September 2011: This Month in JoVE

Summary

Here are some highlights from the September 2011 Issue of Journal of Visualized Experiments (JoVE).

Protocol

Live Imaging of Dorsal Root Axons after Rhizotomy

Andrew Skuba¹, B. Timothy Himes^{2, 3}, Young-Jin Son^4
1Temple University, Shriners Hospitals Pediatric Research Center and Department of Anatomy and Cell Biology, ²Medical Research Service, Department of Veterans Affairs Hospital, ³Department of Neurobiology and Anatomy, Drexel University College of Medicine, ⁴Shriners Hospitals Pediatric Research Center and Department of Anatomy and Cell Biology, Temple University School of Medicine

An in vivo imaging protocol to monitor primary sensory axons following dorsal root crush is described. The procedures utilize wide-field fluorescence microscopy and thy1-YFP transgenic mice, and permit repeated imaging of axon regeneration over 4 cm in the PNS and axon interactions with the interface of the CNS.

Introducing Shear Stress in the Study of Bacterial Adhesion

Magali Soyer, Guillaume Duménil
Blood vessels as a target for infection, Paris center for cardiovascular research, INSERM U970

During the infection process, a key step is the adhesion of pathogens with host cells. In most instances this adhesion step occurs in the presence of mechanical stress generated by flowing liquid. We describe a technique that introduces shear stress as an important parameter in the study of bacterial adhesion.

Guide Wire Assisted Catheterization and Colored Dye Injection for Vascular Mapping of Monochorionic Twin Placentas

Eric B. Jelin¹, Samuel C. Schecter¹, Kelly D. Gonzales¹, Shinjiro Hirose¹, Hanmin Lee¹, Geoffrey A. Machin², Larry Rand³, Vickie A. Feldstein^4
1Division of Pediatric and Fetal Surgery, Department of Surgery, University of California, San Francisco, ²Department of Pathology, University of Alberta, ³Department of Obstretics and Gynecology, University of California, San Francisco, ⁴Department of Radiology, University of California, San Francisco

Vascular mapping of monochorionic (MC) twin placentas after birth provides a means for detailed demonstration of vascular connections between the twins’ circulations. Imbalance of these connections is thought to play a pivotal role in the development of complications of MC twinning including twin-to-twin transfusion syndrome.

Accurate and Simple Evaluation of Vascular Anastomoses in Monochorionic Placenta using Colored Dye

Enrico Lopriore¹, Femke Slaghekke², Johanna M. Middeldorp², Frans J. Klumper², Jan M. van Lith³, Frans J. Walther¹, Dick Oepkes^2
1Division of Neonatology, Department of Pediatrics, Leiden University Medical Center, ²Division of Fetal Therapy, Department of Obstetrics, Leiden University Medical Center, ³Department of Obstetrics, Leiden University Medical Center

Twin-to-twin transfusion syndrome and twin anemia polycythemia sequence are two potentially devastating problems in perinatal medicine. Both disorders occur only in monochorionic twins and result from unbalanced blood flow through placental vascular anastomoses. We provide a simple protocol to accurately evaluate the presence of vascular anastomoses using colored dye injection of placental vessels after birth.

Diagnosis of Ecto- and Endoparasites in Laboratory Rats and Mice

Christina M. Parkinson¹, Alexandra O'Brien¹, Theresa M. Albers¹, Meredith A. Simon¹, Charles B. Clifford¹, Kathleen R. Pritchett-Corning^{2, 3
1}Research Animal Diagnostic Services, Charles River, ²Research Models and Services, Charles River, ³Department of Comparative Medicine, University of Washington

This article describes various procedures for screening rats and mice to detect endo- or ectoparasitism. Several diagnostic assays will be demonstrated, both those suitable for use on live animals and those used after euthanasia of the animal. Photographs to aid in identification of rat and mouse parasites will be included.

Autologous Endothelial Progenitor Cell-Seeding Technology and Biocompatibility Testing For Cardiovascular Devices in Large Animal Model

Alexandra E. Jantzen¹, Whitney O. Lane², Shawn M. Gage³, Justin M. Haseltine¹, Lauren J. Galinat¹, Ryan M. Jamiolkowski⁴, Fu-Hsiung Lin³, George A. Truskey¹, Hardean E. Achneck^3
1Department of Biomedical Engineering, Duke University , ²School of Medicine, Duke University , ³Department of Surgery, Duke University Medical Center, ⁴School of Medicine, University of Pennsylvania

A method for seeding titanium blood-contacting biomaterials with autologous cells and testing biocompatibility is described. This method uses endothelial progenitor cells and titanium tubes, seeded within minutes of surgical implantation into porcine venae cavae. This technique is adaptable to many other implantable biomedical devices.

Multiparametric Optical Mapping of the Langendorff-perfused Rabbit Heart

Qing Lou, Wenwen Li, Igor R. Efimov
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.

Optical Mapping of Action Potentials and Calcium Transients in the Mouse Heart

Di Lang, Matthew Sulkin, Qing Lou, Igor R. Efimov
Department of Biomedical Engineering, Washington University in St. Louis

This paper details the dissection procedure, instrumental setup, and experimental conditions during optical mapping of transmembrane potential (Vm) and intracellular calcium transient (CaT) in intact isolated Langendorff perfused mouse hearts.

Imaging G-protein Coupled Receptor (GPCR)-mediated Signaling Events that Control Chemotaxis of Dictyostelium Discoideum

Xuehua Xu, Tian Jin
Chemotaxis Signal Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health

Here, we describe detailed live cell imaging methods for investigating chemotaxis. We present fluorescence microscopic methods to monitor spatiotemporal dynamics of signaling events in migrating cells. Measurement of signaling events permits us to further understand how a GPCR-signaling network achieves gradient sensing of chemoattractants and controls directional migration of eukaryotic cells.

Using a Comparative Species Approach to Investigate the Neurobiology of Paternal Responses

Catherine L. Franssen¹, Massimo Bardi², Kelly G. Lambert^1
1Department of Psychology, Randolph-Macon College, ²Department of Psychology, Marshall University

The comparative species approach allows behavioral neuroscientists to explore various neurobiological factors associated with specific behaviors viewed as characteristic of a specific animal model. Taking advantage of naturally occurring differences in behavior between closely related species, this technique doesn’t require invasive techniques to manipulate the expression of the behavior.