Behavioral responses of Caenorhabditis elegans to surface acoustic waves

Surface acoustic waves (SAW) at a frequency of 8.8 MHz were used to stimulate the nematode Caenorhabditis elegans on an agar surface on a piezoelectric substrate to study its behavioral response to sonication. Specifically, the dependency of the turning and reversal behaviors of the nematodes on the sonication period, the vibration amplitude of the substrate, and the pulse repetition frequency (PRF) were analyzed. It was found that the response of the nematodes to the high-frequency SAW stimulation was in accordance with the pattern obtained from the previous low-frequency bulk-wave stimulation, i.e., it was similar to the band-pass filters in terms of PRF. By comparing the behavior of temperature perception-deficient mutant nematodes with that of wild-type nematodes, it was clarified that mechanical vibration was dominant in evoking nematode responses, while ultrasonic-thermal effects were not a major factor. On this basis, attempts were made to change the acoustic field distribution through modulating the driving signals to study the acoustic-taxis behavior of the nematodes, and then to realize the preliminary intervention on the reversal behavior of the nematodes.