May 2012: This Month in JoVE
Here are some highlights from the May 2012 Issue of Journal of Visualized Experiments (JoVE).
MPI CyberMotion Simulator: Implementation of a Novel Motion Simulator to Investigate Multisensory Path Integration in Three Dimensions
1Department of Human Perception, Cognition and Action, Max Planck Institute for Biological Cybernetics, 2Laboratoire de Physiologie de la Perception et de l'Action, Collège de France - CNRS, 3Department of Brain and Cognitive Engineering, Korea University
An efficient way to gain insight into how humans navigate themselves in three dimensions is described. The method takes advantage of a motion simulator capable of moving observers in ways unattainable by traditional simulators. Results confirm that movement in the horizontal plane is underestimated, while vertical movement is overestimated.
Operant Learning of Drosophila at the Torque Meter
Department of Neurobiology, Free University of Berlin
Measuring the yaw torque of tethered Drosophila with the torque meter allows the neuroscientist exquisite control of the stimulus situation of the experimental animal. Together with the unique genetic tools available in the fruit fly, this paradigm is used for a wide variety of neurobiological research.
Visually Mediated Odor Tracking During Flight in Drosophila
Department of Physiological Science, University of California, Los Angeles
Here we describe how to optimize the acquired video image for an olfactory magnetic-tether (OMT) apparatus. We also describe two sample experimental protocols for studying visuo-olfactory fusion.
Bringing the Visible Universe into Focus with Robo-AO
1Caltech Optical Observatories, California Institute of Technology, 2Department of Astronomy, California Institute of Technology, 3Dunlap Institute for Astronomy and Astrophysics, University of Toronto, 4Inter-University Centre for Astronomy & Astrophysics, 5Observatories of the Carnegie Institution for Science, 6Benoziyo Center for Astrophysics, Weizmann Institute of Science
Light from astronomical objects must travel through the earth's turbulent atmosphere before it can be imaged by ground-based telescopes. To enable direct imaging at maximum theoretical angular resolution, advanced techniques such as those employed by the Robo-AO adaptive-optics system must be used.
A Magnetic Tether System to Investigate Visual and Olfactory Mediated Flight Control in Drosophila
Department of Physiological Science, University of California, Los Angeles
Here we describe how to tether a fly in an olfactory magnetic-tether (OMT) apparatus. We describe how to align the rare-earth magnets and odor ports, and how to set mass flow rates for both the stimulus delivery and vacuum suction to achieve optimal odor tracking.
Driving Simulation in the Clinic: Testing Visual Exploratory Behavior in Daily Life Activities in Patients with Visual Field Defects
1Department of Neurology, Universitätsmedizin Charité, 2Center for Stroke Research Berlin (CSB), Universitätsmedizin Charité, 3Berlin School of Mind and Brain, Humboldt Universität zu Berlin
Patients with visual deficits after stroke report about different constraints in daily life most likely due to variable compensatory strategies, which are difficult to differentiate in clinical routine. We present a clinical set-up which allows measurement of different compensatory head- and eye-movement-strategies and evaluating their effects on driving performance.
A Novel Technique of Rescuing Capsulorhexis Radial Tear-out using a Cystotome
1Department of Ophthalmology, Hairmyres Hospital, NHS Lanarkshire, 2Department of Ophthalmology, Royal Devon and Exeter NHS Foundation Trust, 3National Institute of Ophthalmology, 4Department of Ophthalmology, South Devon Healthcare NHS Trust
Capsulorhexis is an important step in phacoemulsification surgery. A surgeon creates a continous curvilinear tear on the anterior lens capsule by controlling the tearing vector forces. A peripherally extended tear is a serious complication. This video demonstrates a novel technique of rescuing capsular radial tear out using a cystotome.
A Novel Capsulorhexis Technique Using Shearing Forces with Cystotome
1Department of Ophthalmology, Hairmyres Hospital, NHS Lanarkshire, 2Royal Devon and Exeter NHS Foundation Trust, Department of Ophthalmology, 3Department of Ophthalmology, South Devon Healthcare NHS Trust
This video demonstrates a novel capsulorhexis technique in modern cataract surgery. Capsulorhexis is the most difficult and important part of phacoemulsification surgery.
X-ray Dose Reduction through Adaptive Exposure in Fluoroscopic Imaging
We are developing a dynamic adaptive exposure technique using our scanning beam digital X-ray system. Rather than exposing an object uniformly, the exposure is adapted depending on the opacity of the object. Here we show an experiment on an anthropomorphic phantom that resulted in a dose saving of 30%.
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.
Axon Stretch Growth: The Mechanotransduction of Neuronal Growth
1Departments of Biomedical Engineering, New Jersey Institute of Technology, 2Graduate School of Biomedical Sciences, University of Medicine and Dentistry of New Jersey
A unique tissue engineering method was developed to elongate numerous nerve fibers in culture by recapitulating axon stretch growth; a form of nervous system growth whereby nerves elongate in conjunction with growth of the enlarging body.
Methods to Quantify Pharmacologically Induced Alterations in Motor Function in Human Incomplete SCI
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).
An Experimental Platform to Study the Closed-loop Performance of Brain-machine Interfaces
Department of Bioengineering, Imperial College London
We use a closed-loop fly-machine interface to investigate general principles in neuronal control.
Construction of a High Resolution Microscope with Conventional and Holographic Optical Trapping Capabilities
Department of Physics and Astronomy, University of Utah
The system described herein employs a traditional optical trap as well as an independent holographic optical trapping line, capable of creating and manipulating multiple traps. This allows for the creation of complex geometric arrangements of refractive particles while also permitting simultaneous high-speed, high-resolution measurements of the activity of biological enzymes.
Development of an Audio-based Virtual Gaming Environment to Assist with Navigation Skills in the Blind
1Laboratory for Visual Neuroplasticity, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, 2Department of Computer Science and Center for Advanced Research in Education (CARE), University of Chile
Audio-based Environment Simulator (AbES) is virtual environment software designed to improve real world navigation skills in the blind.
Stereotactic Radiosurgery for Gynecologic Cancer
1Department of Radiation Oncology, University Hospitals Case Medical Center and Case Western Reserve University School of Medicine, 2Department of Obstetrics and Gynecology, Division of Gynecologic Oncology, University Hospitals Case Medical Center and Case Western Reserve University School of Medicine
Stereotactic body radiotherapy (SBRT) involves image-guided, ablative radiation delivered to cancer targets refractory to chemotherapy or to conventional radiation treatment. The robotic-armed Cyberknife SBRT system, using sophisticated target localization, delivers hypofractionated radiation doses capable of sterilizing cancer targets. This article will consider new therapeutic roles of SBRT for gynecological cancers.
A Protocol for Comprehensive Assessment of Bulbar Dysfunction in Amyotrophic Lateral Sclerosis (ALS)
1Department of Speech-Language Pathology, University of Toronto, 2ALS/ MN Clinic, Sunnybrook Health Science Centre, 3Department of Special Education and Communication Disorders, University of Nebraska-Lincoln, 4Department of Neurology, Munroe-Meyer Institute, University of Nebraska Medical Center, 5Department of Neurology, University of Toronto
Objective assessments of the physiological mechanisms that support speech are needed to monitor disease onset and progression in persons with ALS and to quantify treatment effects in clinical trials. In this video, we present a comprehensive, instrumentation-based protocol for quantifying speech motor performance in clinical populations.
Correlating Behavioral Responses to fMRI Signals from Human Prefrontal Cortex: Examining Cognitive Processes Using Task Analysis
1Department of Psychology, Centre for Vision Research, York University, 2Department of Biology, Centre for Vision Research, York University
The goal of our research is to correlate behavior to brain activity. Accurate behavioral measures and imaging techniques allow us to elucidate brain-behavior relationships.
High-Resolution Video Tracking of Locomotion in Adult Drosophila Melanogaster
The study of complex locomotor behavior in Drosophila melanogaster is dependent upon the ability to quantify changes in a given fly's movement. This article demonstrates how to do this using a high-resolution tracking system.
State-Dependency Effects on TMS: A Look at Motive Phosphene Behavior
1Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center, 2Brain Research Unit, Low Temperature Laboratory and Advanced magnetic Imaging Center, Aalto University School of Science and Technology
In this article, we examine the effects of visually relevant state dependency on TMS induced motive phosphenic presentations.
Quantitative Visualization and Detection of Skin Cancer Using Dynamic Thermal Imaging
Department of Mechanical Engineering, The Johns Hopkins University
We demonstrated that malignant pigmented lesions with increased metabolic activity generate quantifiable amounts of heat and the measurement of the transient thermal response of the skin to a cooling excitation allows quantitative identification of melanoma and other skin cancers (vs. non-proliferative nevi) at an early stage of the disease.
March 2013: This Month in JoVE
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).
The Measurement and Treatment of Suppression in Amblyopia
1Department of Optometry and Vision Science, University of Auckland, 2Department of Ophthalmology, McGill University, 3Centre for Intelligent Machines, McGill University
Amblyopia is a developmental disorder of the visual cortex that is often accompanied by strong suppression of one eye. We present a new technique for measuring and treating interocular suppression in patients with amblyopia that can be deployed using virtual reality goggles or a portable iPod Touch device.
A Simple Protocol for Platelet-mediated Clumping of Plasmodium falciparum-infected Erythrocytes in a Resource Poor Setting
1Malawi-Liverpool-Wellcome Trust Clinical Research Programme, 2Liverpool School of Tropical Medicine, 3Department of Microbiology, Division of Medical Parasitology, New York University School of Medicine
This method investigates the platelet-mediated clumping phenotype of Plasmodium falciparum-infected erythrocytes (pRBC) in clinical isolates. This is performed by isolating and co-incubating platelet-rich plasma and a suspension of pRBC.
Optical Trapping of Nanoparticles
Electrical and Computer Engineering, University of Victoria
The following setup approach details low power optical trapping of dielectric nanoparticles using a double-nanohole in metal film.
In vitro Assembly of Semi-artificial Molecular Machine and its Use for Detection of DNA Damage
1Neurosurgery, Baylor College of Medicine, 2Michael E. DeBakey Veterans Affairs Medical Center, 3Molecular & Cellular Biology, Baylor College of Medicine
We demonstrate the assembly and application of a molecular-scale device powered by a topoisomerase protein. The construct is a bio-molecular sensor which labels two major types of DNA breaks in tissue sections by attaching two different fluorophores to their ends.
Monitoring the Wall Mechanics During Stent Deployment in a Vessel
Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln
Stent-induced arterial strain distributions are characterized using an optical surface strain measurement system. This visualization technique is used to gain insights into the impact of stent implantation on the host vessel.
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.
Reverse Total Shoulder Arthroplasty
Reverse total shoulder arthroplasty is indicated for the treatment of conditions that cannot be treated with conventional arthroplasty or other procedures. These primarily include degenerative and incapacitating conditions with irreparable rotator cuff and loss of the normal biomechanical coupling of the shoulder.
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.
Making MR Imaging Child's Play - Pediatric Neuroimaging Protocol, Guidelines and Procedure
1Department of Developmental Medicine, Children’s Hospital Boston, 2Department of Neuropsychology, University of Zurich, 3Graduate School of Education, Harvard, 4Harvard Medical School
Despite an increase in the use of structural and functional magnetic resonance imaging (fMRI) in humans, the study of young pediatric populations remains a challenge. We present a hands-on, step-by-step video protocol including guidelines for clinicians and researchers intending to perform (f)MRI in young children.
Multiparametric Optical Mapping of the Langendorff-perfused Rabbit Heart
Department of Biomedical Engineering, Washington University in St. Louis
This article describes the basic procedures for conducting optical mapping experiments in the Langendorff-perfused rabbit heart using the panoramic imaging system, and the dual (voltage and calcium) imaging modality.
Synthetic, Multi-Layer, Self-Oscillating Vocal Fold Model Fabrication
Department of Mechanical Engineering, Brigham Young University
The methodology for fabricating synthetic vocal fold models is described. The models are life-sized and mimic the multi-layer structure of the human vocal folds. Results show the models to self-oscillate at pressures comparable to lung pressure and demonstrate flow-induced vibratory responses that are similar to those of human vocal folds.
Design and Assembly of an Ultra-light Motorized Microdrive for Chronic Neural Recordings in Small Animals
1Center for Brain Science, Harvard University, 2Program in Neuroscience, Harvard University, 3Department of Organismic and Evolutionary Biology, Harvard University
The design, fabrication and assembly of an ultra-light motorized microdrive is described. The device provides a cost-effective and easy-to-use solution for chronic recordings of single units in small behaving animals.
C. elegans Tracking and Behavioral Measurement
1Donnelly Centre, University of Toronto, 2Department of Physics and Astronomy, Vrije Universiteit, 3Okinawa Institute of Science and Technology, 4Department of Physics, University of Toronto
We have developed a video-rate tracking microscope system that can record and quantify C. elegans behavior at high resolution and high speeds. We have also developed computational methods to reduce the dimensionality of the worm images to a fundamental set of measurements that completely describe the shape of the worm.
Quantifying Glomerular Permeability of Fluorescent Macromolecules Using 2-Photon Microscopy in Munich Wistar Rats
Medicine/Nephrology, Indiana University School of Medicine
A technique utilizing high resolution intavital 2-photon microscopy to directly visualize and quantify gloemrular filtration in surface glomeruli. This method allows for direct determination of permeability characteristics of macromolecules in both normal and diseased states.
Live Imaging of GFP-labeled Proteins in Drosophila Oocytes
Department of Biology, Vassar College
A protocol for live imaging of GFP-tagged proteins or autofluorescent structures in individual Drosophila oocytes is described.
Magnetic Resonance Derived Myocardial Strain Assessment Using Feature Tracking
1The Heart Institute, Cincinnati Children Hospital Medical Center (CCHMC), 2TomTec, Imaging Systems GmbH, 3AMID, Advanced Medical Imaging Development SRL, 4The Heart and Vascular Center, The Christ Hospital
An accurate and practical method to measure parameters like strain in myocardial tissue is of great clinical value, since it has been shown, that strain is a more sensitive and earlier marker for contractile dysfunction than the frequently used parameter EF.
Creating Rigidly Stabilized Fractures for Assessing Intramembranous Ossification, Distraction Osteogenesis, or Healing of Critical Sized Defects
Department of Orthopaedic Surgery, University of California, San Francisco
This article describes a method for stabilizing long bone fractures that is based on the application of modified Ilizarov external fixators 1-3. After application of the fixators and creation of the bone injury, healing can be assessed, distraction osteogenesis can be performed, or non-union or critical sized defect can be created and used to study therapeutic interventions.
Magnetic Resonance Elastography Methodology for the Evaluation of Tissue Engineered Construct Growth
1Department of Biological Systems Engineering, University of Nebraska-Lincoln, 2Department of Engineering Mechanics, University of Nebraska-Lincoln
The procedure demonstrates the methodology of magnetic resonance elastography for monitoring the engineered outcome of adipose and osteogenic tissue engineered constructs through noninvasive local assessment of the mechanical properties using microscopic magnetic resonance elastography (μMRE).
Stretching Short Sequences of DNA with Constant Force Axial Optical Tweezers
1LSA Biophysics, University of Michigan, 2LSA Biophysics, Department of Physics, University of Michigan
We illustrate the use of a constant force axial optical tweezers to explore the mechanical properties of short DNA molecules. By stretching DNA axially, we minimize steric hindrances and artifacts arising in conventional lateral manipulation, allowing us to study DNA molecules as short as ~100 nm.
Quantitatively Measuring In situ Flows using a Self-Contained Underwater Velocimetry Apparatus (SCUVA)
1Applied Ocean Physics and Engineering, Woods Hole Oceanographic Institution, 2Environmental Science and Marine Biology, Roger Williams University, 3Marine Biology Laboratory, Whitman Center, 4Department of Biology, Providence College, 5Departments of Aeronautics and Bioengineering, California Institute of Technology
This protocol provides instructions on how to use a self-contained underwater velocimetry apparatus (SCUVA), which is designed for quantification of in situ animal-generated flows. In addition, this protocol addresses challenges posed by field conditions, and includes operator motion, predicting position of animals, and orientation of SCUVA.
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.
In vivo Measurement of the Mouse Pulmonary Endothelial Surface Layer
Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado School of Medicine
The endothelial glycocalyx/endothelial surface layer is ideally studied using intravital microscopy. Intravital microscopy is technically challenging in a moving organ such as the lung. We demonstrate how simultaneous brightfield and fluorescent microscopy may be used to estimate endothelial surface layer thickness in a freely-moving in vivo mouse lung.
High-resolution Functional Magnetic Resonance Imaging Methods for Human Midbrain
This article describes techniques to perform high-resolution functional magnetic resonance imaging with 1.2 mm sampling in human midbrain and subcortical structures using a 3T scanner. Use of these techniques to resolve topographic maps of visual stimulation in the human superior colliculus (SC) is given as an example.
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.
A Microfluidic-based Hydrodynamic Trap for Single Particles
1Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, 2Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign
In this article, we present a microfluidic-based method for particle confinement based on hydrodynamic flow. We demonstrate stable particle trapping at a fluid stagnation point using a feedback control mechanism, thereby enabling confinement and micromanipulation of arbitrary particles in an integrated microdevice.
Intravital Microscopy of the Inguinal Lymph Node
1Interdisciplinary Science, University of Northern British Columbia, 2Northern Medical Program, University of Northern British Columbia
A technique for performing intravital microscopy of the inguinal lymph node (LN) is outlined. Such technique allows for real-time, in vivo study of the lymph node microvasculature and structure both during homeostasis and infection. This technique can be adapted to cell trafficking studies and to other lymph node sites.
High-Resolution Endocardial and Epicardial Optical Mapping in a Sheep Model of Stretch-Induced Atrial Fibrillation
Center for Arrhythmia Research. Internal Medicine, University of Michigan
This report provides a detailed description of the methodology and results of simultaneous endocardial and epicardial optical mapping of electrical excitation in the intact left atrium of a Langendorff-perfused sheep heart during stretch-induced atrial fibrillation.
