Yen, Jessica, Tan, Trudy, Jin, Suying, Zadoorian, Arbi, Arisaka, Katsushi, Huang, Rebecca, Narain, Shreya, D'Orazio, Etta, Yamada, Mandi, Mai, Phat, Park, Jane, Yang, Karen, Carmona, Javier, Kim, Ted, Liu, Junliang, Mendoza, Steve, Watson, Sonya
[
International Worm Meeting,
2017]
Caenorhabditis elegans exhibit a well-characterized host of thermosensory behaviors necessary for efficient navigation, foraging, and survival in the natural environment. Many of the neural structures responsible for temperature sensing have evolved to exceptional sensitivity over time, giving rise to cognitively complex, deterministic behaviors such as bias orientation and 90 degree turning. In order to better comprehend the underlying neural circuitry responsible for such behaviors, multiple PID-controlled hardware systems have been constructed to generate and control various thermal gradient conditions within 0.05 degrees C, over durations of ~ 30 minutes. Additionally, an IR laser-based thermosensory system has been fabricated, to provide spatiotemporally controlled thermal stimulus at a highly localized region of the worm's body, enabling the establishment of a virtual thermal environment on which the worm can behave. Using these tools, we have investigated several intricacies of C. elegans' response to temperature, including the mechanism governing 90 degree turns and biased orientation during negative thermotaxis. Making use of line confocal calcium imaging microscopy methods, the dynamics of the AFD sensory neuron and the AIY interneuron were observed, yielding multiple noteworthy datasets. Custom-written MatLab image processing tools based on Goodman and NEMO were utilized to conduct a systematic motional analysis in a variety of experimental thermal conditions. This poster aims to outline the some of these recent advancements in thermotaxis investigation in the Elegant Mind Club, along with preliminary supporting datasets, on a case-by-case basis.
Wang, Emily, Tahmazyan , Arman, Zargarian, Ninelle, Dooley, Casey, Mai, Phat, Tan, Trudy, Liu, Junliang, Ovakimyan, Andrew, Ngo, Ryan, Chen, Cindy, Watson, Sonya, Arisaka, Katsushi, Huang, Rebecca, Yamada , Mandi, D'Orazio, Etta, Mendoza, Steve, Carmona, Javier, Ramirez, Erica, Pulkinen, Elena, Jin, Suying
[
International Worm Meeting,
2017]
Caenorhabditis elegans have an ability to exhibit isothermal behavior up to a remarkable precision of a 0.05 degree difference. However, the neural circuitry underlying isothermal behavior remains elusive as it is very difficult to track neuronal activity in freely moving specimen. Furthermore, the computational power of their nervous system is often overlooked due to the small number of neurons - hundreds compared to a mammal's billions. Isothermal tracking appears to be a deterministic behavior that may be a product of a more complex processing system - a behavior facilitated by a network. There is strong evidence sensorimotor integration is occurring; the C. elegans are tracking temperature differences and coordinating their movements to the local temperature in a highly deliberate and precise manner. In this experiment, we created an assay plate over a thermal gradient and physically tracked the worm's movements using a high-powered line confocal microscope with a motorized stage and fluorescently labeled neurons. We were able to track the neural activity of the whole nervous system in real time as the worm moved over the thermal gradient. This eliminates the need for laser ablation or immobilization and allows us to observe how a Caenorhabditis elegans would move in its natural form. We conducted this experiment with worms in the L1 stage as well as worms in the L4 stage to observe possible synaptogenesis or synaptic plasticity.