June 2012: This Month in JoVE
1Department of Ophthalmology, Massachusetts Eye and Ear, 2JoVE Content Production
Back in 1905, in what is now the Czech Republic, Eduard Zirm performed the first corneal transplantation surgery (keratoplasty), which restored vision to a patient blinded by corneal injury. Today, eye banks all over the world prepare, store, and distribute donated corneas to hospitals so that thousands of sight-saving keratoplasties can be performed every year. In June 2012, JoVE has its eye on two research groups, one from Italy and the other from Michigan, who demonstrate two distinct methods for corneal graft preparation prior to transplantation.
Forebrain Electrophysiological Recording in Larval Zebrafish
A simple method to record extracellular field potentials in the larval zebrafish forebrain is described. The method provides a robust in vivo read-out of seizure-like activity. This technique can be used with genetically modified zebrafish larvae carrying epilepsy-related genes or seizures evoked by administration of convulsant drugs.
Methods for ECG Evaluation of Indicators of Cardiac Risk, and Susceptibility to Aconitine-induced Arrhythmias in Rats Following Status Epilepticus
Department of Pharmacology and Toxicology, University of Utah
Techniques for measurement of electrical activity of the heart by electrocardiogram (ECG), and analysis of cardiac risk factors and susceptibility to arrhythmias following status epilepticus (SE) in the rat are described.
Recording Human Electrocorticographic (ECoG) Signals for Neuroscientific Research and Real-time Functional Cortical Mapping
1Wadsworth Center, New York State Department of Health, 2Department of Neurology, Albany Medical College, 3Department of Neurosurgery, Albany Medical College, 4Department of Neurosurgery, Washington University, 5Department of Biomed. Eng., Rensselaer Polytechnic Institute, 6Department of Biomed. Sci., State University of New York at Albany, 7Department of Elec. and Comp. Eng., University of Texas at El Paso
We present a method for collecting electrocorticographic signals for research purposes from humans who are undergoing invasive epilepsy monitoring. We show how to use the BCI2000 software platform for data collection, signal processing and stimulus presentation. Specifically, we demonstrate SIGFRIED, a BCI2000-based tool for real-time functional brain mapping.
High-density EEG Recordings of the Freely Moving Mice using Polyimide-based Microelectrode
1Center for Neural Science , Korea Institute of Science and Technology (KIST), 2Department of Neuroscience, University of Science and Technology, 3Fab Service Department, Korea Advanced Nano Fab Center
In this article, we described the surgery procedure and handling tips for implantation of ultra-thin polyimide-based microelectrode array (PBM-array) on the mouse skull for acquisition of high-density encephalography (EEG) in a mouse model.
Bronchial Thermoplasty: A Novel Therapeutic Approach to Severe Asthma
1Director of Pulmonary Special Procedures and the Lung Cancer Center, Virginia Hospital Center, 2Chief, Division of Pulmonary Critical Care and Sleep Medicine, Virginia Hospital Center
Bronchial thermoplasty is a non-drug procedure for severe persistent asthma that delivers thermal energy to the airway wall in a precisely controlled manner to reduce excessive airway smooth muscle. Reducing airway smooth muscle decreases the ability of the airways to constrict, thereby reducing the frequency of asthma attacks.
A Simplified Technique for Producing an Ischemic Wound Model
Department of Surgery, University of Louisville
We have developed a minimally invasive technique to create a rabbit ischemic ear wound model by dividing the central artery and nerve and the cranial neurovascular bundle. A subcutaneous tunnel then cuts all subcutaneous tissues. This procedure causes minimal skin disruption and can be safely used in diabetic animals.
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.
Quantitative Autonomic Testing
Department of Neurology, University of Massachusetts Medical School
Standardized, comprehensive and fully quantitative testing of autonomic functions is described. The autonomic tests consist of evaluation of all three major autonomic domains including cardiovagal, adrenergic and sudomotor. The severity and distribution of dysautonomia is quantitated using Composite Autonomic Severity Scores.
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.
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.
Assessment of Cerebral Lateralization in Children using Functional Transcranial Doppler Ultrasound (fTCD)
Department of Experimental Psychology, University of Oxford
Functional transcranial Doppler sonography (fTCD) is a simple and non-invasive ultrasound technique which can be used to assess the lateralization of cognitive functions, especially language, and is suitable for use with children.
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.
The Use of Cystometry in Small Rodents: A Study of Bladder Chemosensation
1Laboratory of Experimental Urology, Department of Development and Regeneration, KU Leuven, Belgium, 2Laboratory for Ion Channel Research, Department of Cellular and Molecular Medicine, KU Leuven, Belgium, 3TRP Research Platform Leuven (TRPLe), KU Leuven, Belgium
Cystometry is an efficient technique to measure bladder function of small animals in vivo. The bladder is continuously infused at rates controlled through an intravesical catheter, whereas the urethra is left free for micturition. This allows for repetitive filling and emptying of the bladder, while intravesical pressure and voided volume are recorded.
Targeting of Deep Brain Structures with Microinjections for Delivery of Drugs, Viral Vectors, or Cell Transplants
1 Neuroscience Lab/ Fac. Psicologia, University of Colima, 2Department of Neurosurgery, Johns Hopkins University
In this article, we show a method to make glass capillary needles with a 50-μm lumen. This technique significantly reduces the brain damage, minimizes passive diffusion of drugs and allows a precise targeting into the rodent brain.
A Novel Rescue Technique for Difficult Intubation and Difficult Ventilation
1Department of Anesthesia, Children’s Hospital of Michigan, 2Department of Anesthesia, St. Jude Children’s Research Hospital
We describe a technique to maintain oxygenation and ventilation using an endotracheal tube inserted nasally to the level of the naso-pharynx while sealing the mouth and nares for successful positive pressure ventilation.
Focal Cerebral Ischemia Model by Endovascular Suture Occlusion of the Middle Cerebral Artery in the Rat
Surgical induction of ischemic brain damage in the rat is a widely used model for stroke research. Here we demonstrate the induction of focal cerebral ischemia by occlusion of the middle cerebral artery. Visualization of the resulting infarct by histological staining and magnetic resonance imaging is also shown.
How to Create and Use Binocular Rivalry
1Department of Psychology, New York University, 2Centre for Neural Science, New York University, 3Department of Psychology, Princeton University, 4Neuroscience Institute, Princeton University
Binocular rivalry occurs when the eyes are presented with different images at the same location: one image dominates while the other is suppressed, and dominance alternates periodically. Rivalry is useful for investigating perceptual selection and visual awareness. Here we describe several easy methods for creating and using binocular rivalry stimuli.
Automated Interactive Video Playback for Studies of Animal Communication
1Department of Visualization, Texas A&M University (TAMU), 2Department of Biology, Texas A&M University (TAMU)
Video playback is a widely used technique in animal behavior. We created and evaluated a program that applies rules-based, interactive playback of 3-D computer animations in response to real-time, automated data on subject behavior.
In Vivo Canine Muscle Function Assay
1Department of Neurology and Wake Forest Institute for Regenerative Medicine, Wake Forest University, 2Department of Human Nutrition, Foods and Exercise, Virginia Polytechnic Institute and State University, 3Departments of Pathology and Laboratory Medicine and Neurology and the Gene Therapy Center , University of North Carolina-Chapel Hill
We describe a minimally-invasive and painless method to measure canine hindlimb muscle strength and muscle response to repeated eccentric contractions.
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.
Imaging Leukocyte Adhesion to the Vascular Endothelium at High Intraluminal Pressure
Vascular Pharmacology Laboratory, Baker IDI Heart and Diabetes Institute, Monash University
This is a method to visualise leukocyte adhesion to the endothelium in harvested pressurised vessels. The technique enables studying vascular adhesion under shear flow with differing intraluminal pressures up to 200 mmHg thus mimic-ing the pathophysiological conditions of high blood pressure.
Eye Tracking Young Children with Autism
1School of Behavioral and Brain Sciences, University of Texas at Dallas, 2Carolina Institute for Developmental Disabilities, School of Medicine, University of North Carolina at Chapel Hill
Eye tracking has long been used to study gaze patterns in typically-developing individuals, but recent technological advancements have made its use with clinical populations, including autism, more feasible. While eye-tracking young children with autism can offer insight into early symptom manifestations, it involves methodological challenges. Suggestions for best practices are provided.
Portable Intermodal Preferential Looking (IPL): Investigating Language Comprehension in Typically Developing Toddlers and Young Children with Autism
Department of Psychology, University of Connecticut
A reliable home-based way to assess the language comprehension of very young typically developing children, as well as those with autism, is described. The method analyzes children's eye gaze while viewing side-by-side images but hearing an audio that matches only one image. Stimuli are designed with young participants in mind.
Non-invasive Optical Measurement of Cerebral Metabolism and Hemodynamics in Infants
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.
Optimized System for Cerebral Perfusion Monitoring in the Rat Stroke Model of Intraluminal Middle Cerebral Artery Occlusion
Department of Neuroscience and Biomedical Technologies, University of Milano Bicocca
Cerebral perfusion monitoring has been demonstrated to improve accuracy in ischemic stroke models. Technical difficulties often limit the use of this essential tool for cerebrovascular research. In this video, an optimized system is shown to obtain a single or multi-site hemodynamic monitoring during intraluminal middle cerebral artery occlusion in rats.
Direct Pressure Monitoring Accurately Predicts Pulmonary Vein Occlusion During Cryoballoon Ablation
1Department of Cardiac Electrophysiology, Piedmont Heart Institute, 2Cardiac Rhythm, Medtronic Inc.
Effective pulmonary vein isolation utilizing a cryoballoon depends on complete pulmonary vein occlusion. The point of occlusion can be effectively predicted by direct analysis of pulmonary vein pressure waveform analysis during balloon inflation using a simple and reproducible technique.
Whole-Body Nanoparticle Aerosol Inhalation Exposures
1Department of Physiology and Pharmacology, School of Medicine, West Virginia University, 2Center for Cardiovascular and Respiratory Sciences, West Virginia University, 3National Institute for Occupational Safety and Health
A whole-body nanoparticle aerosol inhalation exposure facility was constructed for nano-sized titanium dioxide (TiO2) inhalation toxicology studies. This system provides nano-TiO2 aerosol test atmospheres that have: 1) a steady mass concentration; 2) a homogenous composition free of contaminants; and 3) a stable particle size distribution during aerosol generation.
Echo Particle Image Velocimetry
Mechanical Engineering Department, University of New Hampshire
An echo particle image velocimetry (EPIV) system capable of acquiring two-dimensional fields of velocity in optically opaque fluids or through optically opaque geometries is described, and validation measurements in pipe flow are reported.
Assaying Locomotor Activity to Study Circadian Rhythms and Sleep Parameters in Drosophila
1Center for Advanced Biotechnology and Medicine, Rutgers University, 2Current Address: Department of Entomology, College of Agricultural and Environmental Sciences, University of California, Davis, 3Department of Molecular Biology and Biochemistry, Rutgers University
We describe procedures for recording daily locomotor activity rhythms of Drosophila and subsequent data analysis. Locomotor activity rhythms are a reliable behavioral output of animal circadian clocks and are used as the standard readout of clock function when studying circadian mutants or examining how the environment regulates the circadian system.
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.
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.
Preparing Undercut Model of Posttraumatic Epileptogenesis in Rodents
Partially isolated cortex (“undercut”) is an efficient animal model of posttraumatic epileptogenesis. Here we demonstrate how to make a novel surgical device and use it to make more precise and consistent lesions to generate this model.
Expired CO2 Measurement in Intubated or Spontaneously Breathing Patients from the Emergency Department
This video describes how to perform CO2 measurement in intubated as well as spontaneously breathing patients. The main clinical indications refer to emergency situations: (1) verifying adequate positioning of an endotracheal tube; (2) achieving normocapnia in trauma patients; (3) monitoring ventilation in the case of procedural sedation.
A Research Method For Detecting Transient Myocardial Ischemia In Patients With Suspected Acute Coronary Syndrome Using Continuous ST-segment Analysis
1Orvis School of Nursing, University of Nevada, Reno, 2The State University of New York at Buffalo, St. Joseph's Medical Center, 3Strong Memorial Hospital, University of Rochester Medical Center
Continuous 12-lead electrocardiographic (ECG) monitoring can identify transient myocardial ischemia, even when asymptomatic, among patients with suspected acute coronary syndrome (ACS). In this article we describe our method for initiating patient monitoring using a Holter device, downloading the ECG data for off-line analysis, and how to utilize the ECG software to identify transient ischemia.
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.
Utilizing Transcranial Magnetic Stimulation to Study the Human Neuromuscular System
Transcranial magnetic stimulation (TMS) is a non-invasive tool to gain insight on the physiology and function of the human nervous system. Here, we present our TMS techniques to study cortical excitability of the upper limb and lumbar musculature.
Neurocircuit Assays for Seizures in Epilepsy Mutants of Drosophila
1Department of Molecular and Cell Biology, University of California, Berkeley, 2Department of Environmental Science, Policy Management, University of California, Berkeley
Using high frequency electrical stimulation, seizure-like activity can be induced in Drosophila. This activity is easily recorded from the giant fiber system.
The Hypoxic Ischemic Encephalopathy Model of Perinatal Ischemia
Department of Neurology and Neurological Sciences, Stanford University School of Medicine
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.
Dissection of Hippocampal Dentate Gyrus from Adult Mouse
1Japan Science and Technology Agency, Core Research for Evolutionary Science and Technology (CREST), 2Division of Systems Medical Science, Institute for Comprehensive Medical Science, Fujita Health University, 3Department of Psychiatry, Graduate School of Medicine, Kyoto University, 4Genetic Engineering and Functional Genomics Group, Horizontal Medical Research Organization, Graduate School of Medicine, Kyoto University, 5Center for Genetic Analysis of Behavior, National Institute for Physiological Sciences, National Institutes of Natural Sciences
A dissection technique for removal of the dentate gyrus from adult mouse under a stereomicroscope was demonstrated in this video-recorded protocol.
Intra-Operative Behavioral Tasks in Awake Humans Undergoing Deep Brain Stimulation Surgery
1Nayef Al-Rodhan Laboratories for Cellular Neurosurgery and Neurosurgical Technology, Harvard Medical School, 2Department of Neurosurgery , Massachusetts General Hospital
Deep brain stimulation surgery offers a unique opportunity to examine information encoding in the awake human brain. This article will describe intra-operative methods used to perform cognitive and behavioral tasks while simultaneously acquiring physiological data such as EMG, single-unit neuronal activity and/or local field potentials.
Studying the Integration of Adult-born Neurons
Department of Neurobiology & Behavior, State University of New York at Stony Brook
A way to study the integration of newborn dentate granule cells in adult animals is described. This technique uses an engineered retrovirus to label newborn neurons, followed by electrophysiological recordings to determine in vivo functional integration.
Paradigms for Pharmacological Characterization of C. elegans Synaptic Transmission Mutants
Department of Biological Sciences, University of Alabama
This video demonstrates how to employ two neural stimulants, aldicarb and pentylenetetrazole (PTZ), in complementary ways to study synaptic function in the nematode, C. elegans. This complementary approach may also be used to shed light on evolutionarily conserved mechanisms for modulating neuronal synchrony and has implications for epilepsy and seizures.
The Use of Carboxyfluorescein Diacetate Succinimidyl Ester (CFSE) to Monitor Lymphocyte Proliferation
Department of Immunology, John Curtin School of Medical Research, Australian National University
CFSE covalently labels long-lived intracellular molecules with the fluorescent dye, carboxyfluorescein. As such, when a CFSE-labeled cell divides, its progeny have half the amount of fluorescence, which can thereby be used to assess cell division. This article describes the procedures typically used for labeling mouse lymphocytes with CFSE.
Long-term Lethal Toxicity Test with the Crustacean Artemia franciscana
1Department of Environmental Quality Monitoring, Institute for Environmental Protection and Research, 2Regional Agency for Environmental Protection in Emilia-Romagna
This study concerns the development and standardization of a valuable methodological protocol to determine long-term (14 days) lethal toxicity exerted by chemical substances, industrial wastewater or sewage and liquid environmental samples on the saltwater crustacean, Artemia franciscana.
Testing Visual Sensitivity to the Speed and Direction of Motion in Lizards
Center for the Integrative Study of Animal Behaviour, Macquarie University
Testing visual sensitivity in lizards using an operant conditioning paradigm that employs video playback of random-dot kinematograms and computer-generated invertebrates.
Computer-Generated Animal Model Stimuli
Center for the Integrative Study of Animal Behaviour, Macquarie University
Computer-generated stimuli using the Jacky dragon as a model.
Using an EEG-Based Brain-Computer Interface for Virtual Cursor Movement with BCI2000
1Department of Biomedical Engineering, University of Wisconsin-Madison, 2Wadsworth Center, New York State Dept. of Health
In this video, we demonstrate the steps required to run a brain-computer interface experiment, including setting up the EEG cap, calibrating the system, and training the user to move a cursor in two dimensions using imagined movements.
Electrospinning Fibrous Polymer Scaffolds for Tissue Engineering and Cell Culture
Department of Bioengineering, University of Pennsylvania
The process of electrospinning polymers for tissue engineering and cell culture is addressed in this article. Specifically, the electrospinning of photoreactive macromers with additional processing capabilities of photopatterning and multi-polymer electrospinning is described.
Transthoracic Echocardiography in Mice
1Department of Molecular Physiology and Biophysics, Baylor College of Medicine (BCM), 2The Margaret M. and Albert B. Alkek Department of Medicine, Baylor College of Medicine (BCM)
Transthoracic echocardiography offers a noninvasive method for the evaluation of cardiac function in mice. A combination of ultrasound and Doppler imaging modalities can be used to obtain dimensional measurements of the heart and intracardiac blood flow, which together provide an assessment of cardiac systolic and diastolic performance.
