JoVE Neuroscience
Optical Imaging of Neurons in the Crab Stomatogastric Ganglion with Voltage-sensitive Dyes
1Institute of Neurobiology, Ulm University, 2School of Computing Science & Institute of Neuroscience, Newcastle University
Here we present the methodology for fast and high resolution fluorescent voltage-sensitive dye imaging of detailed activity of neurons in the crab stomatogastric ganglion.
JoVE Neuroscience
Voltage-sensitive Dye Recording from Axons, Dendrites and Dendritic Spines of Individual Neurons in Brain Slices
Department of Cellular and Molecular Physiology, Yale University School of Medicine
An imaging technique for monitoring of membrane potential changes with sub-micrometer spatial and sub-millisecond temporal resolution is described. The technique, based on laser excitation of voltage-sensitive dyes, allows measurements of signals in axons and axon collaterals, terminal dendritic branches, and individual dendritic spines.
JoVE Neuroscience
Investigations on Alterations of Hippocampal Circuit Function Following Mild Traumatic Brain Injury
1Division of Neurology, Children's Hospital of Philadelphia, 2Neuroscience Graduate Group, Perelman School of Medicine at the University of Pennsylvania, 3Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania
A multi-faceted approach to investigating functional changes to hippocampal circuitry is explained. Electrophysiological techniques are described along with the injury protocol, behavioral testing and regional dissection method. The combination of these techniques can be applied in similar fashion for other brain regions and scientific questions.
JoVE Bioengineering
Multiparametric Optical Mapping of the Langendorff-perfused Rabbit Heart
Department of Biomedical Engineering, Washington University in St. Louis
This article describes the basic procedures for conducting optical mapping experiments in the Langendorff-perfused rabbit heart using the panoramic imaging system, and the dual (voltage and calcium) imaging modality.
JoVE Bioengineering
Optical Mapping of Action Potentials and Calcium Transients in the Mouse Heart
Department of Biomedical Engineering, Washington University in St. Louis
This paper details the dissection procedure, instrumental setup, and experimental conditions during optical mapping of transmembrane potential (Vm) and intracellular calcium transient (CaT) in intact isolated Langendorff perfused mouse hearts.
JoVE Neuroscience
Retrograde Loading of Nerves, Tracts, and Spinal Roots with Fluorescent Dyes
We describe a simple and low cost technique for introducing high concentration of fluorescent and calcium-sensitive dyes into neurons or any neuronal tract using a polyethylene suction pipette.
JoVE General
Optical Recording of Electrical Activity in Guinea-pig Enteric Networks using Voltage-sensitive Dyes
1Department of Neuroscience, University of Pennsylvania-School of Medicine, 2Department of Physiology, University of Pennsylvania-School of Medicine
This protocol illustrates how voltage-sensitive dyes enable optical recording of electrical activity from intact neural networks such as the plexuses of the guinea-pig enteric nervous system, with an adjustable resolution that ranges from single-cells to multi-ganglionic circuitry.
JoVE General
Optical Mapping of Langendorff-perfused Rat Hearts
1Department of Anesthesiology, Perioperative and Pain Medicine, Children's Hospital Boston and Harvard Medical School, 2Departments of Cardiac Surgery, Children's Hospital Boston and Harvard Medical School
This article describes a high temporal and spatial resolution technique to optically image action potential movement on the surface of Langendorff-perfused rat hearts using a potentiometric dye (di-8-ANEPPS).
JoVE Neuroscience
Mapping Inhibitory Neuronal Circuits by Laser Scanning Photostimulation
1Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, 2Department of Biomedical Engineering, School of Engineering, University of California, Irvine
This paper introduces an approach of combining laser scanning photostimulation with whole cell recordings in transgenic mice expressing GFP in limited inhibitory neuron populations. The technique allows for extensive mapping and quantitative analysis of local synaptic circuits of specific inhibitory cortical neurons.
JoVE General
Measuring the Induced Membrane Voltage with Di-8-ANEPPS
Department of Biomedical Engineering, Faculty of Electrical Engineering, University of Ljubljana
External electric field induces a voltage on the membrane of a cell, termed the induced membrane voltage (ΔΦ). By using the potentiometric dye di-8-ANEPPS, it is possible to measure the ΔΦ noninvasively. This video shows the protocol for measuring ΔΦ using di-8-ANEPPS.
JoVE Neuroscience
Extracellularly Identifying Motor Neurons for a Muscle Motor Pool in Aplysia californica
1Department of Biology, Case Western Reserve University, 2Department of Neurosciences, Case Western Reserve University, 3Department of Biomedical Engineering, Case Western Reserve University
In animals with large identified neurons (e.g. mollusks), analysis of motor pools is done using intracellular techniques1,2,3,4. Recently, we developed a technique to extracellularly stimulate and record individual neurons in Aplysia californica5. We now describe a protocol for using this technique to uniquely identify and characterize motor neurons within a motor pool.
JoVE Neuroscience
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.
JoVE Neuroscience
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.
JoVE Neuroscience
Vibrodissociation of Neurons from Rodent Brain Slices to Study Synaptic Transmission and Image Presynaptic Terminals
1Section on Synaptic Pharmacology/Laboratory for Integrative Neuroscience, National Institutes of Health/National Institute on Alcohol Abuse and Alcoholism, 2Department of Electronics Engineering, Ewha Womans University, 3Section on Transmitter Signaling/Laboratory of Molecular Physiology, National Institutes of Health/National Institute on Alcohol Abuse and Alcoholism
This report demonstrates a technique for mechanical isolation of individual viable neurons retaining attached presynaptic boutons. Vibrodissociated neurons have the advantages of rapid production, excellent pharmacological control and improved space-clamp without influence from neighboring cells. This method can be used for imaging of synaptic elements and patch-clamp recording.
JoVE General
Direct Imaging of ER Calcium with Targeted-Esterase Induced Dye Loading (TED)
1Institute for Clinical Neurobiology, University of Wuerzburg, 2Department of Synapses - Circuits - Plasticity, Max Planck Institute of Neurobiology, Martinsried, 3Walter Brendel Centre of Experimental Medicine, Ludwig-Maximilians University of Munich
Targeted-esterase induced dye loading (TED) supports the analysis of intracellular calcium store dynamics by fluorescence imaging. The method bases on targeting of a recombinant Carboxylesterase to the endoplasmic reticulum (ER), where it improves the local unmasking of synthetic low-affinity Ca2+ indicator dyes in the ER lumen.
JoVE General
Imaging Exocytosis in Retinal Bipolar Cells with TIRF Microscopy
Cellular and Molecular Physiology, Yale University School of Medicine
In this video, we demonstrate how to label and visualize single synaptic vesicle exocytosis and trafficking in goldfish retinal bipolar cells using total internal reflectance fluorescence (TIRF) microscopy.
JoVE Neuroscience
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.
JoVE General
Fast and Sensitive Colloidal Coomassie G-250 Staining for Proteins in Polyacrylamide Gels
Biological Medical Research Center (BMFZ), University Duesseldorf
This video shall popularize a colloidal Coomassie G-250 staining protocol according to Kang et al. for the detection of average 4 ng protein in gels. The staining is completed within 2 hours and without any effort. We routinely use Kang's protocol for analytical purposes in gel-based proteomics.
JoVE Neuroscience
Patch-clamp Capacitance Measurements and Ca2+ Imaging at Single Nerve Terminals in Retinal Slices
The Vollum Institute, Oregon Health and Science University
Here we describe a protocol for the preparation of agar-embedded retinal slices that are suitable for electrophysiology and Ca2+ imaging. This method allows one to study ribbon-type synapses in retinal microcircuits using direct patch-clamp recordings of single presynaptic nerve terminals.
JoVE Neuroscience
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.
JoVE Bioengineering
High efficiency, Site-specific Transfection of Adherent Cells with siRNA Using Microelectrode Arrays (MEA)
School of Biological and Health Systems Engineering, Arizona State University
The article details the protocol for site-specific transfection of scrambled sequence of siRNA in an adherent mammalian cell culture using a microelectrode array (MEA).
JoVE Bioengineering
Video-rate Scanning Confocal Microscopy and Microendoscopy
1Program in Biophysics, Harvard University, 2Division of Health Sciences and Technology, Harvard-MIT, 3Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School
The complete construction of a custom, real-time confocal scanning imaging system is described. This system, which can be readily used for video-rate microscopy and microendoscopy, allows for an array of imaging geometries and applications not accessible using standard commercial confocal systems, at a fraction of the cost.
JoVE Immunology and Infection
A TIRF Microscopy Technique for Real-time, Simultaneous Imaging of the TCR and its Associated Signaling Proteins
The compartmentalization of proteins either within the plasma membrane or into intracellular locations is one regulatory mechanism that can greatly influence signaling outcomes; hence, to understand signaling it is important to study the spatial and temporal behavior of the proteins involved. We describe here a TIRF microscopy based system to study signal transduction in T cells, but is broadly applicable.
JoVE Immunology and Infection
Examination of the Telomere G-overhang Structure in Trypanosoma brucei
Biological, Geo. & Env. Sciences, Cleveland State University
Telomeres are essential for chromosome stability and the telomere G-overhang structure is essential for telomerase-mediated telomere maintenance. We have recently adopted two methods for detecting the telomere G-overhang structure in Trypanosoma brucei, which are native in-gel hybridization and ligation-mediated primer extension, which will be described.
JoVE Neuroscience
Gene Transfer to the Developing Mouse Inner Ear by In Vivo Electroporation
Oregon Hearing Research Center, Oregon Health & Science University
The mouse inner ear is a placode-derived sensory organ whose developmental program is elaborated during gestation. We define an in utero gene transfer technique consisting of three steps: mouse ventral laparotomy, transuterine microinjection, and in vivo electroporation. We use digital video microscopy to demonstrate the critical experimental embryological techniques.
JoVE Clinical and Translational Medicine
High-Resolution Endocardial and Epicardial Optical Mapping in a Sheep Model of Stretch-Induced Atrial Fibrillation
Center for Arrhythmia Research. Internal Medicine, University of Michigan
This report provides a detailed description of the methodology and results of simultaneous endocardial and epicardial optical mapping of electrical excitation in the intact left atrium of a Langendorff-perfused sheep heart during stretch-induced atrial fibrillation.
JoVE Neuroscience
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.
JoVE Neuroscience
Preparation of Parasagittal Slices for the Investigation of Dorsal-ventral Organization of the Rodent Medial Entorhinal Cortex
1Neuroinformatics DTC, University of Edinburgh, 2Centre for Integrative Physiology, University of Edinburgh
We describe procedures for preparation and electrophysiological recording from brain slices that maintain the dorsal-ventral axis of the medial entorhinal cortex (MEC). Because neural encoding of location follows a dorsal-ventral organization within the MEC, these procedures facilitate investigation of cellular mechanisms important for navigation and memory.
JoVE General
Denaturing Urea Polyacrylamide Gel Electrophoresis (Urea PAGE)
1School of Biological Sciences, Nanyang Technological University, Singapore - NTU, 2Singapore-MIT Alliance for Reserach and Technology (SMART)
Denaturing urea polyacrylamide gel electrophoresis is used to separate single-stranded DNA or RNA up to a limit of 500 nucleotides. Urea in combination with heat denatures samples and unstructured single strands migrate within the gel matrix according to their molecular weight.
JoVE General
Linearization of the Bradford Protein Assay
Department of Biochemistry, Tel Aviv University
The accuracy and sensitivity of protein determination by the rapid and convenient Bradford assay is compromised by intrinsic nonlinearity. We show a simple linearization procedure that greatly increases the accuracy, improves the sensitivity of the assay about 10-fold, and significantly reduces interference by detergents.
JoVE General
Rapid Homogeneous Detection of Biological Assays Using Magnetic Modulation Biosensing System
1Department of Physical Electronics, Faculty of Engineering, Tel Aviv University, 2Department of Biomedical Engineering, Washington University in St. Louis, 3Department of Biological Sciences, University of Illinois, 4Department of Cell Research and Immunology, Tel Aviv University
Magnetic modulation biosensing system is utilized to rapidly, sensitively and simply detect biological assays, such as DNA molecules and proteins.
JoVE General
Primary Neuronal Cultures from the Brains of Late Stage Drosophila Pupae
This video demonstrates the preparation of primary neuronal cultures from the brains of late stage Drosophila pupae. Views of live cultures show neurite outgrowth and imaging of calcium levels using Fura-2.
JoVE Immunology and Infection
A Simple Protocol for Platelet-mediated Clumping of Plasmodium falciparum-infected Erythrocytes in a Resource Poor Setting
1Malawi-Liverpool-Wellcome Trust Clinical Research Programme, 2Liverpool School of Tropical Medicine, 3Department of Microbiology, Division of Medical Parasitology, New York University School of Medicine
This method investigates the platelet-mediated clumping phenotype of Plasmodium falciparum-infected erythrocytes (pRBC) in clinical isolates. This is performed by isolating and co-incubating platelet-rich plasma and a suspension of pRBC.
JoVE Neuroscience
Preparation of Drosophila Central Neurons for in situ Patch Clamping
School of Life Sciences, Arizona State University
In situ patch clamp recordings are used for electrophysiological characterization of neurons in intact circuitry. In the Drosophila genetic model patch clamping is difficult because the CNS is small and surrounded by a robust sheath. This article describes the procedure to remove the sheath and clean neurons for subsequent patch clamp recordings.
JoVE General
Single Cell Electroporation in vivo within the Intact Developing Brain
1Brain Research Centre, University of British Columbia - UBC, 2Department of Cellular and Physiological Sciences, University of British Columbia - UBC
Single-cell electroporation (SCE) is a specialized technique allowing delivery of DNA or other macromolecules into individual cells within intact tissue, including in vivo preparations. Here we detail the procedure for SCE of a fluorescent dye or plasmid DNA into neurons within the intact brain of the Xenopus laevis tadpole.
JoVE General
Measuring Cation Transport by Na,K- and H,K-ATPase in Xenopus Oocytes by Atomic Absorption Spectrophotometry: An Alternative to Radioisotope Assays
1Institute of Chemistry, Technical University of Berlin, 2The Vollum Institute, Oregon Health & Science University
We describe a method to quantify the activity of K+-countertransporting P-type ATPases by heterologous expression of the enzymes in Xenopus oocytes and measuring Rb+ or Li+ uptake into individual cells by atomic absorption spectrophotometry. The method is a sensitive and safe alternative to radioisotope flux experiments facilitating complex kinetic studies.
JoVE General
Patch Clamp and Perfusion Techniques for Studying Ion Channels Expressed in Xenopus oocytes
1Department of Energy, Environmental & Chemical Engineering, Washington University in St. Louis, 2Department of Biomedical Engineering, Washington University in St. Louis, 3Department of Biomedical Engineering and Cardiac Bioelectricity and Arrhythmia Center, Washington University in St. Louis
Ionic current of BK channels is recorded using patch clamp techniques. BK channels are expressed in Xenopus oocytes by injecting messenger RNA. The intracellular solution during patch clamp recordings is controlled by a perfusion system.
JoVE Bioengineering
Cell-based Calcium Assay for Medium to High Throughput Screening of TRP Channel Functions using FlexStation 3
This video provides a detailed protocol for studying the pharmacological profile of human TRPA1 channels using FlexStation 3. The protocol covers details of cell preparation, dye loading and operation of the microplate reader, FlexStation 3.
JoVE Neuroscience
Preparation of Acute Subventricular Zone Slices for Calcium Imaging
Department of Neurosurgery and Cellular & Molecular Physiology, Yale University School of Medicine
A method to load subventricular zone (SVZ) cells with calcium indicator dyes for recording calcium activity is described. The postnatal SVZ contains tightly packed cells including neural progenitor cells and neuroblasts. Rather than using bath loading we injected the dye by pressure inside the tissue allowing better dye diffusion.
JoVE Immunology and Infection
Live-cell Video Microscopy of Fungal Pathogen Phagocytosis
1Division of Applied Medicine, University of Aberdeen, 2Aberdeen Fungal Group, University of Aberdeen
We describe methods for live-cell video microscopy of Candida albicans phagocytosis by macrophages. These methods enable stage-specific analysis of macrophage migration, recognition, engulfment and phagosome maturation and reveal novel aspects of phagocytosis.
JoVE General
Procedure for Fabricating Biofunctional Nanofibers
1Department of Chemistry, Clark Atlanta University, 2Department of Physics, Clark Atlanta University, 3Department of Chemistry and Chemical Biology, Cornell University
An efficient approach for preparing nanofibers decorated with functional groups capable of specifically interacting with proteins is described. The approach first requires the preparation of a polymer functionalized with the appropriate functional group. The functional polymer is fabricated into nanofibers by electrospinning. The effectiveness of the binding of the nanofibers with a protein is studied by confocal microscopy.
JoVE Neuroscience
How to Build a Laser Speckle Contrast Imaging (LSCI) System to Monitor Blood Flow
Biomedical Engineering Department, University of Texas at Austin
This video demonstrates how to build a Laser Speckle Contrast Imaging (LSCI) system that can easily be used to monitor blood flow.
JoVE Bioengineering
Air Filter Devices Including Nonwoven Meshes of Electrospun Recombinant Spider Silk Proteins
Biomaterials Research Group, University of Bayreuth
Spider silk fibers display extraordinary mechanical properties. Engineered Araneus diadematus Fibroin 4 (eADF4) can be processed into nonwoven meshes using electrospinning. Here, the eADF4 nonwoven meshes are used to improve the performance of air filtering devices.
JoVE General
A Fluorescent Screening Assay for Identifying Modulators of GIRK Channels
A real-time screening procedure for identifying drugs that interact with G protein-gated inward rectifier K+ (GIRK) channels is described. The assay utilizes membrane potential-sensitive fluorescent dyes to measure GIRK channel activity. This technique is adaptable for use on a number of cell lines.
JoVE General
Agarose Gel Electrophoresis for the Separation of DNA Fragments
Department of Molecular, Cell, and Developmental Biology, University of California Los Angeles
A basic protocol for the separation of DNA fragments using agarose gel electrophoresis is described.
JoVE General
Techniques for Imaging Ca2+ Signaling in Human Sperm
1School of Biosciences, University of Birmingham, 2School of Medicine, University of Birmingham, 3Centre for Human Reproductive Science, Birmingham Women’s Hospital
Stimulus-evoked [Ca2+]i signals of individual human sperm are assessed. Motile cells are loaded with Ca2+-sensitive fluorescent dye (AM-ester method) and immobilised in a perfusable chamber. Cells are imaged by time-lapse fluorescence microscopy and stimulated via the perfusing medium. Responses of single cells (or regions) are analysed offline using Excel.
JoVE General
Visualization of Vascular Ca2+ Signaling Triggered by Paracrine Derived ROS
1Department of Biochemistry, Temple University, 2Department of Anesthesiology and Pain Medicine, University of Washington
An efficient method to gain insights into visualizing the paracrine-derived ROS induction of endothelial Ca2+ signaling is described. This method takes advantage of measuring paracrine derived ROS triggered Ca2+ mobilization in vascular endothelial cells in a co-culture model.
JoVE General
Electrophysiological Recording in the Drosophila Embryo
1Department of Biological Sciences, University of Illinois, 2Department of Biological Sciences, Vanderbilt University
Electrophysiological recordings from Drosophila embryos allow analyses of developing muscle and neuron electrical properties, as well as characterization of functional synaptogenesis at the glutamatergic neuromuscular junction and central cholinergic and GABAergic synapses.
JoVE General
Recapitulation of an Ion Channel IV Curve Using Frequency Components
Bioengineering, University of Utah
There are technical obstacles to measuring current flux through multiple ion channels simultaneously, and later discerning what portion of the transmembrane current is due to each channel type. To address this need, this method presents a way to generate the IV curve of individual channel types using specific frequency components.
JoVE General
Title Cell Encapsulation by Droplets
1Bio-Acoustic-MEMS Laboratory in Medicine (BAMM), HST-Center for Bioengineering, Brigham and Women's, Harvard Medical School, 2Bio-Acoustic-MEMS Laboratory in Medicine (BAMM), HST-Center for Bioengineering, Brigham and Women's Hospital, 3Brigham and Women's Hospital, Harvard Medical School, 4Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology; Center for Biomedical Engineering, Department of Medicine, Brigham and Women's Hospital
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