Direct Modulation of High-Frequency Neural Oscillations in the Auditory Cortex Through Electrical Microstimulation Generated by PVDF Sensors

In this work, the effects of biomimetic ultrasonic signals on the primary auditory cortex of mammals through deep brain electrical stimulation have been investigated. Ultrasonic (US) signals were generated by biomimetic sonar which includes two polyvinylidene fluoride transducers, conditioning electronic circuits, and implanted microelectrodes to mimic rat communication processes. The electrical stimulation signal, obtained by mechanical to electrical energy conversion, modulates the neural functional state, increasing the high oscillations in beta and gamma content when the ultrasound frequency matched with the relative tonotopic area. A principal component analysis was performed in order to classify ECoG signals according to the incoming stimuli. Frequency analysis allowed the investigation of the relationship between the processing of US stimuli and the spatiotemporal neural activity. Results demonstrate that the sonar system, according to the information carried out by ultrasounds and through microstimulation, selectively modulated the cortical activity into the primary auditory cortex.