C. elegans is the attractive model organism because this worm has many advantages as experimental model. Also, C. elegans has interesting behavioral responses to various external physical and chemical stimuli. In the past few decades, various researches on C. elegans have been performed, and microsystems have started to be used as a platform within the last 20 years. Therefore, the results of various application studies using C. elegans have begun to release efficiently.
In this dissertation, we demonstrated microsystem for study of behavioral responses and physiological change of C. elegans by various physical stimuli. This dissertation is consisting of three major chapters. In first chapter, we demonstrated the microfluidic platform for analyzing the thermotaxis of C. elegans. Thermotaxis is one of the special behavioral responses based on memory about cultivation temperature. C. elegans can find and follow the cultivation temperature when it is on the temperature gradient. In the previous studies, the analysis area based on agar plate showed low efficiency for analysis of C. elegans distribution on the temperature gradient. Also, the generation of stable temperature gradient was difficult. To overcome this limitation, we introduced the linear microfluidic system with two Peltier modules as temperature controllers. Three strains of C. elegans including wild-type and two mutant strains were tested using our system. They showed quite different thermotactic behavior in the system. In the second chapter, we designed and fabricated the microfluidic system for spatiotemporal analysis of electrotaxis of C. elegans. The microfluidic channel was designed with trap strategy by electrotaxis. Electrotaxis is the behavioral response of C. elegans that following electric field direction. Thus, we generated the electric field in the channel and set the trap zone at the center of channel. The wild-type worms showed trapping by electrotaxis, and we compared the wild-type worms results with two mutant strains. They also difference features with wild-type worms. In the last chapter, we applied the mechanical vibration to C. elegans embryo. The system was fabricated with vibration actuators and simple culture plate. The embryo of C. elegans was collected by egg prep method and were treated by mechanical vibration. We divided the test group based on the vibration applying time, 1, 3, 9h. After the vibration apply, the C. elegans showed promotion of growth with short-term vibration (1h). Thus, we demonstrated the vibration effect to the embryo can affect to the C. elegans growth.
These studies provide the straightforward and efficient platform for analysis of C. elegans studies. The developed platforms are expected to be applied as a basic platform for analyzing the response of a C. elegans and physiological changes to complex stimuli.