Reversible neuroinhibition by focused ultrasound is mediated by a thermal mechanism

David P. Darrow, Parker O'Brien, Thomas J. Richner, Theoden I. Netoff, Emad S. Ebbini

Research output: Contribution to journalArticlepeer-review

12 Scopus citations

Abstract

Background: Transcranial focused ultrasound (tFUS) at low intensities has been reported to directly evoke responses and reversibly inhibit function in the central nervous system. While some doubt has been cast on the ability of ultrasound to directly evoke neuronal responses, spatially-restricted transcranial ultrasound has demonstrated consistent, inhibitory effects, but the underlying mechanism of reversible suppression in the central nervous system is not well understood. Objective/hypothesis: In this study, we sought to characterize the effect of transcranial, low-intensity, focused ultrasound on the thalamus during somatosensory evoked potentials (SSEP) and investigate the mechanism by modulating the parameters of ultrasound. Methods: TFUS was applied to the ventral posterolateral nucleus of the thalamus of a rodent while electrically stimulating the tibial nerve to induce an SSEP. Thermal changes were also induced through an optical fiber that was image-guided to the same target. Results: Focused ultrasound reversibly suppressed SSEPs in a spatially and intensity-dependent manner while remaining independent of duty cycle, peak pressure, or modulation frequency. Suppression was highly correlated and temporally consistent with in vivo temperature changes while producing no pathological changes on histology. Furthermore, stereotactically-guided delivery of thermal energy through an optical fiber produced similar thermal effects and suppression. Conclusion: We confirm that tFUS predominantly causes neuroinhibition and conclude that the most primary biophysical mechanism is the thermal effect of focused ultrasound.

Original languageEnglish (US)
Pages (from-to)1439-1447
Number of pages9
JournalBrain Stimulation
Volume12
Issue number6
DOIs
StatePublished - Aug 5 2019

Bibliographical note

Funding Information:
This work was funded by the United States National Institutes of Health National Institute of Neurological Disorders and Stroke (NINDS) R01 NS098781 and University of Minnesota MNDrive Neuromodulation.

Funding Information:
This work was funded by the United States National Institutes of Health National Institute of Neurological Disorders and Stroke (NINDS) R01 NS098781 and University of Minnesota MNDrive Neuromodulation .

Publisher Copyright:
© 2019 Elsevier Inc.

Copyright:
Copyright 2019 Elsevier B.V., All rights reserved.

Keywords

  • FUS
  • Low intensity
  • Neuromodulation
  • Noninvasive
  • Somatosensory evoked potentials
  • Transcranial focused ultrasound

Fingerprint Dive into the research topics of 'Reversible neuroinhibition by focused ultrasound is mediated by a thermal mechanism'. Together they form a unique fingerprint.

Cite this