Silicon horn transducer based ultrasonically enhanced nerve firing

In this paper we report on enhanced excitation rates from the abdominal nerve cord of the large red crayfish (Procambarus clarkii) upon exposure to ~ 100 kHz ultrasound. We have observed firing rates increases of as much as 10.65% that are linear with the ultrasonic pressure ranging from 8900 to 120,000 Pa. We used a silicon-horn transducer that allows the delivery of high intensity ultrasound over an area that is approximately the size of the nerve. Probe tip temperature increases of 1 - 2 degrees Celsius were measured in saline corresponding to the range of ultrasonic intensities used. The increase in firing rate is also accompanied by an increase in the slopes and amplitude of each individual action potential in the nerve cord. We form initial hypothesis based on the data that suggest mechanisms of ultrasonic effect on triggering nerves.