JoVE 2013: The Year in Review

Summary

 

Protocol

Optogenetic Stimulation of Escape Behavior in Drosophila melanogaster

Saskia E.J. de Vries, Tom Clandinin

Department of Neurobiology, Stanford University

Genetically encoded optogenetic tools enable noninvasive manipulation of specific neurons in the Drosophila brain. Such tools can identify neurons whose activation is sufficient to elicit or suppress particular behaviors. Here we present a method for activating Channelrhodopsin2 that is expressed in targeted neurons in freely walking flies.

Optogenetic Activation of Zebrafish Somatosensory Neurons using ChEF-tdTomato

Ana Marie S. Palanca, Alvaro Sagasti

Department of Molecular, Cell, and Developmental Biology, University of California, Los Angeles

Optogenetic techniques have made it possible to study the contribution of specific neurons to behavior. We describe a method in larval zebrafish for activating single somatosensory neurons expressing a channelrhodopsin variant (ChEF) with a diode-pumped solid state (DPSS) laser and recording the elicited behaviors with a high-speed video camera.

Determining 3D Flow Fields via Multi-camera Light Field Imaging

Tadd T. Truscott¹, Jesse Belden², Joseph R. Nielson¹, David J. Daily¹, Scott L. Thomson¹

¹Department of Mechanical Engineering, Brigham Young University, ²Naval Undersea Warfare Center, Newport, RI

A technique for performing quantitative three-dimensional (3D) imaging for a range of fluid flows is presented. Using concepts from the area of Light Field Imaging, we reconstruct 3D volumes from arrays of images. Our 3D results span a broad range including velocity fields and multi-phase bubble size distributions.

Measuring Intracellular Ca²⁺ Changes in Human Sperm using Four Techniques: Conventional Fluorometry, Stopped Flow Fluorometry, Flow Cytometry and Single Cell Imaging

Esperanza Mata-Martínez¹, Omar José¹, Paulina Torres-Rodríguez¹, Alejandra Solís-López¹, Ana A. Sánchez-Tusie¹, Yoloxochitl Sánchez-Guevara¹, Marcela B. Treviño², Claudia L. Treviño¹

¹Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología-Universidad Nacional Autónoma de México, ²Math and Sciences Department, Edison State College

Intracellular Ca²⁺ dynamics are very important in sperm physiology and Ca²⁺-sensitive fluorescent dyes constitute a versatile tool to study them. Population experiments (fluorometry and stopped flow fluorometry) and single cell experiments (flow cytometry and single cell imaging) are used to track spatio-temporal [Ca²⁺] changes in human sperm cells.

Designing a Bio-responsive Robot from DNA Origami

Eldad Ben-Ishay, Almogit Abu-Horowitz, Ido Bachelet

Faculty of Life Sciences and the Institute for Nanotechnology & Advanced Materials, Bar-Ilan University

DNA origami is a powerful method for fabricating precise nanoscale objects by programming the self-assembly of DNA molecules. Here, we describe how DNA origami can be utilized to design a robotic robot capable of sensing biological cues and responding by shape shifting, subsequently relayed to a desired effect.

Creating Dynamic Images of Short-lived Dopamine Fluctuations with lp-ntPET: Dopamine Movies of Cigarette Smoking

Evan D. Morris^1,2,3,4, Su Jin Kim^1,3, Jenna M. Sullivan^1,3,4, Shuo Wang^3,4, Marc D. Normandin⁵, Cristian C. Constantinescu⁶, Kelly P. Cosgrove^1,2,3

¹Diagnostic Radiology, Yale University, ²Psychiatry, Yale University, ³Yale PET Center, Yale University, ⁴Biomedical Engineering, Yale University, ⁵Nuclear Medicine, Massachusetts General Hospital, ⁶Radiological Sciences, University of California, Irvine

We present a novel PET imaging approach for capturing dopamine fluctuations induced by cigarette smoking. Subjects smoke in the PET scanner. Dynamic PET images are modeled voxel-by-voxel in time by lp-ntPET, which includes a time-varying dopamine term. The results are 'movies' of dopamine fluctuations in the striatum during smoking.

Visualization of Craniofacial Development in the sox10: kaede Transgenic Zebrafish Line Using Time-lapse Confocal Microscopy

Lisa Gfrerer, Max Dougherty, Eric C. Liao

Center for Regenerative Medicine, Massachusetts General Hospital

Visualization of experimental data has become a key element in presenting results to the scientific community. Generation of live time-lapse recording of growing embryos contributes to better presentation and understanding of complex developmental processes. This protocol is a step-by-step guide to cell labeling via photoconversion of kaede protein in zebrafish.