Studying The Effects Of Acoustic Wave On The Reorientations Of C.Elegans

The nematode C.elegans is a typical model organism. With the aid of laser ablation, we can identify different sensory neurons associated with diverse mechanical stimulations. We quantified worm’s response to acoustic vibration with precisely controlled amplitude and frequency for the first time. A custom-built real-time computer vision system was used to record the movements of individual worms navigating the agar surface on a petri dish. Data collected were analyzed using the customized shape analysis and particle-tracking algorithms written in Labview and Matlab. We used a laser vibrometer (Polytec) to characterize the mechanical vibration of the agar surface during the acoustic stimuli. To quantify animal’s response to acoustic wave, we also defined a non-dimensional acoustic sensitive index.We found that the acoustic sensitive index is proportional to the displacement amplitude. However, when we further tested animal’s response to acoustic wave of fixed displacement amplitude and varying frequency, the result shows that the acoustic sensitive index first increases then decreases with the increase of frequency. The worm had habituation to acoustic vibration. It was also shown that mutations in mec-4 and mec-7 diminished acoustic sensitive index. Low intensity ultrasound was proved to have no effect on C.elegans’ reorientations. Our work laid the ground work for studying C.elegans acoustic sensation. It would be interesting to further study the neural circuits and cellular mechanism of the behavior.