JoVE General
Visualizing Bacteria in Nematodes using Fluorescent Microscopy
Department of Bacteriology, University of Wisconsin-Madison
To study the mutualism between Xenorhabdus bacteria and Steinernema nematodes, methods were developed to monitor bacterial presence and location within nematodes. The experimental approach, which can be applied to other systems, entails engineering bacteria to express the green fluorescent protein and visualizing, using fluorescence microscopy bacteria within the transparent nematode.
JoVE Immunology and Infection
Colonization of Euprymna scolopes Squid by Vibrio fischeri
Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University
The method outlines the procedure by which the Hawaiian bobtail squid, Euprymna scolopes and its bacterial symbiont, Vibrio fischeri, are raised separately and then introduced to allow for specific colonization of the squid light organ by the bacteria. Colonization detection by bacterially-derived luminescence and by direct colony counting are described.
JoVE General
Preparation of Aplysia Sensory-motor Neuronal Cell Cultures
1Dept. of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, 2Dept. of Biological Chemistry, University of California, Los Angeles, 3Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles
Primary cultures of Aplysia sensory-motor neurons provide a model preparation for studying synapse formation and synaptic plasticity in vitro. This video demonstrates the identification and microdissection of sensory and motor neurons from Aplysia ganglia as well as the methods for establishing and maintaining sensory-motor neurons in culture.
JoVE Neuroscience
Peering into the Dynamics of Social Interactions: Measuring Play Fighting in Rats
Department of Neuroscience, University of Lethbridge
Play fighting in the rat involves attack and defense of the nape of the neck, which if contacted, is gently nuzzled with the snout. Because the movements of one animal are countered by the actions of its partner, play fighting is a complex, dynamic interaction. This dynamic complexity raises methodological problems about what to score for experimental studies. We present a scoring schema that is sensitive to the correlated nature of the actions performed. Two experiments illustrate how these measurements can be used to detect the effect of brain damage on play fighting even when there is no effect on overall playfulness. That is, the schema presented here is designed to detect and evaluate changes in the content of play following an experimental treatment.
JoVE General
Recordings of Neural Circuit Activation in Freely Behaving Animals
Department of Psychology, Neuroscience and Cognitive Science Program , University of Maryland
Non-invasive measurements of neural activity patterns in freely behaving animals are obtained by combining neurophysiological recordings with high speed videography.
JoVE General
Swimming Performance Assessment in Fishes
Department of Biological Sciences, University of Alberta
The lives of the majority of fish are predicated on swimming. This protocol describes techniques for capturing a range of swimming modes available to individual and schooling fish, and includes metrics associated with swimming physiology and behaviour.
JoVE General
The ex vivo Isolated Skeletal Microvessel Preparation for Investigation of Vascular Reactivity
An ex vivo preparation is described for isolation of the largest gracilis muscle resistance arterioles for interrogation of both vascular responses to vasoactive stimuli and the assessment of basic structural properties via passive wall mechanics.
JoVE Clinical and Translational Medicine
Corneal Confocal Microscopy: A Novel Non-invasive Technique to Quantify Small Fibre Pathology in Peripheral Neuropathies
Division of Cardiovascular Medicine, University of Manchester
Corneal Confocal microscopy is a non-invasive clinical technique which may be used to quantify C fibre damage to diagnose and stratify patients with increasing neuropathic severity.
JoVE General
Murine Model for Parkinson's Disease: from 6-OH Dopamine Lesion to Behavioral Test
Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Brasil
Parkinson disease is caused by loss of dopaminergic innervation to the striatum, which can be experimentally induced by 6-OH-dopamine. We describe how to perform a stereotaxic lesion and to monitor apomorphine-induced rotational behavior in mice. This model is useful and reliable for testing new therapies for Parkinson disease.
JoVE Bioengineering
Elastomeric PGS Scaffolds in Arterial Tissue Engineering
1Department of Bioengineering, University of Pittsburgh, 2McGowan Institute for Regenerative Medicine, University of Pittsburgh
Elastomeric PGS scaffolds with vascular smooth muscle cells cultured in a pulsatile flow bioreactor may lead to promising small-diameter arterial constructs with native ECM production in a relatively short culture period.
JoVE Neuroscience
Investigating Social Cognition in Infants and Adults Using Dense Array Electroencephalography (dEEG)
Department of Psychology, University Toronto Scarborough
Dense array electroencephalography is being used increasingly to study social cognitive functions in infants and adults. Here we present an established methodology that represents a significant improvement on conventional methodologies for studying EEG in infants and adults.
JoVE General
Heart Dissection in Larval, Juvenile and Adult Zebrafish, Danio rerio
Department of Biology, Queens College, City University of New York
A clear, standardized method for dissection and isolation of the zebrafish heart at multiple developmental stages are described. Annotation and quantification techniques are also discussed.
JoVE Immunology and Infection
High and Low Throughput Screens with Root-knot Nematodes Meloidogyne spp.
Department of Nematology, University of California, Riverside
Two distinct methods to screen plants with root-knot nematodes are described. The described approaches include high-throughput screens with nematodes in a nondestructive manner facilitating the use of these plants in breeding programs.
JoVE Editorial
March 2012: This Month in JoVE
Here are some highlights from the March 2012 Issue of Journal of Visualized Experiments (JoVE).
JoVE General
An Introduction to Worm Lab: from Culturing Worms to Mutagenesis
Department of Biology, University of Texas at Arlington
Screening for mutants with phenotypic defects is a straightforward method for identifying genes that function in a given biological process. In this article we describe how to culture free living worms (e.g., Pristionchus pacificus) in the laboratory and show two different mutagenesis methods, EMS and TMP/UV.
JoVE Neuroscience
Preparation of Mouse Brain Tissue for Immunoelectron Microscopy
1Department of Neurobiology and Anatomy, University of Rochester, 2Douglas Mental Health University Institute
We describe a protocol for transcardiac perfusion of mice, removal and sectioning of the brain, as well as immunoperoxidase staining, resin embedding, and ultrathin sectioning of the brain sections. Upon completion of these procedures, the immunostained material is ready for examination with transmission electron microscopy.
JoVE General
Adult and Embryonic Skeletal Muscle Microexplant Culture and Isolation of Skeletal Muscle Stem Cells
School of Biosciences, University of Birmingham
The micro-dissected explants technique is a robust and reliable method for isolating proliferative skeletal muscle cells from juvenile, adult or embryonic muscles as a source of skeletal muscle stem cells. Uniquely, these cells have been clonally derived to produce skeletal muscle stem cell lines used for in vivo transplantation.
JoVE General
Metabolic Profile Analysis of Zebrafish Embryos
Zebrafish represent a powerful vertebrate model that has been under-utilised for metabolic studies. Here we describe a rapid way to measure the in vivo metabolic profile of developing zebrafish that allows the comparison of different mitochondrial function parameters between genetically or pharmacologically manipulated embryos, thereby increasing the applicability of this organism.
JoVE Neuroscience
Preparation of Synaptoneurosomes from Mouse Cortex using a Discontinuous Percoll-Sucrose Density Gradient
1Department of Pathology and Laboratory Medicine, Waisman Center for Developmental Disabilities, University of Wisconsin, 2Department of Biochemistry, Waisman Center for Developmental Disabilities, University of Wisconsin
A method to prepare translationally active, intact synaptoneurosomes (SNs) from mouse brain cortex is described. The method uses a discontinuous Percoll-sucrose density gradient allowing for the quick preparation of active SNs.
JoVE Clinical and Translational Medicine
Development of a Unilaterally-lesioned 6-OHDA Mouse Model of Parkinson's Disease
Centre for Neurobiology of Stress, Dept Biological Sciences, University of Toronto at Scarborough
A protocol for performing unilateral 6-OHDA lesions of the medial forebrain bundle in mice is described. This method has a low mortality rate (13.3 %) with 89% of the surviving animals showing >95% loss of striatal dopamine and 90.63±-4.02 % ipsiversive rotational bias towards the side of the lesion.
JoVE Clinical and Translational Medicine
Near Infrared Optical Projection Tomography for Assessments of β-cell Mass Distribution in Diabetes Research
1Umeå Centre for Molecular Medicine, Umeå University, 2Cell Transplant Center, Diabetes Research Institute, University of Miami,, 3EMBL-CRG Systems Biology Program, Centre for Genomic Regulation, Catalan Institute of Research and Advanced Studies, 4Dept. of Computing Science, Umeå University
We describe the adaptation of optical projection tomography (OPT)1 to imaging in the near infrared spectrum, and the implementation of a number of computational tools. These protocols enable assessments of pancreatic β-cell mass (BCM) in larger specimens, increase the multichannel capacity of the technique and increase the quality of OPT data.
JoVE Clinical and Translational Medicine
Neo-Islet Formation in Liver of Diabetic Mice by Helper-dependent Adenoviral Vector-Mediated Gene Transfer
1Department of Medicine, Baylor College of Medicine, 2Division of Diabetes, Endocrinology & Metabolism, Diabetes & Endocrinology Research Center, Baylor College of Medicine, 3Department of Molecular & Cellular Biology, Baylor College of Medicine
We describe hepatic neo-islet formation in STZ (streptozotocin)-induced diabetic mice by gene transfer of Neurogenin3 (Ngn3) and Betacellulin (Btc) using helper-dependent adenoviral vector (HDAd) and the reversal of hyperglycemia. Our method takes advantages of helper-dependent adenoviral vectors with their highly efficient in vivo transduction and the long lasting gene expression.
JoVE General
Extraction of Tissue Antigens for Functional Assays
1Immunology and Diabetes Unit, St. Vincent's Institute of Medical Research, 2Department of Medicine, University of Melbourne
A simple protocol for preparing extracts of human tissue to be used as a source of antigens in functional T-cell assays is described. This method allows T-cell responses to tissue-derived antigens to be measured in vitro.
JoVE Clinical and Translational Medicine
Staining Protocols for Human Pancreatic Islets
Department of Pathology, Immunology, and Laboratory Medicine, University of Florida
This video demonstrates procedures for characterization of human pancreatic islets using hematoxylin and eosin (H&E) and immunohistochemistry (IHC). Pancreatic sections from head, body, and tail regions are stained by both H&E and IHC to determine islet endocrine composition (insulin, glucagon, and pancreatic polypeptide), cell replication (Ki67), and inflammatory infiltrates (H&E, CD3). The uncinate region is localized using IHC for pancreatic polypeptide.
JoVE Clinical and Translational Medicine
Collection Protocol for Human Pancreas
Department of Pathology, Immunology, and Laboratory Medicine, University of Florida
This video demonstrates a dissection procedure for processing human pancreas into multiple storage formats. Anatomical orientation is maintained throughout the pancreatic regions to allow definition of regional islet composition and density.
JoVE General
Intraperitoneal Injection into Adult Zebrafish
1Department of Organismal Biology and Anatomy, The University of Chicago, 2Committee on Molecular Metabolism and Nutrition, The University of Chicago, 3Department of Medicine, The University of Chicago
We demonstrate intraperitoneal injection into adult zebrafish. We use a 10 μl NanoFil microsyringe controlled by a Micro4 controller and UltraMicroPump III. This demonstration includes the use of cold water as an anesthetic.
JoVE Immunology and Infection
Measuring Bacterial Load and Immune Responses in Mice Infected with Listeria monocytogenes
1St Vincent’s Institute, Department of Medicine, The University of Melbourne, 2Department of Microbiology and Immunology, The University of Melbourne
Listeria monocytogenes is a model organism for studying immune responses and genetic susceptibility to intracellular bacteria in mice. This method enables one to measure bacterial load and generate single-cell suspensions of the liver and spleen from mice for FACS analysis to determine changes in immune cells due to Listeria infection.
JoVE Immunology and Infection
Human In Vitro Suppression as Screening Tool for the Recognition of an Early State of Immune Imbalance
1Department of Pediatrics/Allergy, Medical College of Wisconsin, 2Flow Cytometry Core Facility, Medical College of Wisconsin, 3Max McGee National Research Center for Juvenile Diabetes and Human Molecular Genetics Center, Medical College of Wisconsin
Tregs are potent suppressors of the immune system. There is a lack of unique surface markers to define them, hence, definitions of Tregs are primarily functional. Here we describe an optimized in vitro assay capable of identifying immune imbalance in subjects at risk to develop T1D.
JoVE Immunology and Infection
Methods to Assess Beta Cell Death Mediated by Cytotoxic T Lymphocytes
Cell-mediated lymphocytotoxicity (CML) assays can be used to test autoreactive responses and study mechanisms of cell death in vitro. However, using live-cell confocal microscopic imaging techniques with fluorescent dyes, the type and kinetics of cell death as well as the pathways utilized can be studied in greater detail.
JoVE Neuroscience
Assessment of Social Interaction Behaviors
1Samuel Lunenfeld Research Institute, Mount Sinai Hospital, 2Toronto Centre for Phenogenomics, Mount Sinai Hospital, 3Department of Medical Biophysics, University of Toronto, 4Department of Psychology, University of Toronto, 5Department of Psychiatry, University of Toronto
Here we describe a detailed protocol for examination of sociability in mice by using Crawley's sociability and preference for social novelty test. We describe the advantages and possible applications for this procedure, including critical details important for correct interpretation of the results.
JoVE Neuroscience
Combining Lipophilic dye, in situ Hybridization, Immunohistochemistry, and Histology
1Department of Biology, University of Iowa, 2Molecular Targeting Technologies, Inc.
A combination of different techniques to maximize data collection from mouse tissue is presented.
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 Immunology and Infection
Hybridization in situ of Salivary Glands, Ovaries, and Embryos of Vector Mosquitoes
1Department of Molecular Biology and Biochemistry, University of California, Irvine, 2Department of Microbiology and Molecular Genetics, University of California, Irvine
Temporal and spatial gene expression analyses have a crucial role in functional genomics. Whole-mount hybridization in situ is useful for determining the localization of transcripts within tissues and subcellular compartments. Here we outline a hybridization in situ protocol with modifications for specific target tissues in mosquitoes.
JoVE Neuroscience
Visualization of Mitochondrial DNA Replication in Individual Cells by EdU Signal Amplification
1Michigan Research Community, Undergraduate Research Opportunity Program, University of Michigan, 2Department of Neurology, University of Michigan, 3Department of Internal Medicine, Division of Metabolism, Endocrinology, and Diabetes, University of Michigan
We developed a sensitive technique to label newly synthesized mitochondrial DNA (mtDNA) in individual cells in order to study mtDNA biogenesis. The technique combines the incorporation of EdU together with a tyramide signal amplification (TSA) protocol to visualize mtDNA replication within subcellular compartments of neurons.
JoVE General
Flow Cytometry Purification of Mouse Meiotic Cells
1Genome Plasticity Laboratory, Department of Cancer Biology, The Scripps Research Institute, 2Flow Cytometry Core, The Scripps Research Institute
An efficient method to obtain highly purified viable meiotic fractions from mouse testis is described, which combines a refined cell dissociation protocol with fluorescent activated cell sorting (FACS). This method takes advantage of differences in the DNA content and nuclear density of discrete meiotic fractions.
JoVE General
Radioactive in situ Hybridization for Detecting Diverse Gene Expression Patterns in Tissue
1Howard Hughes Medical Institute, Department of Neurobiology, Duke University, 2Department of Biological Sciences, Hokkaido University
This protocol is successfully used to quantitatively detect levels and spatial patterns of mRNA expression in multiple tissue types across vertebrate species. The method can detect low abundance transcripts and allows processing of hundreds of slides simultaneously. We present this protocol using expression profiling of avian embryonic brain formation as an example.
JoVE Neuroscience
Stereotaxic Surgery for Excitotoxic Lesion of Specific Brain Areas in the Adult Rat
1Helen Wills Neuroscience Institute, University of California Berkeley, 2Office of Laboratory Animal Care, University of California Berkeley, 3McGovern Institute for Brain Research & The Department of Brain and Cognitive Science, Massachusetts Institute of Technology, 4Integrative Biology Department, University of California Berkeley
Targeted ablation of specific brain region(s) by infusion of an excitotoxin using stereotaxic coordinates is described. This technique could also be adapted for infusion of other chemicals into the rat brain.
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