Sherry, Tim, Lam, Brian, Kao, Michelle, Nowak, Nate, Mendoza, Steve, Kim, Taejoon, Arisaka, Katsushi, Madruga, Blake, Jiang, Karen
[
International Worm Meeting,
2015]
Worm tracking of freely moving worms is essential to study the connection between behavior and neural activity. However, these microscopes are often limited in their ability to track worms under various behavioral simulations. We present a fluorescence worm tracking microscope that has an open geometry and thus can track worms even if the behavioral platform is difficult or impossible to move via a motorized stage. As opposed to other automated worm tracking systems, our microscope is fully mobile-where all the optical components are mounted on top of a motorized xy stage-while the sample stage where C. elegans rests is stationary. This platform allows for ratiometric calcium imaging while also tracking a dark field worm image for behavioral analysis, running at 15 frames per second. The current configuration has three cameras, two for each of the YFP and CFP channels, and a dark field image showing the worm body, under a 10x magnification; the microscope can also be adjusted to image at 20x. Being able to track freely moving worms without moving the sample stage, allows our microscope to perform worm tracking in experimental conditions that similar systems have not been able to achieve. In addition, since the sample is stationary, we also avoid introducing confounding effects on the worms due to stage acceleration. To test this novel hardware, we run a thermotaxis experiment tracking a worm without moving the temperature platform. Our worm was labeled with AIY::CAM and we find a correlation between the AIY activity and the temperature of the head location during isothermal behavior. Our methodology could also apply to other behavioral experiments where an external stimulus would be hard to move via a motorized stage, such as an electrotaxis experiment.