karpova
- Janelia Research Campus, Ashburn, VA, USA
- Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Nathaniel D Daw
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
- Department of Psychology, Princeton University, Princeton, NJ, USA
| | - David W Tank
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA.
- Bezos Center for Neural Circuit Dynamics, Princeton University, Princeton, NJ, USA.
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA.
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Liu P, Mu X, Zhang XD, Ming D. The Near-Infrared-II Fluorophores and Advanced Microscopy Technologies Development and Application in Bioimaging. Bioconjug Chem 2019; 31:260-275. [DOI: 10.1021/acs.bioconjchem.9b00610] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Pengfei Liu
- Academy of Medical Engineering and Translational Medicine, Medical College, Tianjin University, Tianjin 300072, China
| | - Xiaoyu Mu
- Department of Physics and Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology, School of Sciences, Tianjin University, Tianjin 300350, China
| | - Xiao-Dong Zhang
- Department of Physics and Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology, School of Sciences, Tianjin University, Tianjin 300350, China
| | - Dong Ming
- Academy of Medical Engineering and Translational Medicine, Medical College, Tianjin University, Tianjin 300072, China
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Two-photon excitation of FluoVolt allows improved interrogation of transmural electrophysiological function in the intact mouse heart. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2019; 154:11-20. [PMID: 31492464 PMCID: PMC7322535 DOI: 10.1016/j.pbiomolbio.2019.08.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 07/17/2019] [Accepted: 08/15/2019] [Indexed: 11/21/2022]
Abstract
BACKGROUND & AIMS Two-photon excitation of voltage sensitive dyes (VSDs) can measure rapidly changing electrophysiological signals deep within intact cardiac tissue with improved three-dimensional resolution along with reduced photobleaching and photo-toxicity compared to conventional confocal microscopy. Recently, a category of VSDs has emerged which records membrane potentials by photo-induced electron transfer. FluoVolt is a novel VSD in this category which promises fast response and a 25% fractional change in fluorescence per 100 mV, making it an attractive optical probe for action potential (AP) recordings within intact cardiac tissue. The purpose of this study was to characterize the fluorescent properties of FluoVolt as well as its utility for deep tissue imaging. METHODS Discrete tissue layers throughout the left ventricular wall of isolated perfused murine hearts loaded with FluoVolt or di-4-ANEPPS were sequentially excited with two-photon microscopy. RESULTS FluoVolt loaded hearts suffered significantly fewer episodes of atrio-ventricular block compared to di-4-ANEPPS loaded hearts, indicating comparatively low toxicity of FluoVolt in the intact heart. APs recorded with FluoVolt were characterized by a lower signal-to-noise ratio and a higher dynamic range compared to APs recorded with di-4-ANEPPS. Although both depolarization and repolarization parameters were similar in APs recorded with either dye, FluoVolt allowed deeper tissue excitation with improved three-dimensional resolution due to reduced out-of-focus fluorescence generation under two-photon excitation. CONCLUSION Our results demonstrate several advantages of two-photon excitation of FluoVolt in functional studies in intact heart preparations, including reduced toxicity and improved fluorescent properties.
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Yang W, Yuste R. In vivo imaging of neural activity. Nat Methods 2017; 14:349-359. [PMID: 28362436 DOI: 10.1038/nmeth.4230] [Citation(s) in RCA: 237] [Impact Index Per Article: 33.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 02/13/2017] [Indexed: 12/18/2022]
Abstract
Since the introduction of calcium imaging to monitor neuronal activity with single-cell resolution, optical imaging methods have revolutionized neuroscience by enabling systematic recordings of neuronal circuits in living animals. The plethora of methods for functional neural imaging can be daunting to the nonexpert to navigate. Here we review advanced microscopy techniques for in vivo functional imaging and offer guidelines for which technologies are best suited for particular applications.
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Affiliation(s)
- Weijian Yang
- Department of Biological Sciences, Neurotechnology Center, Columbia University, New York, New York, USA
| | - Rafael Yuste
- Department of Biological Sciences, Neurotechnology Center, Columbia University, New York, New York, USA
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Dvornikov A, Gratton E. Imaging in turbid media: a transmission detector gives 2-3 order of magnitude enhanced sensitivity compared to epi-detection schemes. BIOMEDICAL OPTICS EXPRESS 2016; 7:3747-3755. [PMID: 27699135 PMCID: PMC5030047 DOI: 10.1364/boe.7.003747] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 08/25/2016] [Accepted: 08/25/2016] [Indexed: 05/26/2023]
Abstract
Imaging depth in turbid media by two-photon fluorescence microscopy depends on the ability of the optical system to detect weak fluorescence signals. We have shown that use of a wide area detector in transmission geometry allows increasing imaging depth in turbid media due to efficient photon collection. Compared to the conventional epi-detection scheme used in most commercial microscopes, the transmission detector was found to be 2-3 orders of magnitude more sensitive when used for in depth imaging in scattering samples simulating brain optical properties.
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Young MD, Field JJ, Sheetz KE, Bartels RA, Squier J. A pragmatic guide to multiphoton microscope design. ADVANCES IN OPTICS AND PHOTONICS 2015; 7:276-378. [PMID: 27182429 PMCID: PMC4863715 DOI: 10.1364/aop.7.000276] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Multiphoton microscopy has emerged as a ubiquitous tool for studying microscopic structure and function across a broad range of disciplines. As such, the intent of this paper is to present a comprehensive resource for the construction and performance evaluation of a multiphoton microscope that will be understandable to the broad range of scientific fields that presently exploit, or wish to begin exploiting, this powerful technology. With this in mind, we have developed a guide to aid in the design of a multiphoton microscope. We discuss source selection, optical management of dispersion, image-relay systems with scan optics, objective-lens selection, single-element light-collection theory, photon-counting detection, image rendering, and finally, an illustrated guide for building an example microscope.
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Affiliation(s)
- Michael D. Young
- Center for Microintegrated Optics for Advanced Biological Control, Department of Physics, Colorado School of Mines, 1500 Illinois Street, Golden, Colorado 80401, USA
| | - Jeffrey J. Field
- W. M. Keck Laboratory for Raman Imaging of Cell-to-Cell Communications, Colorado State University, Fort Collins, Colorado 80523, USA
- Department of Electrical and Computer Engineering, Colorado State University, Fort Collins, Colorado 80523, USA
| | - Kraig E. Sheetz
- Photonics Research Center, Department of Physics and Nuclear Engineering, United States Military Academy, West Point, New York 10996, USA
| | - Randy A. Bartels
- W. M. Keck Laboratory for Raman Imaging of Cell-to-Cell Communications, Colorado State University, Fort Collins, Colorado 80523, USA
- Department of Electrical and Computer Engineering, Colorado State University, Fort Collins, Colorado 80523, USA
- School of Biomedical Engineering, Colorado State University, Fort Collins, Colorado 80523, USA
| | - Jeff Squier
- Center for Microintegrated Optics for Advanced Biological Control, Department of Physics, Colorado School of Mines, 1500 Illinois Street, Golden, Colorado 80401, USA
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Dasgeb B, Smirnov AV, Ardeshirpour Y, Sackett DL, Knutson JR, Mehregan D, Gandjbakhche A, Halpern AC. Multiscale BerEp4 molecular imaging of microtumor phantoms: toward theranostics for basal cell carcinoma. Mol Imaging 2015; 13. [PMID: 25022347 DOI: 10.2310/7290.2014.00016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Basal cell carcinoma (BCC), the most common cancer in humans, appears macroscopically and microscopically similar to many other skin lesions, which makes differential diagnosis difficult. We are developing an approach for quantitative molecular imaging of BerEP4, a transmembrane biomarker for BCC, with the goal of increasing the precision and accuracy of diagnosis. This pilot study was conducted to assess the affinity and selectivity of BerEp4 antibody and assess its possible use in designing theranostic probes for BCC. We provide evidence that our photon-counting fluorescence macrodetection system can recover specific signal increases from a film/pellet phantom. Additionally, we show that a two-photon excited fluorescence /backscatter confocal microscopy system can image BerEP4 antibody/antigen complex on the surface of BerEP4-expressing cancer cells in three dimensions. Based on the initial results, BerEP4 seems to be a promising biomarker for molecular imaging of BCC. To prepare BerEP4 for eventual theranostic use, we examined the feasibility of a combined macro-/micro-optical approach to imaging BCC with various histologies. These optical methods, endowed with the ability to monitor treatment in real time, may open an opportunity for noninvasive diagnosis, treatments, and follow-up.
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Combs CA, Smirnov A, Glancy B, Karamzadeh NS, Gandjbakhche AH, Redford G, Kilborn K, Knutson JR, Balaban RS. Compact non-contact total emission detection for in vivo multiphoton excitation microscopy. J Microsc 2013; 253:83-92. [PMID: 24251437 DOI: 10.1111/jmi.12099] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Accepted: 10/08/2013] [Indexed: 11/28/2022]
Abstract
We describe a compact, non-contact design for a total emission detection (c-TED) system for intra-vital multiphoton imaging. To conform to a standard upright two-photon microscope design, this system uses a parabolic mirror surrounding a standard microscope objective in concert with an optical path that does not interfere with normal microscope operation. The non-contact design of this device allows for maximal light collection without disrupting the physiology of the specimen being examined. Tests were conducted on exposed tissues in live animals to examine the emission collection enhancement of the c-TED device compared to heavily optimized objective-based emission collection. The best light collection enhancement was seen from murine fat (5×-2× gains as a function of depth), whereas murine skeletal muscle and rat kidney showed gains of over two and just under twofold near the surface, respectively. Gains decreased with imaging depth (particularly in the kidney). Zebrafish imaging on a reflective substrate showed close to a twofold gain throughout the entire volume of an intact embryo (approximately 150 μm deep). Direct measurement of bleaching rates confirmed that the lower laser powers, enabled by greater light collection efficiency, yielded reduced photobleaching in vivo. The potential benefits of increased light collection in terms of speed of imaging and reduced photo-damage, as well as the applicability of this device to other multiphoton imaging methods is discussed.
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Affiliation(s)
- Christian A Combs
- NHLBI Light Microscopy Facility, National Institutes of Health, Bethesda, Maryland 20892-1061
| | - Aleksandr Smirnov
- NHLBI Laboratory of Molecular Biophysics, National Institutes of Health, Bethesda, Maryland 20892-1061
| | - Brian Glancy
- NHLBI Laboratory of Cardiac Energetics, National Institutes of Health, Bethesda, Maryland 20892-1061
| | - Nader S Karamzadeh
- NICHD Section on Biomedical Stochastic Physics, National Institutes of Health, Bethesda, Maryland 20892-1061
| | - Amir H Gandjbakhche
- NICHD Section on Biomedical Stochastic Physics, National Institutes of Health, Bethesda, Maryland 20892-1061
| | - Glen Redford
- Intelligent Imaging Innovations, Inc., Denver, CO 80216
| | - Karl Kilborn
- Intelligent Imaging Innovations, Inc., Denver, CO 80216
| | - Jay R Knutson
- NHLBI Laboratory of Molecular Biophysics, National Institutes of Health, Bethesda, Maryland 20892-1061
| | - Robert S Balaban
- NHLBI Laboratory of Cardiac Energetics, National Institutes of Health, Bethesda, Maryland 20892-1061
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Zhu D, Larin KV, Luo Q, Tuchin VV. Recent progress in tissue optical clearing. LASER & PHOTONICS REVIEWS 2013; 7:732-757. [PMID: 24348874 DOI: 10.1002/lpor.2013.7.issue-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2012] [Revised: 12/23/2012] [Accepted: 01/08/2013] [Indexed: 05/20/2023]
Abstract
Tissue optical clearing technique provides a prospective solution for the application of advanced optical methods in life sciences. This paper gives a review of recent developments in tissue optical clearing techniques. The physical, molecular and physiological mechanisms of tissue optical clearing are overviewed and discussed. Various methods for enhancing penetration of optical-clearing agents into tissue, such as physical methods, chemical-penetration enhancers and combination of physical and chemical methods are introduced. Combining the tissue optical clearing technique with advanced microscopy image or labeling technique, applications for 3D microstructure of whole tissues such as brain and central nervous system with unprecedented resolution are demonstrated. Moreover, the difference in diffusion and/or clearing ability of selected agents in healthy versus pathological tissues can provide a highly sensitive indicator of the tissue health/pathology condition. Finally, recent advances in optical clearing of soft or hard tissue for in vivo imaging and phototherapy are introduced. [Formula: see text].
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Affiliation(s)
- Dan Zhu
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology Wuhan, China ; Key Laboratory of Biomedical Photonics of Ministry of Education, Department of Biomedical Engineering, Huazhong University of Science and Technology Wuhan, China
| | - Kirill V Larin
- Department of Biomedical Engineering, University of Houston, Houston, USA and Department of Physiology and Biophysics, Baylor College of Medicine Houston, USA ; Department of Optics and Biophotonics, Saratov State University Saratov, 410012, Russia
| | - Qingming Luo
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology Wuhan, China ; Key Laboratory of Biomedical Photonics of Ministry of Education, Department of Biomedical Engineering, Huazhong University of Science and Technology Wuhan, China
| | - Valery V Tuchin
- Department of Optics and Biophotonics, Saratov State University Saratov, 410012, Russia ; Laboratory of Laser Diagnostics of Technical and Living Systems, Institute of Precise Mechanics and Control RAS Saratov, 410028, Russia ; Optoelectronics and Measurement Techniques Laboratory, P.O. Box 4500, University of Oulu, FIN-90014 Oulu, Finland
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10
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Zhu D, Larin KV, Luo Q, Tuchin VV. Recent progress in tissue optical clearing. LASER & PHOTONICS REVIEWS 2013; 7:732-757. [PMID: 24348874 PMCID: PMC3856422 DOI: 10.1002/lpor.201200056] [Citation(s) in RCA: 186] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2012] [Revised: 12/23/2012] [Accepted: 01/08/2013] [Indexed: 05/18/2023]
Abstract
Tissue optical clearing technique provides a prospective solution for the application of advanced optical methods in life sciences. This paper gives a review of recent developments in tissue optical clearing techniques. The physical, molecular and physiological mechanisms of tissue optical clearing are overviewed and discussed. Various methods for enhancing penetration of optical-clearing agents into tissue, such as physical methods, chemical-penetration enhancers and combination of physical and chemical methods are introduced. Combining the tissue optical clearing technique with advanced microscopy image or labeling technique, applications for 3D microstructure of whole tissues such as brain and central nervous system with unprecedented resolution are demonstrated. Moreover, the difference in diffusion and/or clearing ability of selected agents in healthy versus pathological tissues can provide a highly sensitive indicator of the tissue health/pathology condition. Finally, recent advances in optical clearing of soft or hard tissue for in vivo imaging and phototherapy are introduced. [Formula: see text].
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Affiliation(s)
- Dan Zhu
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and TechnologyWuhan, China
- Key Laboratory of Biomedical Photonics of Ministry of Education, Department of Biomedical Engineering, Huazhong University of Science and TechnologyWuhan, China
| | - Kirill V Larin
- Department of Biomedical Engineering, University of Houston, Houston, USA and Department of Physiology and Biophysics, Baylor College of MedicineHouston, USA
- Department of Optics and Biophotonics, Saratov State UniversitySaratov, 410012, Russia
| | - Qingming Luo
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and TechnologyWuhan, China
- Key Laboratory of Biomedical Photonics of Ministry of Education, Department of Biomedical Engineering, Huazhong University of Science and TechnologyWuhan, China
| | - Valery V Tuchin
- Department of Optics and Biophotonics, Saratov State UniversitySaratov, 410012, Russia
- Laboratory of Laser Diagnostics of Technical and Living Systems, Institute of Precise Mechanics and Control RASSaratov, 410028, Russia
- Optoelectronics and Measurement Techniques Laboratory, P.O. Box 4500, University of Oulu, FIN-90014Oulu, Finland
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11
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Bakalar M, Schroeder JL, Pursley R, Pohida TJ, Glancy B, Taylor J, Chess D, Kellman P, Xue H, Balaban RS. Three-dimensional motion tracking for high-resolution optical microscopy, in vivo. J Microsc 2012; 246:237-247. [PMID: 22582797 DOI: 10.1111/j.1365-2818.2012.03613.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
When conducting optical imaging experiments, in vivo, the signal to noise ratio and effective spatial and temporal resolution is fundamentally limited by physiological motion of the tissue. A three-dimensional (3D) motion tracking scheme, using a multiphoton excitation microscope with a resonant galvanometer, (512 × 512 pixels at 33 frames s(-1)) is described to overcome physiological motion, in vivo. The use of commercially available graphical processing units permitted the rapid 3D cross-correlation of sequential volumes to detect displacements and adjust tissue position to track motions in near real-time. Motion phantom tests maintained micron resolution with displacement velocities of up to 200 μm min(-1), well within the drift observed in many biological tissues under physiologically relevant conditions. In vivo experiments on mouse skeletal muscle using the capillary vasculature with luminal dye as a displacement reference revealed an effective and robust method of tracking tissue motion to enable (1) signal averaging over time without compromising resolution, and (2) tracking of cellular regions during a physiological perturbation.
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Affiliation(s)
- Matthew Bakalar
- Laboratory of Cardiac Energetics National Heart Lung and Blood Institute, Princeton, New Jersey, USA
| | - James L Schroeder
- Laboratory of Cardiac Energetics National Heart Lung and Blood Institute, Princeton, New Jersey, USA
| | | | | | - Brian Glancy
- Laboratory of Cardiac Energetics National Heart Lung and Blood Institute, Princeton, New Jersey, USA
| | - Joni Taylor
- Laboratory of Cardiac Energetics National Heart Lung and Blood Institute, Princeton, New Jersey, USA
| | - David Chess
- Laboratory of Cardiac Energetics National Heart Lung and Blood Institute, Princeton, New Jersey, USA
| | - Peter Kellman
- Laboratory of Cardiac Energetics National Heart Lung and Blood Institute, Princeton, New Jersey, USA
| | - Hui Xue
- Siemens Corporate Research, Princeton, New Jersey, USA
| | - Robert S Balaban
- Laboratory of Cardiac Energetics National Heart Lung and Blood Institute, Princeton, New Jersey, USA
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12
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Timpson P, McGhee EJ, Anderson KI. Imaging molecular dynamics in vivo--from cell biology to animal models. J Cell Sci 2012; 124:2877-90. [PMID: 21878495 DOI: 10.1242/jcs.085191] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Advances in fluorescence microscopy have enabled the study of membrane diffusion, cell adhesion and signal transduction at the molecular level in living cells grown in culture. By contrast, imaging in living organisms has primarily been restricted to the localization and dynamics of cells in tissues. Now, imaging of molecular dynamics is on the cusp of progressing from cell culture to living tissue. This transition has been driven by the understanding that the microenvironment critically determines many developmental and pathological processes. Here, we review recent progress in fluorescent protein imaging in vivo by drawing primarily on cancer-related studies in mice. We emphasize the need for techniques that can be easily combined with genetic models and complement fluorescent protein imaging by providing contextual information about the cellular environment. In this Commentary we will consider differences between in vitro and in vivo experimental design and argue for an approach to in vivo imaging that is built upon the use of intermediate systems, such as 3-D and explant culture models, which offer flexibility and control that is not always available in vivo. Collectively, these methods present a paradigm shift towards the molecular-level investigation of disease and therapy in animal models of disease.
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Affiliation(s)
- Paul Timpson
- The Beatson Institute for Cancer Research, Garscube Estate, Glasgow G611BD, UK
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BiotecVisions 2012, January. Biotechnol J 2012. [DOI: 10.1002/biot.201100482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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14
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Multiphoton microscopy. a powerful tool in skin research and topical drug delivery science. J Drug Deliv Sci Technol 2012. [DOI: 10.1016/s1773-2247(12)50036-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Crosignani V, Dvornikov AS, Gratton E. Enhancement of imaging depth in turbid media using a wide area detector. JOURNAL OF BIOPHOTONICS 2011; 4:592-9. [PMID: 21425242 PMCID: PMC4245154 DOI: 10.1002/jbio.201100001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2011] [Revised: 02/28/2011] [Accepted: 03/01/2011] [Indexed: 05/08/2023]
Abstract
The depth of two-photon fluorescence imaging in turbid media can be significantly enhanced by the use of the here described fluorescence detection method that allows to efficiently collect scattered fluorescence photons from a wide area of the turbid sample. By using this detector we were able to perform imaging of turbid samples, simulating brain tissue, at depths up to 3 mm, where the two-photon induced fluorescence signal is too weak to be detected by means used in conventional two-photon microscopy.
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Affiliation(s)
- Viera Crosignani
- Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering, University of California Irvine, Irvine, California, USA
| | - Alexander S. Dvornikov
- Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering, University of California Irvine, Irvine, California, USA
| | - Enrico Gratton
- Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering, University of California Irvine, Irvine, California, USA
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Ducros M, van 't Hoff M, van't Hoff M, Evrard A, Seebacher C, Schmidt EM, Charpak S, Oheim M. Efficient large core fiber-based detection for multi-channel two-photon fluorescence microscopy and spectral unmixing. J Neurosci Methods 2011; 198:172-80. [PMID: 21458489 DOI: 10.1016/j.jneumeth.2011.03.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2011] [Revised: 03/12/2011] [Accepted: 03/22/2011] [Indexed: 10/18/2022]
Abstract
Low-magnification high-numerical aperture objectives maximize the collection efficiency for scattered two-photon excited fluorescence (2PEF), but non-descanned detection schemes for such objectives demand optical components much bigger than standard microscope optics. Fiber coupling offers the possibility of removing bulky multi-channel detectors from the collection site, but coupling and transmission losses are generally believed to outweigh the benefits of optical fibers. We present here two new developments based on large-core fiber-optic fluorescence detection that illustrate clear advantages over conventional air-coupled 2PEF detection schemes. First, with minimal modifications of a commercial microscope, we efficiently couple the output of a 20×/NA0.95 objective to a large-core liquid light guide and we obtain a 7-fold collection gain when imaging astrocytes at 100 μm depth in acute brain slices of adult ALDH1L1-GFP mice. Second, combining 2PEF microscopy and 4-color detection on a custom microscope, mode scrambling inside a 2-mm plastic optical fiber is shown to cancel out the spatially non-uniform spectral sensitivity observed with air-coupled detectors. Spectral unmixing of images of brainbow mice taken with a fiber-coupled detector revealed a uniform color distribution of hippocampal neurons across a large field of view. Thus, fiber coupling improves both the efficiency and the homogeneity of 2PEF collection.
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Affiliation(s)
- Enrico Gratton
- Biomedical Engineering, University of California, Irvine, CA 92679, USA.
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18
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Schroeder JL, Bakalar M, Pohida TJ, Balaban RS. Rapid overlapping-volume acquisition and reconstruction (ROVAR): automated 3D tiling for high-resolution, large field-of-view optical microscopy. J Microsc 2011; 243:103-10. [PMID: 21348869 DOI: 10.1111/j.1365-2818.2011.03490.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Micrometer-scale three-dimensional data from fluorescence microscopes offer unique insight into cellular morphology and function by resolving subcellular locations of fluorescent dyes and proteins. To increase field-of-view size while using a high-resolution multiphoton microscope, we have created an automated system of rapidly acquiring overlapping image stacks from multiple fields-of-view along a nonplanar tissue surface. Each image stack is acquired only between the surface and the maximal penetrating depth, as determined by the image signal-to-background ratio. This results in the acquisition of the volume containing visible tissue along the tissue surface, excluding the empty volume above the tissue and the volume beyond the maximum imaging depth within the tissue. The automated collection of overlapping volumes is followed by reconstruction that can efficiently generate a single three-dimensional volume of the tissue surface. This approach yields data spanning multiple millimetres at micrometre resolution that is faster while requiring less work from the microscope operator. The advantages of the system are demonstrated by acquisition of data from intact, unfixed organs without a coverglass both in vivo and in situ.
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Affiliation(s)
- J L Schroeder
- NHLBI, Laboratory of Cardiac Energetics, Maryland, U.S.A
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