Focused Ultrasound-Induced Suppression of Auditory Evoked Potentials in Vivo

The goal of this study was to determine the feasibility of focused ultrasound–based neuromodulation affecting auditory evoked potentials (AEPs) in animals. Focused ultrasound–induced suppression of AEPs was performed in 22 rats and 5 pigs: Repetitive sounds were produced, and the induced AEPs were recorded before and repeatedly after FUS treatment of the auditory pathway. All treated animals exhibited a decrease in AEP amplitude post-treatment in contrast to animals undergoing the sham treatment. Suppression was weaker for rats treated at 2.3 W/cm² (amplitudes decreased to 59.8?±?3.3% of baseline) than rats treated at 4.6 W/cm² (36.9?±?7.5%, p?<0.001). Amplitudes of the treated pigs decreased to 27.7?±?5.9% of baseline. This effect lasted between 30?min and 1?mo in most treated animals. No evidence of heating during treatment or later brain damage/edema was observed. These results demonstrate the feasibility of inducing significant neuromodulation with non-thermal, non-invasive, reversible focused ultrasound. The long recovery times may have clinical implications.