The relationship between parameters and effects in transcranial ultrasonic stimulation

Area of Science:

• Neuroscience
• Biomedical Engineering
• Medical Physics

Background:

• Transcranial ultrasonic stimulation (TUS) is an emerging non-invasive technique for human neuromodulation.
• Establishing optimal TUS protocols is crucial for maximizing its therapeutic and research efficacy.
• Current understanding of TUS parameter-outcome relationships requires synthesis and critical evaluation.

Purpose of the Study:

• To review and synthesize empirical evidence linking tunable TUS parameters to in vitro and in vivo outcomes.
• To guide TUS researchers in making informed decisions regarding optimal parameter settings.
• To identify challenges in protocol translation and parameter extrapolation for future TUS interventions.

Main Methods:

• Systematic aggregation and examination of existing empirical data on TUS parameters and their effects.
• Multiscale analysis integrating findings from in vitro and in vivo studies.
• Discussion of challenges in inter-model protocol translation and TUS-brain interactions.

Main Results:

• Empirical evidence suggests lower sub-MHz frequencies, higher intensities/pressures, and longer pulse durations enhance TUS effects.
• A synthesis indicates potential for greater neuromodulatory efficacy with specific parameter adjustments.
• Significant challenges exist in directly extrapolating findings across different experimental paradigms.

Conclusions:

• Refined TUS parameters, informed by this synthesis, can advance human neuromodulation.
• Cautious interpretation of diverse experimental data is necessary for developing robust TUS protocols.
• Further research is needed to overcome challenges in translating TUS protocols and understanding brain interactions.