Serotonin:
A biochemical messenger and regulator, synthesized from the essential amino acid L-Tryptophan. In humans it is found primarily in the central nervous system, gastrointestinal tract, and blood platelets. Serotonin mediates several important physiological functions including neurotransmission, gastrointestinal motility, hemostasis, and cardiovascular integrity. Multiple receptor families (Receptors, Serotonin) explain the broad physiological actions and distribution of this biochemical mediator.
JoVE General
Monitoring Plant Hormones During Stress Responses
Department of Biology, University of Texas
A simple method is provided that allows for the rapid extraction and analysis of multiple plant hormones from small tissue samples. The procedure uses vapor phase extraction as the solemn purification step. Samples are analyzed by GC/MS with chemical ionization that produces mainly (M+1)+ ions.
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 Clinical and Translational Medicine
The Use of Pharmacological-challenge fMRI in Pre-clinical Research: Application to the 5-HT System
1Department of Radiology, Brain Imaging Center, Academic Medical Center Amsterdam, 2Biological Imaging Centre, MRC Clinical Sciences Centre, Imperial College London
The goal of this technique is to assess serotonin (5-HT) neurotransmitter function in the live and free-breathing animal with pharmacological magnetic resonance imaging (phMRI) and an intravenous challenge with a selective serotonin reuptake inhibitor (SSRI), fluoxetine.
JoVE Bioengineering
Separating Beads and Cells in Multi-channel Microfluidic Devices Using Dielectrophoresis and Laminar Flow
1Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, 2Micro and Nanotechnology Lab, University of Illinois at Urbana-Champaign, 3Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, 4Bioengineering, University of Illinois at Urbana-Champaign
Dielectrophoresis (DEP) is an effective method to manipulate cells. Printed circuit boards (PCB) can provide inexpensive, reusable and effective electrodes for contact-free cell manipulation within microfluidic devices. By combining PDMS-based microfluidic channels with coverslips on PCBs, we demonstrate bead and cell manipulation and separation within multichannel microfluidic devices.
JoVE General
ELIME (Enzyme Linked Immuno Magnetic Electrochemical) Method for Mycotoxin Detection
Department of Sciences and Chemical Technologies, University of Rome, Tor Vergata
A protocol to detect trichothecenes (mycotoxins of concern for human health) using a newly developed screening method based on a competitive immunochemical method and a final electrochemical detection is demonstrated.
JoVE Clinical and Translational Medicine
High Content Screening in Neurodegenerative Diseases
1Department of Clinical Genetics, VU University Medical Center, 2Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam
We describe a methodology combining automated cell culturing with high-content imaging to visualize and quantify multiple cellular processes and structures, in a high-throughput manner. Such methods can aid in the further functional annotation of genomes as well as identify disease gene networks and potential drug targets.
JoVE General
A Quantitative Assay for Insulin-expressing Colony-forming Progenitors
1Department of Biotechnology & Bioinformatics, California State University Channel Islands, 2Department of Diabetes, Endocrinology and Metabolism, Beckman Research Institute of City of Hope, 3The Irell & Manella Graduate School of Biological Sciences, Beckman Research Institute of City of Hope
A three-dimensional clonogenic assay that allows pancreatic-like progenitors to differentiate into insulin-expressing colonies is described. This method takes advantage of semi-solid media containing methylcellulose, Matrigel and growth factors, in which single progenitors proliferate and differentiate in vitro, permitting quantification of the number of functional progenitors in a population.
JoVE General
Single Cell Transfection in Chick Embryos
Department of Medical Neurobiology, Hadassah Medical School - Hebrew University
Using fine tip micropipettes we inject plasmid DNA into subdomains of chicken somites or neural tubes. The concentration of the plasmid is adjusted to generate single transfected cells. We then allow the cells to develop into clonal populations.
JoVE Neuroscience
Physiological Recordings of High and Low Output NMJs on the Crayfish Leg Extensor Muscle
Department of Biology, University of Kentucky
This article demonstrates how to conduct electrophysiological recordings of synaptic responses on the extensor muscle in the walking leg of a crayfish and how the nerve terminals are visualized to show the gross morphological differences of high- and low-output nerve terminals.
JoVE Neuroscience
Neuromodulation and Mitochondrial Transport: Live Imaging in Hippocampal Neurons over Long Durations
Department of Experimental Neurobiology, The Neurosciences Institute
We describe a protocol that allows imaging of mitochondria in living neurons via fluorescence microscopy over long durations. Imaging over extended periods is accomplished through lentivirus-mediated expression of a mitochondrially targeted fluorescent protein and use of an inexpensive stage-top incubator that was designed and built in our laboratory.
JoVE Application Notes
IonFlux: Automated Patch Clamp System with Plate Reader Simplicity - ADVERTISEMENT
The IonFlux Automated Patch Clamp System provides high throughput, cost-effective ion channel screening for a wide range of electrophysiology applications. Fast compound exchange, low cost per data point, and convenient well plate formats make the system ideal for both ligand- and voltage-gated ion channel targets. The IonFlux HT provides an industry-leading 10,000 data points per day, while the IonFlux 16 provides true automated patch clamp performance for about the cost of a manual patch clamp rig.
JoVE General
Gastrointestinal Motility Monitor (GIMM)
Department of Anatomy and Neurobiology, The University of Vermont
Evaluation of colonic motility in the guinea pig distal colon with the Gastrointestinal Motility Monitor (GIMM) is a straightforward and simple to learn approach to quantitatively evaluate propulsive motility in the gastrointestinal tract.
JoVE Neuroscience
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.
JoVE Neuroscience
Investigating the Neural Mechanisms of Aware and Unaware Fear Memory with fMRI
Department of Psychology, University of Alabama at Birmingham
A methodology to investigate the neural mechanisms that support aware and unaware memory processes during fear conditioning is described. This method monitors blood oxygen level dependent (BOLD) functional magnetic resonance imaging, skin conductance response, and unconditioned stimulus expectancy during Pavlovian fear conditioning to assess the neural correlates of distinct memory processes.
JoVE Immunology and Infection
A Simple Chelex Protocol for DNA Extraction from Anopheles spp.
1Malaria Institute at Macha, 2Department of Molecular Microbiology & Immunology, Johns Hopkins Bloomberg School of Public Health
A rapid and affordable way to extract quality malaria parasite and vector DNA from mosquito specimens is described. Capitalizing on chelating properties of Chelex resin, the simple method enables genotyping of malaria parasites in mosquito mid-gut and salivary gland phases, as well as molecular identification of the Anopheles sibling species by PCR.
JoVE General
Cell Block Preparation from Cytology Specimen with Predominance of Individually Scattered Cells
Department of Pathology, University of Wisconsin - Milwaukee
Shidham's method for preparation of cell blocks with AV-marker from cytology specimens containing individually scattered cells and small cell groups.
JoVE Clinical and Translational Medicine
Movement Retraining using Real-time Feedback of Performance
Department of Physical Therapy, University of British Columbia
Retraining abnormal movement patterns following injury or disease is a key component of physical rehabilitation. Recent advances in technology have permitted accurate assessment of movement during a variety of tasks, with near instantaneous quantification of results. This provides new opportunities for modification of faulty movement patterns in real time.
JoVE Clinical and Translational Medicine
Biomarkers in an Animal Model for Revealing Neural, Hematologic, and Behavioral Correlates of PTSD
1Department of Psychiatry, Center for the Study of Traumatic Stress, Uniformed Services University of the Health Sciences, Bethesda, Maryland, 2Department of Gene and Protein Biomarkers, GenProMarkers, Inc.
We describe a rat model of post traumatic stress disorder (PTSD) that reveals the persistent alterations in neuroendocrine function and the delayed long-term, exaggerated fear response, characteristic of PTSD patients. The animal model and methods described here are useful for correlating biomarkers in brain nuclei, which are mechanistic but cannot be measured in patients, with biomarkers in peripheral white blood cells, which can.
JoVE Editorial
August 2011: This Month in JoVE
Here are some highlights from the August 2011 Issue of Journal of Visualized Experiments (JoVE).
JoVE Clinical and Translational Medicine
A Simple Guide Screw Method for Intracranial Xenograft Studies in Mice
1Monash Institute of Medical Research, 2MD Anderson Cancer Centre, University of Texas
In order to evaluate novel therapeutic paradigms for the treatment of glioma, physiological relevant models are essential. We utilize an implantable guide screw procedure for establishment of intracranial xenograft models that is more rapid and safer than stereotactic approaches.
JoVE General
Presynaptically Silent Synapses Studied with Light Microscopy
1Department of Psychiatry, Washington University School of Medicine, 2Department of Anatomy, Washington University School of Medicine, 3Department of Neurobiology, Washington University School of Medicine
Glutamatergic synapses can switch from an active mode to a silent mode. We demonstrate that presynaptic activity status in dissociated culture of rodent neurons is visualized using a fixable form of the FM1-43 dye to visualize active synapses and immunostaining with vGluT-1 antibody to visualize all glutamate synapses.
JoVE General
High-throughput Screening and Biosensing with Fluorescent C. elegans Strains
1Department of Biology, University of Florida, 2Mount Desert Island Biological Laboratory
A procedure for liquid-based culturing and dispensing of C. elegans strains expressing fluorescent reporter proteins is described that does not require expensive sorting equipment. This approach can be applied to numerous inducible C. elegans genes for drug discovery or biosensing of contaminants.
JoVE Clinical and Translational Medicine
Intracranial Implantation with Subsequent 3D In Vivo Bioluminescent Imaging of Murine Gliomas
1Neuro-Oncology Research, Barrow Neurological Institute of St. Joseph’s Hospital and Medical Center, 2Neurosurgery Research Laboratory, Barrow Neurological Institute of St. Joseph’s Hospital and Medical Center
Intracranial implantation of GL261 cells into C57BL/6 mice produces malignant gliomas that recapitulate many of the hallmarks of human glioblastoma multiforme. We used GL261 cells stably expressing luciferase to allow us to use in vivo imaging to follow tumor progression. The surgery and 3D in vivo imaging are demonstrated.
JoVE Bioengineering
Viral Nanoparticles for In vivo Tumor Imaging
1Department of Biomedical Engineering, Case Western Reserve University, 2Department of Biomedical Engineering, Radiology, and Materials Science and Engineering, Case Western Reserve University
Plant viral nanoparticles (VNPs) are promising platforms for applications in biomedicine. Here, we describe the procedures for plant VNP propagation, purification, characterization, and bioconjugation. Finally, we show the application of VNPs for tumor homing and imaging using a mouse xenograft model and fluorescence imaging.
JoVE Neuroscience
Methods to Assay Drosophila Behavior
1Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Sciences Center, 2Department of Genetics, Louisiana State University Health Sciences Center
Drosophila melanogaster is a genetically and behaviorally tractable model system that has been used to understand the molecular and cellular basis of many important biological processes for over a century 1. Drosophila has been well exploited to gain insights into the genetic basis of fly behavior.
JoVE Neuroscience
An Organotypic Slice Assay for High-Resolution Time-Lapse Imaging of Neuronal Migration in the Postnatal Brain
This protocol describes an organotypic slice assay optimized for the postnatal brain and high-resolution time-lapse imaging of neuroblast migration in the rostral migratory stream.
JoVE Applied Physics
Simulation, Fabrication and Characterization of THz Metamaterial Absorbers
School of Engineering, University of Glasgow
This protocol outlines the simulation, fabrication and characterization of THz metamaterial absorbers. Such absorbers, when coupled with an appropriate sensor, have applications in THz imaging and spectroscopy.
JoVE Clinical and Translational Medicine
Human Neuroendocrine Tumor Cell Lines as a Three-Dimensional Model for the Study of Human Neuroendocrine Tumor Therapy
1Raymond and Beverly Sackler Foundation, 2The Cancer Institute of New Jersey, University of Medicine and Dentistry of New Jersey, 3School of Natural Sciences, Institute for Advanced Study, Princeton, New Jersey
We present a simple agarose overlay platform to grow 3D multicellular spheroids using neuroendocrine cancer cell lines. This method provides a very convenient way to examine the effect of therapeutic drugs on the neuroendocrine tumor cells. It could also help us establish human neuroendocrine tumor spheroids for cancer therapy.
JoVE Neuroscience
Membrane Potentials, Synaptic Responses, Neuronal Circuitry, Neuromodulation and Muscle Histology Using the Crayfish: Student Laboratory Exercises
1Department of Biology, University of Kentucky, 2Department of Physiology, University of Toronto
The experiments demonstrate an easy approach for students to gain experience in examining muscle structure, synaptic responses, the effects of ion gradients and permeability on membrane potentials. Also, a sensory-CNS-motor-muscle circuit is presented to show a means to test effects of compounds on a neuronal circuit.
JoVE Clinical and Translational Medicine
Evaluation of Nanoparticle Uptake in Tumors in Real Time Using Intravital Imaging
1Department of Medical Biophysics, University of Western Ontario, 2London Regional Cancer Program, London Health Science Centre, 3Department of Pathology, Vanderbilt University, 4Translational Prostate Cancer Research Group, London Health Science Centre
We present a novel approach to quantify nanoparticle localization in the vasculature of human xenografted tumors using dynamic, real-time intravital imaging in an avian embryo model.
JoVE Neuroscience
Transfection of Mouse Retinal Ganglion Cells by in vivo Electroporation
1Department of Neurobiology, Yale University, 2Program in Developmental Biology, Baylor College of Medicine
We demonstrate an in vivo electroporation protocol for transfecting single or small clusters of retinal ganglion cells (RGCs) and other retinal cell types in postnatal mice over a wide range of ages. The ability to label and genetically manipulate postnatal RGCs in vivo is a powerful tool for developmental studies.
JoVE General
Using RNA-mediated Interference Feeding Strategy to Screen for Genes Involved in Body Size Regulation in the Nematode C. elegans
1Department of Science, Borough of Manhattan Community College, City Universtiy of New York (CUNY), 2Department of Biology, Queens College, The City University of New York (CUNY), 3Biochemistry Program, The Graduate Center, Queens College, The City University of New York (CUNY)
We demonstrate how to use the RNAi feeding technique to knock down target genes and score body size phenotype in C. elegans. This method could be used for a large scale screen to identify potential genetic components of interest, such as those involved in body size regulation by DBL-1/TGF-β signaling.
JoVE General
Analysis of SNARE-mediated Membrane Fusion Using an Enzymatic Cell Fusion Assay
Department of Biochemistry and Molecular Biology, University of Louisville School of Medicine
We have developed a cell fusion assay that quantifies SNARE-mediated membrane fusion events by activated expression of β-galactosidase.
JoVE General
Mapping Molecular Diffusion in the Plasma Membrane by Multiple-Target Tracing (MTT)
1Institut National de la Santé et de la Recherche Médicale, UMR 631, Parc scientifique de Luminy, 2Centre National de la Recherche Scientifique, UMR 6102, Parc scientifique de Luminy, 3Centre d'Immunologie de Marseille-Luminy, Aix-Marseille University, 4École Centrale Marseille, Technopôle de Château-Gombert, 5Institut Fresnel, Aix-Marseille University, 6Centre National de la Recherche Scientifique, UMR 6133, Aix-Marseille University
Multiple-Target Tracing is a homemade algorithm developed for tracking individually labeled molecules within the plasma membrane of living cells. Efficiently detecting, estimating and tracing molecules over time at high-density provide a user-friendly, comprehensive tool to investigate nanoscale membrane dynamics.
JoVE Bioengineering
Therapeutic Gene Delivery and Transfection in Human Pancreatic Cancer Cells using Epidermal Growth Factor Receptor-targeted Gelatin Nanoparticles
Department of Pharmaceutical Sciences, School of Pharmacy, Northeastern University
Type B gelatin-based engineered nanovectors system (GENS) was developed for systemic gene delivery and transfection in the treatment of pancreatic cancer. By modification with epidermal growth factor receptor (EGFR) specific peptide on the surface of nanparticles, they could target on EGFR receptor and release plasmid under reducing environment, such as high intracellular glutathione concentrations.
JoVE Neuroscience
Muscle Receptor Organs in the Crayfish Abdomen: A Student Laboratory Exercise in Proprioception
Department of Biology, University of Kentucky
The primary purpose of this experiment is to understand how primary sensory neurons convey information of joint movements and positions as proprioceptive information for an animal. An additional objective of this report is present the anatomy of the preparation by dissection and viewing of neurons under a dissecting microscope.
JoVE Neuroscience
Local Application of Drugs to Study Nicotinic Acetylcholine Receptor Function in Mouse Brain Slices
Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University
In this paper, we describe a useful method to study ligand-gated ion channel function in neurons of acutely isolated brain slices. This method involves the use of a drug-filled micropipette for local application of drugs to neurons recorded using standard patch clamp techniques.
JoVE General
A Video Demonstration of Preserved Piloting by Scent Tracking but Impaired Dead Reckoning After Fimbria-Fornix Lesions in the Rat
Department of Neuroscience, Canadian Centre for Behavioural Neuroscience, University of Lethbridge
In a piloting scent tracking task, the ability of the rats to return to a refuge with food using visual an odor trail or using dead reckoning in infrared light, the integrated record of previous movements, demonstrates that the hippocampus is necessary for dead reckoning.
JoVE Clinical and Translational Medicine
Probing the Brain in Autism Using fMRI and Diffusion Tensor Imaging
Department of Psychology, University of Alabama at Birmingham
Neuroimaging techniques, such as functional MRI and Diffusion Tensor Imaging have become increasingly useful in characterizing the cognitive and neural deficits in autism. An examination of brain connectivity in autism at a network level along with adaptations for scanning children with developmental disabilities is presented.
JoVE Bioengineering
Plasma Lithography Surface Patterning for Creation of Cell Networks
1Aerospace and Mechanical Engineering, University of Arizona, 2Biomedical Engineering IDP and BIO5 Institute, University of Arizona
A versatile plasma lithography technique has been developed to generate stable surface patterns for guiding cellular attachment. This technique can be applied to create cell networks including those that mimic natural tissues and has been used for studying several, distinct cell types.
JoVE General
Growth Assays to Assess Polyglutamine Toxicity in Yeast
Boston Biomedical Research Institute
This manuscript describes three complementary protocols for assessing the toxicity of polyglutamine (polyQ)-expansion proteins in the yeast Saccharomyces cerevisiae. These protocols can easily be modified to monitor the toxicity of other misfolded proteins in yeast.
JoVE Bioengineering
Analyzing Cellular Internalization of Nanoparticles and Bacteria by Multi-spectral Imaging Flow Cytometry
1Department of Veterinary Microbiology and Preventive Medicine, Iowa State University, 2Amnis Corporation, 3Department of Chemical and Biological Engineering, Iowa State University
In this article, we describe a method utilizing multi-spectral imaging flow cytometry to quantify the internalization of polyanhydride nanoparticles or bacteria by RAW 264.7 cells.
JoVE General
In vivo and in vitro Studies of Adaptor-clathrin Interaction
Department of Biochemistry and Molecular Biology, Colorado State University
Clathrin-mediated endocytosis depends on adaptor proteins that coordinate cargo selection and clathrin coat assembly. Here we describe procedures to study adaptor-clathrin physical interaction and live cell imaging approaches using as a model the yeast endocytic adaptor protein Sla1p.
JoVE Bioengineering
Measurement of Aggregate Cohesion by Tissue Surface Tensiometry
Department of Surgery, UMDNJ-Robert Wood Johnson Medical School
We describe a method of measuring binding energy, expressible as tissue surface tension, between cells within 3D tissue-like aggregates. Differences in tissue surface tension have been demonstrated to correlate with invasiveness of lung, muscle, and brain tumors, and are fundamental determinants of establishing spatial relationships between different cell types.
JoVE Neuroscience
GABA-activated Single-channel and Tonic Currents in Rat Brain Slices
Department of Neuroscience, Uppsala University, Sweden
We use the patch-clamp technique to measure GABA-activated single-channel currents (GABAA channels, GABAA receptors) and the synaptic and tonic currents they generate in neurons. Activation of the channels decreases neuronal excitability in health and disease 1,2,3,4.
JoVE Neuroscience
Vertical T-maze Choice Assay for Arthropod Response to Odorants
Entomology and Nematology Department, University of Florida
A vertical, T-maze olfactometer is described for assaying the behavioral response of arthropods. The olfactometer allows the experimenter to measure choices performed by test subjects when subjected to two potential odor fields. Both attraction to and repulsion from odorants can be measured with this device.
JoVE Clinical and Translational Medicine
Three-dimensional Imaging of Nociceptive Intraepidermal Nerve Fibers in Human Skin Biopsies
1Department of Neurology, University of Michigan, 2Department of Internal Medicine, University of Michigan
In order to study the changes of nociceptive intraepidermal nerve fibers (IENFs) in painful neuropathies (PN), we developed protocols that could directly examine three-dimensional morphological changes observed in nociceptive IENFs. Three-dimensional analysis of IENFs has the potential to evaluate the morphological changes of IENF in PN.
JoVE General
Isolation and Analysis of Hematopoietic Stem Cells from the Placenta
Jonsson Comprehensive Cancer Center, University of California, Los Angeles
We have identified the placenta as a major hematopoietic organ during development. We found that hematopoietic stem cells (HSCs) are both generated and expanded in the placenta in unique microenvironmental niches. Here, we describe experimental techniques required for isolation and visualization of HSCs in the mouse placenta.
JoVE General
An In vitro FluoroBlok Tumor Invasion Assay
BD Biosciences, Discovery Labware
This video demonstrates how to measure cell invasion through cell culture inserts using a fluorescence-based methodology.
JoVE General
High-throughput Purification of Affinity-tagged Recombinant Proteins
Department of Life Sciences, Imperial College London
We describe a method for the affinity-tagged purification of recombinant proteins using liquid-handling robotics. This method is generally applicable to the small-scale purification of soluble His-tagged proteins in a high-throughput format.
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