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Ye H, Dima M, Hall V, Hendee J. Cellular mechanisms underlying carry-over effects after magnetic stimulation. Sci Rep 2024; 14:5167. [PMID: 38431662 PMCID: PMC10908793 DOI: 10.1038/s41598-024-55915-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2023] [Accepted: 02/28/2024] [Indexed: 03/05/2024] Open
Abstract
Magnetic fields are widely used for neuromodulation in clinical settings. The intended effect of magnetic stimulation is that neural activity resumes its pre-stimulation state right after stimulation. Many theoretical and experimental works have focused on the cellular and molecular basis of the acute neural response to magnetic field. However, effects of magnetic stimulation can still last after the termination of the magnetic stimulation (named "carry-over effects"), which could generate profound effects to the outcome of the stimulation. However, the cellular and molecular mechanisms of carry-over effects are largely unknown, which renders the neural modulation practice using magnetic stimulation unpredictable. Here, we investigated carry-over effects at the cellular level, using the combination of micro-magnetic stimulation (µMS), electrophysiology, and computation modeling. We found that high frequency magnetic stimulation could lead to immediate neural inhibition in ganglion neurons from Aplysia californica, as well as persistent, carry-over inhibition after withdrawing the magnetic stimulus. Carry-over effects were found in the neurons that fired action potentials under a variety of conditions. The carry-over effects were also observed in the neurons when the magnetic field was applied across the ganglion sheath. The state of the neuron, specifically synaptic input and membrane potential fluctuation, plays a significant role in generating the carry-over effects after magnetic stimulation. To elucidate the cellular mechanisms of such carry-over effects under magnetic stimulation, we simulated a single neuron under magnetic stimulation with multi-compartment modeling. The model successfully replicated the carry-over effects in the neuron, and revealed that the carry-over effect was due to the dysfunction of the ion channel dynamics that were responsible for the initiation and sustaining of membrane excitability. A virtual voltage-clamp experiment revealed a compromised Na conductance and enhanced K conductance post magnetic stimulation, rendering the neurons incapable of generating action potentials and, therefore, leading to the carry over effects. Finally, both simulation and experimental results demonstrated that the carry-over effects could be controlled by disturbing the membrane potential during the post-stimulus inhibition period. Delineating the cellular and ion channel mechanisms underlying carry-over effects could provide insights to the clinical outcomes in brain stimulation using TMS and other modalities. This research incentivizes the development of novel neural engineering or pharmacological approaches to better control the carry-over effects for optimized clinical outcomes.
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Affiliation(s)
- Hui Ye
- Department of Biology, Loyola University Chicago, Quinlan Life Sciences Education and Research Center, 1032 W. Sheridan Rd., Chicago, IL, 60660, USA.
| | - Maria Dima
- Department of Biology, Loyola University Chicago, Quinlan Life Sciences Education and Research Center, 1032 W. Sheridan Rd., Chicago, IL, 60660, USA
| | - Vincent Hall
- Department of Biology, Loyola University Chicago, Quinlan Life Sciences Education and Research Center, 1032 W. Sheridan Rd., Chicago, IL, 60660, USA
| | - Jenna Hendee
- Department of Biology, Loyola University Chicago, Quinlan Life Sciences Education and Research Center, 1032 W. Sheridan Rd., Chicago, IL, 60660, USA
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2
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Reader AT, Coppi S, Trifonova VS, Ehrsson HH. No reduction in motor-evoked potential amplitude during the rubber hand illusion. Brain Behav 2023; 13:e3211. [PMID: 37548563 PMCID: PMC10570491 DOI: 10.1002/brb3.3211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 07/03/2023] [Accepted: 07/26/2023] [Indexed: 08/08/2023] Open
Abstract
INTRODUCTION In the rubber hand illusion (RHI), touches are applied to a fake hand at the same time as touches are applied to a participant's real hand that is hidden in a congruent position. Synchronous (but not asynchronous) tactile stimulation of the two hands may induce the sensation that the fake hand is the participant's own. As such, the illusion is commonly used to examine the sense of body ownership. Some studies indicate that in addition to the subjective experience of limb ownership reported by participants, the RHI can also reduce corticospinal excitability (e.g., as reflected in motor-evoked potential [MEP] amplitude) and alter parietal-motor cortical connectivity in passive participants. These findings have been taken to support a link between motor cortical processing and the subjective experience of body ownership. METHODS In this study, we tried to replicate the reduction in MEP amplitude associated with the RHI and uncover the components of the illusion that might explain these changes. As such, we used single-pulse transcranial magnetic stimulation to probe the excitability of the corticospinal motor system as participants experienced the RHI. RESULTS Despite participants reporting the presence of the illusion and showing shifts in perceived real hand position towards the fake limb supporting its elicitation, we did not observe any associated reduction in MEP amplitude. CONCLUSION We conclude that a reduction in MEP amplitude is not a reliable outcome of the RHI and argue that if such effects do occur, they are unlikely to be large or functionally relevant.
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Affiliation(s)
- Arran T. Reader
- Department of PsychologyFaculty of Natural SciencesUniversity of StirlingStirlingUK
- Department of NeuroscienceKarolinska InstitutetStockholmSweden
| | - Sara Coppi
- Department of NeuroscienceKarolinska InstitutetStockholmSweden
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3
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Tian D, Izumi SI. Different effects of I-wave periodicity repetitive TMS on motor cortex interhemispheric interaction. Front Neurosci 2023; 17:1079432. [PMID: 37457007 PMCID: PMC10349661 DOI: 10.3389/fnins.2023.1079432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 06/12/2023] [Indexed: 07/18/2023] Open
Abstract
Background Activity of the neural circuits in the human motor cortex can be probed using transcranial magnetic stimulation (TMS). Changing TMS-induced current direction recruits different cortical neural circuits. I-wave periodicity repetitive TMS (iTMS) substantially modulates motor cortex excitability through neural plasticity, yet its effect on interhemispheric interaction remains unclear. Objective To explore the modulation of interhemispheric interaction by iTMS applied in different current directions. Materials and Methods Twenty right-handed healthy young volunteers (aged 27.5 ± 5.0 years) participated in this study with three visits. On each visit, iTMS in posterior-anterior/anterior-posterior direction (PA-/AP-iTMS) or sham-iTMS was applied to the right hemisphere, with corticospinal excitability and intracortical facilitation of the non-stimulated left hemisphere evaluated at four timepoints. Ipsilateral silent period was also measured at each timepoint probing interhemispheric inhibition (IHI). Results PA- and AP-iTMS potentiated cortical excitability concurrently in the stimulated right hemisphere. Corticospinal excitability of the non-stimulated left hemisphere increased 10 min after both PA- and AP-iTMS intervention, with a decrease in short-interval intracortical facilitation (SICF) observed in AP-iTMS only. Immediately after the intervention, PA-iTMS tilted the IHI balance toward inhibiting the non-stimulated hemisphere, while AP-iTMS shifted the balance toward the opposite direction. Conclusions Our findings provide systematic evidence on the plastic modulation of interhemispheric interaction by PA- and AP-iTMS. We show that iTMS induces an interhemispheric facilitatory effect, and that PA- and AP-iTMS differs in modulating interhemispheric inhibition.
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Affiliation(s)
- Dongting Tian
- Department of Physical Medicine and Rehabilitation, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Shin-Ichi Izumi
- Department of Physical Medicine and Rehabilitation, Tohoku University Graduate School of Medicine, Sendai, Japan
- Graduate School of Biomedical Engineering, Tohoku University, Sendai, Japan
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4
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Hernandez-Pavon JC, Veniero D, Bergmann TO, Belardinelli P, Bortoletto M, Casarotto S, Casula EP, Farzan F, Fecchio M, Julkunen P, Kallioniemi E, Lioumis P, Metsomaa J, Miniussi C, Mutanen TP, Rocchi L, Rogasch NC, Shafi MM, Siebner HR, Thut G, Zrenner C, Ziemann U, Ilmoniemi RJ. TMS combined with EEG: Recommendations and open issues for data collection and analysis. Brain Stimul 2023; 16:567-593. [PMID: 36828303 DOI: 10.1016/j.brs.2023.02.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 02/10/2023] [Accepted: 02/19/2023] [Indexed: 02/25/2023] Open
Abstract
Transcranial magnetic stimulation (TMS) evokes neuronal activity in the targeted cortex and connected brain regions. The evoked brain response can be measured with electroencephalography (EEG). TMS combined with simultaneous EEG (TMS-EEG) is widely used for studying cortical reactivity and connectivity at high spatiotemporal resolution. Methodologically, the combination of TMS with EEG is challenging, and there are many open questions in the field. Different TMS-EEG equipment and approaches for data collection and analysis are used. The lack of standardization may affect reproducibility and limit the comparability of results produced in different research laboratories. In addition, there is controversy about the extent to which auditory and somatosensory inputs contribute to transcranially evoked EEG. This review provides a guide for researchers who wish to use TMS-EEG to study the reactivity of the human cortex. A worldwide panel of experts working on TMS-EEG covered all aspects that should be considered in TMS-EEG experiments, providing methodological recommendations (when possible) for effective TMS-EEG recordings and analysis. The panel identified and discussed the challenges of the technique, particularly regarding recording procedures, artifact correction, analysis, and interpretation of the transcranial evoked potentials (TEPs). Therefore, this work offers an extensive overview of TMS-EEG methodology and thus may promote standardization of experimental and computational procedures across groups.
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Affiliation(s)
- Julio C Hernandez-Pavon
- Department of Physical Medicine and Rehabilitation, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA; Legs + Walking Lab, Shirley Ryan AbilityLab, Chicago, IL, USA; Center for Brain Stimulation, Shirley Ryan AbilityLab, Chicago, IL, USA.
| | | | - Til Ole Bergmann
- Neuroimaging Center (NIC), Focus Program Translational Neuroscience (FTN), Johannes Gutenberg University Medical Center, Germany; Leibniz Institute for Resilience Research (LIR), Mainz, Germany
| | - Paolo Belardinelli
- Center for Mind/Brain Sciences - CIMeC, University of Trento, Rovereto, TN, Italy; Department of Neurology & Stroke, University of Tübingen, Tübingen, Germany
| | - Marta Bortoletto
- Neurophysiology Lab, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy
| | - Silvia Casarotto
- Department of Biomedical and Clinical Sciences, University of Milan, Milan, Italy; IRCCS Fondazione Don Carlo Gnocchi ONLUS, Milan, Italy
| | - Elias P Casula
- Department of Systems Medicine, University of Tor Vergata, Rome, Italy
| | - Faranak Farzan
- Simon Fraser University, School of Mechatronic Systems Engineering, Surrey, British Columbia, Canada
| | - Matteo Fecchio
- Center for Neurotechnology and Neurorecovery, Department of Neurology, Massachusetts General Hospital, Boston, MA, USA
| | - Petro Julkunen
- Department of Technical Physics, University of Eastern Finland, Kuopio, Finland; Department of Clinical Neurophysiology, Kuopio University Hospital, Kuopio, Finland
| | - Elisa Kallioniemi
- Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, USA
| | - Pantelis Lioumis
- Department of Neuroscience and Biomedical Engineering, Aalto University, Espoo, Finland; BioMag Laboratory, HUS Medical Imaging Center, Helsinki University Hospital, Helsinki University and Aalto University School of Science, Helsinki, Finland
| | - Johanna Metsomaa
- Department of Neuroscience and Biomedical Engineering, Aalto University, Espoo, Finland; BioMag Laboratory, HUS Medical Imaging Center, Helsinki University Hospital, Helsinki University and Aalto University School of Science, Helsinki, Finland
| | - Carlo Miniussi
- Center for Mind/Brain Sciences - CIMeC, University of Trento, Rovereto, TN, Italy
| | - Tuomas P Mutanen
- Department of Neuroscience and Biomedical Engineering, Aalto University, Espoo, Finland; BioMag Laboratory, HUS Medical Imaging Center, Helsinki University Hospital, Helsinki University and Aalto University School of Science, Helsinki, Finland
| | - Lorenzo Rocchi
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom; Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
| | - Nigel C Rogasch
- University of Adelaide, Adelaide, Australia; South Australian Health and Medical Research Institute, Adelaide, Australia; Monash University, Melbourne, Australia
| | - Mouhsin M Shafi
- Berenson-Allen Center for Noninvasive Brain Stimulation, Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Hartwig R Siebner
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital - Amager and Hvidovre, Copenhagen, Denmark; Department of Neurology, Copenhagen University Hospital Bispebjerg and Frederiksberg, Copenhagen, Denmark; Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Gregor Thut
- School of Psychology and Neuroscience, University of Glasgow, United Kingdom
| | - Christoph Zrenner
- Department of Neurology & Stroke, University of Tübingen, Tübingen, Germany; Temerty Centre for Therapeutic Brain Intervention, Centre for Addiction and Mental Health, Toronto, Canada; Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany; Department of Psychiatry, University of Toronto, Toronto, Canada
| | - Ulf Ziemann
- Department of Neurology & Stroke, University of Tübingen, Tübingen, Germany; Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Risto J Ilmoniemi
- Department of Neuroscience and Biomedical Engineering, Aalto University, Espoo, Finland; BioMag Laboratory, HUS Medical Imaging Center, Helsinki University Hospital, Helsinki University and Aalto University School of Science, Helsinki, Finland
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Ye H, Hall V, Hendee J. Improving focality and consistency in micromagnetic stimulation. Front Comput Neurosci 2023; 17:1105505. [PMID: 36817316 PMCID: PMC9932264 DOI: 10.3389/fncom.2023.1105505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 01/17/2023] [Indexed: 02/05/2023] Open
Abstract
The novel micromagnetic stimulation (μMS) technology aims to provide high resolution on neuronal targets. However, consistency of neural activation could be compromised by a lack of surgical accuracy, biological variation, and human errors in operation. We have recently modeled the activation of an unmyelinated axon by a circular micro-coil. Although the coil could activate the axon, its performance sometimes lacked focality and consistency. The site of axonal activation could shift by several experimental factors, including the reversal of the coil current, displacement of the coil, and changes in the intensity of the stimulation. Current clinical practice with transcranial magnetic stimulation (TMS) has suggested that figure-eight coils could provide better performance in magnetic stimulation than circular coils. Here, we estimate the performance of μMS by a figure-eight micro-coil, by exploring the impact of the same experimental factors on its focality and consistency in axonal activation. We derived the analytical expression of the electric field and activating function generated by the figure-eight micro-coil, and estimated the location of axonal activation. Using NEURON modeling of an unmyelinated axon, we found two different types (A and B) of axon activation by the figure-eight micro-coil, mediated by coil currents of reversed direction. Type A activation is triggered by membrane hyperpolarization followed by depolarization; Type B activation is triggered by direct membrane depolarization. Consequently, the two types of stimulation are governed by distinct ion channel mechanisms. In comparison to the circular micro-coil, the figure-eight micro-coil requires significantly less current for axonal activation. Under figure-eight micro-coil stimulation, the site of axonal activation does not change with the reversal of the coil current, displacement of the coil, or changes in the intensity of the stimulation. Ultimately, the figure-eight micro-coil provides a more efficient and consistent site of activation than the circular micro-coil in μMS.
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Ye H, Hendee J, Ruan J, Zhirova A, Ye J, Dima M. Neuron matters: neuromodulation with electromagnetic stimulation must consider neurons as dynamic identities. J Neuroeng Rehabil 2022; 19:116. [PMID: 36329492 PMCID: PMC9632094 DOI: 10.1186/s12984-022-01094-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2022] [Accepted: 10/15/2022] [Indexed: 11/06/2022] Open
Abstract
Neuromodulation with electromagnetic stimulation is widely used for the control of abnormal neural activity, and has been proven to be a valuable alternative to pharmacological tools for the treatment of many neurological diseases. Tremendous efforts have been focused on the design of the stimulation apparatus (i.e., electrodes and magnetic coils) that delivers the electric current to the neural tissue, and the optimization of the stimulation parameters. Less attention has been given to the complicated, dynamic properties of the neurons, and their context-dependent impact on the stimulation effects. This review focuses on the neuronal factors that influence the outcomes of electromagnetic stimulation in neuromodulation. Evidence from multiple levels (tissue, cellular, and single ion channel) are reviewed. Properties of the neural elements and their dynamic changes play a significant role in the outcome of electromagnetic stimulation. This angle of understanding yields a comprehensive perspective of neural activity during electrical neuromodulation, and provides insights in the design and development of novel stimulation technology.
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Affiliation(s)
- Hui Ye
- grid.164971.c0000 0001 1089 6558Department of Biology, Quinlan Life Sciences Education and Research Center, Loyola University Chicago, 1032 W. Sheridan Rd., Chicago, IL 60660 USA
| | - Jenna Hendee
- grid.164971.c0000 0001 1089 6558Department of Biology, Quinlan Life Sciences Education and Research Center, Loyola University Chicago, 1032 W. Sheridan Rd., Chicago, IL 60660 USA
| | - Joyce Ruan
- grid.164971.c0000 0001 1089 6558Department of Biology, Quinlan Life Sciences Education and Research Center, Loyola University Chicago, 1032 W. Sheridan Rd., Chicago, IL 60660 USA
| | - Alena Zhirova
- grid.164971.c0000 0001 1089 6558Department of Biology, Quinlan Life Sciences Education and Research Center, Loyola University Chicago, 1032 W. Sheridan Rd., Chicago, IL 60660 USA
| | - Jayden Ye
- grid.164971.c0000 0001 1089 6558Department of Biology, Quinlan Life Sciences Education and Research Center, Loyola University Chicago, 1032 W. Sheridan Rd., Chicago, IL 60660 USA
| | - Maria Dima
- grid.164971.c0000 0001 1089 6558Department of Biology, Quinlan Life Sciences Education and Research Center, Loyola University Chicago, 1032 W. Sheridan Rd., Chicago, IL 60660 USA
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7
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Lynch CJ, Elbau IG, Ng TH, Wolk D, Zhu S, Ayaz A, Power JD, Zebley B, Gunning FM, Liston C. Automated optimization of TMS coil placement for personalized functional network engagement. Neuron 2022; 110:3263-3277.e4. [PMID: 36113473 DOI: 10.1016/j.neuron.2022.08.012] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 05/20/2022] [Accepted: 08/05/2022] [Indexed: 12/11/2022]
Abstract
Transcranial magnetic stimulation (TMS) is used to treat multiple psychiatric and neurological conditions by manipulating activity in particular brain networks and circuits, but individual responses are highly variable. In clinical settings, TMS coil placement is typically based on either group average functional maps or scalp heuristics. Here, we found that this approach can inadvertently target different functional networks in depressed patients due to variability in their functional brain organization. More precise TMS targeting should be feasible by accounting for each patient's unique functional neuroanatomy. To this end, we developed a targeting approach, termed targeted functional network stimulation (TANS). The TANS approach improved stimulation specificity in silico in 8 highly sampled patients with depression and 6 healthy individuals and in vivo when targeting somatomotor functional networks representing the upper and lower limbs. Code for implementing TANS and an example dataset are provided as a resource.
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Affiliation(s)
- Charles J Lynch
- Department of Psychiatry, Weill Cornell Medicine, 413 East 69th Street, Box 204, New York, NY 10021, USA.
| | - Immanuel G Elbau
- Department of Psychiatry, Weill Cornell Medicine, 413 East 69th Street, Box 204, New York, NY 10021, USA
| | - Tommy H Ng
- Department of Psychiatry, Weill Cornell Medicine, 413 East 69th Street, Box 204, New York, NY 10021, USA
| | - Danielle Wolk
- Department of Psychiatry, Weill Cornell Medicine, 413 East 69th Street, Box 204, New York, NY 10021, USA
| | - Shasha Zhu
- Department of Psychiatry, Weill Cornell Medicine, 413 East 69th Street, Box 204, New York, NY 10021, USA
| | - Aliza Ayaz
- Department of Psychiatry, Weill Cornell Medicine, 413 East 69th Street, Box 204, New York, NY 10021, USA
| | - Jonathan D Power
- Department of Psychiatry, Weill Cornell Medicine, 413 East 69th Street, Box 204, New York, NY 10021, USA
| | - Benjamin Zebley
- Department of Psychiatry, Weill Cornell Medicine, 413 East 69th Street, Box 204, New York, NY 10021, USA
| | - Faith M Gunning
- Department of Psychiatry, Weill Cornell Medicine, 413 East 69th Street, Box 204, New York, NY 10021, USA
| | - Conor Liston
- Department of Psychiatry, Weill Cornell Medicine, 413 East 69th Street, Box 204, New York, NY 10021, USA.
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8
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No robust online effects of transcranial direct current stimulation on corticospinal excitability. Brain Stimul 2022; 15:1254-1268. [PMID: 36084908 DOI: 10.1016/j.brs.2022.08.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 08/05/2022] [Accepted: 08/31/2022] [Indexed: 11/22/2022] Open
Abstract
Transcranial direct current stimulation (tDCS) has been used for over twenty years to modulate cortical (particularly motor corticospinal) excitability both during (online) and outlasting (offline) the stimulation, with the former effects associated to the latter. However, tDCS effects are highly variable, partially because stimulation intensity is commonly not adjusted individually (in contrast to transcranial magnetic stimulation, TMS). In Experiment 1, we therefore explored an empirical approach of personalizing tDCS intensity for the primary motor cortex (M1) based on dose-response curves (DRCs), individually relating tDCS Intensity (in steps from 0.3 to 2.0 mA) and Polarity (anodal, cathodal) to the online modulation of concurrent TMS motor evoked potentials (MEP), assessing DRC reliability across two separate days. No robust DRCs could be observed, neither at the individual nor at the group level, with the only robust effect being a (paradoxical) MEP facilitation during cathodal tDCS at 2.0 mA, but no modulation at traditional intensities of or near 1 mA. In Experiment 2, we therefore attempted to replicate the classical bidirectional online MEP modulation during 1 mA tDCS that had been reported by several of the early seminal tDCS papers. We either closely recreated stimulation parameters and temporal protocol of these original studies (Experiment 2A) or slightly modernized them according to current standards (Experiment 2B). In neither experiment did we observed any significant online MEP modulation. We conclude that an empirical titration of individually effective tDCS intensities may not be feasible as online tDCS effects do not appear to be sufficiently robust.
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9
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Cellular mechanisms underlying state-dependent neural inhibition with magnetic stimulation. Sci Rep 2022; 12:12131. [PMID: 35840656 PMCID: PMC9287388 DOI: 10.1038/s41598-022-16494-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 07/11/2022] [Indexed: 12/29/2022] Open
Abstract
Novel stimulation protocols for neuromodulation with magnetic fields are explored in clinical and laboratory settings. Recent evidence suggests that the activation state of the nervous system plays a significant role in the outcome of magnetic stimulation, but the underlying cellular and molecular mechanisms of state-dependency have not been completely investigated. We recently reported that high frequency magnetic stimulation could inhibit neural activity when the neuron was in a low active state. In this paper, we investigate state-dependent neural modulation by applying a magnetic field to single neurons, using the novel micro-coil technology. High frequency magnetic stimulation suppressed single neuron activity in a state-dependent manner. It inhibited neurons in slow-firing states, but spared neurons from fast-firing states, when the same magnetic stimuli were applied. Using a multi-compartment NEURON model, we found that dynamics of voltage-dependent sodium and potassium channels were significantly altered by the magnetic stimulation in the slow-firing neurons, but not in the fast-firing neurons. Variability in neural activity should be monitored and explored to optimize the outcome of magnetic stimulation in basic laboratory research and clinical practice. If selective stimulation can be programmed to match the appropriate neural state, prosthetic implants and brain-machine interfaces can be designed based on these concepts to achieve optimal results.
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Rogasch NC, Biabani M, Mutanen TP. Designing and comparing cleaning pipelines for TMS-EEG data: a theoretical overview and practical example. J Neurosci Methods 2022; 371:109494. [PMID: 35143852 DOI: 10.1016/j.jneumeth.2022.109494] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 02/01/2022] [Accepted: 02/04/2022] [Indexed: 10/19/2022]
Abstract
Combining transcranial magnetic stimulation (TMS) with electroencephalography (EEG) is growing in popularity as a method for probing the reactivity and connectivity of neural circuits in basic and clinical research. However, using EEG to measure the neural responses to TMS is challenging due to the unique artifacts introduced by combining the two techniques. In this paper, we overview the artifacts present in TMS-EEG data and the offline cleaning methods used to suppress these unwanted signals. We then describe how open science practices, including the development of open-source toolboxes designed for TMS-EEG analysis (e.g., TESA - the TMS-EEG signal analyser), have improved the availability and reproducibility of TMS-EEG cleaning methods. We provide theoretical and practical considerations for designing TMS-EEG cleaning pipelines and then give an example of how to compare different pipelines using TESA. We show that changing even a single step in a pipeline designed to suppress decay artifacts results in TMS-evoked potentials (TEPs) with small differences in amplitude and spatial topography. The variability in TEPs resulting from the choice of cleaning pipeline has important implications for comparing TMS-EEG findings between research groups which use different online and offline approaches. Finally, we discuss the challenges of validating cleaning pipelines and recommend that researchers compare outcomes from TMS-EEG experiments using multiple pipelines to ensure findings are not related to the choice of cleaning methods. We conclude that the continued improvement, availability, and validation of cleaning pipelines is essential to ensure TMS-EEG reaches its full potential as a method for studying human neurophysiology.
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Affiliation(s)
- Nigel C Rogasch
- Discipline of Psychiatry, Adelaide Medical School, University of Adelaide; Hopwood Centre for Neurobiology, Lifelong Health Theme, South Australian Health and Medical Research Institute; Turner Institute for Brain and Mental Health, School of Psychological Sciences, Monash University.
| | - Mana Biabani
- Turner Institute for Brain and Mental Health, School of Psychological Sciences, Monash University
| | - Tuomas P Mutanen
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Finland
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The Brain Electrophysiological recording & STimulation (BEST) toolbox. Brain Stimul 2021; 15:109-115. [PMID: 34826626 DOI: 10.1016/j.brs.2021.11.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 11/17/2021] [Accepted: 11/22/2021] [Indexed: 11/23/2022] Open
Abstract
Non-invasive brain stimulation (NIBS) experiments involve many recurring procedures that are not sufficiently standardized in the community. Given the diversity in experimental design and experience of the investigators, automated but yet flexible data collection and analysis tools are needed to increase objectivity, reliability, and reproducibility of NIBS experiments. The Brain Electrophysiological recording and STimulation (BEST) Toolbox is a MATLAB-based, open-source software with graphical user interface that allows users to design, run, and share freely configurable multi-protocol, multi-session NIBS studies, including transcranial magnetic, electric, and ultrasound stimulation (TMS, tES, TUS). Interfacing with a variety of recording and stimulation devices, the BEST toolbox analyzes EMG and EEG data, and configures stimulation parameters on-the-fly to facilitate closed-loop protocols and real-time applications. Its functionality is continuously expanded and includes e.g., TMS motor hotspot search, threshold estimation, motor evoked potential (MEP) and TMS-evoked EEG potential (TEP) measurements, dose-response curves, paired-pulse and dual-coil TMS, rTMS interventions.
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12
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McInnes AN, Lipp OV, Tresilian JR, Vallence AM, Marinovic W. Premovement inhibition can protect motor actions from interference by response-irrelevant sensory stimulation. J Physiol 2021; 599:4389-4406. [PMID: 34339524 DOI: 10.1113/jp281849] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 07/28/2021] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS Suppression of corticospinal excitability is reliably observed during preparation for a range of motor actions, leading to the belief that this preparatory inhibition is a physiologically obligatory component of motor preparation. The neurophysiological function of this suppression is uncertain. We restricted the time available for participants to engage in preparation and found no evidence for preparatory inhibition. The function of preparatory inhibition can be inferred from our findings that sensory stimulation can disrupt motor output in the absence of preparatory inhibition, but enhance motor output when inhibition is present. These findings suggest preparatory inhibition may be a strategic process which acts to protect prepared actions from external interference. Our findings have significant theoretical implications for preparatory processes. Findings may also have a pragmatic benefit in that acoustic stimulation could be used therapeutically to facilitate movement, but only if the action can be prepared well in advance. ABSTRACT Shortly before movement initiation, the corticospinal system undergoes a transient suppression. This phenomenon has been observed across a range of motor tasks, suggesting that it may be an obligatory component of movement preparation. We probed whether this was also the case when the urgency to perform a motor action was high, in a situation where little time was available to engage in preparatory processes. We controlled the urgency of an impending motor action by increasing or decreasing the foreperiod duration in an anticipatory timing task. Transcranial magnetic stimulation (TMS; experiment 1) or a loud acoustic stimulus (LAS; experiment 2) were used to examine how corticospinal and subcortical excitability were modulated during motor preparation. Preparatory inhibition of the corticospinal tract was absent when movement urgency was high, though motor actions were initiated on time. In contrast, subcortical circuits were progressively inhibited as the time to prepare increased. Interestingly, movement force and vigour were reduced by both TMS and the LAS when movement urgency was high, and enhanced when movement urgency was low. These findings indicate that preparatory inhibition may not be an obligatory component of motor preparation. The behavioural effects we observed in the absence of preparatory inhibition were induced by both TMS and the LAS, suggesting that accessory sensory stimulation may disrupt motor output when such stimulation is presented in the absence of preparatory inhibition. We conclude that preparatory inhibition may be an adaptive strategy which can serve to protect the prepared motor action from external interference.
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Affiliation(s)
- Aaron N McInnes
- School of Population Health, Discipline of Psychology, Curtin University, Perth, Western Australia, Australia
| | - Ottmar V Lipp
- School of Population Health, Discipline of Psychology, Curtin University, Perth, Western Australia, Australia.,School of Psychology and Counselling, Queensland University of Technology, Brisbane, Queensland, Australia
| | | | - Ann-Maree Vallence
- School of Psychology and Exercise Science, Murdoch University, Perth, Western Australia, Australia
| | - Welber Marinovic
- School of Population Health, Discipline of Psychology, Curtin University, Perth, Western Australia, Australia
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Biabani M, Fornito A, Coxon JP, Fulcher BD, Rogasch NC. The correspondence between EMG and EEG measures of changes in cortical excitability following transcranial magnetic stimulation. J Physiol 2021; 599:2907-2932. [DOI: 10.1113/jp280966] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 01/18/2021] [Indexed: 12/31/2022] Open
Affiliation(s)
- Mana Biabani
- The Turner Institute for Brain and Mental Health School of Psychological Sciences Monash University Victoria Australia
| | - Alex Fornito
- The Turner Institute for Brain and Mental Health School of Psychological Sciences Monash University Victoria Australia
| | - James P. Coxon
- The Turner Institute for Brain and Mental Health School of Psychological Sciences Monash University Victoria Australia
| | - Ben D. Fulcher
- The Turner Institute for Brain and Mental Health School of Psychological Sciences Monash University Victoria Australia
- School of Physics The University of Sydney Sydney New South Wales 2006 Australia
| | - Nigel C. Rogasch
- The Turner Institute for Brain and Mental Health School of Psychological Sciences Monash University Victoria Australia
- Discipline of Psychiatry Adelaide Medical School University of Adelaide Adelaide South Australia Australia
- Hopwood Centre for Neurobiology Lifelong Health Theme South Australian Health and Medical Research Institute (SAHMRI) Adelaide South Australia Australia
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14
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Varone G, Hussain Z, Sheikh Z, Howard A, Boulila W, Mahmud M, Howard N, Morabito FC, Hussain A. Real-Time Artifacts Reduction during TMS-EEG Co-Registration: A Comprehensive Review on Technologies and Procedures. SENSORS 2021; 21:s21020637. [PMID: 33477526 PMCID: PMC7831109 DOI: 10.3390/s21020637] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 01/08/2021] [Accepted: 01/11/2021] [Indexed: 01/24/2023]
Abstract
Transcranial magnetic stimulation (TMS) excites neurons in the cortex, and neural activity can be simultaneously recorded using electroencephalography (EEG). However, TMS-evoked EEG potentials (TEPs) do not only reflect transcranial neural stimulation as they can be contaminated by artifacts. Over the last two decades, significant developments in EEG amplifiers, TMS-compatible technology, customized hardware and open source software have enabled researchers to develop approaches which can substantially reduce TMS-induced artifacts. In TMS-EEG experiments, various physiological and external occurrences have been identified and attempts have been made to minimize or remove them using online techniques. Despite these advances, technological issues and methodological constraints prevent straightforward recordings of early TEPs components. To the best of our knowledge, there is no review on both TMS-EEG artifacts and EEG technologies in the literature to-date. Our survey aims to provide an overview of research studies in this field over the last 40 years. We review TMS-EEG artifacts, their sources and their waveforms and present the state-of-the-art in EEG technologies and front-end characteristics. We also propose a synchronization toolbox for TMS-EEG laboratories. We then review subject preparation frameworks and online artifacts reduction maneuvers for improving data acquisition and conclude by outlining open challenges and future research directions in the field.
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Affiliation(s)
- Giuseppe Varone
- Department of Medical and Surgical Sciences, Magna Greacia University of Catanzaro, 88100 Catanzaro, Italy;
| | - Zain Hussain
- College of Medicine and Veterinary Medicine, University of Edinburgh, Edinburgh EH16 4TJ, UK; (Z.H.); (Z.S.)
- Howard Brain Sciences Foundation, Providence, RI 02906, USA;
| | - Zakariya Sheikh
- College of Medicine and Veterinary Medicine, University of Edinburgh, Edinburgh EH16 4TJ, UK; (Z.H.); (Z.S.)
| | - Adam Howard
- Howard Brain Sciences Foundation, Providence, RI 02906, USA;
| | - Wadii Boulila
- RIADI Laboratory, National School of Computer Sciences, University of Manouba, Manouba 2010, Tunisia;
- IS Department, College of Computer Science and Engineering, Taibah University, Medina 42353, Saudi Arabia
| | - Mufti Mahmud
- Department of Computer Science and Medical Technology Innovation Facility, Nottingham Trent University, Clifton, Nottingham NG11 8NS, UK;
| | - Newton Howard
- Nuffield Department of Surgical Sciences, University of Oxford, Oxford OX3 9DU, UK;
| | | | - Amir Hussain
- School of Computing, Edinburgh Napier University, Edinburgh EH11 4BN, UK;
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15
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Intensity- and timing-dependent modulation of motion perception with transcranial magnetic stimulation of visual cortex. Neuropsychologia 2020; 147:107581. [PMID: 32795456 DOI: 10.1016/j.neuropsychologia.2020.107581] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 07/23/2020] [Accepted: 08/04/2020] [Indexed: 12/22/2022]
Abstract
Despite the widespread use of transcranial magnetic stimulation (TMS) in research and clinical care, the dose-response relations and neurophysiological correlates of modulatory effects remain relatively unexplored. To fill this gap, we studied modulation of visual processing as a function of TMS parameters. Our approach combined electroencephalography (EEG) with application of single pulse TMS to visual cortex as participants performed a motion perception task. During each participants' first visit, motion coherence thresholds, 64-channel visual evoked potentials (VEPs), and TMS resting motor thresholds (RMT) were measured. In second and third visits, single pulse TMS was delivered at one of two latencies, either 30 ms before the onset of motion or at the onset latency of the N2 VEP component derived from the first session. TMS was delivered at 0%, 80%, 100%, or 120% of RMT over the site of N2 peak activity, or at 120% over vertex. Behavioral results demonstrated a significant main effect of TMS timing on accuracy, with better performance when TMS was applied at the N2-Onset timing versus Pre-Onset, as well as a significant interaction, indicating that 80% intensity produced higher accuracy than other conditions at the N2-Onset. TMS effects on the P3 VEP showed reduced amplitudes in the 80% Pre-Onset condition, an increase for the 120% N2-Onset condition, and monotonic amplitude scaling with stimulation intensity. The N2 component was not affected by TMS. These findings reveal the influence of TMS intensity and timing on visual perception and electrophysiological responses, with optimal facilitation at stimulation intensities below RMT.
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Interhemispheric symmetry of µ-rhythm phase-dependency of corticospinal excitability. Sci Rep 2020; 10:7853. [PMID: 32398713 PMCID: PMC7217936 DOI: 10.1038/s41598-020-64390-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2020] [Accepted: 04/15/2020] [Indexed: 01/22/2023] Open
Abstract
Oscillatory activity in the µ-frequency band (8–13 Hz) determines excitability in sensorimotor cortex. In humans, the primary motor cortex (M1) in the two hemispheres shows significant anatomical, connectional, and electrophysiological differences associated with motor dominance. It is currently unclear whether the µ-oscillation phase effects on corticospinal excitability demonstrated previously for the motor-dominant M1 are also different between motor-dominant and motor-non-dominant M1 or, alternatively, are similar to reflect a ubiquitous physiological trait of the motor system at rest. Here, we applied single-pulse transcranial magnetic stimulation to the hand representations of the motor-dominant and the motor-non-dominant M1 of 51 healthy right-handed volunteers when electroencephalography indicated a certain µ-oscillation phase (positive peak, negative peak, or random). We determined resting motor threshold (RMT) as a marker of corticospinal excitability in the three µ-phase conditions. RMT differed significantly depending on the pre-stimulus phase of the µ-oscillation in both M1, with highest RMT in the positive-peak condition, and lowest RMT in the negative-peak condition. µ-phase-dependency of RMT correlated directly between the two M1, and interhemispheric differences in µ-phase-dependency were absent. In conclusion, µ-phase-dependency of corticospinal excitability appears to be a ubiquitous physiological trait of the motor system at rest, without hemispheric dominance.
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Affiliation(s)
- Til O Bergmann
- Department of Neurology and Stroke, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany.,Institute of Medical Psychology and Behavioral Neurobiology, University of Tübingen, Tübingen, Germany.,Deutsches Resilienz Zentrum, University Medical Center Mainz, Mainz, Germany
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