Bioeffects of low dose ultrasound on neuronal cell function

A growing body of work demonstrates the therapeutic value of sub-ablation ultrasound on various tissues. If ultrasound can safely manipulate neuronal tissue, then it might be possible to use it to treat neurodegenerative diseases. Anticipating such future applications, we investigated reversible bioeffects of very low dose focused ultrasound on neuronal cell function in vitro. A rat hippocampal slice was cultured for 6 days and transferred to the well of a 60-channel multi-electrode array. An f/2.1 ultrasound transducer with a water-filled coupling cone was focused on a culture and excited with 100-¿s, 4.04-MHz pulses ranging from 0.10 W through 1.43 W acoustic power. Ultrasonically-evoked field potentials with biphasic amplitudes as high as 329.1 ¿V_pp were observed in the dentate gyrus region. There appears to be a stimulus threshold that lies between an acoustic power of 0.37 and 0.90 W.