Calcium Channels:
Voltage-dependent cell membrane glycoproteins selectively permeable to calcium ions. They are categorized as L-, T-, N-, P-, Q-, and R-types based on the activation and inactivation kinetics, ion specificity, and sensitivity to drugs and toxins. The L- and T-types are present throughout the cardiovascular and central nervous systems and the N-, P-, Q-, & R-types are located in neuronal tissue.
JoVE General
In vitro Labeling of Human Embryonic Stem Cells for Magnetic Resonance Imaging
Division of Cardiovascular Medicine, Stanford University
In this video, we are showing how to label human embryonic stem cells (hESC) with manganese chloride (MnCl2) which can enter cells via voltage-gated calcium channels when the cells are biologically active. Additionally, we show the use of MnCl2 as cellular MRI contrast agent to determine the in vitro viability of hESC.
JoVE General
Optimized Transfection Strategy for Expression and Electrophysiological Recording of Recombinant Voltage-Gated Ion Channels in HEK-293T Cells
Department of Biology, University of Waterloo
Reliable method for highly efficient in vitro expression and subsequent electrophysiological recording of recombinant voltage-gated ion channels in cultured human embryonic kidney cells (HEK-293T).
JoVE General
Intranuclear Microinjection of DNA into Dissociated Adult Mammalian Neurons
Direct intranuclear injection of cDNA is an effective transfection technique for post-mitotic cells. This method provides high levels of heterologous protein expression from single or multiple cDNA constructs and enables protein function to be studied in a physiologically relevant environment with a variety of single cell assays.
JoVE General
Fluorescence-based Measurement of Store-operated Calcium Entry in Live Cells: from Cultured Cancer Cell to Skeletal Muscle Fiber
1Department of Physiology and Biophysics, Confocal Microscopy and Cell Imaging Core, Robert Wood Johnson Medical School, 2Department of Physiology and Biophysics, Robert Wood Johnson Medical School, 3Muscle Biology Research Group-MUBIG Schools of Nursing & Medicine, University of Missouri-Kansas City
The extent of store-operated Ca2+ entry (SOCE) can be monitored using fluorescent Ca2+ indicators. Mn2+ quenching of such indicators assays SOCE in cultured cells and skeletal muscle fibers. A technique allowing spatial and temporal resolution of SOCE by confocal imaging of mechanically skinned muscle fibers is also described.
JoVE General
Primary Culture of Adult Rat Heart Myocytes
1Department of Physiology and Cellular Biophysics, Columbia University, 2Department of Pharmacology, Columbia University
In this paper, we described a typical way to isolate and culture adult rat heart myocytes. Collagenase and protease are used to digest and isolate single myocytes. Myocytes cultured follow this protocol meet most experiment requirements.
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 General
Visualizing the Live Drosophila Glial-neuromuscular Junction with Fluorescent Dyes
Department of Zoology, University of British Columbia - UBC
We described structural features of the Glia-neuromuscular synapses in a novel Inside-out tissue preparation of live fly larvae using fluorescent dyes with confocal microscopy. We labeled live neuron terminals with fluorescent primary antibodies to HRP, and also visualized the perisynaptic space with fluorescent Dextrans.
JoVE General
Whole-Cell Recording of Calcium Release-Activated Calcium (CRAC) Currents in Human T Lymphocytes
Department of Physiology and Membrance Biology, University of California, Davis
We provide a step-by-step protocol for whole-cell patch clamp recording of Calcium Release-Activated Calcium (CRAC) currents in peripheral blood mononuclear cell-derived human T lymphocytes.
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 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 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
Measuring Intracellular Ca2+ Changes in Human Sperm using Four Techniques: Conventional Fluorometry, Stopped Flow Fluorometry, Flow Cytometry and Single Cell Imaging
1Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología-Universidad Nacional Autónoma de México, 2Math and Sciences Department, Edison State College
Intracellular Ca2+ dynamics are very important in sperm physiology and Ca2+-sensitive fluorescent dyes constitute a versatile tool to study them. Population experiments (fluorometry and stopped flow fluorometry) and single cell experiments (flow cytometry and single cell imaging) are used to track spatio-temporal [Ca2+] changes in human sperm cells.
JoVE Clinical and Translational Medicine
In vitro Measurements of Tracheal Constriction Using Mice
Department of Physiology, UT Health Science Center, San Antonio
Transgenic mice have been extremely useful in ascribing physiological function to genes. As such, research in general, and functional studies of airway, in particular, have undergone a remarkable shift toward murine models. Here we provide protocols for in vitro trachea constriction studies to evaluate smooth muscle function in murine airway.
JoVE Neuroscience
Dissection, Culture, and Analysis of Xenopus laevis Embryonic Retinal Tissue
Department of Biology, College of William and Mary
Xenopus laevis provides an ideal model system for studying cell fate specification and physiological function of individual retinal cells in primary cell culture. Here we present a technique for dissecting retinal tissues and generating primary cell cultures that are imaged for calcium activity and analyzed by in situ hybridization.
JoVE Neuroscience
Preparation of Acute Hippocampal Slices from Rats and Transgenic Mice for the Study of Synaptic Alterations during Aging and Amyloid Pathology
1Graduate Center for Gerontology, University of Kentucky College of Public Health, 2Department of Molecular and Biomedical Pharmacology, University of Kentucky College of Medicine, 3Sanders-Brown Center on Aging, University of Kentucky College of Medicine
This article outlines procedures for preparing hippocampal slices from rats and transgenic mice for the study of synaptic alterations associated with brain aging and age-related neurodegenerative diseases, such as Alzheimer’s disease.
JoVE General
Exploring Arterial Smooth Muscle Kv7 Potassium Channel Function using Patch Clamp Electrophysiology and Pressure Myography
Department of Molecular Pharmacology & Therapeutics, Loyola University Chicago
Measurements of Kv7 (KCNQ) potassium channel activity in isolated arterial myocytes (using patch clamp electrophysiological techniques) in parallel with measurements of constrictor/dilator responses (using pressure myography) can reveal important information about the roles of Kv7 channels in vascular smooth muscle physiology and pharmacology.
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 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 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 Neuroscience
Quantifying Synapses: an Immunocytochemistry-based Assay to Quantify Synapse Number
1Department of Neurobiology, Duke University, 2Department of Cell Biology, Duke University
This protocol details how to quantify synapse number both in dissociated neuronal culture and in brain sections using immunocytochemistry. Using compartment-specific antibodies, we label presynaptic terminals as well as sites of postsynaptic specialization. We define synapses as points of colocalization between the signals generated by these markers.
JoVE Neuroscience
Simultaneous Whole-cell Recordings from Photoreceptors and Second-order Neurons in an Amphibian Retinal Slice Preparation
1Department of Ophthalmology and Visual Sciences, University of Nebraska Medical Center, 2Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center
We describe the preparation of thin retinal slices from aquatic tiger salamanders (Ambystoma tigrinum) and explain how we use these slices to study synaptic processing in the retina by obtaining dual whole-cell voltage clamp recordings from photoreceptors and second-order horizontal and bipolar cells.
JoVE Clinical and Translational Medicine
Spectral Karyotyping to Study Chromosome Abnormalities in Humans and Mice with Polycystic Kidney Disease
1Department of Pharmacology, University of Toledo, College of Pharmacy and Pharmaceutical Sciences, 2Department of Emergency and Intensive Care, ProMedica Sponsored Research
Spectral Karyotyping (SKY) is an advanced cytogenetics technique to identify genomic and chromosomal aberrations. This technique takes advantage of chromosome painting probes, which allow classification of all chromosomes. SKY can also identify complex chromosome aberrations and segregation defects in mice and humans with various diseases, including polycystic kidney disease.
JoVE Neuroscience
Video-oculography in Mice
1Department of Neuroscience, Erasmus MC, Rotterdam, The Netherlands, 2Department of Neuroscience, Royal Dutch Academy of Arts & Sciences (KNAW)
Video-oculography is a very quantitative method to investigate ocular motor performance as well as motor learning. Here, we describe how to measure video-oculography in mice. Applying this technique on normal, pharmacologically-treated or genetically modified mice is a powerful research tool to explore the underlying physiology of motor behaviors.
JoVE General
Ex Vivo Assessment of Contractility, Fatigability and Alternans in Isolated Skeletal Muscles
1Department of Physiology and Biophysics, UMDNJ-Robert Wood Johnson Medical School, 2Muscle Biology Research Group, University of Missouri-Kansas City, 3Pharmacology division, College of Pharmacy, DHLRI, Ohio State University
We describe a method to directly measure muscle force, muscle power, contractile kinetics and fatigability of isolated skeletal muscles in an in vitro system using field stimulation. Valuable information on Ca2+ handling properties and contractile machinery of the muscle can be obtained using different stimulating protocols.
JoVE Neuroscience
Dual Somatic Recordings from Gonadotropin-Releasing Hormone (GnRH) Neurons Identified by Green Fluorescent Protein (GFP) in Hypothalamic Slices
Department of Biology, University of Texas San Antonio - UTSA
Activity in neuronal systems often requires synchronous action potential discharges from neurons within a specific population. For example, pulses of gonadotropin-releasing hormone (GnRH) likely require coordinated activity between GnRH neurons. We present our methodological approach for reliably obtaining simultaneous electrophysiological recordings from the diffusely distributed GnRH neurons.
JoVE General
Methods for Patch Clamp Capacitance Recordings from the Calyx
National Institute of Neurological Disorders and Stroke, National Institute of Health
We demonstrate the basic techniques for presynaptic patch clamp recording at the calyx of Held, a mammalian central nervous system nerve terminal.
JoVE Neuroscience
In vivo Neuronal Calcium Imaging in C. elegans
1Department of Physiology and Biophysics, Boston University School of Medicine, 2Boston University Photonics Center
With its small transparent body, well-documented neuroanatomy and a host of amenable genetic techniques and reagents, C. elegans makes an ideal model organism for in vivo neuronal imaging using relatively simple, low-cost techniques. Here we describe single neuron imaging within intact adult animals using genetically encoded fluorescent calcium indicators.
JoVE Neuroscience
Paired Nanoinjection and Electrophysiology Assay to Screen for Bioactivity of Compounds using the Drosophila melanogaster Giant Fiber System
1Department of Biological Sciences, Florida Atlantic University, 2Department of Chemistry & Biochemistry, Florida Atlantic University
A rapid in vivo assay to test for neuromodulatory compounds using the Giant Fiber System (GFS) of Drosophila melanogaster is described. Nanoinjections in the head of the animal along with electrophysiological recordings of the GFS can reveal bioactivity of compounds on neurons or muscles.
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
Proteomics to Identify Proteins Interacting with P2X2 Ligand-Gated Cation Channels
1Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, 2Department of Anesthesiology, David Geffen School of Medicine, University of California, Los Angeles, 3Department of Anesthesiology, Medicine and Physiology, David Geffen School of Medicine, University of California, Los Angeles
We describe a simple protocol to identify brain proteins that bind to the full length C terminus of ATP-gated P2X2 receptors. The extension and systematic application of this approach to all P2X receptors is expected to lead to a better understanding of P2X receptor signaling.
JoVE Neuroscience
Dual Electrophysiological Recordings of Synaptically-evoked Astroglial and Neuronal Responses in Acute Hippocampal Slices
1Neuroglial Interactions in Cerebral Physiopathology, Center for Interdisciplinary Research in Biology, CNRS UMR 7241, INSERM U1050, Collège de France, 2Paris Diderot University
The preparation of acute brain slices from isolated hippocampi, as well as the simultaneous electrophysiological recordings of astrocytes and neurons in stratum radiatum during stimulation of schaffer collaterals is described. The pharmacological isolation of astroglial potassium and glutamate transporter currents is demonstrated.
JoVE General
Measuring Caenorhabditis elegans Life Span in 96 Well Microtiter Plates
1Department of Chemical Physiology, The Scripps Research Institute, 2Department of Molecular and Experimental Medicine, The Scripps Research Institute
In this protocol we present a method to measure Caenorhabditis elegans lifespan in 96 well microtiter plates.
JoVE General
Live Cell Calcium Imaging Combined with siRNA Mediated Gene Silencing Identifies Ca2+ Leak Channels in the ER Membrane and their Regulatory Mechanisms
1Medical Biochemistry and Molecular Biology, Saarland University, 2Experimental and Clinical Pharmacology and Toxicology, Saarland University
The endoplasmic reticulum plays a key role in protein biogenesis and in calcium homeostasis. We have established an experimental system that allows us to address the role of Ca2+ leak channels and to characterize their putative regulatory mechanisms. This system involves siRNA mediated gene silencing and live cell Ca2+ imaging.
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 Neuroscience
Monitoring Changes in the Intracellular Calcium Concentration and Synaptic Efficacy in the Mollusc Aplysia
1Fishberg Department of Neuroscience and Friedman Brain Institute, Mt. Sinai School of Medicine, 2Phase Five Communications Inc.
We demonstrate how changes in the intracellular free calcium concentration and synaptic efficacy can be simultaneously monitored in a ganglion preparation of Aplysia. We image intracellular calcium using a fluorescent dye, Calcium Orange, and induce and monitor synaptic transmission with sharp (intracellular) electrodes.
JoVE General
Measuring Fast Calcium Fluxes in Cardiomyocytes
1Department of Biological Sciences and Geology, Queensborough Community College, 2Department of Physiology & Biophysics, Stony Brook University
We present a method to isolate rapid (microsecond) calcium events from slower fluxes in living cells using laser scanning confocal microscopy. The method measures fluorescence intensity fluctuations of calcium indicators by recording line scans of several hundred pixels in a cell. Histogram analysis allows us to isolate the time scales of different calcium fluxes.
JoVE General
In vitro Differentiation of Mouse Embryonic Stem (mES) Cells Using the Hanging Drop Method
Division of Cardiovascular Medicine, Stanford University
This video demonstrates how to conduct in vitro differentiation of mouse embryonic stem cells to embryoid bodies using the hanging drop method.
JoVE Neuroscience
Implementing Dynamic Clamp with Synaptic and Artificial Conductances in Mouse Retinal Ganglion Cells
1Discipline of Biomedical Science, School of Medical Sciences, Sydney Medical School and Bosch Institute, University of Sydney, 2The MARCS Institute, University of Western Sydney, 3Discipline of Physiology, School of Medical Sciences, Sydney Medical School and Bosch Institute, University of Sydney
This video article illustrates the set-up, the procedures to patch cell bodies and how to implement dynamic clamp recordings from ganglion cells in whole-mount mouse retinae. This technique allows the investigation of the precise contribution of excitatory and inhibitory synaptic inputs, and their relative magnitude and timing to neuronal spiking.
JoVE Neuroscience
Imaging Pheromone Sensing in a Mouse Vomeronasal Acute Tissue Slice Preparation
1Department of Pharmacology and Toxicology, University of Lausanne, 2Department of Genetics and Evolution, University of Geneva
In mice, the ability to detect pheromones is principally mediated by the vomeronasal organ (VNO). Here, an acute tissue slice preparation of VNO for performing calcium imaging is described. This physiological approach allows observations of subpopulations and/or individual neurons in a living tissue and is convenient for receptor-ligand identification.
JoVE General
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.
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 General
Sexual Development and Ascospore Discharge in Fusarium graminearum
1Genetics Program, Michigan State University, 2Department of Plant Biology, Michigan State University, 3Human Biology Program, Michigan State University, 4Department of Plant Pathology, Michigan State University
Sexual crosses and isolation of recombinant progeny are important research tools for the filamentous fungus, Fusarium graminearum, The techniques necessary successfully carry out these processes are presented.
JoVE General
Isolation and Kv Channel Recordings in Murine Atrial and Ventricular Cardiomyocytes
1Experimental and Clinical Research Center (ECRC), Charité Medical Faculty and Max-Delbrück Center for Molecular Medicine (MDC), 2Medical Department, Division of Cardiology, Campus Virchow-Klinikum, Charité - Universitätsmedizin Berlin, 3Medical Department, Division of Cardiology and Angiology, Campus Mitte, Charité - Universitätsmedizin Berlin
Kv channel dysfunction is associated with cardiac arrhythmias. In order to study the molecular mechanisms that lead to such arrhythmias we utilize a systematic protocol for isolation of atrial and ventricular cardiomyocytes from Kv channel ancillary subunit knockout mice. Isolated cardiomyocytes can then immediately be used for cellular electrophysiological studies, biochemical or immunofluorescence (IF) assays.
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 General
A Multi-Parametric Islet Perifusion System within a Microfluidic Perifusion Device
1Department of Surgery, University of Illinois, Chicago, 2Department of Bioengineering, University of Illinois, Chicago
A microfluidic islet perifusion device was developed for the assessment of dynamic insulin secretion of multiple islets and simultaneous fluorescence imaging of calcium influx and mitochondrial potential changes.
JoVE General
Preparing E18 Cortical Rat Neurons for Compartmentalization in a Microfluidic Device
1Department of Biomedical Engineering, University of California, Irvine (UCI), 2Stem Cell Research Center, University of California, Irvine (UCI), 3Institute for Brain Aging and Dementia, University of California, Irvine (UCI)
In this video we demonstrate the preparation of E18 Cortical Rat Neurons.
JoVE Immunology and Infection
Measurement of Factor V Activity in Human Plasma Using a Microplate Coagulation Assay
1Applied Bioscience Program, Faculty of Science, University of Ontario Institute of Technology, 2Nursing Program, Faculty of Health Sciences, University of Ontario Institute of Technology, 3Medical Laboratory Science Program, Faculty of Health Sciences, University of Ontario Institute of Technology
This study describes a novel microplate assay that measures FV coagulation activity during fibrin clot formation in human plasma which has not been reported previously. The method uses a kinetic microplate reader to continuously measure the change in absorbance at 405nm during fibrin clot formation in human plasma.
JoVE General
Historical View and Physiology Demonstration at the NMJ of the Crayfish Opener Muscle
Department of Biology, University of Kentucky
The opener muscle of the crayfish leg is presented for its historical importance and experimental versatility in muscle phenotype, synaptic physiology and plasticity.
JoVE General
Modeling Biological Membranes with Circuit Boards and Measuring Electrical Signals in Axons: Student Laboratory Exercises
1Department of Biology, University of Kentucky, 2Department of Physiology, University of Toronto
This is a demonstration of how biological membranes can be understood using electrical models. We also demonstrate procedures for recording action potentials from the ventral nerve cord of the crayfish for student orientated laboratories.
JoVE Neuroscience
Imaging Calcium Responses in GFP-tagged Neurons of Hypothalamic Mouse Brain Slices
Department of Physiology, School of Medicine, University of Saarland, Homburg, Germany
In this protocol, we update recent progress in imaging Ca2+ signals of GFP-tagged neurons in brain tissue slices using a red fluorescent Ca2+ indicator dye.
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