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Li S, Liu Y, Zhang N, Li W, Xu WJ, Xu YQ, Chen YY, Cui X, Zhu B, Gao XY. Perspective of Calcium Imaging Technology Applied to Acupuncture Research. Chin J Integr Med 2024; 30:3-9. [PMID: 36795265 DOI: 10.1007/s11655-023-3692-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/18/2022] [Indexed: 02/17/2023]
Abstract
Acupuncture, a therapeutic treatment defined as the insertion of needles into the body at specific points (ie, acupoints), has growing in popularity world-wide to treat various diseases effectively, especially acute and chronic pain. In parallel, interest in the physiological mechanisms underlying acupuncture analgesia, particularly the neural mechanisms have been increasing. Over the past decades, our understanding of how the central nervous system and peripheral nervous system process signals induced by acupuncture has developed rapidly by using electrophysiological methods. However, with the development of neuroscience, electrophysiology is being challenged by calcium imaging in view field, neuron population and visualization in vivo. Owing to the outstanding spatial resolution, the novel imaging approaches provide opportunities to enrich our knowledge about the neurophysiological mechanisms of acupuncture analgesia at subcellular, cellular, and circuit levels in combination with new labeling, genetic and circuit tracing techniques. Therefore, this review will introduce the principle and the method of calcium imaging applied to acupuncture research. We will also review the current findings in pain research using calcium imaging from in vitro to in vivo experiments and discuss the potential methodological considerations in studying acupuncture analgesia.
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Affiliation(s)
- Sha Li
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Yun Liu
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Nan Zhang
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Wang Li
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Wen-Jie Xu
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Yi-Qian Xu
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Yi-Yuan Chen
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Xiang Cui
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Bing Zhu
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Xin-Yan Gao
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, 100700, China.
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2
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Ghosh S, Dahiya M, Kumar A, Bheri M, Pandey GK. Calcium imaging: a technique to monitor calcium dynamics in biological systems. PHYSIOLOGY AND MOLECULAR BIOLOGY OF PLANTS : AN INTERNATIONAL JOURNAL OF FUNCTIONAL PLANT BIOLOGY 2023; 29:1777-1811. [PMID: 38222278 PMCID: PMC10784449 DOI: 10.1007/s12298-023-01405-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2023] [Revised: 12/07/2023] [Accepted: 12/11/2023] [Indexed: 01/16/2024]
Abstract
Calcium ion (Ca2+) is a multifaceted signaling molecule that acts as an important second messenger. During the course of evolution, plants and animals have developed Ca2+ signaling in order to respond against diverse stimuli, to regulate a large number of physiological and developmental pathways. Our understanding of Ca2+ signaling and its components in physiological phenomena ranging from lower to higher organisms, and from single cell to multiple tissues has grown exponentially. The generation of Ca2+ transients or signatures for various stress factor is a well-known mechanism adopted in plant and animal systems. However, the decoding of such remarkable signatures is an uphill task and is always an interesting goal for the scientific community. In the past few decades, studies on the concentration and dynamics of intracellular Ca2+ are significantly increasing and have become a trend in modern biology. The advancement in approaches from Ca2+ binding dyes to in vivo Ca2+ imaging through the use of Ca2+ biosensors to achieve spatio-temporal resolution in micro and milliseconds range, provide us phenomenal opportunities to study live cell Ca2+ imaging or dynamics. Here, we describe the usage, improvement and advancement of Ca2+ based dyes, genetically encoded probes and sensors to achieve extraordinary Ca2+ imaging in plants and animals. Graphical abstract
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Affiliation(s)
- Soma Ghosh
- Department of Plant Molecular Biology, University of Delhi South Campus, Benito Juarez Road, Dhaula Kuan, New Delhi, 110021 India
| | - Monika Dahiya
- Department of Plant Molecular Biology, University of Delhi South Campus, Benito Juarez Road, Dhaula Kuan, New Delhi, 110021 India
| | - Amit Kumar
- Department of Plant Molecular Biology, University of Delhi South Campus, Benito Juarez Road, Dhaula Kuan, New Delhi, 110021 India
| | - Malathi Bheri
- Department of Plant Molecular Biology, University of Delhi South Campus, Benito Juarez Road, Dhaula Kuan, New Delhi, 110021 India
| | - Girdhar K. Pandey
- Department of Plant Molecular Biology, University of Delhi South Campus, Benito Juarez Road, Dhaula Kuan, New Delhi, 110021 India
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Welton TA, George NM, Ozbay BN, Gentile Polese A, Osborne G, Futia GL, Kushner JK, Kleinschmidt-DeMasters B, Alexander AL, Abosch A, Ojemann S, Restrepo D, Gibson EA. Two-photon microendoscope for label-free imaging in stereotactic neurosurgery. BIOMEDICAL OPTICS EXPRESS 2023; 14:3705-3725. [PMID: 37497482 PMCID: PMC10368057 DOI: 10.1364/boe.492552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 05/26/2023] [Accepted: 06/15/2023] [Indexed: 07/28/2023]
Abstract
We demonstrate a gradient refractive index (GRIN) microendoscope with an outer diameter of ∼1.2 mm and a length of ∼186 mm that can fit into a stereotactic surgical cannula. Two photon imaging at an excitation wavelength of 900 nm showed a field of view of ∼180 microns and a lateral and axial resolution of 0.86 microns and 9.6 microns respectively. The microendoscope was tested by imaging autofluorescence and second harmonic generation (SHG) in label-free human brain tissue. Furthermore, preliminary image analysis indicates that image classification models can predict if an image is from the subthalamic nucleus or the surrounding tissue using conventional, bench-top two-photon autofluorescence.
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Affiliation(s)
- Tarah A. Welton
- Department of Bioengineering, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Nicholas M. George
- Neuroscience Graduate Program, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Baris N. Ozbay
- Intelligent Imaging Innovations, Denver, Colorado, 80216, USA
| | - Arianna Gentile Polese
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Gregory Osborne
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Gregory L. Futia
- Department of Bioengineering, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - J. Keenan Kushner
- Neuroscience Graduate Program, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Bette Kleinschmidt-DeMasters
- Department of Pathology, University of Colorado School of Medicine, Aurora, CO 80045, USA
- Department of Neurology, University of Colorado School of Medicine, Aurora, CO 80045, USA
- Department of Neurosurgery, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Allyson L. Alexander
- Department of Neurosurgery, University of Colorado School of Medicine, Aurora, CO 80045, USA
- Division of Pediatric Neurosurgery, Children’s Hospital Colorado, Aurora CO 80045, USA
| | - Aviva Abosch
- Department of Neurosurgery, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Steven Ojemann
- Department of Neurosurgery, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Diego Restrepo
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Emily A. Gibson
- Department of Bioengineering, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
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4
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Accanto N, Blot FGC, Lorca-Cámara A, Zampini V, Bui F, Tourain C, Badt N, Katz O, Emiliani V. A flexible two-photon fiberscope for fast activity imaging and precise optogenetic photostimulation of neurons in freely moving mice. Neuron 2023; 111:176-189.e6. [PMID: 36395773 DOI: 10.1016/j.neuron.2022.10.030] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 07/28/2022] [Accepted: 10/19/2022] [Indexed: 11/17/2022]
Abstract
We developed a flexible two-photon microendoscope (2P-FENDO) capable of all-optical brain investigation at near cellular resolution in freely moving mice. The system performs fast two-photon (2P) functional imaging and 2P holographic photostimulation of single and multiple cells using axially confined extended spots. Proof-of-principle experiments were performed in freely moving mice co-expressing jGCaMP7s and the opsin ChRmine in the visual or barrel cortex. On a field of view of 250 μm in diameter, we demonstrated functional imaging at a frame rate of up to 50 Hz and precise photostimulation of selected groups of cells. With the capability to simultaneously image and control defined neuronal networks in freely moving animals, 2P-FENDO will enable a precise investigation of neuronal functions in the brain during naturalistic behaviors.
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Affiliation(s)
- Nicolò Accanto
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012 Paris, France.
| | - François G C Blot
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012 Paris, France
| | | | - Valeria Zampini
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012 Paris, France
| | - Florence Bui
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012 Paris, France
| | - Christophe Tourain
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012 Paris, France
| | - Noam Badt
- Department of Applied Physics, Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Ori Katz
- Department of Applied Physics, Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Valentina Emiliani
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012 Paris, France.
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5
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NAD(P)H fluorescence lifetime imaging of live intestinal nematodes reveals metabolic crosstalk between parasite and host. Sci Rep 2022; 12:7264. [PMID: 35508502 PMCID: PMC9068778 DOI: 10.1038/s41598-022-10705-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Accepted: 04/11/2022] [Indexed: 11/29/2022] Open
Abstract
Infections with intestinal nematodes have an equivocal impact: they represent a burden for human health and animal husbandry, but, at the same time, may ameliorate auto-immune diseases due to the immunomodulatory effect of the parasites. Thus, it is key to understand how intestinal nematodes arrive and persist in their luminal niche and interact with the host over long periods of time. One basic mechanism governing parasite and host cellular and tissue functions, metabolism, has largely been neglected in the study of intestinal nematode infections. Here we use NADH (nicotinamide adenine dinucleotide) and NADPH (nicotinamide adenine dinucleotide phosphate) fluorescence lifetime imaging of explanted murine duodenum infected with the natural nematode Heligmosomoides polygyrus and define the link between general metabolic activity and possible metabolic pathways in parasite and host tissue, during acute infection. In both healthy and infected host intestine, energy is effectively produced, mainly via metabolic pathways resembling oxidative phosphorylation/aerobic glycolysis features. In contrast, the nematodes shift their energy production from balanced fast anaerobic glycolysis-like and effective oxidative phosphorylation-like metabolic pathways, towards mainly anaerobic glycolysis-like pathways, back to oxidative phosphorylation/aerobic glycolysis-like pathways during their different life cycle phases in the submucosa versus the intestinal lumen. Additionally, we found an increased NADPH oxidase (NOX) enzymes-dependent oxidative burst in infected intestinal host tissue as compared to healthy tissue, which was mirrored by a similar defense reaction in the parasites. We expect that, the here presented application of NAD(P)H-FLIM in live tissues constitutes a unique tool to study possible shifts between metabolic pathways in host-parasite crosstalk, in various parasitic intestinal infections.
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6
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Zong W, Obenhaus HA, Skytøen ER, Eneqvist H, de Jong NL, Vale R, Jorge MR, Moser MB, Moser EI. Large-scale two-photon calcium imaging in freely moving mice. Cell 2022; 185:1240-1256.e30. [PMID: 35305313 PMCID: PMC8970296 DOI: 10.1016/j.cell.2022.02.017] [Citation(s) in RCA: 109] [Impact Index Per Article: 54.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 01/12/2022] [Accepted: 02/14/2022] [Indexed: 11/29/2022]
Abstract
We developed a miniaturized two-photon microscope (MINI2P) for fast, high-resolution, multiplane calcium imaging of over 1,000 neurons at a time in freely moving mice. With a microscope weight below 3 g and a highly flexible connection cable, MINI2P allowed stable imaging with no impediment of behavior in a variety of assays compared to untethered, unimplanted animals. The improved cell yield was achieved through a optical system design featuring an enlarged field of view (FOV) and a microtunable lens with increased z-scanning range and speed that allows fast and stable imaging of multiple interleaved planes, as well as 3D functional imaging. Successive imaging across multiple, adjacent FOVs enabled recordings from more than 10,000 neurons in the same animal. Large-scale proof-of-principle data were obtained from cell populations in visual cortex, medial entorhinal cortex, and hippocampus, revealing spatial tuning of cells in all areas.
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Affiliation(s)
- Weijian Zong
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Norwegian University of Science and Technology (NTNU), Trondheim NO-7491, Norway.
| | - Horst A Obenhaus
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Norwegian University of Science and Technology (NTNU), Trondheim NO-7491, Norway
| | - Emilie R Skytøen
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Norwegian University of Science and Technology (NTNU), Trondheim NO-7491, Norway
| | - Hanna Eneqvist
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Norwegian University of Science and Technology (NTNU), Trondheim NO-7491, Norway
| | - Nienke L de Jong
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Norwegian University of Science and Technology (NTNU), Trondheim NO-7491, Norway
| | - Ruben Vale
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Norwegian University of Science and Technology (NTNU), Trondheim NO-7491, Norway
| | - Marina R Jorge
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Norwegian University of Science and Technology (NTNU), Trondheim NO-7491, Norway
| | - May-Britt Moser
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Norwegian University of Science and Technology (NTNU), Trondheim NO-7491, Norway
| | - Edvard I Moser
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Norwegian University of Science and Technology (NTNU), Trondheim NO-7491, Norway.
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7
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Peng Y, Schöneberg N, Esposito MS, Geiger JRP, Sharott A, Tovote P. Current approaches to characterize micro- and macroscale circuit mechanisms of Parkinson's disease in rodent models. Exp Neurol 2022; 351:114008. [PMID: 35149118 PMCID: PMC7612860 DOI: 10.1016/j.expneurol.2022.114008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 01/17/2022] [Accepted: 02/04/2022] [Indexed: 11/24/2022]
Abstract
Accelerating technological progress in experimental neuroscience is increasing the scale as well as specificity of both observational and perturbational approaches to study circuit physiology. While these techniques have also been used to study disease mechanisms, a wider adoption of these approaches in the field of experimental neurology would greatly facilitate our understanding of neurological dysfunctions and their potential treatments at cellular and circuit level. In this review, we will introduce classic and novel methods ranging from single-cell electrophysiological recordings to state-of-the-art calcium imaging and cell-type specific optogenetic or chemogenetic stimulation. We will focus on their application in rodent models of Parkinson’s disease while also presenting their use in the context of motor control and basal ganglia function. By highlighting the scope and limitations of each method, we will discuss how they can be used to study pathophysiological mechanisms at local and global circuit levels and how novel frameworks can help to bridge these scales.
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Affiliation(s)
- Yangfan Peng
- Institute of Neurophysiology, Charité - Universitätsmedizin Berlin, Freie Universität Berlin and Humboldt Universität zu Berlin, Charitéplatz 1, 10117 Berlin, Germany; Department of Neurology, Charité - Universitätsmedizin Berlin, Freie Universität Berlin and Humboldt Universität zu Berlin, Charitéplatz 1, 10117 Berlin, Germany; MRC Brain Network Dynamics Unit, University of Oxford, Mansfield Road, Oxford OX1 3TH, United Kingdom.
| | - Nina Schöneberg
- Institute of Clinical Neurobiology, University Hospital Wuerzburg, Versbacher Str. 5, 97078 Wuerzburg, Germany
| | - Maria Soledad Esposito
- Medical Physics Department, Centro Atomico Bariloche, Comision Nacional de Energia Atomica (CNEA), Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Av. E. Bustillo 9500, R8402AGP San Carlos de Bariloche, Rio Negro, Argentina
| | - Jörg R P Geiger
- Institute of Neurophysiology, Charité - Universitätsmedizin Berlin, Freie Universität Berlin and Humboldt Universität zu Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Andrew Sharott
- MRC Brain Network Dynamics Unit, University of Oxford, Mansfield Road, Oxford OX1 3TH, United Kingdom
| | - Philip Tovote
- Institute of Clinical Neurobiology, University Hospital Wuerzburg, Versbacher Str. 5, 97078 Wuerzburg, Germany; Center for Mental Health, University of Wuerzburg, Margarete-Höppel-Platz 1, 97080 Wuerzburg, Germany.
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8
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Markicevic M, Savvateev I, Grimm C, Zerbi V. Emerging imaging methods to study whole-brain function in rodent models. Transl Psychiatry 2021; 11:457. [PMID: 34482367 PMCID: PMC8418612 DOI: 10.1038/s41398-021-01575-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 08/05/2021] [Accepted: 08/23/2021] [Indexed: 02/07/2023] Open
Abstract
In the past decade, the idea that single populations of neurons support cognition and behavior has gradually given way to the realization that connectivity matters and that complex behavior results from interactions between remote yet anatomically connected areas that form specialized networks. In parallel, innovation in brain imaging techniques has led to the availability of a broad set of imaging tools to characterize the functional organization of complex networks. However, each of these tools poses significant technical challenges and faces limitations, which require careful consideration of their underlying anatomical, physiological, and physical specificity. In this review, we focus on emerging methods for measuring spontaneous or evoked activity in the brain. We discuss methods that can measure large-scale brain activity (directly or indirectly) with a relatively high temporal resolution, from milliseconds to seconds. We further focus on methods designed for studying the mammalian brain in preclinical models, specifically in mice and rats. This field has seen a great deal of innovation in recent years, facilitated by concomitant innovation in gene-editing techniques and the possibility of more invasive recordings. This review aims to give an overview of currently available preclinical imaging methods and an outlook on future developments. This information is suitable for educational purposes and for assisting scientists in choosing the appropriate method for their own research question.
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Affiliation(s)
- Marija Markicevic
- Neural Control of Movement Lab, HEST, ETH Zürich, Zürich, Switzerland
- Neuroscience Center Zurich, University and ETH Zürich, Zürich, Switzerland
| | - Iurii Savvateev
- Neural Control of Movement Lab, HEST, ETH Zürich, Zürich, Switzerland
- Neuroscience Center Zurich, University and ETH Zürich, Zürich, Switzerland
- Decision Neuroscience Lab, HEST, ETH Zürich, Zürich, Switzerland
| | - Christina Grimm
- Neural Control of Movement Lab, HEST, ETH Zürich, Zürich, Switzerland
- Neuroscience Center Zurich, University and ETH Zürich, Zürich, Switzerland
| | - Valerio Zerbi
- Neural Control of Movement Lab, HEST, ETH Zürich, Zürich, Switzerland.
- Neuroscience Center Zurich, University and ETH Zürich, Zürich, Switzerland.
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9
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Laing BT, Siemian JN, Sarsfield S, Aponte Y. Fluorescence microendoscopy for in vivo deep-brain imaging of neuronal circuits. J Neurosci Methods 2021; 348:109015. [PMID: 33259847 PMCID: PMC8745022 DOI: 10.1016/j.jneumeth.2020.109015] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 11/24/2020] [Accepted: 11/26/2020] [Indexed: 11/16/2022]
Abstract
Imaging neuronal activity in awake, behaving animals has become a groundbreaking method in neuroscience that has rapidly enhanced our understanding of how the brain works. In vivo microendoscopic imaging has enabled researchers to see inside the brains of experimental animals and thus has emerged as a technology fit to answer many experimental questions. By combining microendoscopy with cutting edge targeting strategies and sophisticated analysis tools, neuronal activity patterns that underlie changes in behavior and physiology can be identified. However, new users may find it challenging to understand the techniques and to leverage this technology to best suit their needs. Here we present a background and overview of the necessary components for performing in vivo optical calcium imaging and offer some detailed guidance for current recommended approaches.
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Affiliation(s)
- Brenton T Laing
- Neuronal Circuits and Behavior Unit, National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, Baltimore, MD, 21224-6823, USA
| | - Justin N Siemian
- Neuronal Circuits and Behavior Unit, National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, Baltimore, MD, 21224-6823, USA
| | - Sarah Sarsfield
- Neuronal Circuits and Behavior Unit, National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, Baltimore, MD, 21224-6823, USA
| | - Yeka Aponte
- Neuronal Circuits and Behavior Unit, National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, Baltimore, MD, 21224-6823, USA; The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
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10
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Campos P, Walker JJ, Mollard P. Diving into the brain: deep-brain imaging techniques in conscious animals. J Endocrinol 2020; 246:R33-R50. [PMID: 32380471 PMCID: PMC7354703 DOI: 10.1530/joe-20-0028] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 05/07/2020] [Indexed: 01/28/2023]
Abstract
In most species, survival relies on the hypothalamic control of endocrine axes that regulate critical functions such as reproduction, growth, and metabolism. For decades, the complexity and inaccessibility of the hypothalamic-pituitary axis has prevented researchers from elucidating the relationship between the activity of endocrine hypothalamic neurons and pituitary hormone secretion. Indeed, the study of central control of endocrine function has been largely dominated by 'traditional' techniques that consist of studying in vitro or ex vivo isolated cell types without taking into account the complexity of regulatory mechanisms at the level of the brain, pituitary and periphery. Nowadays, by exploiting modern neuronal transfection and imaging techniques, it is possible to study hypothalamic neuron activity in situ, in real time, and in conscious animals. Deep-brain imaging of calcium activity can be performed through gradient-index lenses that are chronically implanted and offer a 'window into the brain' to image multiple neurons at single-cell resolution. With this review, we aim to highlight deep-brain imaging techniques that enable the study of neuroendocrine neurons in awake animals whilst maintaining the integrity of regulatory loops between the brain, pituitary and peripheral glands. Furthermore, to assist researchers in setting up these techniques, we discuss the equipment required and include a practical step-by-step guide to performing these deep-brain imaging studies.
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Affiliation(s)
- Pauline Campos
- College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, UK
- Correspondence should be addressed to P Campos:
| | - Jamie J Walker
- College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, UK
- EPSRC Centre for Predictive Modelling in Healthcare, University of Exeter, Exeter, UK
- Bristol Medical School, Translational Health Sciences, University of Bristol, Bristol, UK
| | - Patrice Mollard
- IGF, University of Montpellier, CNRS, INSERM, Montpellier, France
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11
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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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12
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Eastman AE, Guo S. The palette of techniques for cell cycle analysis. FEBS Lett 2020; 594:10.1002/1873-3468.13842. [PMID: 32441778 PMCID: PMC9261528 DOI: 10.1002/1873-3468.13842] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 04/20/2020] [Accepted: 05/08/2020] [Indexed: 12/13/2022]
Abstract
The cell division cycle is the generational period of cellular growth and propagation. Cell cycle progression needs to be highly regulated to preserve genomic fidelity while increasing cell number. In multicellular organisms, the cell cycle must also coordinate with cell fate specification during development and tissue homeostasis. Altered cell cycle dynamics play a central role also in a number of pathophysiological processes. Thus, extensive effort has been made to define the biochemical machineries that execute the cell cycle and their regulation, as well as implementing more sensitive and accurate cell cycle measurements. Here, we review the available techniques for cell cycle analysis, revisiting the assumptions behind conventional population-based measurements and discussing new tools to better address cell cycle heterogeneity in the single-cell era. We weigh the strengths, weaknesses, and trade-offs of methods designed to measure temporal aspects of the cell cycle. Finally, we discuss emerging techniques for capturing cell cycle speed at single-cell resolution in live animals.
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Affiliation(s)
- Anna E Eastman
- Department of Cell Biology and Yale Stem Cell Center, Yale University, New Haven, CT, USA
| | - Shangqin Guo
- Department of Cell Biology and Yale Stem Cell Center, Yale University, New Haven, CT, USA
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13
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Soulet D, Lamontagne-Proulx J, Aubé B, Davalos D. Multiphoton intravital microscopy in small animals: motion artefact challenges and technical solutions. J Microsc 2020; 278:3-17. [PMID: 32072642 PMCID: PMC7187339 DOI: 10.1111/jmi.12880] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 02/06/2020] [Accepted: 02/14/2020] [Indexed: 12/28/2022]
Abstract
Since its invention 29 years ago, two‐photon laser‐scanning microscopy has evolved from a promising imaging technique, to an established widely available imaging modality used throughout the biomedical research community. The establishment of two‐photon microscopy as the preferred method for imaging fluorescently labelled cells and structures in living animals can be attributed to the biophysical mechanism by which the generation of fluorescence is accomplished. The use of powerful lasers capable of delivering infrared light pulses within femtosecond intervals, facilitates the nonlinear excitation of fluorescent molecules only at the focal plane and determines by objective lens position. This offers numerous benefits for studies of biological samples at high spatial and temporal resolutions with limited photo‐damage and superior tissue penetration. Indeed, these attributes have established two‐photon microscopy as the ideal method for live‐animal imaging in several areas of biology and have led to a whole new field of study dedicated to imaging biological phenomena in intact tissues and living organisms. However, despite its appealing features, two‐photon intravital microscopy is inherently limited by tissue motion from heartbeat, respiratory cycles, peristalsis, muscle/vascular tone and physiological functions that change tissue geometry. Because these movements impede temporal and spatial resolution, they must be properly addressed to harness the full potential of two‐photon intravital microscopy and enable accurate data analysis and interpretation. In addition, the sources and features of these motion artefacts are varied, sometimes unpredictable and unique to specific organs and multiple complex strategies have previously been devised to address them. This review will discuss these motion artefacts requirement and technical solutions for their correction and after intravital two‐photon microscopy.
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Affiliation(s)
- D Soulet
- Centre de recherche du CHUL, Department of Neurosciences, Quebec, Canada.,Faculty of Pharmacy, Université Laval, Quebec, Canada
| | - J Lamontagne-Proulx
- Centre de recherche du CHUL, Department of Neurosciences, Quebec, Canada.,Faculty of Pharmacy, Université Laval, Quebec, Canada
| | - B Aubé
- Centre de recherche du CHUL, Department of Neurosciences, Quebec, Canada
| | - D Davalos
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, U.S.A
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14
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Werner CT, Williams CJ, Fermelia MR, Lin DT, Li Y. Circuit Mechanisms of Neurodegenerative Diseases: A New Frontier With Miniature Fluorescence Microscopy. Front Neurosci 2019; 13:1174. [PMID: 31736701 PMCID: PMC6834692 DOI: 10.3389/fnins.2019.01174] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 10/17/2019] [Indexed: 12/13/2022] Open
Abstract
Neurodegenerative diseases (NDDs), such as Alzheimer’s disease (AD), Parkinson’s disease (PD), Huntington’s disease (HD), amyotrophic lateral sclerosis (ALS), and frontotemporal dementia (FTD), are devastating age-associated brain disorders. Significant efforts have been made to uncover the molecular and cellular pathogenic mechanisms that underlie NDDs. However, our understanding of the neural circuit mechanisms that mediate NDDs and associated symptomatic features have been hindered by technological limitations. Our inability to identify and track individual neurons longitudinally in subcortical brain regions that are preferentially targeted in NDDs has left gaping holes in our knowledge of NDDs. Recent development and advancement of the miniature fluorescence microscope (miniscope) has opened up new avenues for examining spatially and temporally coordinated activity from hundreds of cells in deep brain structures in freely moving rodents. In the present mini-review, we examine the capabilities of current and future miniscope tools and discuss the innovative applications of miniscope imaging techniques that can push the boundaries of our understanding of neural circuit mechanisms of NDDs into new territories.
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Affiliation(s)
- Craig T Werner
- Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, United States
| | | | - Mercedes R Fermelia
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY, United States
| | - Da-Ting Lin
- Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, United States.,The Solomon H. Snyder Department of Neuroscience, Johns Hopkins School of Medicine, Johns Hopkins University, Baltimore, MD, United States
| | - Yun Li
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY, United States
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15
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Heffernan BM, Meyer SA, Restrepo D, Siemens ME, Gibson EA, Gopinath JT. A Fiber-Coupled Stimulated Emission Depletion Microscope for Bend-Insensitive Through-Fiber Imaging. Sci Rep 2019; 9:11137. [PMID: 31366899 PMCID: PMC6668468 DOI: 10.1038/s41598-019-47319-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Accepted: 07/15/2019] [Indexed: 01/27/2023] Open
Abstract
We present results for a new type of fiber-coupled stimulated emission depletion (STED) microscope which uses a single fiber to transport STED and excitation light, as well as collect the fluorescence signal. Our method utilizes two higher-order eigenmodes of polarization maintaining (PM) fiber to generate the doughnut-shaped STED beam. The modes are excited with separate beams that share no temporal coherence, yielding output that is independent of fiber bending. We measured the resolution using 45 nm fluorescent beads and found a median bead image size of 116 nm. This resolution does not change as function of fiber bending radius, demonstrating robust operation. We report, for the first time, STED images of fixed biological samples collected in the epi-direction through fiber. Our microscope design shows promise for future use in super-resolution micro-endoscopes and in vivo neural imaging in awake and freely-behaving animals.
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Affiliation(s)
- Brendan M Heffernan
- Department of Physics, University of Colorado Boulder, Boulder, CO, 80309, USA.
| | - Stephanie A Meyer
- Department of Bioengineering, University of Colorado Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - Diego Restrepo
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - Mark E Siemens
- Department of Physics and Astronomy, University of Denver, Denver, CO, 80210, USA
| | - Emily A Gibson
- Department of Bioengineering, University of Colorado Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - Juliet T Gopinath
- Department of Physics, University of Colorado Boulder, Boulder, CO, 80309, USA
- Department of Electrical, Computer, and Energy Engineering, University of Colorado Boulder, Boulder, CO, 80309, USA
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16
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Goedeke J, Schreiber P, Seidmann L, Li G, Birkenstock J, Simon F, König J, Muensterer OJ. Multiphoton microscopy in the diagnostic assessment of pediatric solid tissue in comparison to conventional histopathology: results of the first international online interobserver trial. Cancer Manag Res 2019; 11:3655-3667. [PMID: 31118788 PMCID: PMC6503203 DOI: 10.2147/cmar.s195470] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 03/06/2019] [Indexed: 12/17/2022] Open
Abstract
Purpose: Clear resection margins are paramount for good outcome in children undergoing solid tumor resections. Multiphoton microscopy (MPM) can provide high-resolution, real-time, intraoperative microscopic images of tumor tissue. Objective: This prospective international multicenter study evaluates the diagnostic accuracy, feasibility, and interobserver congruence of MPM in diagnosing solid pediatric tissue and tumors for the first time. Material and methods: Representative fresh sections from six different neonatal solid tissues (liver, lung, kidney, adrenal gland, heart muscle, testicle) and two types of typical pediatric solid tumors (neuroblastoma, rhabdomyosarcoma) with adjacent nonneoplastic tissue were imaged with MPM and then presented online with corresponding H&E stained slides of the exact same tissue region. Both image sets of each tissue type were interpreted by 38 randomly selected international attending pediatric pathologists via an online evaluation software. Results: The quality of MPM was sufficient to make the diagnosis of all normal tissue types except cardiac muscle in >94% of assessors with high interobserver congruence and 95% sensitivity. Heart muscle was interpreted as skeletal muscle in 55% of cases. Based on MPM imaging, participating pathologists diagnosed the presented pediatric neoplasms with 100% specificity, although the sensitivity reached only about 50%. Conclusion: Even without prior training, pathologists are able to diagnose normal pediatric tissues with valuable accuracy using MPM. While current MPM imaging protocols are not yet sensitive enough to reliably rule out neuroblastoma or rhabdomyosarcoma, they seem to be specific and therefore useful to confirm a diagnosis intraoperatively. We are confident that improved algorithms, specific training, and more experience with the method will make MPM a valuable future alternative to frozen section analysis. Registration: The trial was registered at www.researchregistry.com, registration number 2967.
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Affiliation(s)
- Jan Goedeke
- Department of Pediatric Surgery, University Medical Center of the Johannes Gutenberg-University Mainz, 55131Mainz, Germany
| | - Peter Schreiber
- Department of Pediatric Surgery, University Medical Center of the Johannes Gutenberg-University Mainz, 55131Mainz, Germany
| | - Larissa Seidmann
- Institute for Pathology, University Medical Center of the Johannes Gutenberg-University Mainz, 55131Mainz, Germany
| | - Geling Li
- Department of Pediatric Pathology, Childrens Hospital of Alabama, University of Alabama at Birmingham, Birmingham, AL35233, USA
| | - Jérôme Birkenstock
- Forschungszentrum für Translationale Neurowissenschaften, University Medical Center of the Johannes Gutenberg-University Mainz, 55131Mainz, Germany
| | - Frank Simon
- Department of Pediatric Surgery, University Medical Center of the Johannes Gutenberg-University Mainz, 55131Mainz, Germany
| | - Jochem König
- Institute of Medical Biostatistics, Epidemiology and Informatics (IMBEI), University Medical Center of the Johannes Gutenberg-University Mainz, 55131Mainz, Germany
| | - Oliver J Muensterer
- Department of Pediatric Surgery, University Medical Center of the Johannes Gutenberg-University Mainz, 55131Mainz, Germany
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17
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Siciliano CA, Tye KM. Leveraging calcium imaging to illuminate circuit dysfunction in addiction. Alcohol 2019; 74:47-63. [PMID: 30470589 PMCID: PMC7575247 DOI: 10.1016/j.alcohol.2018.05.013] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Revised: 05/08/2018] [Accepted: 05/28/2018] [Indexed: 12/28/2022]
Abstract
Alcohol and drug use can dysregulate neural circuit function to produce a wide range of neuropsychiatric disorders, including addiction. To understand the neural circuit computations that mediate behavior, and how substances of abuse may transform them, we must first be able to observe the activity of circuits. While many techniques have been utilized to measure activity in specific brain regions, these regions are made up of heterogeneous sub-populations, and assessing activity from neuronal populations of interest has been an ongoing challenge. To fully understand how neural circuits mediate addiction-related behavior, we must be able to reveal the cellular granularity within brain regions and circuits by overlaying functional information with the genetic and anatomical identity of the cells involved. The development of genetically encoded calcium indicators, which can be targeted to populations of interest, allows for in vivo visualization of calcium dynamics, a proxy for neuronal activity, thus providing an avenue for real-time assessment of activity in genetically and anatomically defined populations during behavior. Here, we highlight recent advances in calcium imaging technology, compare the current technology with other state-of-the-art approaches for in vivo monitoring of neural activity, and discuss the strengths, limitations, and practical concerns for observing neural circuit activity in preclinical addiction models.
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Affiliation(s)
- Cody A Siciliano
- The Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, United States.
| | - Kay M Tye
- The Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, United States; The Salk Institute for Biological Sciences, 10010 N Torrey Pines Road, La Jolla, CA 92037, United States.
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18
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Liao C, Zhu X, Zhou L, Wang Z, Liu W, Chen J. Visualize and quantify the structural alteration of the rat spinal cord injury based on multiphoton microscopy. Lasers Med Sci 2018; 34:561-569. [PMID: 30196440 DOI: 10.1007/s10103-018-2630-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 08/28/2018] [Indexed: 11/25/2022]
Abstract
The development of imaging technique to visualize and quantify the structural alteration of the spinal cord injury (SCI) may lead to better understanding and treatments of the injuries. In this work, multiphoton microscopy (MPM) based on two-photon excited fluorescence (TPEF) and second-harmonic generation (SHG) was tentatively applied to quantitatively visualize the cellular microstructures of SCI to demonstrate the feasibility and superiority of MPM in SCI imaging. High-contrast MPM images of normal and injured spinal cord tissue were obtained for comparison. Moreover, the changes of injured spinal cord were characterized by the quantitative analysis of the MPM images. These results showed that MPM combined with quantitative method has the ability to identify the characteristics of spinal cord injury including the changes in the contents of nerve fibers and extracellular matrix. With the advancement of MPM, we believe that this technique has great potential to provide the histological diagnosis for the monitoring and evaluation of SCI.
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Affiliation(s)
- Chenxi Liao
- Key Laboratory of OptoElectronic Science and Technology for Medicine of Ministry of Education, Fujian Provincial Key Laboratory of Photonics Technology, Fujian Normal University, Fuzhou, 350007, China
| | - Xiaoqin Zhu
- Key Laboratory of OptoElectronic Science and Technology for Medicine of Ministry of Education, Fujian Provincial Key Laboratory of Photonics Technology, Fujian Normal University, Fuzhou, 350007, China.
| | - Linquan Zhou
- Department of Orthopedics, Affiliated Union Hospital of Fujian Medical University, Fuzhou, 350001, People's Republic of China
| | - Zhenyu Wang
- Department of Orthopedics, Affiliated Union Hospital of Fujian Medical University, Fuzhou, 350001, People's Republic of China.
| | - Wenge Liu
- Department of Orthopedics, Affiliated Union Hospital of Fujian Medical University, Fuzhou, 350001, People's Republic of China
| | - Jianxin Chen
- Key Laboratory of OptoElectronic Science and Technology for Medicine of Ministry of Education, Fujian Provincial Key Laboratory of Photonics Technology, Fujian Normal University, Fuzhou, 350007, China
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19
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Three dimensional two-photon brain imaging in freely moving mice using a miniature fiber coupled microscope with active axial-scanning. Sci Rep 2018; 8:8108. [PMID: 29802371 PMCID: PMC5970169 DOI: 10.1038/s41598-018-26326-3] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 05/09/2018] [Indexed: 02/06/2023] Open
Abstract
We present a miniature head mounted two-photon fiber-coupled microscope (2P-FCM) for neuronal imaging with active axial focusing enabled using a miniature electrowetting lens. We show three-dimensional two-photon imaging of neuronal structure and record neuronal activity from GCaMP6s fluorescence from multiple focal planes in a freely-moving mouse. Two-color simultaneous imaging of GFP and tdTomato fluorescence is also demonstrated. Additionally, dynamic control of the axial scanning of the electrowetting lens allows tilting of the focal plane enabling neurons in multiple depths to be imaged in a single plane. Two-photon imaging allows increased penetration depth in tissue yielding a working distance of 450 μm with an additional 180 μm of active axial focusing. The objective NA is 0.45 with a lateral resolution of 1.8 μm, an axial resolution of 10 μm, and a field-of-view of 240 μm diameter. The 2P-FCM has a weight of only ~2.5 g and is capable of repeatable and stable head-attachment. The 2P-FCM with dynamic axial scanning provides a new capability to record from functionally distinct neuronal layers, opening new opportunities in neuroscience research.
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20
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Wang S, Du H, Lin B, Liao C, Zhu X, Wang X, Chen H, Zhuo S, Jiang L, Li L, Tu H, Chen J. Spatial and temporal identification of cerebral infarctions based on multiphoton microscopic imaging. BIOMEDICAL OPTICS EXPRESS 2018; 9:2312-2325. [PMID: 29760990 PMCID: PMC5946791 DOI: 10.1364/boe.9.002312] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 04/08/2018] [Accepted: 04/18/2018] [Indexed: 05/06/2023]
Abstract
Ischemic stroke is a leading cause of death and permanent disability worldwide. Middle cerebral artery occlusion (MCAO) of variable duration times could be anticipated to result in varying degrees of injury that evolve spatially over time. Therefore, investigations following strokes require information concerning the spatiotemporal dimensions of the ischemic core as well as of perilesional areas. In the present study, multiphoton microscopy (MPM) based on two-photon excited fluorescence (TPEF) and second harmonic generation (SHG) was applied to image such pathophysiological events. The ischemic time-points for evaluation were set at 6, 24, 48, and 72 hours after MCAO. Our results demonstrated that MPM has the ability to not only identify the normal and ischemic brain regions, but also reveal morphological changes of the cortex and striatum at various times following permanent MCAO. These findings corresponded well with the hematoxylin and eosin (H&E) stained tissue images. With the technologic progression of miniaturized imaging devices, MPM can be developed into an effective diagnostic and monitoring tool for ischemic stroke.
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Affiliation(s)
- Shu Wang
- Key Laboratory of OptoElectronic Science and Technology for Medicine of Ministry of Education, Fujian Provincial Key Laboratory of Photonics Technology, Fujian Normal University, Fuzhou 350007, China
- These authors contributed equally to this work
| | - Huiping Du
- Key Laboratory of OptoElectronic Science and Technology for Medicine of Ministry of Education, Fujian Provincial Key Laboratory of Photonics Technology, Fujian Normal University, Fuzhou 350007, China
- These authors contributed equally to this work
| | - Bingbing Lin
- Fujian University of Traditional Chinese Medicine, Fuzhou 350122, China
- These authors contributed equally to this work
| | - Chenxi Liao
- Key Laboratory of OptoElectronic Science and Technology for Medicine of Ministry of Education, Fujian Provincial Key Laboratory of Photonics Technology, Fujian Normal University, Fuzhou 350007, China
| | - Xiaoqin Zhu
- Key Laboratory of OptoElectronic Science and Technology for Medicine of Ministry of Education, Fujian Provincial Key Laboratory of Photonics Technology, Fujian Normal University, Fuzhou 350007, China
| | - Xingfu Wang
- Department of Pathology, The First Affiliated Hospital, Fujian Medical University, Fuzhou 350001, China
| | - Hong Chen
- Department of Pathology, The First Affiliated Hospital, Fujian Medical University, Fuzhou 350001, China
| | - Shuangmu Zhuo
- Key Laboratory of OptoElectronic Science and Technology for Medicine of Ministry of Education, Fujian Provincial Key Laboratory of Photonics Technology, Fujian Normal University, Fuzhou 350007, China
| | - Liwei Jiang
- Key Laboratory of OptoElectronic Science and Technology for Medicine of Ministry of Education, Fujian Provincial Key Laboratory of Photonics Technology, Fujian Normal University, Fuzhou 350007, China
| | - Lianhuang Li
- Key Laboratory of OptoElectronic Science and Technology for Medicine of Ministry of Education, Fujian Provincial Key Laboratory of Photonics Technology, Fujian Normal University, Fuzhou 350007, China
| | - Haohua Tu
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Jianxin Chen
- Key Laboratory of OptoElectronic Science and Technology for Medicine of Ministry of Education, Fujian Provincial Key Laboratory of Photonics Technology, Fujian Normal University, Fuzhou 350007, China
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21
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Supekar OD, Ozbay BN, Zohrabi M, Nystrom PD, Futia GL, Restrepo D, Gibson EA, Gopinath JT, Bright VM. Two-photon laser scanning microscopy with electrowetting-based prism scanning. BIOMEDICAL OPTICS EXPRESS 2017; 8:5412-5426. [PMID: 29296477 PMCID: PMC5745092 DOI: 10.1364/boe.8.005412] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Revised: 10/31/2017] [Accepted: 11/02/2017] [Indexed: 05/24/2023]
Abstract
Laser scanners are an integral part of high resolution biomedical imaging systems such as confocal or 2-photon excitation (2PE) microscopes. In this work, we demonstrate the utility of electrowetting on dielectric (EWOD) prisms as a lateral laser-scanning element integrated in a conventional 2PE microscope. To the best of our knowledge, this is the first such demonstration for EWOD prisms. EWOD devices provide a transmissive, low power consuming, and compact alternative to conventional adaptive optics, and hence this technology has tremendous potential. We demonstrate 2PE microscope imaging of cultured mouse hippocampal neurons with a FOV of 130 × 130 μm2 using EWOD prism scanning. In addition, we show simulations of the optical system with the EWOD prism, to evaluate the effect of propagating a Gaussian beam through the EWOD prism on the imaging quality. Based on the simulation results a beam size of 0.91 mm full width half max was chosen to conduct the imaging experiments, resulting in a numerical aperture of 0.17 of the imaging system.
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Affiliation(s)
- Omkar D. Supekar
- Department of Mechanical Engineering, University of Colorado, Boulder, CO, 80309, USA
| | - Baris N. Ozbay
- Department of Bioengineering, University of Colorado Anschutz Medical Campus, Aurora, Colorado, 80045, USA
| | - Mo Zohrabi
- Department of Electrical, Computer, and Energy Engineering, University of Colorado, Boulder, CO, 80309, USA
| | - Philip D. Nystrom
- Department of Mechanical Engineering, University of Colorado, Boulder, CO, 80309, USA
| | - Gregory L. Futia
- Department of Bioengineering, University of Colorado Anschutz Medical Campus, Aurora, Colorado, 80045, USA
| | - Diego Restrepo
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, 80045, USA
| | - Emily A. Gibson
- Department of Bioengineering, University of Colorado Anschutz Medical Campus, Aurora, Colorado, 80045, USA
| | - Juliet T. Gopinath
- Department of Electrical, Computer, and Energy Engineering, University of Colorado, Boulder, CO, 80309, USA
- Department of Physics, University of Colorado, Boulder, CO 80309-0390, USA
| | - Victor M. Bright
- Department of Mechanical Engineering, University of Colorado, Boulder, CO, 80309, USA
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22
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Clopath C, Bonhoeffer T, Hübener M, Rose T. Variance and invariance of neuronal long-term representations. Philos Trans R Soc Lond B Biol Sci 2017; 372:rstb.2016.0161. [PMID: 28093555 PMCID: PMC5247593 DOI: 10.1098/rstb.2016.0161] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/01/2016] [Indexed: 12/13/2022] Open
Abstract
The brain extracts behaviourally relevant sensory input to produce appropriate motor output. On the one hand, our constantly changing environment requires this transformation to be plastic. On the other hand, plasticity is thought to be balanced by mechanisms ensuring constancy of neuronal representations in order to achieve stable behavioural performance. Yet, prominent changes in synaptic strength and connectivity also occur during normal sensory experience, indicating a certain degree of constitutive plasticity. This raises the question of how stable neuronal representations are on the population level and also on the single neuron level. Here, we review recent data from longitudinal electrophysiological and optical recordings of single-cell activity that assess the long-term stability of neuronal stimulus selectivities under conditions of constant sensory experience, during learning, and after reversible modification of sensory input. The emerging picture is that neuronal representations are stabilized by behavioural relevance and that the degree of long-term tuning stability and perturbation resistance directly relates to the functional role of the respective neurons, cell types and circuits. Using a 'toy' model, we show that stable baseline representations and precise recovery from perturbations in visual cortex could arise from a 'backbone' of strong recurrent connectivity between similarly tuned cells together with a small number of 'anchor' neurons exempt from plastic changes.This article is part of the themed issue 'Integrating Hebbian and homeostatic plasticity'.
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Affiliation(s)
- Claudia Clopath
- Bioengineering Department, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
| | - Tobias Bonhoeffer
- Max Planck Institute of Neurobiology, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Mark Hübener
- Max Planck Institute of Neurobiology, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Tobias Rose
- Max Planck Institute of Neurobiology, Am Klopferspitz 18, 82152 Martinsried, Germany
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23
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Dunn KW, Ryan JC. Using quantitative intravital multiphoton microscopy to dissect hepatic transport in rats. Methods 2017; 128:40-51. [PMID: 28434905 DOI: 10.1016/j.ymeth.2017.04.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 04/14/2017] [Accepted: 04/17/2017] [Indexed: 12/24/2022] Open
Abstract
Hepatic solute transport is a complex process whose disruption is associated with liver disease and drug-induced liver injury. Intravital multiphoton fluorescence excitation microscopy provides the spatial and temporal resolution necessary to characterize hepatic transport at the level of individual hepatocytes in vivo and thus to identify the mechanisms and cellular consequences of cholestasis. Here we present an overview of the use of fluorescence microscopy for studies of hepatic transport in living animals, and describe how we have combined methods of intravital microscopy and digital image analysis to dissect the effects of drugs and pathological conditions on the function of hepatic transporters in vivo.
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Affiliation(s)
- Kenneth W Dunn
- Department of Medicine, Division of Nephrology, Indiana University School of Medicine, Indianapolis, IN 46202, United States.
| | - Jennifer C Ryan
- Department of Medicine, Division of Nephrology, Indiana University School of Medicine, Indianapolis, IN 46202, United States
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24
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Tykocki NR, Boerman EM, Jackson WF. Smooth Muscle Ion Channels and Regulation of Vascular Tone in Resistance Arteries and Arterioles. Compr Physiol 2017; 7:485-581. [PMID: 28333380 DOI: 10.1002/cphy.c160011] [Citation(s) in RCA: 222] [Impact Index Per Article: 31.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Vascular tone of resistance arteries and arterioles determines peripheral vascular resistance, contributing to the regulation of blood pressure and blood flow to, and within the body's tissues and organs. Ion channels in the plasma membrane and endoplasmic reticulum of vascular smooth muscle cells (SMCs) in these blood vessels importantly contribute to the regulation of intracellular Ca2+ concentration, the primary determinant of SMC contractile activity and vascular tone. Ion channels provide the main source of activator Ca2+ that determines vascular tone, and strongly contribute to setting and regulating membrane potential, which, in turn, regulates the open-state-probability of voltage gated Ca2+ channels (VGCCs), the primary source of Ca2+ in resistance artery and arteriolar SMCs. Ion channel function is also modulated by vasoconstrictors and vasodilators, contributing to all aspects of the regulation of vascular tone. This review will focus on the physiology of VGCCs, voltage-gated K+ (KV) channels, large-conductance Ca2+-activated K+ (BKCa) channels, strong-inward-rectifier K+ (KIR) channels, ATP-sensitive K+ (KATP) channels, ryanodine receptors (RyRs), inositol 1,4,5-trisphosphate receptors (IP3Rs), and a variety of transient receptor potential (TRP) channels that contribute to pressure-induced myogenic tone in resistance arteries and arterioles, the modulation of the function of these ion channels by vasoconstrictors and vasodilators, their role in the functional regulation of tissue blood flow and their dysfunction in diseases such as hypertension, obesity, and diabetes. © 2017 American Physiological Society. Compr Physiol 7:485-581, 2017.
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Affiliation(s)
- Nathan R Tykocki
- Department of Pharmacology, University of Vermont, Burlington, Vermont, USA
| | - Erika M Boerman
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri, USA
| | - William F Jackson
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Michigan, USA
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Hickman HD. New insights into antiviral immunity gained through intravital imaging. Curr Opin Virol 2017; 22:59-63. [PMID: 28081484 DOI: 10.1016/j.coviro.2016.11.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Accepted: 11/22/2016] [Indexed: 01/25/2023]
Abstract
Viral infections pose an ongoing challenge for mankind. Much of our knowledge of the immune response to viral infections comes from ex vivo analyses of infected animals, which provide important yet static information about events occurring within the host. Recently, a relatively new technique known as intravital microscopy (IVM) has been applied to the study of antiviral immunity. Intravital imaging affords a unique, real-time view of both viral dynamics and the ensuing immune response (along with their interplay) in the living animal. This review details some of the newest observations about the antiviral immune response gained using IVM.
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Affiliation(s)
- Heather D Hickman
- Laboratory of Viral Diseases, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, United States.
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26
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Rougon G, Brasselet S, Debarbieux F. Advances in Intravital Non-Linear Optical Imaging of the Central Nervous System in Rodents. Brain Plast 2016; 2:31-48. [PMID: 29765847 PMCID: PMC5928564 DOI: 10.3233/bpl-160028] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Purpose of review: Highly coordinated cellular interactions occur in the healthy or pathologic adult rodent central nervous system (CNS). Until recently, technical challenges have restricted the analysis of these events to largely static modes of study such as immuno-fluorescence and electron microscopy on fixed tissues. The development of intravital imaging with subcellular resolution is required to probe the dynamics of these events in their natural context, the living brain. Recent findings: This review focuses on the recently developed live non-linear optical imaging modalities, the core principles involved, the identified technical challenges that limit their use and the scope of their applications. We highlight some practical applications for these modalities with a specific attention given to Experimental Autoimmune Encephalomyelitis (EAE), a rodent model of a chronic inflammatory disease of the CNS characterized by the formation of disseminated demyelinating lesions accompanied by axonal degeneration. Summary: We conclude that label-free nonlinear optical imaging combined to two photon imaging will continue to contribute richly to comprehend brain function and pathogenesis and to develop effective therapeutic strategies.
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Affiliation(s)
- Geneviève Rougon
- Aix-Marseille Université, CNRS, Institut des Neurosciences de la Timone, UMR 7289, Marseille, France
| | - Sophie Brasselet
- Aix-Marseille Université, CNRS, Centrale Marseille, Institut Fresnel, UMR 7249, Marseille, France
| | - Franck Debarbieux
- Aix-Marseille Université, CNRS, Institut des Neurosciences de la Timone, UMR 7289, Marseille, France
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27
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Do Monte FH, Quirk GJ, Li B, Penzo MA. Retrieving fear memories, as time goes by…. Mol Psychiatry 2016; 21:1027-36. [PMID: 27217148 PMCID: PMC4956525 DOI: 10.1038/mp.2016.78] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Revised: 03/22/2016] [Accepted: 04/05/2016] [Indexed: 12/12/2022]
Abstract
Research in fear conditioning has provided a comprehensive picture of the neuronal circuit underlying the formation of fear memories. In contrast, our understanding of the retrieval of fear memories is much more limited. This disparity may stem from the fact that fear memories are not rigid, but reorganize over time. To bring some clarity and raise awareness about the time-dependent dynamics of retrieval circuits, we review current evidence on the neuronal circuitry participating in fear memory retrieval at both early and late time points following auditory fear conditioning. We focus on the temporal recruitment of the paraventricular nucleus of the thalamus (PVT) for the retrieval and maintenance of fear memories. Finally, we speculate as to why retrieval circuits change with time, and consider the functional strategy of recruiting structures not previously considered as part of the retrieval circuit.
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Affiliation(s)
- Fabricio H. Do Monte
- Departments of Psychiatry and Anatomy & Neurobiology, University of Puerto Rico School of Medicine, PO Box 365067, San Juan 00936, Puerto Rico
| | - Gregory J. Quirk
- Departments of Psychiatry and Anatomy & Neurobiology, University of Puerto Rico School of Medicine, PO Box 365067, San Juan 00936, Puerto Rico
| | - Bo Li
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724
| | - Mario A. Penzo
- National Institute of Mental Health, 35 Convent Drive, Bldg. 35A Room 2E621, Bethesda, MD 20850
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28
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Abstract
The growth and migration of neurons require continuous remodelling of the neuronal cytoskeleton, providing a versatile cellular framework for force generation and guided movement, in addition to structural support. Actin filaments and microtubules are central to the dynamic action of the cytoskeleton and rapid advances in imaging technologies are enabling ever more detailed visualisation of the dynamic intracellular networks that they form. However, these filaments do not act individually and an expanding body of evidence emphasises the importance of actin-microtubule crosstalk in orchestrating cytoskeletal dynamics. Here, we summarise our current understanding of the structure and dynamics of actin and microtubules in isolation, before reviewing both the mechanisms and the molecular players involved in mediating actin-microtubule crosstalk in neurons.
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Affiliation(s)
- Charlotte H Coles
- Laboratory for Axon Growth and Regeneration, German Center for Neurodegenerative Diseases (DZNE), Ludwig-Erhard-Allee 2, 53175, Bonn, Germany.
| | - Frank Bradke
- Laboratory for Axon Growth and Regeneration, German Center for Neurodegenerative Diseases (DZNE), Ludwig-Erhard-Allee 2, 53175, Bonn, Germany.
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Huang L, Mills AK, Zhao Y, Jones DJ, Tang S. Miniature fiber-optic multiphoton microscopy system using frequency-doubled femtosecond Er-doped fiber laser. BIOMEDICAL OPTICS EXPRESS 2016; 7:1948-56. [PMID: 27231633 PMCID: PMC4871093 DOI: 10.1364/boe.7.001948] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 04/05/2016] [Accepted: 04/06/2016] [Indexed: 05/08/2023]
Abstract
We report on a miniature fiber-optic multiphoton microscopy (MPM) system based on a frequency-doubled femtosecond Er-doped fiber laser. The femtosecond pulses from the laser source are delivered to the miniature fiber-optic probe at 1.58 µm wavelength, where a standard single mode fiber is used for delivery without the need of free-space dispersion compensation components. The beam is frequency-doubled inside the probe by a periodically poled MgO:LiNbO3 crystal. Frequency-doubled pulses at 786 nm with a maximum power of 80 mW and a pulsewidth of 150 fs are obtained and applied to excite intrinsic signals from tissues. A MEMS scanner, a miniature objective, and a multimode collection fiber are further used to make the probe compact. The miniature fiber-optic MPM system is highly portable and robust. Ex vivo multiphoton imaging of mammalian skins demonstrates the capability of the system in imaging biological tissues. The results show that the miniature fiber-optic MPM system using frequency-doubled femtosecond fiber laser can potentially bring the MPM imaging for clinical applications.
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Affiliation(s)
- Lin Huang
- Department of Electrical and Computer Engineering, University of British Columbia, Vancouver, V6T 1Z4, Canada
| | - Arthur K. Mills
- Department of Physics & Astronomy, University of British Columbia, Vancouver, V6T 1Z4, Canada
| | - Yuan Zhao
- Department of Electrical and Computer Engineering, University of British Columbia, Vancouver, V6T 1Z4, Canada
| | - David J. Jones
- Department of Physics & Astronomy, University of British Columbia, Vancouver, V6T 1Z4, Canada
| | - Shuo Tang
- Department of Electrical and Computer Engineering, University of British Columbia, Vancouver, V6T 1Z4, Canada
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30
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Stolp B, Melican K. Microbial pathogenesis revealed by intravital microscopy: pros, cons and cautions. FEBS Lett 2016; 590:2014-26. [PMID: 26938770 DOI: 10.1002/1873-3468.12122] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 02/15/2016] [Accepted: 02/29/2016] [Indexed: 12/22/2022]
Abstract
Intravital multiphoton imaging allows visualization of infections and pathogenic mechanisms within intact organs in their physiological context. Today, most organs of mice and rats are applicable to in vivo or ex vivo imaging, opening completely new avenues for many researchers. Advances in fluorescent labeling of pathogens and infected cells, as well as improved small animal models for human pathogens, led to the increased application of in vivo imaging in infectious diseases research in recent years. Here, we review the latest literature on intravital or ex vivo imaging of viral and bacterial infections and critically discuss requirements, benefits and drawbacks of applied animal models, labeling strategies, and imaged organs.
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Affiliation(s)
- Bettina Stolp
- Heidelberg University Hospital, Center of Infectious Diseases, Integrative Virology, Heidelberg, Germany
| | - Keira Melican
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
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31
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Dendritic integration: 60 years of progress. Nat Neurosci 2015; 18:1713-21. [PMID: 26605882 DOI: 10.1038/nn.4157] [Citation(s) in RCA: 261] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 09/24/2015] [Indexed: 12/12/2022]
Abstract
Understanding how individual neurons integrate the thousands of synaptic inputs they receive is critical to understanding how the brain works. Modeling studies in silico and experimental work in vitro, dating back more than half a century, have revealed that neurons can perform a variety of different passive and active forms of synaptic integration on their inputs. But how are synaptic inputs integrated in the intact brain? With the development of new techniques, this question has recently received substantial attention, with new findings suggesting that many of the forms of synaptic integration observed in vitro also occur in vivo, including in awake animals. Here we review six decades of progress, which collectively highlights the complex ways that single neurons integrate their inputs, emphasizing the critical role of dendrites in information processing in the brain.
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32
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Hamel EJO, Grewe BF, Parker JG, Schnitzer MJ. Cellular level brain imaging in behaving mammals: an engineering approach. Neuron 2015; 86:140-59. [PMID: 25856491 PMCID: PMC5758309 DOI: 10.1016/j.neuron.2015.03.055] [Citation(s) in RCA: 101] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Fluorescence imaging offers expanding capabilities for recording neural dynamics in behaving mammals, including the means to monitor hundreds of cells targeted by genetic type or connectivity, track cells over weeks, densely sample neurons within local microcircuits, study cells too inactive to isolate in extracellular electrical recordings, and visualize activity in dendrites, axons, or dendritic spines. We discuss recent progress and future directions for imaging in behaving mammals from a systems engineering perspective, which seeks holistic consideration of fluorescent indicators, optical instrumentation, and computational analyses. Today, genetically encoded indicators of neural Ca(2+) dynamics are widely used, and those of trans-membrane voltage are rapidly improving. Two complementary imaging paradigms involve conventional microscopes for studying head-restrained animals and head-mounted miniature microscopes for imaging in freely behaving animals. Overall, the field has attained sufficient sophistication that increased cooperation between those designing new indicators, light sources, microscopes, and computational analyses would greatly benefit future progress.
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Affiliation(s)
| | | | - Jones G Parker
- CNC Program, Stanford University, Stanford, CA 94305, USA; Pfizer Neuroscience Research Unit, Cambridge, MA 02139, USA
| | - Mark J Schnitzer
- CNC Program, Stanford University, Stanford, CA 94305, USA; Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA.
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Ozbay BN, Losacco JT, Cormack R, Weir R, Bright VM, Gopinath JT, Restrepo D, Gibson EA. Miniaturized fiber-coupled confocal fluorescence microscope with an electrowetting variable focus lens using no moving parts. OPTICS LETTERS 2015; 40:2553-6. [PMID: 26030555 PMCID: PMC4517461 DOI: 10.1364/ol.40.002553] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
We report a miniature, lightweight fiber-coupled confocal fluorescence microscope that incorporates an electrowetting variable focus lens to provide axial scanning for full three-dimensional (3D) imaging. Lateral scanning is accomplished by coupling our device to a laser-scanning confocal microscope through a coherent imaging fiber-bundle. The optical components of the device are combined in a custom 3D-printed adapter with an assembled weight of <2 g that can be mounted onto the head of a mouse. Confocal sectioning provides an axial resolution of ∼12 μm and an axial scan range of ∼80 μm. The lateral field-of-view is 300 μm, and the lateral resolution is 1.8 μm. We determined these parameters by imaging fixed sections of mouse neuronal tissue labeled with green fluorescent protein (GFP) and fluorescent bead samples in agarose gel. To demonstrate viability for imaging intact tissue, we resolved multiple optical sections of ex vivo mouse olfactory nerve fibers expressing yellow fluorescent protein (YFP).
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Affiliation(s)
- Baris N. Ozbay
- Department of Bioengineering, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
| | - Justin T. Losacco
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
| | - Robert Cormack
- Department of Electrical, Computer and Energy Engineering, University of Colorado Boulder, Colorado 80309, USA
| | - Richard Weir
- Department of Bioengineering, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
| | - Victor M. Bright
- Department of Mechanical Engineering, University of Colorado Boulder, Colorado 80309, USA
| | - Juliet T. Gopinath
- Department of Electrical, Computer and Energy Engineering, University of Colorado Boulder, Colorado 80309, USA
| | - Diego Restrepo
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
| | - Emily A. Gibson
- Department of Bioengineering, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
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34
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Ziv Y, Ghosh KK. Miniature microscopes for large-scale imaging of neuronal activity in freely behaving rodents. Curr Opin Neurobiol 2015; 32:141-7. [PMID: 25951292 DOI: 10.1016/j.conb.2015.04.001] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Revised: 03/27/2015] [Accepted: 04/08/2015] [Indexed: 01/04/2023]
Abstract
Recording neuronal activity in behaving subjects has been instrumental in studying how information is represented and processed by the brain. Recent advances in optical imaging and bioengineering have converged to enable time-lapse, cell-type specific recordings of neuronal activities from large neuronal populations in deep-brain structures of freely behaving rodents. We will highlight these advancements, with an emphasis on miniaturized integrated microscopy for large-scale imaging in freely behaving mice. This technology potentially enables studies that were difficult to perform using previous generation imaging and current electrophysiological techniques. These studies include longitudinal and population-level analyses of neuronal representations associated with different types of naturalistic behaviors and cognitive or emotional processes.
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Affiliation(s)
- Yaniv Ziv
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel.
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35
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Hollensteiner KJ, Pieper F, Engler G, König P, Engel AK. Crossmodal integration improves sensory detection thresholds in the ferret. PLoS One 2015; 10:e0124952. [PMID: 25970327 PMCID: PMC4430165 DOI: 10.1371/journal.pone.0124952] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Accepted: 03/20/2015] [Indexed: 11/19/2022] Open
Abstract
During the last two decades ferrets (Mustela putorius) have been established as a highly efficient animal model in different fields in neuroscience. Here we asked whether ferrets integrate sensory information according to the same principles established for other species. Since only few methods and protocols are available for behaving ferrets we developed a head-free, body-restrained approach allowing a standardized stimulation position and the utilization of the ferret’s natural response behavior. We established a behavioral paradigm to test audiovisual integration in the ferret. Animals had to detect a brief auditory and/or visual stimulus presented either left or right from their midline. We first determined detection thresholds for auditory amplitude and visual contrast. In a second step, we combined both modalities and compared psychometric fits and the reaction times between all conditions. We employed Maximum Likelihood Estimation (MLE) to model bimodal psychometric curves and to investigate whether ferrets integrate modalities in an optimal manner. Furthermore, to test for a redundant signal effect we pooled the reaction times of all animals to calculate a race model. We observed that bimodal detection thresholds were reduced and reaction times were faster in the bimodal compared to unimodal conditions. The race model and MLE modeling showed that ferrets integrate modalities in a statistically optimal fashion. Taken together, the data indicate that principles of multisensory integration previously demonstrated in other species also apply to crossmodal processing in the ferret.
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Affiliation(s)
- Karl J. Hollensteiner
- Dept. of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
- * E-mail:
| | - Florian Pieper
- Dept. of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Gerhard Engler
- Dept. of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Peter König
- Dept. of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
- Institute of Cognitive Science, University of Osnabrück, 49069 Osnabrück, Germany
| | - Andreas K. Engel
- Dept. of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
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36
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Miniaturized optical neuroimaging in unrestrained animals. Neuroimage 2015; 113:397-406. [PMID: 25791782 DOI: 10.1016/j.neuroimage.2015.02.070] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Revised: 01/26/2015] [Accepted: 02/20/2015] [Indexed: 11/23/2022] Open
Abstract
The confluence of technological advances in optics, miniaturized electronic components and the availability of ever increasing and affordable computational power have ushered in a new era in functional neuroimaging, namely, an era in which neuroimaging of cortical function in unrestrained and unanesthetized rodents has become a reality. Traditional optical neuroimaging required animals to be anesthetized and restrained. This greatly limited the kinds of experiments that could be performed in vivo. Now one can assess blood flow and oxygenation changes resulting from functional activity and image functional response in disease models such as stroke and seizure, and even conduct long-term imaging of tumor physiology, all without the confounding effects of anesthetics or animal restraints. These advances are shedding new light on mammalian brain organization and function, and helping to elucidate loss of this organization or 'dysfunction' in a wide array of central nervous system disease models. In this review, we highlight recent advances in the fabrication, characterization and application of miniaturized head-mounted optical neuroimaging systems pioneered by innovative investigators from a wide array of disciplines. We broadly classify these systems into those based on exogenous contrast agents, such as single- and two-photon microscopy systems; and those based on endogenous contrast mechanisms, such as multispectral or laser speckle contrast imaging systems. Finally, we conclude with a discussion of the strengths and weaknesses of these approaches along with a perspective on the future of this exciting new frontier in neuroimaging.
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Boccara CN, Kjonigsen LJ, Hammer IM, Bjaalie JG, Leergaard TB, Witter MP. A three-plane architectonic atlas of the rat hippocampal region. Hippocampus 2015; 25:838-57. [PMID: 25533645 DOI: 10.1002/hipo.22407] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/18/2014] [Indexed: 11/06/2022]
Abstract
The hippocampal region, comprising the hippocampal formation and the parahippocampal region, has been one of the most intensively studied parts of the brain for decades. Better understanding of its functional diversity and complexity has led to an increased demand for specificity in experimental procedures and manipulations. In view of the complex 3D structure of the hippocampal region, precisely positioned experimental approaches require a fine-grained architectural description that is available and readable to experimentalists lacking detailed anatomical experience. In this paper, we provide the first cyto- and chemoarchitectural description of the hippocampal formation and parahippocampal region in the rat at high resolution and in the three standard sectional planes: coronal, horizontal and sagittal. The atlas uses a series of adjacent sections stained for neurons and for a number of chemical marker substances, particularly parvalbumin and calbindin. All the borders defined in one plane have been cross-checked against their counterparts in the other two planes. The entire dataset will be made available as a web-based interactive application through the Rodent Brain WorkBench (http://www.rbwb.org) which, together with this paper, provides a unique atlas resource.
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Affiliation(s)
- Charlotte N Boccara
- Centre for Neural Computation, Kavli Institute for System Neuroscience, Norwegian University of Science and Technology (NTNU), Trondheim, Norway.,Institute of Science and Technology IST, Klosterneuburg, Austria
| | - Lisa J Kjonigsen
- Department of Anatomy, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Ingvild M Hammer
- Centre for Neural Computation, Kavli Institute for System Neuroscience, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Jan G Bjaalie
- Department of Anatomy, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Trygve B Leergaard
- Department of Anatomy, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Menno P Witter
- Centre for Neural Computation, Kavli Institute for System Neuroscience, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
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Leung SJ, Rice PS, Barton JK. In vivo molecular mapping of the tumor microenvironment in an azoxymethane-treated mouse model of colon carcinogenesis. Lasers Surg Med 2014; 47:40-9. [PMID: 25487746 DOI: 10.1002/lsm.22309] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/18/2014] [Indexed: 01/05/2023]
Abstract
BACKGROUND AND OBJECTIVE Development of miniaturized imaging systems with molecular probes enables examination of molecular changes leading to initiation and progression of colorectal cancer in an azoxymethane (AOM)-induced mouse model of the disease. Through improved and novel studies of animal disease models, more effective diagnostic and treatment strategies may be developed for clinical translation. We introduce use of a miniaturized multimodal endoscope with lavage-delivered fluorescent probes to examine dynamic microenvironment changes in an AOM-treated mouse model. STUDY DESIGN/MATERIALS AND METHODS The endoscope is equipped with optical coherence tomography (OCT) and laser induced fluorescence (LIF) imaging modalities. It is used with Cy5.5-conjugated antibodies to create time-resolved molecular maps of colon carcinogenesis. We monitored in vivo changes in molecular expression over a five month period for four biomarkers: epithelial growth factor receptor (EGFR), transferrin receptor (TfR), transforming growth factor beta 1 (TGFβ1), and chemokine (C-X-C motif) receptor 2 (CXCR2). In vivo OCT and LIF images were compared over multiple time points to correlate increases in biomarker expression with adenoma development. RESULTS This system is uniquely capable of tracking in vivo changes in molecular expression over time. Increased expression of the biomarker panel corresponded to sites of disease and offered predictive utility in highlighting sites of disease prior to detectable structural changes. Biomarker expression also tended to increase with higher tumor burden and growth rate in the colon. CONCLUSION We can use miniaturized dual modality endoscopes with fluorescent probes to study the tumor microenvironment in developmental animal models of cancer and supplement findings from biopsy and tissue harvesting.
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Affiliation(s)
- Sarah J Leung
- Department of Biomedical Engineering, University of Arizona, Tucson, AZ
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39
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Lecoq J, Savall J, Vučinić D, Grewe BF, Kim H, Li JZ, Kitch LJ, Schnitzer MJ. Visualizing mammalian brain area interactions by dual-axis two-photon calcium imaging. Nat Neurosci 2014; 17:1825-9. [PMID: 25402858 DOI: 10.1038/nn.3867] [Citation(s) in RCA: 94] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Accepted: 10/10/2014] [Indexed: 01/26/2023]
Abstract
Fluorescence Ca(2+) imaging enables large-scale recordings of neural activity, but collective dynamics across mammalian brain regions are generally inaccessible within single fields of view. Here we introduce a two-photon microscope possessing two articulated arms that can simultaneously image two brain areas (∼0.38 mm(2) each), either nearby or distal, using microendoscopes. Concurrent Ca(2+) imaging of ∼100-300 neurons in primary visual cortex (V1) and lateromedial (LM) visual area in behaving mice revealed that the variability in LM neurons' visual responses was strongly dependent on that in V1, suggesting that fluctuations in sensory responses propagate through extended cortical networks.
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Affiliation(s)
- Jérôme Lecoq
- James H. Clark Center for Biomedical Engineering &Sciences, Stanford University, Stanford, California, USA
| | - Joan Savall
- 1] James H. Clark Center for Biomedical Engineering &Sciences, Stanford University, Stanford, California, USA. [2] Howard Hughes Medical Institute, Stanford University, Stanford, California, USA
| | - Dejan Vučinić
- James H. Clark Center for Biomedical Engineering &Sciences, Stanford University, Stanford, California, USA
| | - Benjamin F Grewe
- James H. Clark Center for Biomedical Engineering &Sciences, Stanford University, Stanford, California, USA
| | - Hyun Kim
- James H. Clark Center for Biomedical Engineering &Sciences, Stanford University, Stanford, California, USA
| | - Jin Zhong Li
- James H. Clark Center for Biomedical Engineering &Sciences, Stanford University, Stanford, California, USA
| | - Lacey J Kitch
- James H. Clark Center for Biomedical Engineering &Sciences, Stanford University, Stanford, California, USA
| | - Mark J Schnitzer
- 1] James H. Clark Center for Biomedical Engineering &Sciences, Stanford University, Stanford, California, USA. [2] Howard Hughes Medical Institute, Stanford University, Stanford, California, USA. [3] CNC Program, Stanford University, Stanford, California, USA
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Shi L, Rodríguez-Contreras A, Budansky Y, Pu Y, An Nguyen T, Alfano RR. Deep two-photon microscopic imaging through brain tissue using the second singlet state from fluorescent agent chlorophyll α in spinach leaf. JOURNAL OF BIOMEDICAL OPTICS 2014; 19:066009. [PMID: 24967915 PMCID: PMC4071303 DOI: 10.1117/1.jbo.19.6.066009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Accepted: 05/28/2014] [Indexed: 05/04/2023]
Abstract
Two-photon (2P) excitation of the second singlet (S₂) state was studied to achieve deep optical microscopic imaging in brain tissue when both the excitation (800 nm) and emission (685 nm) wavelengths lie in the "tissue optical window" (650 to 950 nm). S₂ state technique was used to investigate chlorophyll α (Chl α) fluorescence inside a spinach leaf under a thick layer of freshly sliced rat brain tissue in combination with 2P microscopic imaging. Strong emission at the peak wavelength of 685 nm under the 2P S₂ state of Chl α enabled the imaging depth up to 450 μm through rat brain tissue.
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Affiliation(s)
- Lingyan Shi
- The City College of the City University of New York, Department of Biomedical Engineering, 160 Convent Avenue, New York 10031
- The City College of the City University of New York, Institute for Ultrafast Spectroscopy and Lasers, Departments of Electrical Engineering and Physics, 160 Convent Avenue, New York 10031
| | - Adrián Rodríguez-Contreras
- The City College of the City University of New York, Department of Biology, 160 Convent Avenue, New York 10031
| | - Yury Budansky
- The City College of the City University of New York, Institute for Ultrafast Spectroscopy and Lasers, Departments of Electrical Engineering and Physics, 160 Convent Avenue, New York 10031
| | - Yang Pu
- The City College of the City University of New York, Institute for Ultrafast Spectroscopy and Lasers, Departments of Electrical Engineering and Physics, 160 Convent Avenue, New York 10031
| | - Thien An Nguyen
- The City College of the City University of New York, Institute for Ultrafast Spectroscopy and Lasers, Departments of Electrical Engineering and Physics, 160 Convent Avenue, New York 10031
| | - Robert R. Alfano
- The City College of the City University of New York, Institute for Ultrafast Spectroscopy and Lasers, Departments of Electrical Engineering and Physics, 160 Convent Avenue, New York 10031
- Address all correspondence to: Robert R. Alfano, E-mail:
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Dorand RD, Barkauskas DS, Evans TA, Petrosiute A, Huang AY. Comparison of intravital thinned skull and cranial window approaches to study CNS immunobiology in the mouse cortex. INTRAVITAL 2014; 3:e29728. [PMID: 25568834 PMCID: PMC4283137 DOI: 10.4161/intv.29728] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2014] [Revised: 06/06/2014] [Accepted: 06/25/2014] [Indexed: 01/11/2023]
Abstract
Fluorescent imaging coupled with high-resolution femto-second pulsed infrared lasers allows for interrogation of cellular interactions deeper in living tissues than ever imagined. Intra-vital imaging of the central nervous system (CNS) has provided insights into neuronal development, synaptic transmission, and even immune interactions. In this review we will discuss the two most common intravital approaches for studying the cerebral cortex in the live mouse brain for pre-clinical studies, the thinned skull and cranial window techniques, and focus on the advantages and drawbacks of each approach. In addition, we will discuss the use of neuronal physiologic parameters as determinants of successful surgical and imaging preparation.
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Affiliation(s)
- R Dixon Dorand
- Department of Pathology; Case Western Reserve University School of Medicine; Cleveland, Ohio USA
| | - Deborah S Barkauskas
- Department of Biomedical Engineering; Case Western Reserve University School of Medicine; Cleveland, Ohio USA
| | - Teresa A Evans
- Department of Neurosciences; Case Western Reserve University School of Medicine; Cleveland, Ohio USA
| | - Agne Petrosiute
- Department of Pediatrics; Case Western Reserve University School of Medicine; Cleveland, Ohio USA
| | - Alex Y Huang
- Department of Pathology; Case Western Reserve University School of Medicine; Cleveland, Ohio USA
- Department of Biomedical Engineering; Case Western Reserve University School of Medicine; Cleveland, Ohio USA
- Department of Pediatrics; Case Western Reserve University School of Medicine; Cleveland, Ohio USA
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