Measuring left ventricular pressure (LV) in embryonic and neonatal mice is described. Pressure is measured by inserting a needle connected to a fluid-filled transducer into the LV under ultrasound guidance. Care must be taken to maintain normal cardiac function during the experimental protocol.
Large animal models have good translational values in the examination of physiology and pharmacology of neonatal asphyxia. Using newborn piglets, we develop an experimental protocol to simulate neonatal asphyxia which has advantages of studying the systemic and regional hemodynamics, oxygen transport with biochemical and pathologic pathways and correlations.
1Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, 2Lab. PALM, Université de Caen Basse-Normandie, 3Fetal-Neonatal Neuroimaging and Developmental Science Center, Boston Children's Hospital, Harvard Medical School, 4ISS, INC.
We combined frequency-domain near-infrared spectroscopy measures of cerebral hemoglobin oxygenation with diffuse correlation spectroscopy measures of cerebral blood flow index to estimate an index of oxygen metabolism. We tested the utility of this measure as a bedside screening tool to evaluate the health and development of the newborn brain.
1Division of Cardiovascular Medicine, Department of Medicine, Stanford University Medical Center, 2Division of Cardiology, Department of Medicine, University of California, San Francisco, 3San Francisco VAMC
Early detection of apoptosis may identify at-risk cell populations in a variety of diseases. Here we demonstrate a method to link an early apoptosis-detection protein (Annexin V) to a MRI-detectable iron oxide nanoparticle (SPIO). This method may be extended to other proteins of interest to generate MRI-detectable molecular imaging probes.
Isolating primary microglia from the cellular heterogeneity of the brain is essential to investigate their role in both physiological and pathological conditions. This protocol describes a mechanical isolation and mixed cell culture technique that provides high yield and high purity, viable primary microglial cells for in vitro study and downstream applications.
Flow cytometry is a powerful tool allowing for the isolation and study of specific cell populations. This protocol describes steps for isolating LacZ-expressing cells from cochlear tissues from neonatal transgenic mice. Dissociated cochlear cells were labeled using fluorescent-conjugated substrates of β-galactosidase prior to separation via flow cytometry.
1Department of Children's Clinical Neurophysiology, Helsinki University Hospital, University of Helsinki, 2Department of Biosciences, University of Helsinki, 3Department of Pediatrics, Helsinki University Hospital, University of Helsinki, 4Neuroscience Center, University of Helsinki
This video explains the background theory of the neonatal EEG activity and the sensory responses, followed by a live demonstration of their recording in neonatal intensive care unit.
1Solomon H. Snyder Department of Neuroscience, Johns Hopkins School of Medicine, 2Department of Neurology, Johns Hopkins School of Medicine, 3Department of Ophthalmology, Johns Hopkins School of Medicine, 4Center for High-Throughput Biology, Johns Hopkins School of Medicine, 5Institute for Cell Engineering, Johns Hopkins School of Medicine
A method for the incorporation of plasmid DNA into murine retinal cells for the purpose of performing either gain- or loss of function studies in vivo is presented. This method capitalizes on the transient increase in permeability of cell plasma membranes induced by the application of an external electrical field.
Delivery of Therapeutic Agents Through Intracerebroventricular (ICV) and Intravenous (IV) Injection in Mice
1Department of Molecular Microbiology and Immunology, Bond Life Sciences Center, University of Missouri, 2Department of Biological Sciences, Columbia University, 3Department of Veterinary Pathobiology, Bond Life Sciences Center, University of Missouri
This article demonstrates two very different methods of injection: 1) into the brain (intracerebroventricular) and 2) systemic (intravenous) to introduce the therapeutic agents into the central nervous system of neonatal mice.
We demonstrate a minimally invasive technique referred to as neonatal subventricular zone electroporation. The technique consists of injecting plasmid DNA into the lateral ventricles of neonatal pups and applying electrical current to deliver and genetically manipulate neural stem cells
Here are some highlights from the February 2012 Issue of Journal of Visualized Experiments (JoVE).
We present step-by-step instructions for the generation of neonatal chimeras as well as the dissection and preparation of the thymus for ex vivo imaging by 2-Photon Microscopy.
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.
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.
A demonstration of the isolation of neonatal mouse spinal cord for electrophysiologic studies.
A method is described to measure biochemical markers of neonatal hypoxia-ischemia. The approach utilizes high pressure liquid chromatography (HPLC) and Gas Chromatography Mass Spectrometry (GC/MS).
Derivation of Enriched Oligodendrocyte Cultures and Oligodendrocyte/Neuron Myelinating Co-cultures from Post-natal Murine Tissues
1Regenerative Medicine Program, Ottawa Hospital Research Institute, 2Department of Cellular and Molecular Medicine, University of Ottawa, 3Department of Pharmacological Sciences, Stony Brook University, 4Department of Medicine, University of Ottawa
This article describes methods to derive enriched populations of murine oligodendrocyte precursor cells (OPCs) in primary culture, which differentiate to produce mature oligodendrocytes (OLs). In addition, this report describes techniques to produce murine myelinating co-cultures by seeding mouse OPCs onto a neurite bed of mouse dorsal root ganglion neurons (DRGNs).
This protocol describes a non-viral method of delivery of genetic constructs to a certain area of living rodent brain. The method consists of plasmid preparation, micropipette fabrication, neonatal rat pup surgery, microinjection of the construct, and in vivo electroporation.
Bioluminescence Imaging for Assessment of Immune Responses Following Implantation of Engineered Heart Tissue (EHT)
1Transplant and Stem Cell Immunobiology Lab (TSI) and CVRC, University Hospital Hamburg, University Heart Center Hamburg, 2Department of Experimental and Clinical Pharmacology and Toxicology, University Heart Center Hamburg, 3CT Surgery, Stanford University School of Medicine
This video demonstrates the use of in vivo bioluminescence imaging to study immune responses after implantation of Engineered Heart Tissue (EHT) in rats.
The following protocol outlines the process of pancreatic dissection for virtual slice imaging, and the subsequent quantification of all GFP-tagged beta-cells in the entire pancreas.
We have developed a decellularized lung extracellular matrix and novel biomimetic bioreactor that can be used to generate functional lung tissue. By seeding cells into the matrix and culturing in the bioreactor, we generate tissue that demonstrates effective gas exchange when transplanted in vivo for short periods of time.
We describe the isolation of neonatal cardiomyocytes and the preparation of the cells for encapsulation in fibrin hydrogel constructs for tissue engineering. We describe methods for analyzing the tissue engineered myocardium after the culture period including active force generated upon electrical stimulation and cell viability and immunohistological staining.
The presented method offers a way to detect functional effective cardiotropic autoantibodies in the plasma of patients with dilated cardiomyopathy, irrespective of the specific antigen, by analysing the impact of isolated patient immunoglobulin on cellular shortening and intracellular calcium transients in isolated rat cardiomyocytes.
A Novel Surgical Approach for Intratracheal Administration of Bioactive Agents in a Fetal Mouse Model
1Molecular Virology and Gene Therapy, KU Leuven, 2Department of Woman and Child, KU Leuven, 3Neurobiology and Gene Therapy, KU Leuven, 4Division of Nuclear Medicine, KU Leuven, 5Biomedical NMR Unit/ MoSAIC, KU Leuven
We developed a novel surgical approach for intratracheal administration of bioactive agents into the mouse fetus. The delivery route is more efficient in targeting the fetal mouse lungs than the commonly used intra-amniotic injection. This procedure has to date not been described in a mouse model.
The postnatal rat model for hypoxic-ischemic brain injury is a well-established model of human neonatal hypoxic ischemic encephalopathy (HIE). In this article, we describe the model of HIE in post-natal rat pups.
1Department of Ophthalmology, Massachusetts Eye and Ear, 2JoVE Content Production
Here are some highlights from the March 2013 issue of Journal of Visualized Experiments (JoVE).
Mosaic Analysis of Gene Function in Postnatal Mouse Brain Development by Using Virus-based Cre Recombination
1Neuroscience Graduate Program, Keck School of Medicine, University of Southern California, 2Zilkha Neurogenetic Institute, University of Southern California, 3Department of Cell and Neurobiology, Neuroscience Graduate Program, Keck School of Medicine, University of Southern California
An in vivo method to test gene function in postnatal brain is described. Recombinant AAVs expressing Cre and/or a fluorescent protein are injected into neonatal mouse brain. Mosaic gene inactivation and sparse neuronal labeling are achieved, allowing rapid analysis of gene function in processes critical to neural circuit development.
1Department of Dermatology, University of Freiburg, 2Kepler High School Freiburg, 3Centre for Biological Signalling Studies (BIOSS), University of Freiburg
In the animal model described in our present work, purified IgG antibodies against a stretch of 200 amino acids (aa 757-967) of collagen VII are injected repeatedly into mice reproducing the blistering phenotype as well as the histo- and immunopathological features characteristic to human epidermolysis bullosa acquisita (EBA)1.
A demonstration of the fabrication and use of an extracellular suction electrode used to measure electrophysiological recordings of neonatal rodent spinal cords in vitro
We established mouse models of periventricular leukomalacia (PVL), the predominant brain injury in premature infants characterized by periventricular white matter lesions. Hypoxia/ischemia with/without systemic infection are the primary causes of PVL. Unilateral carotid ligation and hypoxia exposure with/without lipopolysaccharide injection creates PVL-like lesions in P6 mice.
We describe a novel surgical method for catheterizing 'intestinal loops' within the ileum of sheep. Once animals have recovered from surgery and have cleared antibiotics and analgesics, multiple treatments can be deposited directly in loops via the catheters.
Meatoplasty, surgical management of meatal stenosis.
This video shows how to induce autoimmune hypophysitis in SJL mice and how to assess its severity by histopathology.
1Department of Paediatrics, Division of Infectious and Immunological Diseases, Child and Family Research Institute, University of British Columbia, 2Department of Computer Science, University of British Columbia, 3Department of Psychology, University of British Columbia
Visual analytics (VA) is a new approach of analyzing data interactively. In this video, we discuss the data overload problem brought on by high-throughput biological experiments, and propose VA as a solution to such problem. The video demonstrates analysis within and between immunological datasets using a VA tool called Tableau.
Using Bioluminescent Imaging to Investigate Synergism Between Streptococcus pneumoniae and Influenza A Virus in Infant Mice
1Department of Microbiology and Immunology, University of Melbourne, 2Laboratory of Pediatric Infectious Diseases, Radboud University Nijmegen Medical Centre, 3The Centre for Dynamic Imaging, The Walter and Eliza Hall Institute for Medical Research
A concurrent infection with influenza A virus is one of the factors implicated in the induction of invasive pneumococcal disease during asymptomatic Streptococcus pneumoniae carriage. Here we describe a mixed infection method using infant mice to investigate the synergism between these two respiratory pathogens.
Telemetric ECG has emerged as an essential tool in evaluating animal models for cardiac arrhythmias and sudden cardiac death. Here, we present a stepwise guide to telemetric ECG recordings for application in long-term ambulatory ECG monitoring in mice.
This video demonstrates the procedure for isolating whole brains from adult Drosophila in preparation for recording from single neurons using standard whole cell technology. It includes images of GFP labeled cells and neurons viewed during recording.
The urease method of sample preparation for GC/MS analysis of intermediary metabolites is presented by its inventor. The method allows one-step follow-up of newborn screening for inborn errors by tandem mass spectrometry by quantifying carbohydrates, organic and amino acids all in a single process.
We present a protocol that permits to view and to quantitatively asses the morphology of the dendritic tree of individual Purkinje cells grown in organotypic cerebellar slice cultures. This protocol is intended to promote studies on the mechanisms of Purkinje cell dendritic development.
Engineering Skeletal Muscle Tissues from Murine Myoblast Progenitor Cells and Application of Electrical Stimulation
Engineered muscle tissue has great potential in regenerative medicine, as disease model and also as an alternative source for meat. Here we describe the engineering of a muscle construct, in this case from mouse myoblast progenitor cells, and the stimulation by electrical pulses.
We provide a reproducible method to induce type 1 diabetes (T1D) in mice within two weeks by the adoptive transfer of islet antigen-specific, primary CD4+ T cells.
Here, we describe a protocol for isolation and culture of murine pulmonary endothelial cells. This method comprises mechanic and enzymatic lung tissue dissociation as well as a 2-step purification process using anti-PECAM-1 and anti-ICAM-2 antibodies conjugated to magnetic beads, which produces a pure endothelial cell population of mostly microvascular origin.
Here, we demonstrate fabrication of collagen-based, tissue constructs containing skeletal myoblasts. These 3-D engineered constructs may be used to replace or repair tissues in vivo. For our purposes, we have designed these as an atrioventricular electrical conduit for the repair of complete heart block.
This is a protocol describing how to isolate and culture primary sympathetic neurons from superior cervical ganglia (SCG) of newborn rat pups.
1Neuroscience, Physiology and Pharmacology, University College London, 2Department of Clinical Neurophysiology, Great Ormond Street Hospital, 3Elizabeth Garrett Anderson Obstetric Hospital, University College Hospital, 4Nuffield Department of Anaesthetics, University of Oxford
The assessment and treatment of pain in infants is difficult because infants cannot verbally report their experience. In this video we describe quantitative electrophysiological methods and analysis techniques that can be used to measure the response to noxious events from the infant nervous system.
This article describes a method for labeling embryonic skin and thymus blood vessels.
1Sensory Motor Performance Program, Rehabilitation Institute of Chicago, 2Department of Kinesiology and Nutrition, University of Illinois at Chicago, 3Department of Physical Therapy, University of Illinois at Chicago
This video demonstrates modulation of reflex activity, volitional strength and ambulation through clinical and quantitative assessments in individuals with motor incomplete SCI as a result of acute oral administration of a serotonin reuptake inhibitor (SSRI).
1Lehrstuhl für Biomolekulare Sensoren, Technische Universität München, 2Center for Integrated Protein Science (Munich) at the Institute of Neuroscience, Technische Universität München, 3TUM Institute for Advanced Study and German Center for Neurodegenerative Diseases, Technische Universität München, 4Munich Cluster for Systems Neurology (SyNergy), Technische Universität München
Visualizing individual cells in densely packed tissues, such as terminal Schwann cells (SCs) at neuromuscular junctions (NMJs), is challenging. "Sequential photo-bleaching" allows delineating single terminal SCs, for instance in the triangularis sterni muscle explant, a convenient nerve-muscle preparation, where sequential bleaching can be combined with time-lapse imaging and post-hoc immunostainings.
Astrocytes have been recognized to be versatile cells participating in fundamental biological processes that are essential for normal brain development and function, and central nervous system repair. Here we present a rapid procedure to obtain pure mouse astrocyte cultures to study the biology of this major class of central nervous system cells.
The mouse heterotopic heart transplantation model has been proven by many investigators to be an important method for studying mechanisms of rejection and immune response. However, the techniques involved are still challenging. By modifying standard techniques we have had success with more than 1000 transplants.