Non-invasive Imaging of Leukocyte Homing and Migration in vivo
1Department of Pathology and Immunology, Washington University in St. Louis, 2National Institute of Neurological Disorders and Stroke, NINDS, NIH - National Institute of Health
Here, we describe a non-invasive two-photon (2P) microscopy approach to study leukocyte homing in the mouse footpad. We discuss the technical aspects of our tissue imaging preparation and walk the reader through a typical experiment from initial set up to execution and data collection.
Multi-photon Imaging of Tumor Cell Invasion in an Orthotopic Mouse Model of Oral Squamous Cell Carcinoma
1Department of Neurobiology and Anatomy, Program in Cancer Cell Biology, Mary Babb Randolph Cancer Center, West Virginia University, 2Sensory Neuroscience Research Center, West Virginia University, 3Departments of Otolaryngology and Physiology, Center for Neuroscience, West Virginia University
A comprehensive overview of the techniques involved in generating a mouse model of oral cancer and quantitative monitoring of tumor invasion within the tongue through multi-photon microscopy of labeled cells is presented. This system can serve as a useful platform for the molecular assessment and drug efficacy of anti-invasive compounds.
Thinned-skull Cortical Window Technique for In Vivo Optical Coherence Tomography Imaging
1Division of Biomedical Sciences, University of California, Riverside, 2Department of Bioengineering, University of California, Riverside
We present a method of creating a thinned-skull cortical window (TSCW) in a mouse model for in vivo OCT imaging of the cerebral cortex.
Transplantation into the Anterior Chamber of the Eye for Longitudinal, Non-invasive In vivo Imaging with Single-cell Resolution in Real-time
1Diabetes Research Institute, University of Miami Miller School of Medicine, 2Department of Surgery, University of Miami Miller School of Medicine, 3Department of Medicine, University of Miami Miller School of Medicine, 4Department of Physiology & Biophysics, University of Miami Miller School of Medicine, 5The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet
A new approach combining intraocular transplantation and confocal microscopy enables longitudinal, non-invasive real-time imaging with single-cell resolution within grafted tissues in vivo. We demonstrate how to transplant pancreatic islets into the anterior chamber of the mouse eye.
Dissection and 2-Photon Imaging of Peripheral Lymph Nodes in Mice
1Department of Physiology and Biophysics, University of California, Irvine (UCI), 2Department of Neurobiology and Behaviour, University of California, Irvine (UCI)
Two-photon imaging has uncovered lymphocyte motility and cellular interactions within the lymph node under basal conditions and durring an immune response 1. Here, we demonstrate adoptive transfer of T cells, isolation of lymph nodes, and imaging motility of CD4+ T cells in the explanted lymph node.
Two-Photon-Based Photoactivation in Live Zebrafish Embryos
Molecular Cell Biology, Weizmann Institute of Science
Multiphoton microscopy allows control of low energy photons with deep optical penetration and reduced phototoxicity. We describe the use of this technology for live cell labeling in zebrafish embryos. This protocol can be readily adapted for photo-induction of various light-responsive molecules.
In Vivo Two-photon Imaging Of Experience-dependent Molecular Changes In Cortical Neurons
1Unit on Neural Circuits and Adaptive Behaviors, Genes Cognition and Psychosis Program, National Institute of Mental Health, 2Department of Neuroscience, Brown University - National Institutes of Health Graduate Partnership Program, 3Section on Synaptic Pharmacology, Laboratory for Integrative Neuroscience, National Institute on Alcohol Abuse and Alcoholism, 4Champalimaud Neuroscience Programme, Champalimaud Center for the Unknown
Experience-dependent molecular changes in neurons are essential for the brain's ability to adapt in response to behavioral challenges. An in vivo two-photon imaging method is described here that allows the tracking of such molecular changes in individual cortical neurons through genetically encoded reporters.
A Method for 2-Photon Imaging of Blood Flow in the Neocortex through a Cranial Window
Department of Neurology, University of California, Los Angeles
Cortical blood flow dynamics can be studied in vivo by imaging fluorescent dextran dyes injected into the tail vein of rodents with 2-photon microscopy. This video shows how to image blood flow dynamics in neocortex of mice through a glass-covered cranial window preparation.
A Craniotomy Surgery Procedure for Chronic Brain Imaging
Department of Neurology, University of California, Los Angeles
This video and protocol demonstrate how to implant a glass-covered cranial window in rodents. These preparations can be used for chronic in vivo two-photon imaging of the neocortex over time scales of months. It may also be used for other types of imaging, including optical intrinsic signal imaging.
Chronic Imaging of Mouse Visual Cortex Using a Thinned-skull Preparation
Neurobiology and Anatomy, University of Rochester
In this video and supplemental material, we show a protocol for chronic in vivo imaging of the intact brain using a thinned-skull preparation.
In Vivo 2-Photon Calcium Imaging in Layer 2/3 of Mice
Department of Neurology, University of California, Los Angeles
To understand network dynamics of microcircuits in the neocortex, it is essential to simultaneously record the activity of a large number of neurons . In-vivo two-photon calcium imaging is the only method that allows one to record the activity of a dense neuronal population with single-cell resolution .
In vivo Imaging of the Mouse Spinal Cord Using Two-photon Microscopy
1Gladstone Institute of Neurological Disease, University of California, San Francisco, 2Department of Neurology, University of California, San Francisco
A minimally invasive protocol to stabilize the mouse spinal column and perform repetitive in vivo spinal cord imaging using two-photon microscopy is described. This method combines a spinal stabilization device and an anesthetic regimen to minimize respiratory-induced movements and produce raw imaging data that require no alignment or other post-processing.
Targeted Labeling of Neurons in a Specific Functional Micro-domain of the Neocortex by Combining Intrinsic Signal and Two-photon Imaging
Department of Neuroscience, Medical University of South Carolina
A method is described for labeling neurons with fluorescent dyes in predetermined functional micro-domains of the neocortex. First, intrinsic signal optical imaging is used to obtain a functional map. Then two-photon microscopy is used to label and image neurons within a micro-domain of the map.
Quantifying Glomerular Permeability of Fluorescent Macromolecules Using 2-Photon Microscopy in Munich Wistar Rats
Medicine/Nephrology, Indiana University School of Medicine
A technique utilizing high resolution intavital 2-photon microscopy to directly visualize and quantify gloemrular filtration in surface glomeruli. This method allows for direct determination of permeability characteristics of macromolecules in both normal and diseased states.
Imaging Effector Memory T cells in the Ear After Induction of Adoptive DTH
1Department of Physiology and Biophysics, University of California, Irvine (UCI), 2Department of Neurobiology and Behavior, University of California, Irvine (UCI)
Here we demonstrate a method for inducing and recording the progress of a delayed type-hypersensitivity (DTH) reaction in the rat ear. This is followed by a demonstration of the preparation of rat ear tissue for two-photon imaging of the effector / memory T cell response.
A Polished and Reinforced Thinned-skull Window for Long-term Imaging of the Mouse Brain
1Department of Physics, University of California, San Diego, 2Department of Engineering Science and Mechanics, Pennsylvania State University, 3Department of Neurosurgery, Pennsylvania State University, 4Section of Neurobiology, University of California, San Diego
We present a method to form an imaging window in the mouse skull that spans millimeters and is stable for months without inflammation of the brain. This method is well suited for longitudinal studies of blood flow, cellular dynamics, and cell/vascular structure using two-photon microscopy.
Calcium Imaging of Odor-evoked Responses in the Drosophila Antennal Lobe
1Center for Integrative Genomics, University of Lausanne, 2Department of Biology, University of Konstanz
We describe an established technique to measure and analyze odor-evoked calcium responses in the antennal lobe of living Drosophila melanogaster.
Ex vivo Imaging of T Cells in Murine Lymph Node Slices with Widefield and Confocal Microscopes
1Institut Cochin, Université Paris Descartes, CNRS (UMR 8104), 2Inserm, U1016, Paris, France
This protocol describes a method to image fluorescent T cells introduced into lymph node slices. The technique permits real-time analyses of T cell migration with traditional widefield fluorescence or confocal microscopes.
Cryosectioning Yeast Communities for Examining Fluorescence Patterns
Division of Basic Sciences, Fred Hutchinson Cancer Research Center
We present a protocol for freezing and cryosectioning yeast communities to observe internal patterns of fluorescent cells. The method relies on methanol-fixing and OCT-embedding to preserve the spatial distribution of cells without inactivating fluorescent proteins within a community.
Live Imaging of Dorsal Root Axons after Rhizotomy
1Temple University, Shriners Hospitals Pediatric Research Center and Department of Anatomy and Cell Biology, 2Medical Research Service, Department of Veterans Affairs Hospital, 3Department of Neurobiology and Anatomy, Drexel University College of Medicine, 4Shriners Hospitals Pediatric Research Center and Department of Anatomy and Cell Biology, Temple University School of Medicine
An in vivo imaging protocol to monitor primary sensory axons following dorsal root crush is described. The procedures utilize wide-field fluorescence microscopy and thy1-YFP transgenic mice, and permit repeated imaging of axon regeneration over 4 cm in the PNS and axon interactions with the interface of the CNS.
Electrophysiological Characterization of GFP-Expressing Cell Populations in the Intact Retina
Department of Neurobiology, University of Oldenburg
This article depicts the recording of individual cells from fluorescently tagged neuronal populations in the intact mouse retina. By using two-photon infrared excitation transgenetically labeled cells were targeted for patch-clamp recording to study their light responses, receptive field properties, and morphology.
BioMEMS: Forging New Collaborations Between Biologists and Engineers
Department of Biomedical Engineering, University of California, Irvine (UCI)
Direct Observation of Phagocytosis and NET-formation by Neutrophils in Infected Lungs using 2-photon Microscopy
1Institute for Molecular and Clinical Immunology, Otto-von-Guericke University Magdeburg, 2Department of Immunoregulation, Helmholtz Center for Infection Research
We show, how to use 2-photon microscopy for the observation of the dynamics of neutrophil granulocytes in infected lungs while they phagocytose pathogens or produce neutrophil extracellular traps (NETs).
Synthesis and Calibration of Phosphorescent Nanoprobes for Oxygen Imaging in Biological Systems
Department of Biochemistry and Biophysics, University of Pennsylvania
We present principles of oxygen measurements by phosphorescence quenching and review design of porphyrin-based dendritic nanosensors for oxygen imaging in biological systems.
In situ Imaging of the Mouse Thymus Using 2-Photon Microscopy
Department of Molecular and Cell Biology, University of California, Berkeley
We present step-by-step instructions for the generation of neonatal chimeras as well as the dissection and preparation of the thymus for ex vivo imaging by 2-Photon Microscopy.
Dendra2 Photoswitching through the Mammary Imaging Window
1Department of Anatomy and Structural Biology, Albert Einstein College of Medicine - Yeshiva University, 2Gruss Lipper Biophotonics Center, Albert Einstein College of Medicine - Yeshiva University, 3Hubrecht Institute-KNAW and University Medical Center Utrecht
Intravital photoswitching and tracking of Dendra2-labeled tumor cells through the Mammary Imaging Window is a technique which allows us to image the metastatic behavior of tumor cells in chosen tumor microenvironments over a timescale of days.
The Analysis of Purkinje Cell Dendritic Morphology in Organotypic Slice Cultures
Anatomical Institute, Department of Biomedicine, University of Basel
We present a protocol that permits to view and to quantitatively asses the morphology of the dendritic tree of individual Purkinje cells grown in organotypic cerebellar slice cultures. This protocol is intended to promote studies on the mechanisms of Purkinje cell dendritic development.
Intravital Microscopy of the Inguinal Lymph Node
1Interdisciplinary Science, University of Northern British Columbia, 2Northern Medical Program, University of Northern British Columbia
A technique for performing intravital microscopy of the inguinal lymph node (LN) is outlined. Such technique allows for real-time, in vivo study of the lymph node microvasculature and structure both during homeostasis and infection. This technique can be adapted to cell trafficking studies and to other lymph node sites.
In vivo Quantification of G Protein Coupled Receptor Interactions using Spectrally Resolved Two-photon Microscopy
1Department of Physics, University of Wisconsin - Milwaukee, 2Department of Biological Sciences, University of Wisconsin - Milwaukee
By employing a spectrally resolved two-photon microscopy imaging system, pixel-level maps of Förster Resonance Energy Transfer (FRET) efficiencies are obtained for cells expressing membrane receptors hypothesized to form homo-oligomeric complexes. From the FRET efficiency maps, we are able to estimate stoichiometric information about the oligomer complex under study.
A Thin-skull Window Technique for Chronic Two-photon In vivo Imaging of Murine Microglia in Models of Neuroinflammation
1Center for Neural Development and Disease, Department of Neurology, Child Neurology Division, University of Rochester, 2Department of Neurobiology and Anatomy, University of Rochester
We describe a method for repeatedly visualizing murine microglia and circulating monocytes in vivo over hours, days or weeks using transcranial two-photon microscopy. We demonstrate how to prepare a thinned-skull window that allows intermittent observation of quiescent microglia that can be activated by adjacent stereotactic injection of the HIV-1 regulatory protein Tat.
DNA Transfection of Mammalian Skeletal Muscles using In Vivo Electroporation
Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles
We describe detailed procedures for the efficient transfection of plasmid DNA into the fibers of foot muscles of live mice using electroporation and the subsequent visualization of protein expression using fluorescence microscopy.
Preparation of Living Isolated Vertebrate Photoreceptor Cells for Fluorescence Imaging
Storm Eye Institute, Medical University of South Carolina
A method is described for the preparation of single living photoreceptor cells from different vertebrate species for fluorescence imaging. The method can be used to image the fluorescence of endogenous fluorophores, such as NADH or vitamin A, or that of exogenously added fluorescent dyes sensitive to Ca2+ or other factors.
Intravital Microscopy of the Spleen: Quantitative Analysis of Parasite Mobility and Blood Flow
1Department of poverty related diseases, Barcelona Centre for International Health Research, 2Confocal Microscopy Unit, University of Barcelona- Scientific and Technological Centers, 3Institució Catalana de Recerca i Estudis Avançats (ICREA)
We show the method for performing intravital microscopy of the spleen using GFP transgenic malaria parasites and the quantification of parasite mobility and blood flow within this organ.
Functional Calcium Imaging in Developing Cortical Networks
Department of Integrative Neurophysiology, VU University, Amsterdam
Spontaneous activity of developing neuronal networks can be measured using AM-ester forms of calcium-sensitive indicator dyes. Changes in intracellular calcium, indicating neuronal activation, are detected as transient changes in indicator fluorescence with one- or two-photon imaging. This protocol can be adapted for a range of developmentally-dependent neuronal networks in vitro.
Intravital Imaging of the Mouse Popliteal Lymph Node
1Department of Pediatrics, Case Western Reserve University, 2Department of Pediatrics, Pathology and Biomedical Engineering, Case Western Reserve University
Recent advances in 2-photon microscopy have enabled real-time in situ imaging of live tissues in animal models, thereby enhancing our ability to investigate cellular behavior in both physiologic and pathologic conditions. Here, we outline the preparations required to perform intravital imaging of the mouse popliteal lymph node.
Time-lapse Microscopy of Early Embryogenesis in Caenorhabditis elegans
1Department of Biological Sciences, University of Alabama in Huntsville, 2NIDDK-National Institutes of Health
This article describes a technique for the visualization of the early events of embryogenesis in the nematode Caenorhabditis elegans.
Lineage Labeling of Zebrafish Cells with Laser Uncagable Fluorescein Dextran
1Department of Biological Sciences, Vanderbilt University, 2Department of Chemical and Systems Biology, Stanford University
This protocol delineates a way to label and trace the fate of small groups of cells zebrafish embryos using UV-uncaging of caged fluorescein, followed by whole mount immunolabeling to amplify the signal from the uncaged fluorescein.
Intravital Imaging of the Mouse Thymus using 2-Photon Microscopy
Laboratory of Immune Regulation, Instituto Gulbenkian de Ciência
We have developed novel laboratory tools and protocols for intravital imaging acquisition of the thymus. Our technique should help in the identification of “niches” within the thymus where T cell development occurs.
Measuring Diffusion Coefficients via Two-photon Fluorescence Recovery After Photobleaching
1Department of Physics and Astronomy, University of Rochester, 2Department of Biomedical Engineering, University of Rochester
In this article we will describe the procedure for measuring diffusion coefficients using multi-photon fluorescence recovery after photobleaching. We will begin by aligning the laser along the optical path to the sample and determining the proper experimental parameters, then continue generating and finally fitting fluorescence recovery curves.
Cerebral Blood Oxygenation Measurement Based on Oxygen-dependent Quenching of Phosphorescence
1Optics Division, Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, 2Department of Biochemistry and Biophysics, University of Pennsylvania, 3Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital and Harvard Medical School, 4Departments of Neurosciences and Radiology, University of California
We present an experimental procedure for measuring the partial pressure of oxygen (pO2) in cerebral vasculature based on oxygen-dependent quenching of phosphorescence. Animal preparation and imaging procedures were outlined for both large field of view CCD-based imaging of pO2 in rats and 2-photon excitation based imaging of pO2 in mice.
Preparation of Gene Gun Bullets and Biolistic Transfection of Neurons in Slice Culture
Center for Neuroscience, University of California, Davis
We describe a method for preparing DNA coated gold bullets and demonstrate the use of such bullets to biolistically transfect neurons in cultured hippocampal slices.
Imaging Glioma Initiation In Vivo Through a Polished and Reinforced Thin-skull Cranial Window
By combining a polished and reinforced thin-skull (PoRTS) cranial window and glioblastoma (GBM) cell injection, we can observe glioma initiation and growth from injected GBM cells in the brain of a live mouse longitudinally.
Optical Recording of Suprathreshold Neural Activity with Single-cell and Single-spike Resolution
Section of Neurobiology, Center for Learning and Memory, The University of Texas at Austin
Understanding the function of the vertebrate central nervous system requires recordings from many neurons because cortical function arises on the level of populations of neurons. Here we describe an optical method to record suprathreshold neural activity with single-cell and single-spike resolution, dithered random-access scanning. This method records somatic fluorescence calcium signals from up to 100 neurons with high temporal resolution. A maximum-likelihood algorithm deconvolves the underlying suprathreshold neural activity from the somatic fluorescence calcium signals. This method reliably detects spikes with high detection efficiency and a low rate of false positives and can be used to study neural populations in vitro and in vivo.
Multicolor Time-lapse Imaging of Transgenic Zebrafish: Visualizing Retinal Stem Cells Activated by Targeted Neuronal Cell Ablation
Department of Cellular Biology and Anatomy, Medical College of Georgia
In this video, techniques for multicolor confocal time-lapse imaging and targeted cell ablation are provided. Time-lapse imaging is used to monitor the behavior of multiple cell types of interest in vivo. Targeted cell ablation facilitates the study neural circuit function and cell-specific neuronal regeneration paradigms.
Differential Imaging of Biological Structures with Doubly-resonant Coherent Anti-stokes Raman Scattering (CARS)
1Center for Biophotonics, University of California, Davis, 2Department of Internal Medicine, University of California, Davis
A combination of three single wavelength short-pulsed lasers is used to generate coherent anti-Stokes Raman scattering (CARS) and doubly-resonant CARS (DR-CARS). The difference between these signals provides enhanced sensitivity for otherwise difficult to detect coherent Raman signals, enabling imaging of weak Raman scatterers.
Two-photon axotomy and time-lapse confocal imaging in live zebrafish embryos
1Department of Molecular Cell and Developmental Biology, University of California, Los Angeles, 2Departments of Neurology and Neurobiology, University of California, Los Angeles
Here we describe a method for mounting zebrafish embryos for long-term imaging, two-photon imaging and tissue-damage techniques, and time-lapse confocal imaging.
A Rapid Approach to High-Resolution Fluorescence Imaging in Semi-Thick Brain Slices
1Department of Molecular & Human Genetics, Baylor College of Medicine (BCM), 2Precisionary Instruments Inc., 3Departments of Molecular & Human Genetics and Neuroscience, Baylor College of Medicine (BCM), 4Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital
Here we describe a rapid and simple method to image fluorescently labeled cells in semi-thick brain slices. By fixing, slicing, and optically clearing brain tissue we describe how standard epifluorescent or confocal imaging can be used to visualize individual cells and neuronal networks within intact nervous tissue.
Multimodal Imaging of Stem Cell Implantation in the Central Nervous System of Mice
1Laboratory of Experimental Hematology, University of Antwerp, 2Bio Imaging Lab, University of Antwerp
This article describes an optimized sequence of events for multimodal imaging of cellular grafts in rodent brain using: (i) in vivo bioluminescence and magnetic resonance imaging, and (ii) post mortem histological analysis. Combining these imaging modalities on a single animal allows cellular graft evaluation with high resolution, sensitivity and specificity.
Single Cell Fate Mapping in Zebrafish
1Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, 2Division of Hematology/Oncology, Cincinnati Children's Hospital Medical Center
A method is described to photoactivate single cells containing a caged fluorescent protein using two-photon absorption from a Ti:Sapphire femtosecond laser oscillator. To fate map the photoactivated cell, immunohistochemistry is used. This technique can be applied to any cell type.
Mesoscopic Fluorescence Tomography for In-vivo Imaging of Developing Drosophila
1Center for Systems Biology, Massachusetts General Hospital, 2Institute for Biological and Medical Imaging (IBMI), Technical University of Munich and Helmholtz Center Munich, 3Department of Genetics, Harvard Medical School and Howard Hughes Medical Institute
Mesoscopic fluorescence tomography operates beyond the penetration limits of tissue-sectioning fluorescence microscopy. The technique is based on multi-projection illumination and a photon transport description. We demonstrate in-vivo whole-body 3D visualization of the morphogenesis of GFP-expressing wing imaginal discs in Drosophila melanogaster.
