Transcranial focused ultrasound neuromodulation of the human primary motor cortex

Wynn Legon, Priya Bansal, Roman Tyshynsky, Leo Ai, Jerel K Mueller, Wynn Legon, Priya Bansal, Roman Tyshynsky, Leo Ai, Jerel K Mueller

Abstract

Transcranial focused ultrasound is an emerging form of non-invasive neuromodulation that uses acoustic energy to affect neuronal excitability. The effect of ultrasound on human motor cortical excitability and behavior is currently unknown. We apply ultrasound to the primary motor cortex in humans using a novel simultaneous transcranial ultrasound and magnetic stimulation paradigm that allows for concurrent and concentric ultrasound stimulation with transcranial magnetic stimulation (TMS). This allows for non-invasive inspection of the effect of ultrasound on motor neuronal excitability using the motor evoked potential (MEP). We test the effect of ultrasound on single pulse MEP recruitment curves and paired pulse protocols including short interval intracortical inhibition (SICI) and intracortical facilitation (ICF). In addition, we test the effect of ultrasound to motor cortex on a stimulus response reaction time task. Results show ultrasound inhibits the amplitude of single-pulse MEPs and attenuates intracortical facilitation but does not affect intracortical inhibition. Ultrasound also reduces reaction time on a simple stimulus response task. This is the first report of the effect of ultrasound on human motor cortical excitability and motor behavior and confirms previous results in the somatosensory cortex that ultrasound results in effective neuronal inhibition that confers a performance advantage.

Conflict of interest statement

The authors declare no competing interests.

Figures

Figure 1
Figure 1
Transcranial ultrasound and magnetic stimulation. (A) Photograph of the Ultrasound/TMS device showing the TMS coil (beige), ultrasound transducer (white) and the holder (purple). Tracking bulbs are also visible and used to guide Ultrasound/TMS to a specific brain target using stereotaxic neuronavigation. (B) Ultrasound pulsing strategy. PRF = pulse repetition frequency; Af = acoustic frequency. (C) Pseudo-color and line free water plots of ultrasound pressure field. Scales are normalized to maximum pressure. Black arrow indicates direction of sonication.
Figure 2
Figure 2
Interaction of ultrasound and TMS. (A) Ultrasound field as measured in free water. Grey line represents on time of ultrasound. (Middle) Artifact from single 100% TMS stimulator output pulse. Black line depicts length of pulse artifact. (Bottom) Both ultrasound and TMS are delivered at the same time to determine impact of TMS on the sound field pressure. No effect of the TMS pulse was found on the sound field. The US transducer does not impact the amplitude of the TMS pulse. msec = milliseconds; MPa = megapascals. (B) Average magnetic vector potential (A) relative to maximum (Amax) as measured from the plane of the face of the TMS coil without the ultrasound transducer (TMS) and with the ultrasound transducer affixed to the TMS coil (TMS + US). There was no difference in the average magnetic vector potential with the addition of the ultrasound transducer. The central line is the median, the edges of the box represent the 25% and 75% percentiles and the whiskers extend to the most extreme data points.
Figure 3
Figure 3
Modelled Ultrasound/TMS field and ultrasound field in the brain. (A) Modelled induced electric field in the human brain from the TMS coil without the ultrasound transducer (left) and with the ultrasound transducer (right). (B) Acoustic model of the ultrasound waveform positioned over primary motor cortex. CS = central sulcus. Note: Middle figure is transverse section taken through the plane (white dashed line) in the left coronal figure. kPa = kilopascals.
Figure 4
Figure 4
Ultrasound effects on single pulse TMS recruitment curves. (A) Group average (N = 12) raw data ± SEM recruitment curves for Ultrasound/TMS (grey) and sham (black) neuromodulation. *Represents p < 0.05 from post hoc testing. (B) Main effect of Ultrasound/TMS versus Sham neuromodulation collapsed across stimulator intensities 75–100%. *Represents p = 0.0126.
Figure 5
Figure 5
Ultrasound effects on paired-pulse TMS. (A) Raw group average (N = 10) paired pulse average motor evoked potential (MEP) amplitude ± SEM for inter-stimulus intervals (ISI) 1–15 milliseconds. Transcranial ultrasonic and magnetic stimulation (Ultrasound/TMS) (grey) and sham (black) neuromodulation. Amplitudes are presented relative to a single pulse baseline (horizontal dashed line). *Represents p < 0.05. (B) Averaged normalized MEP amplitude ± SEM collapsed across grouped ISIs known to reflect short intracortical inhibition (SICI) and intracortical facilitation (ICF). *Represents p < 0.05.
Figure 6
Figure 6
Effect of ultrasound on motor behavior. (A) Group average (N = 28) reaction time ± SEM in milliseconds (msec) to a stimulus response task. Active sham represents ultrasound delivered to the vertex. M1 sham represents transducer over primary motor cortex (M1) but no ultrasound. M1 tFUS is transcranial focused ultrasound to primary motor cortex. *Denotes p < 0.05. (B) Data from catch trials during the reaction time task. Data is represented as percent correct ± SEM.

References

    1. Legon W, et al. Transcranial focused ultrasound modulates the activity of primary somatosensory cortex in humans. Nat. Neurosci. 2014;17:322–329. doi: 10.1038/nn.3620.
    1. Tufail Y, et al. Transcranial pulsed ultrasound stimulates intact brain circuits. Neuron. 2010;66:681–694. doi: 10.1016/j.neuron.2010.05.008.
    1. King RL, Brown JR, Newsome WT, Pauly KB. Effective parameters for ultrasound-induced in vivo neurostimulation. Ultrasound Med. Biol. 2013;39:312–331. doi: 10.1016/j.ultrasmedbio.2012.09.009.
    1. Kim H, Chiu A, Lee SD, Fischer K, Yoo SS. Focused ultrasound-mediated non-invasive brain stimulation: examination of sonication parameters. Brain Stimul. 2014;7:748–756. doi: 10.1016/j.brs.2014.06.011.
    1. Younan Y, et al. Influence of the pressure field distribution in transcranial ultrasonic neurostimulation. Med. Phys. 2013;40:082902. doi: 10.1118/1.4812423.
    1. Yoo SS, et al. Focused ultrasound modulates region-specific brain activity. Neuroimage. 2011;56:1267–1275. doi: 10.1016/j.neuroimage.2011.02.058.
    1. Lee W, et al. Image-Guided Focused Ultrasound-Mediated Regional Brain Stimulation in Sheep. Ultrasound Med. Biol. 2016;42:459–470. doi: 10.1016/j.ultrasmedbio.2015.10.001.
    1. Dallapiazza, R. F. et al. Noninvasive neuromodulation and thalamic mapping with low-intensity focused ultrasound. J. Neurosurg., 1–10 (2017).
    1. Deffieux T, et al. Low-intensity focused ultrasound modulates monkey visuomotor behavior. Curr. Biol. 2013;23:2430–2433. doi: 10.1016/j.cub.2013.10.029.
    1. Lee W, et al. Image-guided transcranial focused ultrasound stimulates human primary somatosensory cortex. Sci. Rep. 2015;5:8743. doi: 10.1038/srep08743.
    1. Lee W, Chung YA, Jung Y, Song IU, Yoo SS. Simultaneous acoustic stimulation of human primary and secondary somatosensory cortices using transcranial focused ultrasound. BMC Neurosci. 2016;17:68. doi: 10.1186/s12868-016-0303-6.
    1. Lee W, et al. Transcranial focused ultrasound stimulation of human primary visual cortex. Sci. Rep. 2016;6:34026. doi: 10.1038/srep34026.
    1. Legon W, Ai L, Bansal P, Mueller JK. Neuromodulation with single-element transcranial focused ultrasound in human thalamus. Human Brain Mapping. 2018;00:1–12.
    1. Di Lazzaro V, et al. I-wave origin and modulation. Brain Stimul. 2012;5:512–525. doi: 10.1016/j.brs.2011.07.008.
    1. Di Lazzaro, V., Rothwell, J. & Capogna, M. Noninvasive Stimulation of the Human Brain: Activation of Multiple Cortical Circuits. Neuroscientist, 1073858417717660 (2017).
    1. Rossi S, Hallett M, Rossini PM, Pascual-Leone A. & Safety of TMS Consensus Group. Safety, ethical considerations, and application guidelines for the use of transcranial magnetic stimulation in clinical practice and research. Clin. Neurophysiol. 2009;120:2008–2039. doi: 10.1016/j.clinph.2009.08.016.
    1. Kim Y, et al. Rapid prototyping fabrication of focused ultrasound transducers. IEEE Trans. Ultrason. Ferroelectr. Freq. Control. 2014;61:1559–1574. doi: 10.1109/TUFFC.2014.3070.
    1. Opitz A, et al. Is sham cTBS real cTBS? The effect on EEG dynamics. Front. Hum. Neurosci. 2015;8:1043. doi: 10.3389/fnhum.2014.01043.
    1. Mueller J, Legon W, Opitz A, Sato TF, Tyler WJ. Transcranial focused ultrasound modulates intrinsic and evoked EEG dynamics. Brain Stimul. 2014;7:900–908. doi: 10.1016/j.brs.2014.08.008.
    1. Ai, L., Mueller, J. K., Bansal, P. & Legon W. Transcranial focused ultrasound for BOLD fMRI signal modulation in humans. EMBC, 1758–1761 (2016).
    1. Spitzer VM, Whitlock DG. The Visible Human Dataset: the anatomical platform for human simulation. Anat. Rec. 1998;253:49–57. doi: 10.1002/(SICI)1097-0185(199804)253:2<49::AID-AR8>;2-9.
    1. Treeby BE, Cox BT. k-Wave: MATLAB toolbox for the simulation and reconstruction of photoacoustic wave fields. J. Biomed. Opt. 2010;15:021314. doi: 10.1117/1.3360308.
    1. Mueller, J. K., Ai, L., Bansal, P. & Legon, W. Numerical evaluation of the skull for human neuromodulation with transcranial focused ultrasound. J. Neural Eng. 10.1088/1741-2552/aa843e (2017).
    1. Kujirai T, et al. Corticocortical inhibition in human motor cortex. J. Physiol. 1993;471:501–519. doi: 10.1113/jphysiol.1993.sp019912.
    1. Mueller, J. K., Ai, L., Bansal, P. & Legon, W. Computational exploration of wave propagation and heating from transcranial focused ultrasound for neuromodulation. J. Neural Eng. 13, 056002-2560/13/5/056002, Epub 2016 Jul 28 (2016).
    1. Beveridge AC, Wang S, Diebold GJ. Imaging based on the ultrasonic vibration potential. Applied Physics Letters. 2004;85:5466. doi: 10.1063/1.1827350.
    1. Perkins KL. Cell-attached voltage-clamp and current-clamp recording and stimulation techniques in brain slices. J. Neurosci. Methods. 2006;154:1–18. doi: 10.1016/j.jneumeth.2006.02.010.
    1. Tseng N, Roth BJ. The potential induced in anisotropic tissue by the ultrasonically-induced Lorentz force. Med. Biol. Eng. Comput. 2008;46:195–197. doi: 10.1007/s11517-007-0292-9.
    1. Montalibet A, Jossinet J, Matias A, Cathignol D. Electric current generated by ultrasonically induced Lorentz force in biological media. Med. Biol. Eng. Comput. 2001;39:15–20. doi: 10.1007/BF02345261.
    1. IT’IS Foundation. Tissue Properties Database V3.1. .
    1. Kowalski T, Silny J, Buchner H. Current density threshold for the stimulation of neurons in the motor cortex area. Bioelectromagnetics. 2002;23:421–428. doi: 10.1002/bem.10036.
    1. Neuling T, Wagner S, Wolters CH, Zaehle T, Herrmann CS. Finite-Element Model Predicts Current Density Distribution for Clinical Applications of tDCS and tACS. Front. Psychiatry. 2012;3:83. doi: 10.3389/fpsyt.2012.00083.
    1. Duyn, J. H. & Schenck, J. Contributions to magnetic susceptibility of brain tissue. NMR Biomed. 30, 10.1002/nbm.3546. Epub 2016 May 30 (2017).
    1. Hu G, He B. Magnetoacoustic imaging of magnetic iron oxide nanoparticles embedded in biological tissues with microsecond magnetic stimulation. Appl. Phys. Lett. 2012;100:13704–137043. doi: 10.1063/1.3675457.
    1. Beissner K. On the plane-wave approximation of acoustic intensity. The Journal of the Acoustical Society of America. 1982;71:1406. doi: 10.1121/1.387835.
    1. Di Lazzaro V, et al. Comparison of descending volleys evoked by transcranial magnetic and electric stimulation in conscious humans. Electroencephalogr. Clin. Neurophysiol. 1998;109:397–401. doi: 10.1016/S0924-980X(98)00038-1.
    1. Deng ZD, Lisanby SH, Peterchev AV. Coil design considerations for deep transcranial magnetic stimulation. Clin. Neurophysiol. 2014;125:1202–1212. doi: 10.1016/j.clinph.2013.11.038.
    1. Windhoff M, Opitz A, Thielscher A. Electric field calculations in brain stimulation based on finite elements: an optimized processing pipeline for the generation and usage of accurate individual head models. Hum. Brain Mapp. 2013;34:923–935. doi: 10.1002/hbm.21479.
    1. Kubanek J, et al. Ultrasound modulates ion channel currents. Sci. Rep. 2016;6:24170. doi: 10.1038/srep24170.
    1. Prieto, M. L., Butrus, K. F., Khuri-Yakub, T. & Maduke, M. Mechanical activation of piezo1 but not Nav1.2 channels by ultrasound. biorxiv (2017).
    1. Wright CJ, Haqshenas SR, Rothwell J, Saffari N. Unmyelinated Peripheral Nerves Can Be Stimulated in Vitro Using Pulsed Ultrasound. Ultrasound Med. Biol. 2017;43:2269–2283. doi: 10.1016/j.ultrasmedbio.2017.05.008.
    1. Di Lazzaro V, et al. Direct demonstration of the effect of lorazepam on the excitability of the human motor cortex. Clin. Neurophysiol. 2000;111:794–799. doi: 10.1016/S1388-2457(99)00314-4.
    1. Di Lazzaro V, et al. Magnetic transcranial stimulation at intensities below active motor threshold activates intracortical inhibitory circuits. Exp. Brain Res. 1998;119:265–268. doi: 10.1007/s002210050341.
    1. Weise D, et al. Microcircuit mechanisms involved in paired associative stimulation-induced depression of corticospinal excitability. J. Physiol. 2013;591:4903–4920. doi: 10.1113/jphysiol.2013.253989.
    1. Tyler WJ. The mechanobiology of brain function. Nat. Rev. Neurosci. 2012;13:867–878. doi: 10.1038/nrn3383.
    1. Plaksin, M., Kimmel, E. & Shoham, S. Cell-Type-Selective Effects of Intramembrane Cavitation as a Unifying Theoretical Framework for Ultrasonic Neuromodulation. eNeuro3, 10.1523/ENEURO.0136-15.2016. eCollection 2016 May-Jun (2016).
    1. Krasovitski B, Frenkel V, Shoham S, Kimmel E. Intramembrane cavitation as a unifying mechanism for ultrasound-induced bioeffects. Proc. Natl. Acad. Sci. USA. 2011;108:3258–3263. doi: 10.1073/pnas.1015771108.
    1. Brohawn SG. How ion channels sense mechanical force: insights from mechanosensitive K2P channels TRAAK, TREK1, and TREK2. Ann. N. Y. Acad. Sci. 2015;1352:20–32. doi: 10.1111/nyas.12874.
    1. Coste B, et al. Piezo1 and Piezo2 are essential components of distinct mechanically activated cation channels. Science. 2010;330:55–60. doi: 10.1126/science.1193270.
    1. Jordao JF, et al. Amyloid-beta plaque reduction, endogenous antibody delivery and glial activation by brain-targeted, transcranial focused ultrasound. Exp. Neurol. 2013;248:16–29. doi: 10.1016/j.expneurol.2013.05.008.
    1. Kirischuk, S. In Mechanosensitivity in cells and tissues 2: Mechanosensitivity of the nervous system (eds Kamkin, A. & Kiseleva, I.) 3–22 (Springer, 2009).
    1. Di Lazzaro V, Ziemann U. The contribution of transcranial magnetic stimulation in the functional evaluation of microcircuits in human motor cortex. Front. Neural Circuits. 2013;7:18. doi: 10.3389/fncir.2013.00018.
    1. Paulus W, et al. State of the art: Pharmacologic effects on cortical excitability measures tested by transcranial magnetic stimulation. Brain Stimul. 2008;1:151–163. doi: 10.1016/j.brs.2008.06.002.
    1. Mehic E, et al. Increased anatomical specificity of neuromodulation via modulated focused ultrasound. PLoS One. 2014;9:e86939. doi: 10.1371/journal.pone.0086939.
    1. Guo, H. et al. Ultrasound produces extensive brain activation via a cochlear pathway. biorxiv (2017).
    1. Wright, C. J., Rothwell, J. & Saffari, N. Ultrasonic stimulation of peripheral nervous tissue: an investigation into mechanisms. (Journal of Physics: Conference series. Ser. 581, 2015).
    1. Legon W, et al. Altered Prefrontal Excitation/Inhibition Balance and Prefrontal Output: Markers of Aging in Human Memory Networks. Cereb. Cortex. 2016;26:4315–4326. doi: 10.1093/cercor/bhv200.
    1. Lewis DA, Hashimoto T, Volk DW. Cortical inhibitory neurons and schizophrenia. Nat. Rev. Neurosci. 2005;6:312–324. doi: 10.1038/nrn1648.
    1. Hallett M. Neurophysiology of dystonia: The role of inhibition. Neurobiol. Dis. 2011;42:177–184. doi: 10.1016/j.nbd.2010.08.025.
    1. Schieber MH. Individuated finger movements of rhesus monkeys: a means of quantifying the independence of the digits. J. Neurophysiol. 1991;65:1381–1391. doi: 10.1152/jn.1991.65.6.1381.
    1. Beck S, Hallett M. Surround inhibition in the motor system. Exp. Brain Res. 2011;210:165–172. doi: 10.1007/s00221-011-2610-6.
    1. Dechent P, Frahm J. Functional somatotopy of finger representations in human primary motor cortex. Hum. Brain Mapp. 2003;18:272–283. doi: 10.1002/hbm.10084.

Source: PubMed

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구독하다