Symposium
Transcranial ultrasound stimulation (TUS) is an emerging non-invasive neuromodulation technique that is a promising alternative to pharmacological treatments for psychiatric and neurological disorders [1,2]. While traditional functional analysis has played a crucial role in understanding TUS effects, further investigation is needed to reveal the underlying mechanisms [3-4]. Whole-brain models, meanwhile, are valuable for testing hypotheses and predicting outcomes in real experimental settings [5-6]. In this study, we developed a whole-brain model representing functional changes measured by fMRI to explain how TUS spread throughout the brain as stimulus intensity increases. We implemented two mechanisms: one based on distance and another on a broadcasting process, enabling us to examine plasticity-driven changes in specific brain regions at several stimulus intensities. Furthermore, we demonstrated the extent of high-order functional interactions, localizing the spatial effects of off-line TUS in humans at two target areas—the right thalamus and inferior frontal cortex—highlighting distinct patterns of functional reorganization [7].
References
[1] Legon, W., Sato, T., Opitz, A. et al. Transcranial focused ultrasound modulates the activity of primary somatosen- sory cortex in humans. Nat Neurosci 17, 322–329 (2014). https://doi.org/10.1038/nn.3620
[2] Polania, R., Nitsche, M.A. & Ruff, C.C. Studying and modifying brain function with non-invasive brain stimulation. Nat Neurosci 21, 174–187 (2018). https://doi.org/10.1038/s41593-017-0054-4
[3] Dell’Italia J, Sanguinetti JL, Monti MM, Bystritsky A, Reggente N. Current State of Potential Mechanisms Sup- porting Low Intensity Focused Ultrasound for Neuromodulation. Front Hum Neurosci. 2022 Apr 25;16:872639. https://doi.org/10.3389/fnhum.2022.872639
[4] Sarica C, Nankoo JF, Fomenko A, Grippe TC, Yamamoto K, Samuel N, Milano V, Vetkas A, Darmani G, Cizmeci MN, Lozano AM, Chen R. Human Studies of Transcranial Ultrasound neuromodulation: A systematic review of effectiveness and safety. Brain Stimul. 2022 May-Jun;15(3):737-746. https://doi.org/10.1016/j.brs.2022.05.002 [5] Deco, G., Tononi, G., Boly, M. et al. Rethinking segregation and integration: contributions of whole-brain modelling. Nat Rev Neurosci 16, 430–439 (2015).https://doi.org/10.1038/nrn3963
[6] Lynn, C.W., Bassett, D.S. The physics of brain network structure, function and control. Nat Rev Phys 1, 318–332 (2019). https://doi.org/10.1038/s42254-019-0040-8
[7] In preparation Marilyn Gatica, Cyril Atkinson-Clement, Carlos Coronel-Oliveros, Mohammad Alkhawashki, Pedro A. M. Mediano, Enzo Tagliazucchi, Fernando E. Rosas, Marcus Kaiser, Giovanni Petri