High pressure transcranial focused ultrasound stimulation induces parameter-dependent cell-type specific effects

Area of Science:

• Neuroscience
• Biomedical Engineering
• Acoustic Technology

Background:

• Transcranial focused ultrasound (tFUS) offers precise, deep brain stimulation with cell-type specificity.
• Intracranial electrophysiology records neural responses to tFUS but faces challenges with vibration artifacts from conventional electrodes under high acoustic pressure.

Purpose of the Study:

• To demonstrate the cell-type selective effects of tFUS under high acoustic pressure using novel ultraflexible nanoelectric thread electrodes.
• To evaluate the mitigation of tFUS-induced vibration artifacts by these flexible electrodes.

Main Methods:

• Utilized ultraflexible nanoelectric thread electrodes for intracranial electrophysiological recordings during tFUS.
• Applied a broad range of ultrasound parameters and high acoustic pressure levels.
• Assessed neural responses, including time-locked and delayed spiking, across multiple cell types.

Main Results:

• The flexibility of nanoelectric thread electrodes effectively mitigated vibrations, eliminating artifacts even at high tFUS pressure levels.
• A positive nonlinear relationship was observed between acoustic pressure and both time-locked and delayed neural spiking responses.
• Higher pressure levels resulted in distinct response patterns when pulse repetition frequency and duty cycle were independently varied.

Conclusions:

• Ultraflexible nanoelectric thread electrodes are effective for artifact-free neural recordings during high-pressure tFUS.
• Acoustic pressure significantly influences tFUS-evoked neural responses in a cell-type specific manner.
• Further research is needed to fully elucidate the complex effects of acoustic pressure on tFUS neuromodulation.