1
|
Madadi Asl M, Valizadeh A. Entrainment by transcranial alternating current stimulation: Insights from models of cortical oscillations and dynamical systems theory. Phys Life Rev 2025; 53:147-176. [PMID: 40106964 DOI: 10.1016/j.plrev.2025.03.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2025] [Accepted: 03/12/2025] [Indexed: 03/22/2025]
Abstract
Signature of neuronal oscillations can be found in nearly every brain function. However, abnormal oscillatory activity is linked with several brain disorders. Transcranial alternating current stimulation (tACS) is a non-invasive brain stimulation technique that can potentially modulate neuronal oscillations and influence behavior both in health and disease. Yet, a complete understanding of how interacting networks of neurons are affected by tACS remains elusive. Entrainment effects by which tACS synchronizes neuronal oscillations is one of the main hypothesized mechanisms, as evidenced in animals and humans. Computational models of cortical oscillations may shed light on the entrainment effects of tACS, but current modeling studies lack specific guidelines to inform experimental investigations. This study addresses the existing gap in understanding the mechanisms of tACS effects on rhythmogenesis within the brain by providing a comprehensive overview of both theoretical and experimental perspectives. We explore the intricate interactions between oscillators and periodic stimulation through the lens of dynamical systems theory. Subsequently, we present a synthesis of experimental findings that demonstrate the effects of tACS on both individual neurons and collective oscillatory patterns in animal models and humans. Our review extends to computational investigations that elucidate the interplay between tACS and neuronal dynamics across diverse cortical network models. To illustrate these concepts, we conclude with a simple oscillatory neuron model, showcasing how fundamental theories of oscillatory behavior derived from dynamical systems, such as phase response of neurons to external perturbation, can account for the entrainment effects observed with tACS. Studies reviewed here render the necessity of integrated experimental and computational approaches for effective neuromodulation by tACS in health and disease.
Collapse
Affiliation(s)
- Mojtaba Madadi Asl
- School of Biological Sciences, Institute for Research in Fundamental Sciences (IPM), Tehran, Iran; Pasargad Institute for Advanced Innovative Solutions (PIAIS), Tehran, Iran.
| | - Alireza Valizadeh
- Pasargad Institute for Advanced Innovative Solutions (PIAIS), Tehran, Iran; Department of Physics, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan, Iran; The Zapata-Briceño Institute of Neuroscience, Madrid, Spain
| |
Collapse
|
2
|
Dubcek T, Ledergerber D, Thomann J, Aiello G, Serra Garcia M, Imbach L, Polania R. Electroencephalography-driven brain-network models for personalized interpretation and prediction of neural oscillations. Clin Neurophysiol 2025; 174:1-9. [PMID: 40179632 DOI: 10.1016/j.clinph.2025.03.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2024] [Revised: 03/19/2025] [Accepted: 03/20/2025] [Indexed: 04/05/2025]
Abstract
OBJECTIVE Develop an encephalography (EEG)-driven method that integrates interpretability, predictiveness, and personalization to assess the dynamics of the brain network, with a focus on pathological conditions such as pharmacoresistant epilepsy. METHODS We propose a method to identify dominant coherent oscillations from EEG recordings. It relies on the Koopman operator theory to achieve individualized EEG prediction and electrophysiological interpretability. We extend it with concepts from adiabatic theory to address the nonstationary and noisy EEG signals. RESULTS By simultaneously capturing the local spectral and connectivity aspects of patient-specific oscillatory dynamics, we are able to clarify the underlying dynamical mechanism. We use it to construct the corresponding generative models of the brain network. We demonstrate the proposed approach on recordings of patients in status epilepticus. CONCLUSIONS The proposed EEG-driven method opens new perspectives on integrating interpretability, predictiveness, and personalization within a unified framework. It provides a quantitative approach for assessing EEG recordings, crucial for understanding and modulating pathological brain activity. SIGNIFICANCE This work bridges theoretical neuroscience and clinical practice, offering a novel framework for understanding and predicting brain network dynamics. The resulting approach paves the way for data-driven insights into brain network mechanisms and the design of personalized neuromodulation therapies.
Collapse
Affiliation(s)
- Tena Dubcek
- Swiss Epilepsy Center, Klinik Lengg, Zurich, Switzerland; ETH Zurich, Department of Health Sciences and Technology, Switzerland.
| | | | - Jana Thomann
- ETH Zurich, Department of Health Sciences and Technology, Switzerland
| | - Giovanna Aiello
- ETH Zurich, Department of Health Sciences and Technology, Switzerland; Neuroscience Center Zurich, University of Zurich and ETH Zurich, Switzerland
| | | | - Lukas Imbach
- Swiss Epilepsy Center, Klinik Lengg, Zurich, Switzerland; Neuroscience Center Zurich, University of Zurich and ETH Zurich, Switzerland
| | - Rafael Polania
- ETH Zurich, Department of Health Sciences and Technology, Switzerland
| |
Collapse
|
3
|
Barzegar S, Kakies CFM, Ciupercӑ D, Wischnewski M. Transcranial alternating current stimulation for investigating complex oscillatory dynamics and interactions. Int J Psychophysiol 2025; 212:112579. [PMID: 40315997 DOI: 10.1016/j.ijpsycho.2025.112579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2025] [Revised: 04/04/2025] [Accepted: 04/28/2025] [Indexed: 05/04/2025]
Abstract
Neural oscillations play a fundamental role in human cognition and behavior. While electroencephalography (EEG) and related methods provide precise temporal recordings of these oscillations, they are limited in their ability to generate causal conclusions. Transcranial alternating current stimulation (tACS) has emerged as a promising non-invasive neurostimulation technique to modulate neural oscillations, which offers insights into their functional role and relation to human cognition and behavior. Originally, tACS is applied between two or more electrodes at a given frequency. However, recent advances have aimed to apply different current waveforms to target specific oscillatory dynamics. This systematic review evaluates the efficacy of non-standard tACS applications designed to investigate oscillatory patterns beyond simple sinusoidal stimulation. We categorized these approaches into three key domains: (1) phase synchronization techniques, including in-phase, anti-phase, and traveling wave stimulation; (2) non-sinusoidal tACS, which applies alternative waveforms such as composite, broadband or triangular oscillations; and (3) amplitude-modulated tACS and temporal interference stimulation, which allow for concurrent EEG recordings and deeper cortical targeting. While a number of studies provide evidence for the added value of these non-standard tACS procedures, other studies show opposing or null findings. Crucially, the number of studies for most applications is currently low, and as such, the goal of this review is to highlight both the promise and current limitations of these techniques, providing a foundation for future research in neurostimulation.
Collapse
Affiliation(s)
- Samira Barzegar
- Department of Psychology, University of Groningen, Groningen, the Netherlands
| | - Carolina F M Kakies
- Department of Psychology, University of Groningen, Groningen, the Netherlands
| | - Dorina Ciupercӑ
- Department of Psychology, University of Groningen, Groningen, the Netherlands
| | - Miles Wischnewski
- Department of Psychology, University of Groningen, Groningen, the Netherlands.
| |
Collapse
|
4
|
Farahani F, Vöröslakos M, Birnbaum AM, FallahRad M, Williams PTJA, Martin JH, Parra LC. Repeated tDCS at Clinically Relevant Field Intensity Can Boost Concurrent Motor Learning in Rats. J Neurosci 2025; 45:e1495242025. [PMID: 40216548 PMCID: PMC12079733 DOI: 10.1523/jneurosci.1495-24.2025] [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: 08/07/2024] [Revised: 01/27/2025] [Accepted: 02/05/2025] [Indexed: 04/25/2025] Open
Abstract
Clinical trials with transcranial direct current stimulation (tDCS) use weak electric fields that have yet to demonstrate measurable behavioral effects in animal models. We hypothesized that weak stimulation will produce sizable effects, provided it is applied concurrently with behavioral training and repeated over multiple sessions. We tested this in a rodent model of dexterous motor skill learning using a pellet-reaching task in ad libitum behaving rats. The task was automated to minimize experimenter bias. We measured field magnitudes intracranially to calibrate the stimulation current. Male rats were trained for 20 min with concurrent epicranial tDCS over 10 daily sessions. We developed a new electrode montage that enabled stable stimulation over the 10 sessions with a field intensity of 2 V/m at the motor cortex. Behavior was recorded with high-speed video to quantify reaching dynamics. We also measured motor-evoked potentials (MEPs) bilaterally with epidural microstimulation. The number of successful reaches improved across days of training, and the rate of learning was higher in the anodal group as compared with sham-control animals (F (1) = 7.12; p = 0.008; N = 24). MEPs were not systematically affected by tDCS. Post hoc analysis suggests that tDCS modulated motor learning only for right-pawed animals, improving success of reaching but limiting stereotypy in these animals. Repeated and concurrent anodal tDCS can boost motor skill learning at clinically relevant field intensities. In this animal model, the effect interacted with paw preference and was not associated with corticospinal excitability.
Collapse
Affiliation(s)
- Forouzan Farahani
- Biomedical Engineering Department, City College of New York, New York, New York 10031
| | - Mihály Vöröslakos
- Neuroscience Institute, NYU Grossman School of Medicine, New York University, New York, New York 10016
| | - Andrew M Birnbaum
- Biomedical Engineering Department, City College of New York, New York, New York 10031
| | - Mohamad FallahRad
- Biomedical Engineering Department, City College of New York, New York, New York 10031
| | - Preston T J A Williams
- Molecular, Cellular and Biomedical Science, CUNY School of Medicine, New York, New York 10031
| | - John H Martin
- Molecular, Cellular and Biomedical Science, CUNY School of Medicine, New York, New York 10031
| | - Lucas C Parra
- Biomedical Engineering Department, City College of New York, New York, New York 10031
| |
Collapse
|
5
|
van Bree S, Levenstein D, Krause MR, Voytek B, Gao R. Processes and measurements: a framework for understanding neural oscillations in field potentials. Trends Cogn Sci 2025; 29:448-466. [PMID: 39753446 DOI: 10.1016/j.tics.2024.12.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2024] [Revised: 12/03/2024] [Accepted: 12/04/2024] [Indexed: 05/09/2025]
Abstract
Various neuroscientific theories maintain that brain oscillations are important for neuronal computation, but opposing views claim that these macroscale dynamics are 'exhaust fumes' of more relevant processes. Here, we approach the question of whether oscillations are functional or epiphenomenal by distinguishing between measurements and processes, and by reviewing whether causal or inferentially useful links exist between field potentials, electric fields, and neurobiological events. We introduce a vocabulary for the role of brain signals and their underlying processes, demarcating oscillations as a distinct entity where both processes and measurements can exhibit periodicity. Leveraging this distinction, we suggest that electric fields, oscillating or not, are causally and computationally relevant, and that field potential signals can carry information even without causality.
Collapse
Affiliation(s)
- Sander van Bree
- Department of Medicine, Justus Liebig University, Giessen, Germany; Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany; Centre for Cognitive Neuroimaging, School of Psychology and Neuroscience, University of Glasgow, Glasgow, UK
| | - Daniel Levenstein
- MILA - Quebec AI Institute, Montreal, QC, Canada; Montreal Neurological Institute and Hospital, McGill University, Montreal, QC, Canada
| | - Matthew R Krause
- Montreal Neurological Institute and Hospital, McGill University, Montreal, QC, Canada
| | - Bradley Voytek
- Department of Cognitive Science, Halıcıŏglu Data Science Institute, Kavli Institute for Brain & Mind, University of California, San Diego, La Jolla, CA, USA
| | - Richard Gao
- Machine Learning in Science, Excellence Cluster Machine Learning and Tübingen AI Center, University of Tübingen, Tübingen, Germany.
| |
Collapse
|
6
|
Ferrazzano G, Maccarrone D, Guerra A, Collura A, Satriano F, Fratino M, Ievolella F, Belvisi D, Amato MP, Centonze D, Altieri M, Conte A, Leodori G. The effects of gamma-tACS on cognitive impairment in multiple sclerosis: A randomized, double-blind, sham-controlled, pilot study. Mult Scler 2025; 31:728-739. [PMID: 40285586 DOI: 10.1177/13524585251333575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2025]
Abstract
BACKGROUND Multiple sclerosis (MS) often causes impairment in working memory (WM), information processing speed (IPS), and verbal memory (VM). These deficits are linked to disrupted neural oscillatory activity. Transcranial alternating current stimulation (tACS), which modulates cortical oscillations, may hold promise for treating cognitive impairment in MS. OBJECTIVES To evaluate online and offline effects of gamma (γ)-tACS on WM, IPS, and VM while assessing changes in brain rhythms using electroencephalography (EEG). METHODS Thirty-six MS patients with single-domain impairment in WM (12), IPS (13), or VM (11) underwent γ-tACS and sham-tACS over the left dorsolateral prefrontal cortex (DLPFC) (WM, IPS) or precuneus (VM). Cognitive performance was assessed pre-tACS (T0), during (T1), and post-tACS (T2) using the Digit Span Backward (DSBW) for WM, Symbol Digit Modalities Test (SDMT) for IPS, and Rey Auditory Verbal Learning Test (RAVLT) for VM. EEG was recorded at T0 and T2 to analyze local power spectral density and local-to-global connectivity. RESULTS DSBW, SDMT, and RAVLT scores transiently improved during γ-tACS and not during sham. IPS-impaired patients showed a reduction in spectral power across all frequency bands, at the stimulation site, post-DLPFC γ-tACS. CONCLUSION γ-tACS briefly improves WM, IPS, and VM in MS patients, warranting further trials of this non-invasive intervention.
Collapse
Affiliation(s)
- Gina Ferrazzano
- Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy
| | - Davide Maccarrone
- Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy
| | - Andrea Guerra
- Padova Neuroscience Center, University of Padua, Padua, Italy
- Parkinson and Movement Disorders Unit, Study Center on Neurodegeneration, Department of Neuroscience, University of Padua, Padua, Italy
| | - Angelo Collura
- Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy
| | - Federica Satriano
- Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy
| | - Mariangela Fratino
- Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy
| | - Fabrizio Ievolella
- Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy
| | - Daniele Belvisi
- Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy
- IRCCS Neuromed, Pozzilli, Italy
| | - Maria Pia Amato
- Department Neurofarba, University of Florence, Florence, Italy
- IRCCS Fondazione Don Carlo Gnocchi, Florence, Italy
| | - Diego Centonze
- IRCCS Neuromed, Pozzilli, Italy
- Department of Systems Medicine, Tor Vergata University, Rome, Italy
| | - Marta Altieri
- Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy
| | - Antonella Conte
- Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy
- IRCCS Neuromed, Pozzilli, Italy
| | - Giorgio Leodori
- Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy
- IRCCS Neuromed, Pozzilli, Italy
| |
Collapse
|
7
|
Heise KF, Albouy G, Dolfen N, Peeters R, Mantini D, Swinnen SP. Induced zero-phase synchronization as a potential neural code for optimized visuomotor integration. Brain Stimul 2025; 18:756-767. [PMID: 40164305 DOI: 10.1016/j.brs.2025.03.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2024] [Revised: 03/09/2025] [Accepted: 03/28/2025] [Indexed: 04/02/2025] Open
Abstract
BACKGROUND Goal-directed behavior requires the integration of information from the outside world and internal (somatosensory) sources about our own actions. Expectations (or 'internal models') are generated from prior knowledge and constantly updated based on sensory feedback. This optimized information integration ('predictive coding') results in a global behavioral advantage of anticipated action in the presence of uncertainty. Our goal was to probe the effect of phase entrainment of the sensorimotor mu-rhythm on visuomotor integration. METHODS Participants received transcranial alternating current stimulation over bilateral motor cortices (M1) while performing a visually-guided force adjustment task during functional magnetic resonance imaging. RESULTS Inter-hemispheric zero-phase entrainment resulted in effector-specific modulation of performance precision and effector-generic minimization of force signal complexity paralleled by BOLD activation changes in bilateral caudate and increased functional connectivity between the right M1 and contralateral putamen, inferior parietal, and medial temporal regions. While effector-specific changes in performance precision were associated with contralateral caudate and hippocampal activation decreases, only the global reduction in force signal complexity was associated with increased functional M1 connectivity with bilateral striatal regions. CONCLUSION We propose that zero-phase synchronization represents a neural mode of optimized information integration related to internal model updating within the recursive perception-action continuum associated with predictive coding.
Collapse
Affiliation(s)
- Kirstin-Friederike Heise
- Movement Control and Neuroplasticity Research Group, Biomedical Sciences, KU Leuven, Belgium; KU Leuven Brain Institute, Leuven, Belgium; Integrative Neuromodulation and Recovery (iNR) Laboratory, Department of Health Sciences and Research, Medical University of South Carolina, Charleston, SC, USA.
| | - Geneviève Albouy
- Movement Control and Neuroplasticity Research Group, Biomedical Sciences, KU Leuven, Belgium; KU Leuven Brain Institute, Leuven, Belgium; Department of Health and Kinesiology, College of Health, University of Utah, Salt Lake City, UT, USA
| | - Nina Dolfen
- Department of Psychology, Columbia University, New York City, NY, USA; Department of Experimental Psychology, Ghent University, Belgium
| | - Ronald Peeters
- Department of Imaging & Pathology, KU Leuven, Leuven, Belgium; Department of Radiology, University Hospitals Leuven, Leuven, Belgium
| | - Dante Mantini
- Movement Control and Neuroplasticity Research Group, Biomedical Sciences, KU Leuven, Belgium; KU Leuven Brain Institute, Leuven, Belgium
| | - Stephan P Swinnen
- Movement Control and Neuroplasticity Research Group, Biomedical Sciences, KU Leuven, Belgium; KU Leuven Brain Institute, Leuven, Belgium
| |
Collapse
|
8
|
Matta R, Reato D, Lombardini A, Moreau D, O’Connor RP. Inkjet-printed transparent electrodes: Design, characterization, and initial in vivo evaluation for brain stimulation. PLoS One 2025; 20:e0320376. [PMID: 40168427 PMCID: PMC11960977 DOI: 10.1371/journal.pone.0320376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2024] [Accepted: 02/17/2025] [Indexed: 04/03/2025] Open
Abstract
Electrical stimulation is a powerful tool for investigating and modulating brain activity, as well as for treating neurological disorders. However, understanding the precise effects of electrical stimulation on neural activity has been hindered by limitations in recording neuronal responses near the stimulating electrode, such as stimulation artifacts in electrophysiology or obstruction of the field of view in imaging. In this study, we introduce a novel stimulation device fabricated from conductive polymers that is transparent and therefore compatible with optical imaging techniques. The device is manufactured using a combination of microfabrication and inkjet printing techniques and is flexible, allowing better adherence to the brain's natural curvature. We characterized the electrical and optical properties of the electrodes, focusing on the trade-off between the maximum current that can be delivered and optical transmittance. We found that a 1 mm diameter, 350 nm thick PEDOT:PSS electrode could be used to apply a maximum current of 130 μA while maintaining 84% transmittance (approximately 50% under 2-photon imaging conditions). We then evaluated the electrode performance in the brain of an anesthetized mouse by measuring the electric field with a nearby recording electrode and found values up to 30 V/m. Finally, we combined experimental data with a finite-element model of the in vivo experimental setup to estimate the distribution of the electric field underneath the electrode in the mouse brain. Our findings indicate that the device can generate an electric field as high as 300 V/m directly beneath the electrode, demonstrating its potential for studying and manipulating neural activity using a range of electrical stimulation techniques relevant to human applications. Overall, this work presents a promising approach for developing versatile new tools to apply and study electrical brain stimulation.
Collapse
Affiliation(s)
- Rita Matta
- Mines Saint-Etienne, Centre CMP, Departement BEL, F - 13541 Gardanne, France
| | - Davide Reato
- Mines Saint-Etienne, Centre CMP, Departement BEL, F - 13541 Gardanne, France
- Institut de Neurosciences de la Timone, UMR 7289, CNRS and Aix Marseille Université, 13005 Marseille, France
| | - Alberto Lombardini
- Institut de Neurosciences de la Timone, UMR 7289, CNRS and Aix Marseille Université, 13005 Marseille, France
| | - David Moreau
- Mines Saint-Etienne, Centre CMP, Departement BEL, F - 13541 Gardanne, France
| | - Rodney P. O’Connor
- Mines Saint-Etienne, Centre CMP, Departement BEL, F - 13541 Gardanne, France
| |
Collapse
|
9
|
Ding X, Zhou Y, Liu Y, Yao XL, Wang JX, Xie Q. Application and research progress of different frequency tACS in stroke rehabilitation: A systematic review. Brain Res 2025; 1852:149521. [PMID: 39983809 DOI: 10.1016/j.brainres.2025.149521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2024] [Revised: 02/09/2025] [Accepted: 02/18/2025] [Indexed: 02/23/2025]
Abstract
After a stroke, abnormal changes in neural oscillations that are related to the severity and prognosis of the disease can occur. Resetting these abnormal neural oscillations is a potential approach for stroke rehabilitation. Transcranial alternating current stimulation (tACS) can modulate intrinsic neural oscillations noninvasively and has attracted attention as a possible technique to improve multiple post-stroke symptoms, including deficits in speech, vision, and motor ability and overall neurological recovery. The clinical effect of tACS varies according to the selected frequency. Therefore, choosing an appropriate frequency to optimize outcomes for specific dysfunctions is essential. This review focuses on the current research status and possibilities of tACS with different frequencies in stroke rehabilitation. We also discuss the possible mechanisms of tACS in stroke to provide a theoretical foundation for the method and highlight the controversial aspects that need further exploration. Although tACS has great potential, few clinical studies have applied it in the treatment of stroke, and no consensus has been reached. We analyze limitations in experimental designs and identify potential tACS approaches worthy of exploration in the future.
Collapse
Affiliation(s)
- Xue Ding
- Department of Rehabilitation Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Department of Rehabilitation Medicine, Shanghai Ruijin Rehabilitation Hospital, Shanghai, China
| | - Yu Zhou
- Department of Rehabilitation Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yang Liu
- Department of Rehabilitation Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xiao-Ling Yao
- Department of Rehabilitation Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Ji-Xian Wang
- Department of Rehabilitation Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| | - Qing Xie
- Department of Rehabilitation Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Department of Rehabilitation Medicine, Shanghai Ruijin Rehabilitation Hospital, Shanghai, China.
| |
Collapse
|
10
|
Sveva V, Guerra A, Mangone M, Agostini F, Bernetti A, Berardelli A, Paoloni M, Bologna M. Effects of cerebellar transcranial alternating current stimulation on balance and gait in healthy subjects. Clin Neurophysiol 2025:S1388-2457(25)00453-5. [PMID: 40180842 DOI: 10.1016/j.clinph.2025.03.033] [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: 03/11/2024] [Revised: 02/24/2025] [Accepted: 03/24/2025] [Indexed: 04/05/2025]
Abstract
BACKGROUND Transcranial Alternating Current Stimulation (tACS) is a non-invasive brain stimulation technique that modulates cortical oscillations and influences behavior. OBJECTIVES This study aimed to explore the effects of cerebellar theta (5 Hz) and gamma (50 Hz) tACS on human balance and gait through kinematic analysis. MATERIALS AND METHODS Nineteen right-handed healthy subjects participated in three randomized motor tasks: postural standing (PS), gait initiation (GI), and gait cycle (GC). Participants underwent theta-, gamma-, or sham-tACS over the cerebellum while kinematic data were collected using a force platform and an 8-camera optoelectronic system. RESULTS Theta-tACS significantly influenced motor behavior during PS and GC, but not GI. Specifically, it reduced the Maximum Radius, Total Trace Length, Longitudinal Range, and Area during PS, and decreased Stride Width during GC. In contrast, cerebellar gamma-tACS had no significant effect on any kinematic parameters across the tasks. CONCLUSIONS Cerebellar theta-tACS may enhance postural stability and gait control in healthy individuals. We hypothesize that theta-tACS may entrain theta-resonant neurons in the cerebellar cortex, affecting motor control networks involved in balance and gait. SIGNIFICANCE This study highlights tACS's potential as a non-invasive treatment for balance and gait disorders associated with cerebellar dysfunction.
Collapse
Affiliation(s)
- Valerio Sveva
- Department of Anatomical and Histological Sciences, Legal Medicine and Orthopedics, Sapienza University, Piazzale Aldo Moro 5, 00185 Rome, Italy; Department of Human Neurosciences, Sapienza University of Rome, Viale dell'Università 30, 00185 Rome, Italy
| | - Andrea Guerra
- Parkinson and Movement Disorders Unit, Study Center for Neurodegeneration (CESNE), Department of Neuroscience, University of Padua, Via Giustiniani 2, 35128 Padua, Italy; Padova Neuroscience Center (PNC), University of Padua, Via Giuseppe Orus, 2, 35131 Padua, Italy
| | - Massimiliano Mangone
- Department of Anatomical and Histological Sciences, Legal Medicine and Orthopedics, Sapienza University, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Francesco Agostini
- Department of Anatomical and Histological Sciences, Legal Medicine and Orthopedics, Sapienza University, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Andrea Bernetti
- Department of Science and Biological and Ambient Technologies, University of Salento, Via Lecce-Monteroni, 73100 Lecce, LE, Italy
| | - Alfredo Berardelli
- Department of Human Neurosciences, Sapienza University of Rome, Viale dell'Università 30, 00185 Rome, Italy; IRCCS Neuromed, Via Atinense 18, 86077 Pozzilli, IS, Italy
| | - Marco Paoloni
- Department of Anatomical and Histological Sciences, Legal Medicine and Orthopedics, Sapienza University, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Matteo Bologna
- Department of Human Neurosciences, Sapienza University of Rome, Viale dell'Università 30, 00185 Rome, Italy; IRCCS Neuromed, Via Atinense 18, 86077 Pozzilli, IS, Italy.
| |
Collapse
|
11
|
Tingting L, Lilin C, Chuangjia W, Jiamen S, Shuxian Z, Yinan A, Hanjun L, Haiqing Z. Frequency-specific modulation of motor cortical excitability by transcranial alternating current stimulation. J Neuroeng Rehabil 2025; 22:69. [PMID: 40148968 PMCID: PMC11948692 DOI: 10.1186/s12984-025-01610-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2024] [Accepted: 03/17/2025] [Indexed: 03/29/2025] Open
Abstract
BACKGROUND Transcranial alternating current stimulation (tACS) is a non-invasive technique that modulates neural oscillations, yet its specific effects on cortical excitability are not well-understood. This study investigated the effects of tACS on neuroplasticity in the primary motor cortex (M1) across different frequencies. METHODS In this randomized, sham-controlled, crossover study, 18 healthy young adults received β-tACS γ-tACS, and sham stimulation over the M1. Neurophysiological responses were assessed using motor evoked potentials (MEPs), electroencephalograms (EEG), and transcranial evoked potentials (TEPs) to determine the frequency-specific effects of tACS on cortical excitability and neuroplasticity. RESULTS γ-tACS significantly enhanced cortical excitability, as reflected by larger MEP amplitudes compared to both β-tACS and sham stimulation. In addition, γ-tACS resulted in significantly smaller M1-P15 amplitudes in TEP than other stimulation conditions. In contrast, β-tACS did not produce significant changes in either MEPs or TEPs compared to sham stimulation. CONCLUSION These findings provide evidence that tACS induces frequency-dependent effects on cortical excitability and neuroplasticity within the M1. This selective modulation of cortical excitability with γ-tACS suggests its potential as a therapeutic intervention for optimizing motor function and rehabilitation. TRIAL REGISTRATION This study was registered in the Chinese Clinical Trial Registry (ChiCTR2300074898, date of registration: 2023/08/18).
Collapse
Affiliation(s)
- Lei Tingting
- Department of Rehabilitation Medicine, the Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510630, Guangdong, China
- Department of Cardiovascular Medicine, Xi'an Central Hospital, Xi'an, Shanxi, China
| | - Chen Lilin
- Department of Rehabilitation Medicine, the Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510630, Guangdong, China
- School of optometry, The Hong Kong Polytechnic University, Hong Kong, China
| | - Wang Chuangjia
- Department of Rehabilitation Medicine, the Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510630, Guangdong, China
| | - Si Jiamen
- Southern Medical University, Guangzhou, Guangdong, China
| | - Zhang Shuxian
- Department of Rehabilitation Medicine, the Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510630, Guangdong, China
| | - Ai Yinan
- Department of Rehabilitation Medicine, the Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510630, Guangdong, China
| | - Liu Hanjun
- Department of Rehabilitation Medicine, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510080, Guangdong, China.
| | - Zheng Haiqing
- Department of Rehabilitation Medicine, the Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510630, Guangdong, China.
| |
Collapse
|
12
|
Agboada D, Zhao Z, Wischnewski M. Neuroplastic effects of transcranial alternating current stimulation (tACS): from mechanisms to clinical trials. Front Hum Neurosci 2025; 19:1548478. [PMID: 40144589 PMCID: PMC11936966 DOI: 10.3389/fnhum.2025.1548478] [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: 12/19/2024] [Accepted: 02/18/2025] [Indexed: 03/28/2025] Open
Abstract
Transcranial alternating current stimulation (tACS) is a promising non-invasive neuromodulation technique with the potential for inducing neuroplasticity and enhancing cognitive and clinical outcomes. A unique feature of tACS, compared to other stimulation modalities, is that it modulates brain activity by entraining neural activity and oscillations to an externally applied alternating current. While many studies have focused on online effects during stimulation, growing evidence suggests that tACS can induce sustained after-effects, which emphasizes the potential to induce long-term neurophysiological changes, essential for therapeutic applications. In the first part of this review, we discuss how tACS after-effects could be mediated by four non-mutually exclusive mechanisms. First, spike-timing-dependent plasticity (STDP), where the timing of pre- and postsynaptic spikes strengthens or weakens synaptic connections. Second, spike-phase coupling and oscillation phase as mediators of plasticity. Third, homeostatic plasticity, emphasizing the importance of neural activity to operate within dynamic physiological ranges. Fourth, state-dependent plasticity, which highlights the importance of the current brain state in modulatory effects of tACS. In the second part of this review, we discuss tACS applications in clinical trials targeting neurological and psychiatric disorders, including major depressive disorder, schizophrenia, Parkinson's disease, and Alzheimer's disease. Evidence suggests that repeated tACS sessions, optimized for individual oscillatory frequencies and combined with behavioral interventions, may result in lasting effects and enhance therapeutic outcomes. However, critical challenges remain, including the need for personalized dosing, improved current modeling, and systematic investigation of long-term effects. In conclusion, this review highlights the mechanisms and translational potential of tACS, emphasizing the importance of bridging basic neuroscience and clinical research to optimize its use as a therapeutic tool.
Collapse
Affiliation(s)
- Desmond Agboada
- Department of Psychology, University of the Bundeswehr Munich, Neubiberg, Germany
| | - Zhihe Zhao
- Department of Biomedical Engineering, University of Minnesota, Twin Cities, MN, United States
| | - Miles Wischnewski
- Department of Psychology, University of Groningen, Groningen, Netherlands
| |
Collapse
|
13
|
Geffen A, Bland N, Sale M. μ-Transcranial Alternating Current Stimulation Induces Phasic Entrainment and Plastic Facilitation of Corticospinal Excitability. Eur J Neurosci 2025; 61:e70042. [PMID: 40040311 PMCID: PMC11880748 DOI: 10.1111/ejn.70042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2024] [Revised: 02/04/2025] [Accepted: 02/19/2025] [Indexed: 03/06/2025]
Abstract
Transcranial alternating current stimulation (tACS) has been proposed to modulate neural activity through two primary mechanisms: entrainment and neuroplasticity. The current study aimed to probe both of these mechanisms in the context of the sensorimotor μ-rhythm using transcranial magnetic stimulation (TMS) and electroencephalography (EEG) to assess entrainment of corticospinal excitability (CSE) during stimulation (i.e., online) and immediately following stimulation, as well as neuroplastic aftereffects on CSE and μ EEG power. Thirteen participants received three sessions of stimulation. Each session consisted of 90 trials of μ-tACS tailored to each participant's individual μ frequency (IMF), with each trial consisting of 16 s of tACS followed by 8 s of rest (for a total of 24 min of tACS and 12 min of rest per session). Motor-evoked potentials (MEPs) were acquired at the start and end of the session (n = 41), and additional MEPs were acquired across the different phases of tACS at three epochs within each tACS trial (n = 90 for each epoch): early online, late online and offline echo. Resting EEG activity was recorded at the start, end and throughout the tACS session. The data were then pooled across the three sessions for each participant to maximise the MEP sample size per participant. We present preliminary evidence of CSE entrainment persisting immediately beyond tACS and have also replicated the plastic CSE facilitation observed in previous μ-tACS studies, thus supporting both entrainment and neuroplasticity as mechanisms by which tACS can modulate neural activity.
Collapse
Affiliation(s)
- Asher Geffen
- School of Health and Rehabilitation SciencesThe University of QueenslandSt LuciaQueenslandAustralia
| | - Nicholas Bland
- School of Health and Rehabilitation SciencesThe University of QueenslandSt LuciaQueenslandAustralia
| | - Martin V. Sale
- School of Health and Rehabilitation SciencesThe University of QueenslandSt LuciaQueenslandAustralia
| |
Collapse
|
14
|
Godin C, Krause MR, Vieira PG, Pack CC, Thivierge JP. Control of Inhibition-Stabilized Oscillations in Wilson-Cowan Networks with Homeostatic Plasticity. ENTROPY (BASEL, SWITZERLAND) 2025; 27:215. [PMID: 40003212 PMCID: PMC11854103 DOI: 10.3390/e27020215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2024] [Revised: 01/23/2025] [Accepted: 02/17/2025] [Indexed: 02/27/2025]
Abstract
Interactions between excitatory and inhibitory neurons in the cerebral cortex give rise to different regimes of activity and modulate brain oscillations. A prominent regime in the cortex is the inhibition-stabilized network (ISN), defined by strong recurrent excitation balanced by inhibition. While theoretical models have captured the response of brain circuits in the ISN state, their connectivity is typically hard-wired, leaving unanswered how a network may self-organize to an ISN state and dynamically switch between ISN and non-ISN states to modulate oscillations. Here, we introduce a mean-rate model of coupled Wilson-Cowan equations, link ISN and non-ISN states to Kolmogorov-Sinai entropy, and demonstrate how homeostatic plasticity (HP) allows the network to express both states depending on its level of tonic activity. This mechanism enables the model to capture a broad range of experimental effects, including (i) a paradoxical decrease in inhibitory activity, (ii) a phase offset between excitation and inhibition, and (iii) damped gamma oscillations. Further, the model accounts for experimental work on asynchronous quenching, where an external input suppresses intrinsic oscillations. Together, findings show that oscillatory activity is modulated by the dynamical regime of the network under the control of HP, thus advancing a framework that bridges neural dynamics, entropy, oscillations, and synaptic plasticity.
Collapse
Affiliation(s)
- Camille Godin
- School of Psychology, University of Ottawa, 156 Jean-Jacques Lussier, Ottawa, ON K1N 6N5, Canada
| | - Matthew R. Krause
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC H3A 2B4, Canada
| | - Pedro G. Vieira
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC H3A 2B4, Canada
| | - Christopher C. Pack
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC H3A 2B4, Canada
| | - Jean-Philippe Thivierge
- School of Psychology, University of Ottawa, 156 Jean-Jacques Lussier, Ottawa, ON K1N 6N5, Canada
- Brain and Mind Research Institute, University of Ottawa, 451 Smyth Rd., Ottawa, ON K1H 8M5, Canada
| |
Collapse
|
15
|
Gaugain G, Al Harrach M, Yochum M, Wendling F, Bikson M, Modolo J, Nikolayev D. Frequency-dependent phase entrainment of cortical cell types during tACS: computational modeling evidence. J Neural Eng 2025; 22:016028. [PMID: 39569929 DOI: 10.1088/1741-2552/ad9526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Accepted: 11/20/2024] [Indexed: 11/22/2024]
Abstract
Objective. Transcranial alternating current stimulation (tACS) enables non-invasive modulation of brain activity, holding promise for clinical and research applications. Yet, it remains unclear how the stimulation frequency differentially impacts various neuron types. Here, we aimed to quantify the frequency-dependent behavior of key neocortical cell types.Approach. We used both detailed (anatomical multicompartments) and simplified (three compartments) single-cell modeling approaches based on the Hodgkin-Huxley formalism to study neocortical excitatory and inhibitory cells under various tACS intensities and frequencies within the 5-50 Hz range at rest and during basal 10 Hz activity.Main results. L5 pyramidal cells (PCs) exhibited the highest polarizability at direct current, ranging from 0.21 to 0.25 mm and decaying exponentially with frequency. Inhibitory neurons displayed membrane resonance in the 5-15 Hz range with lower polarizability, although bipolar cells had higher polarizability. Layer 5 PC demonstrated the highest entrainment close to 10 Hz, which decayed with frequency. In contrast, inhibitory neurons entrainment increased with frequency, reaching levels akin to PC. Results from simplified models could replicate phase preferences, while amplitudes tended to follow opposite trends in PC.Significance. tACS-induced membrane polarization is frequency-dependent, revealing observable resonance behavior. Whilst optimal phase entrainment of sustained activity is achieved in PC when tACS frequency matches endogenous activity, inhibitory neurons tend to be entrained at higher frequencies. Consequently, our results highlight the potential for precise, cell-specific targeting for tACS.
Collapse
Affiliation(s)
- Gabriel Gaugain
- Institut d'électronique et des technologies du numérique (IETR UMR 6164), CNRS / University of Rennes, 35000 Rennes, France
| | - Mariam Al Harrach
- Laboratoire Traitement du Signal et de l'Image (LTSI UMR 1099), INSERM / University of Rennes, 35000 Rennes, France
| | - Maxime Yochum
- Laboratoire Traitement du Signal et de l'Image (LTSI UMR 1099), INSERM / University of Rennes, 35000 Rennes, France
| | - Fabrice Wendling
- Laboratoire Traitement du Signal et de l'Image (LTSI UMR 1099), INSERM / University of Rennes, 35000 Rennes, France
| | - Marom Bikson
- The City College of New York, New York, NY 11238, United States of America
| | - Julien Modolo
- Laboratoire Traitement du Signal et de l'Image (LTSI UMR 1099), INSERM / University of Rennes, 35000 Rennes, France
| | - Denys Nikolayev
- Institut d'électronique et des technologies du numérique (IETR UMR 6164), CNRS / University of Rennes, 35000 Rennes, France
| |
Collapse
|
16
|
Kaiser M, Wang Y, Ten Oever S, Duecker F, Sack AT, van de Ven V. Simultaneous tACS-fMRI reveals state- and frequency-specific modulation of hippocampal-cortical functional connectivity. COMMUNICATIONS PSYCHOLOGY 2025; 3:19. [PMID: 39900978 PMCID: PMC11791075 DOI: 10.1038/s44271-025-00202-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Accepted: 01/23/2025] [Indexed: 02/05/2025]
Abstract
Non-invasive indirect hippocampal-targeted stimulation is of broad scientific and clinical interest. Transcranial alternating current stimulation (tACS) is appealing because it allows oscillatory stimulation to study hippocampal theta (3-8 Hz) activity. We found that tACS administered during functional magnetic resonance imaging yielded a frequency-, mental state- and topologically-specific effect of theta stimulation (but not other frequencies) enhancing right (but not left) hippocampal-cortical connectivity during resting blocks but not during task blocks. Control analyses showed that this effect was not due to possible stimulation-induced changes in signal quality or head movement. Our findings are promising for targeted network modulations of deep brain structures for research and clinical intervention.
Collapse
Affiliation(s)
- Max Kaiser
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, PO Box 616, 6200MD, The Netherlands
| | - Yuejuan Wang
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, PO Box 616, 6200MD, The Netherlands
| | - Sanne Ten Oever
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, PO Box 616, 6200MD, The Netherlands
| | - Felix Duecker
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, PO Box 616, 6200MD, The Netherlands
| | - Alexander T Sack
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, PO Box 616, 6200MD, The Netherlands
| | - Vincent van de Ven
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, PO Box 616, 6200MD, The Netherlands.
| |
Collapse
|
17
|
Luo H, Ye X, Cai HT, Wang M, Wang Y, Liu Q, Xu Y, Mao Z, Cai Y, Hong J, Zhang C, Wei P, Lu Y, Liu Q, Xu J, Yuan TF. Frequency-specific and state-dependent neural responses to brain stimulation. Mol Psychiatry 2025:10.1038/s41380-025-02892-7. [PMID: 39833357 DOI: 10.1038/s41380-025-02892-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2024] [Revised: 12/10/2024] [Accepted: 01/10/2025] [Indexed: 01/22/2025]
Abstract
Non-invasive brain stimulation is promising for treating many neuropsychiatric and neurological conditions. It could be optimized by understanding its intracranial responses in different brain regions. We implanted multi-site intracranial electrodes and systematically assessed the acute responses in these regions to transcranial alternating current stimulation (tACS) at different frequencies. We observed robust neural oscillation changes in the hippocampus and amygdala in response to non-invasive tACS procedures, and these effects were frequency-specific and state-dependent. Notably, the hippocampus responded most strongly and stably to 10 Hz stimulation, with pronounced changes across a wide frequency range, suggesting the potential of 10 Hz oscillatory stimulation to modulate a broad range of neural activity related to cognitive functions. Future work with increased sample sizes is required to determine the clinical implications of these findings for therapeutic efficiency.
Collapse
Affiliation(s)
- Huichun Luo
- Department of Neurosurgery, Clinical Neuroscience Center Comprehensive Epilepsy Unit, Ruijin Hospital Luwan Branch, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Shanghai Key Laboratory of Psychotic Disorders, Brain Health Institute, National Center for Mental Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine and School of Psychology, Shanghai, China
- Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Xiaolai Ye
- Department of Neurosurgery, Clinical Neuroscience Center Comprehensive Epilepsy Unit, Ruijin Hospital Luwan Branch, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Department of Neurosurgery, Clinical Neuroscience Center Comprehensive Epilepsy Unit, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Department of Neurology, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Hui-Ting Cai
- Shanghai Key Laboratory of Psychotic Disorders, Brain Health Institute, National Center for Mental Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine and School of Psychology, Shanghai, China
- Shanghai Xuhui Mental Health Center, Shanghai, China
| | - Mo Wang
- Shenzhen Key Laboratory of Smart Healthcare Engineering, Southern University of Science and Technology, Shenzhen, China
| | - Yue Wang
- Shenzhen Key Laboratory of Smart Healthcare Engineering, Southern University of Science and Technology, Shenzhen, China
| | - Qiangqiang Liu
- Department of Neurosurgery, Clinical Neuroscience Center Comprehensive Epilepsy Unit, Ruijin Hospital Luwan Branch, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Department of Neurosurgery, Clinical Neuroscience Center Comprehensive Epilepsy Unit, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Ying Xu
- Shanghai Key Laboratory of Psychotic Disorders, Brain Health Institute, National Center for Mental Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine and School of Psychology, Shanghai, China
| | - Ziyu Mao
- Department of Neurosurgery, Clinical Neuroscience Center Comprehensive Epilepsy Unit, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yanqing Cai
- Department of Neurosurgery, Clinical Neuroscience Center Comprehensive Epilepsy Unit, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jing Hong
- Department of Neurosurgery, Clinical Neuroscience Center Comprehensive Epilepsy Unit, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Chencheng Zhang
- Department of Neurosurgery, Center for Functional Neurosurgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Pengfei Wei
- Shenzhen Key Laboratory of Neuropsychiatric Modulation and Collaborative Innovation Center for Brain Science, Guangdong Provincial Key Laboratory of Brain Connectome and Behavior, CAS Center for Excellence in Brain Science and Intelligence Technology, Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science, Shenzhen Fundamental Research Institutions, Shenzhen, China
| | - Yong Lu
- Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Quanying Liu
- Shenzhen Key Laboratory of Smart Healthcare Engineering, Southern University of Science and Technology, Shenzhen, China.
| | - Jiwen Xu
- Department of Neurosurgery, Clinical Neuroscience Center Comprehensive Epilepsy Unit, Ruijin Hospital Luwan Branch, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
- Department of Neurosurgery, Clinical Neuroscience Center Comprehensive Epilepsy Unit, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| | - Ti-Fei Yuan
- Shanghai Key Laboratory of Psychotic Disorders, Brain Health Institute, National Center for Mental Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine and School of Psychology, Shanghai, China.
- Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China.
| |
Collapse
|
18
|
Burke R, Maÿe A, Misselhorn J, Fiene M, Engelhardt FJ, Schneider TR, Engel AK. The role of delta phase for temporal predictions investigated with bilateral parietal tACS. Brain Stimul 2025; 18:103-113. [PMID: 39725001 DOI: 10.1016/j.brs.2024.12.1476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2024] [Revised: 12/13/2024] [Accepted: 12/22/2024] [Indexed: 12/28/2024] Open
Abstract
BACKGROUND Previous research has shown that temporal prediction processes are associated with phase resets of low-frequency delta oscillations in a network of parietal, sensory and frontal areas during non-rhythmic sensory stimulation. Transcranial alternating current stimulation (tACS) modulates perceptually relevant brain oscillations in a frequency and phase-specific manner, allowing the assessment of their functional qualities in certain cognitive functions like temporal prediction. OBJECTIVE We addressed the relation between oscillatory activity and temporal prediction by using tACS to manipulate brain activity in a sinusoidal manner. This enables the investigation of the relevance of low-frequency oscillations' phase for temporal prediction. METHODS Delta tACS was applied over the left and right parietal cortex in two separate unimodal and crossmodal temporal prediction experiments. Participants judged either the visual or the tactile reappearance of a uniformly moving visual stimulus, which shortly disappeared behind an occluder. tACS was applied with six different phase shifts relative to sensory stimulation in both experiments. Additionally, a computational model was developed and analysed to elucidate oscillation-based functional principles for the generation of temporal predictions. RESULTS Only in the unimodal experiment, the application of delta tACS resulted in a phase-dependent modulation of temporal prediction performance. By considering the effect of sustained tACS in the computational model, we demonstrate that the entrained dynamics can phase-specifically modulate temporal prediction accuracy. CONCLUSION Our results suggest that delta oscillatory phase contributes to unimodal temporal prediction. Crossmodal prediction may involve a broader brain network or cross-frequency interactions, extending beyond parietal delta phase and the scope of our current stimulation design.
Collapse
Affiliation(s)
- Rebecca Burke
- Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, Hamburg, 20246, Germany; Hamburg Center of Neuroscience, University Medical Center Hamburg-Eppendorf, Martinistr. 52, Hamburg, 20246, Germany.
| | - Alexander Maÿe
- Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, Hamburg, 20246, Germany
| | - Jonas Misselhorn
- Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, Hamburg, 20246, Germany
| | - Marina Fiene
- Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, Hamburg, 20246, Germany; Hamburg Center of Neuroscience, University Medical Center Hamburg-Eppendorf, Martinistr. 52, Hamburg, 20246, Germany
| | - Felix J Engelhardt
- Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, Hamburg, 20246, Germany
| | - Till R Schneider
- Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, Hamburg, 20246, Germany; Hamburg Center of Neuroscience, University Medical Center Hamburg-Eppendorf, Martinistr. 52, Hamburg, 20246, Germany
| | - Andreas K Engel
- Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, Hamburg, 20246, Germany; Hamburg Center of Neuroscience, University Medical Center Hamburg-Eppendorf, Martinistr. 52, Hamburg, 20246, Germany
| |
Collapse
|
19
|
Boetzel C, Stecher HI, Herrmann CS. Aligning Event-Related Potentials with Transcranial Alternating Current Stimulation for Modulation-a Review. Brain Topogr 2024; 37:933-946. [PMID: 38689065 PMCID: PMC11408541 DOI: 10.1007/s10548-024-01055-1] [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: 03/08/2024] [Accepted: 04/18/2024] [Indexed: 05/02/2024]
Abstract
This review aims to demonstrate the connections between event-related potentials (ERPs), event-related oscillations (EROs), and non-invasive brain stimulation (NIBS), with a specific focus on transcranial alternating current stimulation (tACS). We begin with a short examination and discussion of the relation between ERPs and EROs. Then, we investigate the diverse fields of NIBS, highlighting tACS as a potent tool for modulating neural oscillations and influencing cognitive performance. Emphasizing the impact of tACS on individual ERP components, this article offers insights into the potential of conventional tACS for targeted stimulation of single ERP components. Furthermore, we review recent articles that explore a novel approach of tACS: ERP-aligned tACS. This innovative technique exploits the temporal precision of ERP components, aligning tACS with specific neural events to optimize stimulation effects and target the desired neural response. In conclusion, this review combines current knowledge to explore how ERPs, EROs, and NIBS interact, particularly highlighting the modulatory possibilities offered by tACS. The incorporation of ERP-aligned tACS introduces new opportunities for future research, advancing our understanding of the complex connection between neural oscillations and cognitive processes.
Collapse
Affiliation(s)
- Cindy Boetzel
- Experimental Psychology Lab, Department of Psychology, European Medical School, Cluster for Excellence "Hearing for All", Carl Von Ossietzky University, Ammerländer Heerstr. 114 - 118, 26129, Oldenburg, Germany
| | - Heiko I Stecher
- Experimental Psychology Lab, Department of Psychology, European Medical School, Cluster for Excellence "Hearing for All", Carl Von Ossietzky University, Ammerländer Heerstr. 114 - 118, 26129, Oldenburg, Germany
| | - Christoph S Herrmann
- Experimental Psychology Lab, Department of Psychology, European Medical School, Cluster for Excellence "Hearing for All", Carl Von Ossietzky University, Ammerländer Heerstr. 114 - 118, 26129, Oldenburg, Germany.
- Neuroimaging Unit, European Medical School, Carl Von Ossietzky University, Oldenburg, Germany.
- Research Center Neurosensory Science, Carl Von Ossietzky University, Oldenburg, Germany.
| |
Collapse
|
20
|
Wischnewski M, Shirinpour S, Alekseichuk I, Lapid MI, Nahas Z, Lim KO, Croarkin PE, Opitz A. Real-time TMS-EEG for brain state-controlled research and precision treatment: a narrative review and guide. J Neural Eng 2024; 21:061001. [PMID: 39442548 PMCID: PMC11528152 DOI: 10.1088/1741-2552/ad8a8e] [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: 02/01/2024] [Revised: 10/13/2024] [Accepted: 10/23/2024] [Indexed: 10/25/2024]
Abstract
Transcranial magnetic stimulation (TMS) modulates neuronal activity, but the efficacy of an open-loop approach is limited due to the brain state's dynamic nature. Real-time integration with electroencephalography (EEG) increases experimental reliability and offers personalized neuromodulation therapy by using immediate brain states as biomarkers. Here, we review brain state-controlled TMS-EEG studies since the first publication several years ago. A summary of experiments on the sensorimotor mu rhythm (8-13 Hz) shows increased cortical excitability due to TMS pulse at the trough and decreased excitability at the peak of the oscillation. Pre-TMS pulse mu power also affects excitability. Further, there is emerging evidence that the oscillation phase in theta and beta frequency bands modulates neural excitability. Here, we provide a guide for real-time TMS-EEG application and discuss experimental and technical considerations. We consider the effects of hardware choice, signal quality, spatial and temporal filtering, and neural characteristics of the targeted brain oscillation. Finally, we speculate on how closed-loop TMS-EEG potentially could improve the treatment of neurological and mental disorders such as depression, Alzheimer's, Parkinson's, schizophrenia, and stroke.
Collapse
Affiliation(s)
- Miles Wischnewski
- Department of Psychology, Experimental Psychology, University of Groningen, Groningen, The Netherlands
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, United States of America
| | - Sina Shirinpour
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, United States of America
| | - Ivan Alekseichuk
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, United States of America
- Department of Psychiatry and Behavioral Sciences, Northwestern University, Chicago, IL, United States of America
| | - Maria I Lapid
- Department of Psychiatry & Psychology, Mayo Clinic, Rochester, MN, United States of America
| | - Ziad Nahas
- Department of Psychiatry and Behavioral Sciences, University of Minnesota, Minneapolis, MN, United States of America
| | - Kelvin O Lim
- Department of Psychiatry and Behavioral Sciences, University of Minnesota, Minneapolis, MN, United States of America
| | - Paul E Croarkin
- Department of Psychiatry & Psychology, Mayo Clinic, Rochester, MN, United States of America
| | - Alexander Opitz
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, United States of America
| |
Collapse
|
21
|
Lee S, Zhao Z, Alekseichuk I, Shirinpour S, Linn G, Schroeder CE, Falchier AY, Opitz A. Layer-specific dynamics of local field potentials in monkey V1 during electrical stimulation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.10.19.619242. [PMID: 39484447 PMCID: PMC11526877 DOI: 10.1101/2024.10.19.619242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2024]
Abstract
The mammalian neocortex, organized into six cellular layers or laminae, forms a cortical network within layers. Layer specific computations are crucial for sensory processing of visual stimuli within primary visual cortex. Laminar recordings of local field potentials (LFPs) are a powerful tool to study neural activity within cortical layers. Electric brain stimulation is widely used in basic neuroscience and in a large range of clinical applications. However, the layer-specific effects of electric stimulation on LFPs remain unclear. To address this gap, we conducted laminar LFP recordings of the primary visual cortex in monkeys while presenting a flash visual stimulus. Simultaneously, we applied a low frequency sinusoidal current to the occipital lobe with offset frequency to the flash stimulus repetition rate. We analyzed the modulation of visual-evoked potentials with respect to the applied phase of the electric stimulation. Our results reveal that only the deeper layers, but not the superficial layers, show phase-dependent changes in LFP components with respect to the applied current. Employing a cortical column model, we demonstrate that these in vivo observations can be explained by phase-dependent changes in the driving force within neurons of deeper layers. Our findings offer crucial insight into the selective modulation of cortical layers through electric stimulation, thus advancing approaches for more targeted neuromodulation.
Collapse
|
22
|
Wansbrough K, Marinovic W, Fujiyama H, Vallence AM. Beta tACS of varying intensities differentially affect resting-state and movement-related M1-M1 connectivity. Front Neurosci 2024; 18:1425527. [PMID: 39371612 PMCID: PMC11450697 DOI: 10.3389/fnins.2024.1425527] [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: 04/29/2024] [Accepted: 08/29/2024] [Indexed: 10/08/2024] Open
Abstract
Due to the interconnected nature of the brain, changes in one region are likely to affect other structurally and functionally connected regions. Emerging evidence indicates that single-site transcranial alternating current stimulation (tACS) can modulate functional connectivity between stimulated and interconnected unstimulated brain regions. However, our understanding of the network response to tACS is incomplete. Here, we investigated the effect of beta tACS of different intensities on phase-based connectivity between the left and right primary motor cortices in 21 healthy young adults (13 female; mean age 24.30 ± 4.84 years). Participants underwent four sessions of 20 min of 20 Hz tACS of varying intensities (sham, 0.5 mA, 1.0 mA, or 1.5 mA) applied to the left primary motor cortex at rest. We recorded resting-state and event-related electroencephalography (EEG) before and after tACS, analyzing changes in sensorimotor beta (13-30 Hz) imaginary coherence (ImCoh), an index of functional connectivity. Event-related EEG captured movement-related beta activity as participants performed self-paced button presses using their right index finger. For resting-state connectivity, we observed intensity-dependent changes in beta ImCoh: sham and 0.5 mA stimulation resulted in an increase in beta ImCoh, while 1.0 mA and 1.5 mA stimulation decreased beta ImCoh. For event-related connectivity, 1.5 mA stimulation decreased broadband ImCoh (4-90 Hz) during movement execution. None of the other stimulation intensities significantly modulated event-related ImCoh during movement preparation, execution, or termination. Interestingly, changes in ImCoh during movement preparation following 1.0 mA and 1.5 mA stimulation were significantly associated with participants' pre-tACS peak beta frequency, suggesting that the alignment of stimulation frequency and peak beta frequency affected the extent of neuromodulation. Collectively, these results suggest that beta tACS applied to a single site influences connectivity within the motor network in a manner that depends on the intensity and frequency of stimulation. These findings have significant implications for both research and clinical applications.
Collapse
Affiliation(s)
- Kym Wansbrough
- School of Psychology, College of Health and Education, Murdoch University, Perth, WA, Australia
- Centre for Healthy Ageing, Health Futures Institute, Murdoch University, Perth, WA, Australia
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Perth, WA, Australia
| | - Welber Marinovic
- School of Population Health, Curtin University, Perth, WA, Australia
| | - Hakuei Fujiyama
- School of Psychology, College of Health and Education, Murdoch University, Perth, WA, Australia
- Centre for Healthy Ageing, Health Futures Institute, Murdoch University, Perth, WA, Australia
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Perth, WA, Australia
| | - Ann-Maree Vallence
- School of Psychology, College of Health and Education, Murdoch University, Perth, WA, Australia
- Centre for Healthy Ageing, Health Futures Institute, Murdoch University, Perth, WA, Australia
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Perth, WA, Australia
| |
Collapse
|
23
|
Grigutsch LS, Haverland B, Timmsen LS, Asmussen L, Braaß H, Wolf S, Luu TV, Stagg CJ, Schulz R, Quandt F, Schwab BC. Differential effects of theta-gamma tACS on motor skill acquisition in young individuals and stroke survivors: A double-blind, randomized, sham-controlled study. Brain Stimul 2024; 17:1076-1085. [PMID: 39245294 DOI: 10.1016/j.brs.2024.09.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2024] [Revised: 08/09/2024] [Accepted: 09/04/2024] [Indexed: 09/10/2024] Open
Abstract
BACKGROUND Theta-gamma transcranial alternating current stimulation (tACS) was recently found to enhance thumb acceleration in young, healthy participants, suggesting a potential role in facilitating motor skill acquisition. Given the relevance of motor skill acquisition in stroke rehabilitation, theta-gamma tACS may hold potential for treating stroke survivors. OBJECTIVE We aimed to examine the effects of theta-gamma tACS on motor skill acquisition in young, healthy participants and stroke survivors. METHODS In a pre-registered, double-blind, randomized, sham-controlled study, 78 young, healthy participants received either theta-gamma peak-coupled (TGP) tACS, theta-gamma trough-coupled (TGT) tACS or sham stimulation. 20 individuals with a chronic stroke received either TGP or sham. TACS was applied over motor cortical areas while participants performed an acceleration-dependent thumb movement task. Stroke survivors were characterized using standardized testing, with a subgroup receiving additional structural brain imaging. RESULTS Neither TGP nor TGT tACS significantly modified general motor skill acquisition in the young, healthy cohort. In contrast, in the stroke cohort, TGP diminished motor skill acquisition compared to sham. Exploratory analyses revealed that, independent of general motor skill acquisition, healthy participants receiving TGP or TGT exhibited greater peak thumb acceleration than those receiving sham. CONCLUSION Although theta-gamma tACS increased thumb acceleration in young, healthy participants, consistent with previous reports, it did not enhance overall motor skill acquisition in a more complex motor task. Furthermore, it even had detrimental effects on motor skill acquisition in stroke survivors.
Collapse
Affiliation(s)
- L S Grigutsch
- Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - B Haverland
- Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - L S Timmsen
- Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - L Asmussen
- Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - H Braaß
- Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - S Wolf
- Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - T V Luu
- Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - C J Stagg
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK; Medical Research Council Brain Network Dynamics Unit, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - R Schulz
- Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - F Quandt
- Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
| | - B C Schwab
- Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; Biomedical Signals and Systems, Technical Medical Centre, University of Twente, Enschede, the Netherlands.
| |
Collapse
|
24
|
Thibaut A, Martens G. Neuromodulation for severe brain injury: time for a paradigm shift? Nat Rev Neurol 2024; 20:441-442. [PMID: 38945982 DOI: 10.1038/s41582-024-00980-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/02/2024]
Affiliation(s)
- Aurore Thibaut
- GIGA-Consciousness, University of Liège, Liège, Belgium.
- Centre du Cerveau², University Hospital of Liège, Liège, Belgium.
| | - Géraldine Martens
- GIGA-Consciousness, University of Liège, Liège, Belgium
- Sport and Trauma Applied Research Lab, Department of Surgery, University of Montreal, Montreal, Quebec, Canada
| |
Collapse
|
25
|
Vassiliadis P, Beanato E, Popa T, Windel F, Morishita T, Neufeld E, Duque J, Derosiere G, Wessel MJ, Hummel FC. Non-invasive stimulation of the human striatum disrupts reinforcement learning of motor skills. Nat Hum Behav 2024; 8:1581-1598. [PMID: 38811696 PMCID: PMC11343719 DOI: 10.1038/s41562-024-01901-z] [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: 11/07/2022] [Accepted: 04/23/2024] [Indexed: 05/31/2024]
Abstract
Reinforcement feedback can improve motor learning, but the underlying brain mechanisms remain underexplored. In particular, the causal contribution of specific patterns of oscillatory activity within the human striatum is unknown. To address this question, we exploited a recently developed non-invasive deep brain stimulation technique called transcranial temporal interference stimulation (tTIS) during reinforcement motor learning with concurrent neuroimaging, in a randomized, sham-controlled, double-blind study. Striatal tTIS applied at 80 Hz, but not at 20 Hz, abolished the benefits of reinforcement on motor learning. This effect was related to a selective modulation of neural activity within the striatum. Moreover, 80 Hz, but not 20 Hz, tTIS increased the neuromodulatory influence of the striatum on frontal areas involved in reinforcement motor learning. These results show that tTIS can non-invasively and selectively modulate a striatal mechanism involved in reinforcement learning, expanding our tools for the study of causal relationships between deep brain structures and human behaviour.
Collapse
Affiliation(s)
- Pierre Vassiliadis
- Defitech Chair of Clinical Neuroengineering, Neuro-X Institute, École Polytechnique Fédérale de Lausanne (EPFL), Geneva, Switzerland
- Defitech Chair of Clinical Neuroengineering, Neuro-X Institute, EPFL Valais, Clinique Romande de Réadaptation, Sion, Switzerland
- Institute of Neuroscience, Université Catholique de Louvain, Brussels, Belgium
| | - Elena Beanato
- Defitech Chair of Clinical Neuroengineering, Neuro-X Institute, École Polytechnique Fédérale de Lausanne (EPFL), Geneva, Switzerland
- Defitech Chair of Clinical Neuroengineering, Neuro-X Institute, EPFL Valais, Clinique Romande de Réadaptation, Sion, Switzerland
| | - Traian Popa
- Defitech Chair of Clinical Neuroengineering, Neuro-X Institute, École Polytechnique Fédérale de Lausanne (EPFL), Geneva, Switzerland
- Defitech Chair of Clinical Neuroengineering, Neuro-X Institute, EPFL Valais, Clinique Romande de Réadaptation, Sion, Switzerland
| | - Fabienne Windel
- Defitech Chair of Clinical Neuroengineering, Neuro-X Institute, École Polytechnique Fédérale de Lausanne (EPFL), Geneva, Switzerland
- Defitech Chair of Clinical Neuroengineering, Neuro-X Institute, EPFL Valais, Clinique Romande de Réadaptation, Sion, Switzerland
| | - Takuya Morishita
- Defitech Chair of Clinical Neuroengineering, Neuro-X Institute, École Polytechnique Fédérale de Lausanne (EPFL), Geneva, Switzerland
- Defitech Chair of Clinical Neuroengineering, Neuro-X Institute, EPFL Valais, Clinique Romande de Réadaptation, Sion, Switzerland
| | - Esra Neufeld
- Foundation for Research on Information Technologies in Society, Zurich, Switzerland
| | - Julie Duque
- Institute of Neuroscience, Université Catholique de Louvain, Brussels, Belgium
| | - Gerard Derosiere
- Institute of Neuroscience, Université Catholique de Louvain, Brussels, Belgium
- Lyon Neuroscience Research Center, Impact Team, Inserm U1028, CNRS UMR5292, Lyon 1 University, Bron, France
| | - Maximilian J Wessel
- Defitech Chair of Clinical Neuroengineering, Neuro-X Institute, École Polytechnique Fédérale de Lausanne (EPFL), Geneva, Switzerland
- Defitech Chair of Clinical Neuroengineering, Neuro-X Institute, EPFL Valais, Clinique Romande de Réadaptation, Sion, Switzerland
- Department of Neurology, University Hospital Würzburg, Würzburg, Germany
| | - Friedhelm C Hummel
- Defitech Chair of Clinical Neuroengineering, Neuro-X Institute, École Polytechnique Fédérale de Lausanne (EPFL), Geneva, Switzerland.
- Defitech Chair of Clinical Neuroengineering, Neuro-X Institute, EPFL Valais, Clinique Romande de Réadaptation, Sion, Switzerland.
- Clinical Neuroscience, University of Geneva Medical School, Geneva, Switzerland.
| |
Collapse
|
26
|
Ikarashi H, Otsuru N, Gomez-Tames J, Hirata A, Nagasaka K, Miyaguchi S, Sakurai N, Ohno K, Kodama N, Onishi H. Modulation of pain perception through transcranial alternating current stimulation and its nonlinear relationship with the simulated electric field magnitude. Eur J Pain 2024; 28:1018-1028. [PMID: 38318653 DOI: 10.1002/ejp.2249] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 01/18/2024] [Accepted: 01/21/2024] [Indexed: 02/07/2024]
Abstract
BACKGROUND Oscillatory activities observed in multiple regions are closely associated with the experience of pain. Specifically, oscillatory activities within the theta- and beta-frequency bands, observed in the left dorsolateral prefrontal cortex (DLPFC), have been implicated in pain perception among healthy individuals and those with chronic pain. However, their physiological significance remains unclear. METHODS We explored the modulation of pain perception in healthy individuals by theta- and beta-band transcranial alternating current stimulation (tACS) over the left DLPFC and examined the relationship between the modulation effect and magnitude of the electric field elicited by tACS in the left DLPFC using computational simulation. RESULTS Our findings revealed that both theta- and beta-tACS increased the heat pain threshold during and after stimulation. Notably, the simulated electric field magnitude in the left DLPFC exhibited an inverted U-shaped relationship with the pain modulation effect for theta-tACS. CONCLUSIONS Our study findings suggested that there would be an optimal electric field strength to produce a high analgesic effect for theta-tACS. SIGNIFICANCE The application of theta- and beta-tACS interventions targeting the left DLPFC might facilitate the treatment of chronic pain. Furthermore, the attainment of effective pain modulation via theta-tACS over the DLPFC warrants the use of optimal stimulus intensity.
Collapse
Affiliation(s)
- H Ikarashi
- Graduate School, Niigata University of Health and Welfare, Niigata, Japan
| | - N Otsuru
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan
| | - J Gomez-Tames
- Department of Electromechanical Engineering, Nagoya Institute of Technology, Nagoya, Aichi, Japan
- Center of Biomedical Physics and Information Technology, Nagoya Institute of Technology, Nagoya, Aichi, Japan
| | - A Hirata
- Department of Electromechanical Engineering, Nagoya Institute of Technology, Nagoya, Aichi, Japan
- Center of Biomedical Physics and Information Technology, Nagoya Institute of Technology, Nagoya, Aichi, Japan
| | - K Nagasaka
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan
| | - S Miyaguchi
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan
| | - N Sakurai
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan
| | - K Ohno
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan
| | - N Kodama
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan
| | - H Onishi
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan
| |
Collapse
|
27
|
Haslacher D, Cavallo A, Reber P, Kattein A, Thiele M, Nasr K, Hashemi K, Sokoliuk R, Thut G, Soekadar SR. Working memory enhancement using real-time phase-tuned transcranial alternating current stimulation. Brain Stimul 2024; 17:850-859. [PMID: 39029737 DOI: 10.1016/j.brs.2024.07.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Revised: 07/02/2024] [Accepted: 07/12/2024] [Indexed: 07/21/2024] Open
Abstract
BACKGROUND Prior work has shown that transcranial alternating current stimulation (tACS) of parietooccipital alpha oscillations (8-14 Hz) can modulate working memory (WM) performance as a function of the phase lag to endogenous oscillations. However, leveraging this effect using real-time phase-tuned tACS has not been feasible so far due to stimulation artifacts preventing continuous phase tracking. OBJECTIVES AND HYPOTHESIS We aimed to develop a system that tracks and adapts the phase lag between tACS and ongoing parietooccipital alpha oscillations in real-time. We hypothesized that such real-time phase-tuned tACS enhances working memory performance, depending on the phase lag. METHODS We developed real-time phase-tuned closed-loop amplitude-modulated tACS (CLAM-tACS) targeting parietooccipital alpha oscillations. CLAM-tACS was applied at six different phase lags relative to ongoing alpha oscillations while participants (N = 21) performed a working memory task. To exclude that behavioral effects of CLAM-tACS were mediated by other factors such as sensory co-stimulation, a second group of participants (N = 25) received equivalent stimulation of the forehead. RESULTS WM accuracy improved in a phase lag dependent manner (p = 0.0350) in the group receiving parietooccipital stimulation, with the strongest enhancement observed at 330° phase lag between tACS and ongoing alpha oscillations (p = 0.00273, d = 0.976). Moreover, across participants, modulation of frontoparietal alpha oscillations correlated both in amplitude (p = 0.0248) and phase (p = 0.0270) with the modulation of WM accuracy. No such effects were observed in the control group receiving frontal stimulation. CONCLUSIONS Our results demonstrate the feasibility and efficacy of real-time phase-tuned CLAM-tACS in modulating both brain activity and behavior, thereby paving the way for further investigation into brain-behavior relationships and the exploration of innovative therapeutic applications.
Collapse
Affiliation(s)
- David Haslacher
- Clinical Neurotechnology Laboratory, Department of Psychiatry and Neurosciences, Charité Campus Mitte, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Alessia Cavallo
- Clinical Neurotechnology Laboratory, Department of Psychiatry and Neurosciences, Charité Campus Mitte, Charité - Universitätsmedizin Berlin, Berlin, Germany; Department of Neurology and Experimental Neurology, Charité Campus Mitte, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Philipp Reber
- Clinical Neurotechnology Laboratory, Department of Psychiatry and Neurosciences, Charité Campus Mitte, Charité - Universitätsmedizin Berlin, Berlin, Germany; Department of Psychology, University of California, Berkeley, CA, USA
| | - Anna Kattein
- Clinical Neurotechnology Laboratory, Department of Psychiatry and Neurosciences, Charité Campus Mitte, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Moritz Thiele
- Clinical Neurotechnology Laboratory, Department of Psychiatry and Neurosciences, Charité Campus Mitte, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Khaled Nasr
- Clinical Neurotechnology Laboratory, Department of Psychiatry and Neurosciences, Charité Campus Mitte, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Kimia Hashemi
- Clinical Neurotechnology Laboratory, Department of Psychiatry and Neurosciences, Charité Campus Mitte, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Rodika Sokoliuk
- Clinical Neurotechnology Laboratory, Department of Psychiatry and Neurosciences, Charité Campus Mitte, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Gregor Thut
- School of Psychology & Neuroscience, University of Glasgow, Glasgow, UK
| | - Surjo R Soekadar
- Clinical Neurotechnology Laboratory, Department of Psychiatry and Neurosciences, Charité Campus Mitte, Charité - Universitätsmedizin Berlin, Berlin, Germany.
| |
Collapse
|
28
|
De Paolis ML, Paoletti I, Zaccone C, Capone F, D'Amelio M, Krashia P. Transcranial alternating current stimulation (tACS) at gamma frequency: an up-and-coming tool to modify the progression of Alzheimer's Disease. Transl Neurodegener 2024; 13:33. [PMID: 38926897 PMCID: PMC11210106 DOI: 10.1186/s40035-024-00423-y] [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: 01/08/2024] [Accepted: 05/24/2024] [Indexed: 06/28/2024] Open
Abstract
The last decades have witnessed huge efforts devoted to deciphering the pathological mechanisms underlying Alzheimer's Disease (AD) and to testing new drugs, with the recent FDA approval of two anti-amyloid monoclonal antibodies for AD treatment. Beyond these drug-based experimentations, a number of pre-clinical and clinical trials are exploring the benefits of alternative treatments, such as non-invasive stimulation techniques on AD neuropathology and symptoms. Among the different non-invasive brain stimulation approaches, transcranial alternating current stimulation (tACS) is gaining particular attention due to its ability to externally control gamma oscillations. Here, we outline the current knowledge concerning the clinical efficacy, safety, ease-of-use and cost-effectiveness of tACS on early and advanced AD, applied specifically at 40 Hz frequency, and also summarise pre-clinical results on validated models of AD and ongoing patient-centred trials.
Collapse
Affiliation(s)
- Maria Luisa De Paolis
- Department of Medicine and Surgery, Università Campus Bio-Medico Di Roma, Via Alvaro del Portillo, 21 - 00128, Rome, Italy
| | - Ilaria Paoletti
- Department of Medicine and Surgery, Università Campus Bio-Medico Di Roma, Via Alvaro del Portillo, 21 - 00128, Rome, Italy
| | - Claudio Zaccone
- Department of Medicine and Surgery, Università Campus Bio-Medico Di Roma, Via Alvaro del Portillo, 21 - 00128, Rome, Italy
| | - Fioravante Capone
- Department of Medicine and Surgery, Università Campus Bio-Medico Di Roma, Via Alvaro del Portillo, 21 - 00128, Rome, Italy
- Fondazione Policlinico Universitario Campus Bio-Medico, Via Alvaro del Portillo, 200 - 00128, Rome, Italy
| | - Marcello D'Amelio
- Department of Medicine and Surgery, Università Campus Bio-Medico Di Roma, Via Alvaro del Portillo, 21 - 00128, Rome, Italy.
- Department of Experimental Neurosciences, IRCCS Santa Lucia Foundation, Via del Fosso Di Fiorano, 64 - 00143, Rome, Italy.
| | - Paraskevi Krashia
- Department of Experimental Neurosciences, IRCCS Santa Lucia Foundation, Via del Fosso Di Fiorano, 64 - 00143, Rome, Italy
- Department of Sciences and Technologies for Sustainable Development and One Health, Università Campus Bio-Medico Di Roma, Via Alvaro del Portillo, 21 - 00128, Rome, Italy
| |
Collapse
|
29
|
Misselhorn J, Fiene M, Radecke JO, Engel AK, Schneider TR. Transcranial Alternating Current Stimulation over Frontal Eye Fields Mimics Attentional Modulation of Visual Processing. J Neurosci 2024; 44:e1510232024. [PMID: 38729759 PMCID: PMC11209665 DOI: 10.1523/jneurosci.1510-23.2024] [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: 08/07/2023] [Revised: 04/16/2024] [Accepted: 04/17/2024] [Indexed: 05/12/2024] Open
Abstract
Attentional control over sensory processing has been linked to neural alpha oscillations and related inhibition of cerebral cortex. Despite the wide consensus on the functional relevance of alpha oscillations for attention, precise neural mechanisms of how alpha oscillations shape perception and how this top-down modulation is implemented in cortical networks remain unclear. Here, we tested the hypothesis that alpha oscillations in frontal eye fields (FEFs) are causally involved in the top-down regulation of visual processing in humans (male and female). We applied sham-controlled, intermittent transcranial alternating current stimulation (tACS) over bilateral FEF at either 10 Hz (alpha) or 40 Hz (gamma) to manipulate attentional preparation in a visual discrimination task. Under each stimulation condition, we measured psychometric functions for contrast perception and introduced a novel linear mixed modeling approach for statistical control of neurosensory side effects of the electric stimulation. tACS at alpha frequency reduced the slope of the psychometric function, resulting in improved subthreshold and impaired superthreshold contrast perception. Side effects on the psychometric functions were complex and showed large interindividual variability. Controlling for the impact of side effects on the psychometric parameters by using covariates in the linear mixed model analysis reduced this variability and strengthened the perceptual effect. We propose that alpha tACS over FEF mimicked a state of endogenous attention by strengthening a fronto-occipitoparietal network in the alpha band. We speculate that this network modulation enhanced phasic gating in occipitoparietal cortex leading to increased variability of single-trial psychometric thresholds, measurable as a reduction of psychometric slope.
Collapse
Affiliation(s)
- Jonas Misselhorn
- Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, Hamburg 20246, Germany
| | - Marina Fiene
- Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, Hamburg 20246, Germany
| | - Jan-Ole Radecke
- Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, Hamburg 20246, Germany
- Department of Psychiatry and Psychotherapy, University of Lübeck, Lübeck 23562, Germany
- Center of Brain, Behavior and Metabolism (CBBM), University of Lübeck, Lübeck 23562, Germany
| | - Andreas K Engel
- Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, Hamburg 20246, Germany
| | - Till R Schneider
- Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, Hamburg 20246, Germany
| |
Collapse
|
30
|
Kim Y, Lee JH, Park JC, Kwon J, Kim H, Seo J, Min BK. Neuromodulation of inhibitory control using phase-lagged transcranial alternating current stimulation. J Neuroeng Rehabil 2024; 21:93. [PMID: 38816860 PMCID: PMC11138099 DOI: 10.1186/s12984-024-01385-y] [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: 01/04/2024] [Accepted: 05/15/2024] [Indexed: 06/01/2024] Open
Abstract
BACKGROUND Transcranial alternating current stimulation (tACS) is a prominent non-invasive brain stimulation method for modulating neural oscillations and enhancing human cognitive function. This study aimed to investigate the effects of individualized theta tACS delivered in-phase and out-of-phase between the dorsal anterior cingulate cortex (dACC) and left dorsolateral prefrontal cortex (lDLPFC) during inhibitory control performance. METHODS The participants engaged in a Stroop task with phase-lagged theta tACS over individually optimized high-density electrode montages targeting the dACC and lDLPFC. We analyzed task performance, event-related potentials, and prestimulus electroencephalographic theta and alpha power. RESULTS We observed significantly reduced reaction times following out-of-phase tACS, accompanied by reduced frontocentral N1 and N2 amplitudes, enhanced parieto-occipital P1 amplitudes, and pronounced frontocentral late sustained potentials. Out-of-phase stimulation also resulted in significantly higher prestimulus frontocentral theta and alpha activity. CONCLUSIONS These findings suggest that out-of-phase theta tACS potently modulates top-down inhibitory control, supporting the feasibility of phase-lagged tACS to enhance inhibitory control performance.
Collapse
Affiliation(s)
- Yukyung Kim
- Department of Brain and Cognitive Engineering, Korea University, Seoul, 02841, Korea
| | - Je-Hyeop Lee
- Department of Brain and Cognitive Engineering, Korea University, Seoul, 02841, Korea
- BK21 Four Institute of Precision Public Health, Korea University, Seoul, 02841, Korea
| | - Je-Choon Park
- Department of Brain and Cognitive Engineering, Korea University, Seoul, 02841, Korea
| | - Jeongwook Kwon
- Department of Brain and Cognitive Engineering, Korea University, Seoul, 02841, Korea
| | - Hyoungkyu Kim
- Center for Neuroscience Imaging Research, Institute for Basic Science, Sungkyunkwan University, Suwon, 16419, Korea
- Institute of Brain and Cognitive Engineering, Korea University, Seoul, 02841, Korea
| | - Jeehye Seo
- BK21 Four Institute of Precision Public Health, Korea University, Seoul, 02841, Korea
- Institute of Brain and Cognitive Engineering, Korea University, Seoul, 02841, Korea
| | - Byoung-Kyong Min
- Department of Brain and Cognitive Engineering, Korea University, Seoul, 02841, Korea.
- BK21 Four Institute of Precision Public Health, Korea University, Seoul, 02841, Korea.
- Institute of Brain and Cognitive Engineering, Korea University, Seoul, 02841, Korea.
| |
Collapse
|
31
|
Vieira PG, Krause MR, Pack CC. Temporal interference stimulation disrupts spike timing in the primate brain. Nat Commun 2024; 15:4558. [PMID: 38811618 PMCID: PMC11137077 DOI: 10.1038/s41467-024-48962-2] [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: 11/06/2023] [Accepted: 05/16/2024] [Indexed: 05/31/2024] Open
Abstract
Electrical stimulation can regulate brain activity, producing clear clinical benefits, but focal and effective neuromodulation often requires surgically implanted electrodes. Recent studies argue that temporal interference (TI) stimulation may provide similar outcomes non-invasively. During TI, scalp electrodes generate multiple electrical fields in the brain, modulating neural activity only at their intersection. Despite considerable enthusiasm for this approach, little empirical evidence demonstrates its effectiveness, especially under conditions suitable for human use. Here, using single-neuron recordings in non-human primates, we establish that TI reliably alters the timing, but not the rate, of spiking activity. However, we show that TI requires strategies-high carrier frequencies, multiple electrodes, and amplitude-modulated waveforms-that also limit its effectiveness. Combined, these factors make TI 80 % weaker than other forms of non-invasive brain stimulation. Although unlikely to cause widespread neuronal entrainment, TI may be ideal for disrupting pathological oscillatory activity, a hallmark of many neurological disorders.
Collapse
Affiliation(s)
- Pedro G Vieira
- Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
| | - Matthew R Krause
- Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada.
| | - Christopher C Pack
- Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
| |
Collapse
|
32
|
Liu R, Zhu G, Wu Z, Gan Y, Zhang J, Liu J, Wang L. Temporal interference stimulation targets deep primate brain. Neuroimage 2024; 291:120581. [PMID: 38508293 DOI: 10.1016/j.neuroimage.2024.120581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2024] [Revised: 03/10/2024] [Accepted: 03/17/2024] [Indexed: 03/22/2024] Open
Abstract
Temporal interference (TI) stimulation, a novel non-invasive stimulation strategy, has recently been shown to modulate neural activity in deep brain regions of living mice. Yet, it is uncertain if this method is applicable to larger brains and whether the electric field produced under traditional safety currents can penetrate deep regions as observed in mice. Despite recent model-based simulation studies offering positive evidence at both macro- and micro-scale levels, the absence of electrophysiological data from actual brains hinders comprehensive understanding and potential application of TI. This study aims to directly measure the spatiotemporal properties of the interfered electric field in the rhesus monkey brain and to validate the effects of TI on the human brain. Two monkeys were involved in the measurement, with implantation of several stereo-electroencephalography (SEEG) depth electrodes. TI stimulation was applied to anesthetized monkeys using two pairs of surface electrodes at differing stimulation parameters. Model-based simulations were also conducted and subsequently compared with actual recordings. Additionally, TI stimulation was administered to patients with motor disorders to validate its effects on motor symptoms. Through the integration of computational electric field simulation with empirical measurements, it was determined that the temporally interfering electric fields in the deep central regions are capable of attaining a magnitude sufficient to induce a subthreshold modulation effect on neural signals. Additionally, an improvement in movement disorders was observed as a result of TI stimulation. This study is the first to systematically measure the TI electric field in living non-human primates, offering empirical evidence that TI holds promise as a more focal and precise method for modulating neural activities in deep regions of a large brain. This advancement paves the way for future applications of TI in treating neuropsychiatric disorders.
Collapse
Affiliation(s)
- Ruobing Liu
- CAS Key Laboratory of Mental Health, Institute of Psychology, Beijing, PR China; Department of Psychology, University of Chinese Academy of Sciences, Beijing, PR China
| | - Guanyu Zhu
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, PR China
| | - Zhengping Wu
- School of Innovations, Sanjiang University, Nanjing, PR China
| | - Yifei Gan
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, PR China
| | - Jianguo Zhang
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, PR China
| | - Jiali Liu
- CAS Key Laboratory of Mental Health, Institute of Psychology, Beijing, PR China; Department of Psychology, University of Chinese Academy of Sciences, Beijing, PR China
| | - Liang Wang
- CAS Key Laboratory of Mental Health, Institute of Psychology, Beijing, PR China; Department of Psychology, University of Chinese Academy of Sciences, Beijing, PR China.
| |
Collapse
|
33
|
Farahani F, Khadka N, Parra LC, Bikson M, Vöröslakos M. Transcranial electric stimulation modulates firing rate at clinically relevant intensities. Brain Stimul 2024; 17:561-571. [PMID: 38631548 PMCID: PMC466978 DOI: 10.1016/j.brs.2024.04.007] [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: 12/20/2023] [Revised: 03/25/2024] [Accepted: 04/11/2024] [Indexed: 04/19/2024] Open
Abstract
BACKGROUND Notwithstanding advances with low-intensity transcranial electrical stimulation (tES), there remain questions about the efficacy of clinically realistic electric fields on neuronal function. OBJECTIVE To measure electric fields magnitude and their effects on neuronal firing rate of hippocampal neurons in freely moving rats, and to establish calibrated computational models of current flow. METHODS Current flow models were calibrated on electric field measures in the motor cortex (n = 2 anesthetized rats) and hippocampus. A Neuropixels 2.0 probe with 384 channels was used in an in-vivo rat model of tES (n = 4 freely moving and 2 urethane anesthetized rats) to detect effects of weak fields on neuronal firing rate. High-density field mapping and computational models verified field intensity (1 V/m in hippocampus per 50 μA of applied skull currents). RESULTS Electric fields of as low as 0.35 V/m (0.25-0.47) acutely modulated average firing rate in the hippocampus. At these intensities, firing rate effects increased monotonically with electric field intensity at a rate of 11.5 % per V/m (7.2-18.3). For the majority of excitatory neurons, firing increased for soma-depolarizing stimulation and diminished for soma-hyperpolarizing stimulation. While more diverse, the response of inhibitory neurons followed a similar pattern on average, likely as a result of excitatory drive. CONCLUSION In awake animals, electric fields modulate spiking rate above levels previously observed in vitro. Firing rate effects are likely mediated by somatic polarization of pyramidal neurons. We recommend that all future rodent experiments directly measure electric fields to insure rigor and reproducibility.
Collapse
Affiliation(s)
- Forouzan Farahani
- Department of Biomedical Engineering, The City College of New York, New York, NY, USA
| | - Niranjan Khadka
- Department of Biomedical Engineering, The City College of New York, New York, NY, USA
| | - Lucas C Parra
- Department of Biomedical Engineering, The City College of New York, New York, NY, USA
| | - Marom Bikson
- Department of Biomedical Engineering, The City College of New York, New York, NY, USA
| | - Mihály Vöröslakos
- Neuroscience Institute and Department of Neurology, NYU Grossman School of Medicine, New York University, New York, NY, USA.
| |
Collapse
|
34
|
Seo J, Lee J, Min BK. Out-of-phase transcranial alternating current stimulation modulates the neurodynamics of inhibitory control. Neuroimage 2024; 292:120612. [PMID: 38648868 DOI: 10.1016/j.neuroimage.2024.120612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Revised: 03/25/2024] [Accepted: 04/12/2024] [Indexed: 04/25/2024] Open
Abstract
Transcranial alternating current stimulation (tACS) is an efficient neuromodulation technique that enhances cognitive function in a non-invasive manner. Using functional magnetic resonance imaging, we investigated whether tACS with different phase lags (0° and 180°) between the dorsal anterior cingulate and left dorsolateral prefrontal cortices modulated inhibitory control performance during the Stroop task. We found out-of-phase tACS mediated improvements in task performance, which was neurodynamically reflected as putamen, dorsolateral prefrontal, and primary motor cortical activation as well as prefrontal-based top-down functional connectivity. Our observations uncover the neurophysiological bases of tACS-phase-dependent neuromodulation and provide a feasible non-invasive approach to effectively modulate inhibitory control.
Collapse
Affiliation(s)
- Jeehye Seo
- Institute of Brain and Cognitive Engineering, Korea University, Seoul 02841, Korea; BK21 Four Institute of Precision Public Health, Korea University, Seoul 02841, Korea
| | - Jehyeop Lee
- BK21 Four Institute of Precision Public Health, Korea University, Seoul 02841, Korea; Department of Brain and Cognitive Engineering, Korea University, Seoul 02841, Korea
| | - Byoung-Kyong Min
- Institute of Brain and Cognitive Engineering, Korea University, Seoul 02841, Korea; BK21 Four Institute of Precision Public Health, Korea University, Seoul 02841, Korea; Department of Brain and Cognitive Engineering, Korea University, Seoul 02841, Korea.
| |
Collapse
|
35
|
Fang Z, Sack AT, Leunissen I. The phase of tACS-entrained pre-SMA beta oscillations modulates motor inhibition. Neuroimage 2024; 290:120572. [PMID: 38490584 DOI: 10.1016/j.neuroimage.2024.120572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 03/06/2024] [Accepted: 03/08/2024] [Indexed: 03/17/2024] Open
Abstract
Inhibitory control has been linked to beta oscillations in the fronto-basal ganglia network. Here we aim to investigate the functional role of the phase of this oscillatory beta rhythm for successful motor inhibition. We applied 20 Hz transcranial alternating current stimulation (tACS) to the pre-supplementary motor area (pre-SMA) while presenting stop signals at 4 (Experiment 1) and 8 (Experiment 2) equidistant phases of the tACS entrained beta oscillations. Participants showed better inhibitory performance when stop signals were presented at the trough of the beta oscillation whereas their inhibitory control performance decreased with stop signals being presented at the oscillatory beta peak. These results are consistent with the communication through coherence theory, in which postsynaptic effects are thought to be greater when an input arrives at an optimal phase within the oscillatory cycle of the target neuronal population. The current study provides mechanistic insights into the neural communication principles underlying successful motor inhibition and may have implications for phase-specific interventions aimed at treating inhibitory control disorders such as PD or OCD.
Collapse
Affiliation(s)
- Zhou Fang
- Section Brain Stimulation and Cognition, Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, P.O. Box 616, 6200 MD, Maastricht, The Netherlands; Maastricht Brain Imaging Centre (MBIC), Maastricht University, Oxfordlaan 55, 6229EV, Maastricht, The Netherlands
| | - Alexander T Sack
- Section Brain Stimulation and Cognition, Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, P.O. Box 616, 6200 MD, Maastricht, The Netherlands; Maastricht Brain Imaging Centre (MBIC), Maastricht University, Oxfordlaan 55, 6229EV, Maastricht, The Netherlands; Centre for Integrative Neuroscience, Faculty of Psychology and Neuroscience, Faculty of Health, Medicine and Life Sciences, Maastricht University, P.O. Box 616, 6200 MD, Maastricht, The Netherlands
| | - Inge Leunissen
- Section Brain Stimulation and Cognition, Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, P.O. Box 616, 6200 MD, Maastricht, The Netherlands; Maastricht Brain Imaging Centre (MBIC), Maastricht University, Oxfordlaan 55, 6229EV, Maastricht, The Netherlands.
| |
Collapse
|
36
|
Mendes AJ, Lema A, Carvalho S, Leite J. Tailoring transcranial alternating current stimulation based on endogenous event-related P3 to modulate premature responses: a feasibility study. PeerJ 2024; 12:e17144. [PMID: 38584936 PMCID: PMC10998630 DOI: 10.7717/peerj.17144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 02/29/2024] [Indexed: 04/09/2024] Open
Abstract
Background Transcranial alternating current stimulation (tACS) is a brain stimulation method for modulating ongoing endogenous oscillatory activity at specified frequency during sensory and cognitive processes. Given the overlap between event-related potentials (ERPs) and event-related oscillations (EROs), ERPs can be studied as putative biomarkers of the effects of tACS in the brain during cognitive/sensory task performance. Objective This preliminary study aimed to test the feasibility of individually tailored tACS based on individual P3 (latency and frequency) elicited during a cued premature response task. Thus, tACS frequency was individually tailored to match target-P3 ERO for each participant. Likewise, the target onset in the task was adjusted to match the tACS phase and target-P3 latency. Methods Twelve healthy volunteers underwent tACS in two separate sessions while performing a premature response task. Target-P3 latency and ERO were calculated in a baseline block during the first session to allow a posterior synchronization between the tACS and the endogenous oscillatory activity. The cue and target-P3 amplitudes, delta/theta ERO, and power spectral density (PSD) were evaluated pre and post-tACS blocks. Results Target-P3 amplitude significantly increased after activetACS, when compared to sham. Evoked-delta during cue-P3 was decreased after tACS. No effects were found for delta ERO during target-P3 nor for the PSD and behavioral outcomes. Conclusion The present findings highlight the possible effect of phase synchronization between individualized tACS parameters and endogenous oscillatory activity, which may result in an enhancement of the underlying process (i.e., an increase of target-P3). However, an unsuccessful synchronization between tACS and EEG activity might also result in a decrease in the evoked-delta activity during cue-P3. Further studies are needed to optimize the parameters of endogenous activity and tACS synchronization. The implications of the current results for future studies, including clinical studies, are further discussed since transcranial alternating current stimulation can be individually tailored based on endogenous event-related P3 to modulate responses.
Collapse
Affiliation(s)
- Augusto J. Mendes
- Geneva Memory Center, Department of Rehabilitation and Geriatrics, University of Geneva, Geneva, Switzerland
- Laboratory of Neuroimaging of Aging (LANVIE), University of Geneva, Geneva, Switzerland
- Psychological Neuroscience Laboratory, CIPsi, School of Psychology, Universidade do Minho, Braga, Portugal
| | - Alberto Lema
- Psychological Neuroscience Laboratory, CIPsi, School of Psychology, Universidade do Minho, Braga, Portugal
| | - Sandra Carvalho
- Translational Neuropsychology Lab, Department of Education and Psychology, William James Center for Research (WJCR), University of Aveiro, Aveiro, Portugal
| | - Jorge Leite
- CINTESIS@RISE, CINTESIS.UPT, Universidade Portucalense Infante D. Henrique, Porto, Portugal
| |
Collapse
|
37
|
Zhao Z, Shirinpour S, Tran H, Wischnewski M, Opitz A. intensity- and frequency-specific effects of transcranial alternating current stimulation are explained by network dynamics. J Neural Eng 2024; 21:026024. [PMID: 38530297 DOI: 10.1088/1741-2552/ad37d9] [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: 09/19/2023] [Accepted: 03/26/2024] [Indexed: 03/27/2024]
Abstract
Objective. Transcranial alternating current stimulation (tACS) can be used to non-invasively entrain neural activity and thereby cause changes in local neural oscillatory power. Despite its increased use in cognitive and clinical neuroscience, the fundamental mechanisms of tACS are still not fully understood.Approach. We developed a computational neuronal network model of two-compartment pyramidal neurons (PY) and inhibitory interneurons, which mimic the local cortical circuits. We modeled tACS with electric field strengths that are achievable in human applications. We then simulated intrinsic network activity and measured neural entrainment to investigate how tACS modulates ongoing endogenous oscillations.Main results. The intensity-specific effects of tACS are non-linear. At low intensities (<0.3 mV mm-1), tACS desynchronizes neural firing relative to the endogenous oscillations. At higher intensities (>0.3 mV mm-1), neurons are entrained to the exogenous electric field. We then further explore the stimulation parameter space and find that the entrainment of ongoing cortical oscillations also depends on stimulation frequency by following an Arnold tongue. Moreover, neuronal networks can amplify the tACS-induced entrainment via synaptic coupling and network effects. Our model shows that PY are directly entrained by the exogenous electric field and drive the inhibitory neurons.Significance. The results presented in this study provide a mechanistic framework for understanding the intensity- and frequency-specific effects of oscillating electric fields on neuronal networks. This is crucial for rational parameter selection for tACS in cognitive studies and clinical applications.
Collapse
Affiliation(s)
- Zhihe Zhao
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, United States of America
| | - Sina Shirinpour
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, United States of America
| | - Harry Tran
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, United States of America
| | - Miles Wischnewski
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, United States of America
| | - Alexander Opitz
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, United States of America
| |
Collapse
|
38
|
Wischnewski M, Berger TA, Opitz A, Alekseichuk I. Causal functional maps of brain rhythms in working memory. Proc Natl Acad Sci U S A 2024; 121:e2318528121. [PMID: 38536752 PMCID: PMC10998564 DOI: 10.1073/pnas.2318528121] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Accepted: 02/27/2024] [Indexed: 04/08/2024] Open
Abstract
Human working memory is a key cognitive process that engages multiple functional anatomical nodes across the brain. Despite a plethora of correlative neuroimaging evidence regarding the working memory architecture, our understanding of critical hubs causally controlling overall performance is incomplete. Causal interpretation requires cognitive testing following safe, temporal, and controllable neuromodulation of specific functional anatomical nodes. Such experiments became available in healthy humans with the advance of transcranial alternating current stimulation (tACS). Here, we synthesize findings of 28 placebo-controlled studies (in total, 1,057 participants) that applied frequency-specific noninvasive stimulation of neural oscillations and examined working memory performance in neurotypical adults. We use a computational meta-modeling method to simulate each intervention in realistic virtual brains and test reported behavioral outcomes against the stimulation-induced electric fields in different brain nodes. Our results show that stimulating anterior frontal and medial temporal theta oscillations and occipitoparietal gamma rhythms leads to significant dose-dependent improvement in working memory task performance. Conversely, prefrontal gamma modulation is detrimental to performance. Moreover, we found distinct spatial expression of theta subbands, where working memory changes followed orbitofrontal high-theta modulation and medial temporal low-theta modulation. Finally, all these results are driven by changes in working memory accuracy rather than processing time measures. These findings provide a fresh view of the working memory mechanisms, complementary to neuroimaging research, and propose hypothesis-driven targets for the clinical treatment of working memory deficits.
Collapse
Affiliation(s)
- Miles Wischnewski
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN55455
- Department of Experimental Psychology, University of Groningen, Groningen9712TS, The Netherlands
| | - Taylor A. Berger
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN55455
| | - Alexander Opitz
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN55455
| | - Ivan Alekseichuk
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN55455
| |
Collapse
|
39
|
Libri I, Cantoni V, Benussi A, Rivolta J, Ferrari C, Fancellu R, Synofzik M, Alberici A, Padovani A, Borroni B. Comparing Cerebellar tDCS and Cerebellar tACS in Neurodegenerative Ataxias Using Wearable Sensors: A Randomized, Double-Blind, Sham-Controlled, Triple-Crossover Trial. CEREBELLUM (LONDON, ENGLAND) 2024; 23:570-578. [PMID: 37349632 PMCID: PMC10951038 DOI: 10.1007/s12311-023-01578-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 06/09/2023] [Indexed: 06/24/2023]
Abstract
Cerebellar transcranial direct current stimulation (tDCS) represents a promising therapeutic approach for both motor and cognitive symptoms in neurodegenerative ataxias. Recently, transcranial alternating current stimulation (tACS) was also demonstrated to modulate cerebellar excitability by neuronal entrainment. To compare the effectiveness of cerebellar tDCS vs. cerebellar tACS in patients with neurodegenerative ataxia, we performed a double-blind, randomized, sham controlled, triple cross-over trial with cerebellar tDCS, cerebellar tACS or sham stimulation in twenty-six participants with neurodegenerative ataxia. Before entering the study, each participant underwent motor assessment with wearable sensors considering gait cadence (steps/minute), turn velocity (degrees/second) and turn duration (seconds), and a clinical evaluation with the scale for the Assessment and Rating of Ataxia (SARA) and the International Cooperative Ataxia Rating Scale (ICARS). After each intervention, participants underwent the same clinical assessment along with cerebellar inhibition (CBI) measurement, a marker of cerebellar activity. The gait cadence, turn velocity, SARA, and ICARS significantly improved after both tDCS and tACS, compared to sham stimulation (all p<0.010). Comparable effects were observed for CBI (p<0.001). Overall, tDCS significantly outperformed tACS on clinical scales and CBI (p<0.01). A significant correlation between changes of wearable sensors parameters from baseline and changes of clinical scales and CBI scores was detected. Cerebellar tDCS and cerebellar tACS are effective in ameliorating symptoms of neurodegenerative ataxias, with the former being more beneficial than the latter. Wearable sensors may serve as rater-unbiased outcome measures in future clinical trials. ClinicalTrial.gov Identifier: NCT05621200.
Collapse
Affiliation(s)
- Ilenia Libri
- Neurology Unit, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
| | - Valentina Cantoni
- Neurology Unit, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
| | - Alberto Benussi
- Neurology Unit, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
- Neurology Unit, Department of Neurological and Vision Sciences, ASST Spedali Civili, Brescia, Italy
| | - Jasmine Rivolta
- Neurology Unit, Department of Neurological and Vision Sciences, ASST Spedali Civili, Brescia, Italy
| | - Camilla Ferrari
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Florence, Italy
| | - Roberto Fancellu
- UO Neurologia, IRCCS Ospedale Policlinico San Martino, 16132, Genoa, Italy
| | - Matthis Synofzik
- Department of Neurodegeneration, Hertie Institute for Clinical Brain Research and Centre of Neurology, Tübingen, Germany
- German Research Center for Neurodegenerative Diseases (DZNE), Tübingen, Germany
| | - Antonella Alberici
- Neurology Unit, Department of Neurological and Vision Sciences, ASST Spedali Civili, Brescia, Italy
| | - Alessandro Padovani
- Neurology Unit, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
- Neurology Unit, Department of Neurological and Vision Sciences, ASST Spedali Civili, Brescia, Italy
| | - Barbara Borroni
- Neurology Unit, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy.
- Neurology Unit, Department of Neurological and Vision Sciences, ASST Spedali Civili, Brescia, Italy.
| |
Collapse
|
40
|
Brus J, Heng JA, Beliaeva V, Gonzalez Pinto F, Cassarà AM, Neufeld E, Grueschow M, Imbach L, Polanía R. Causal phase-dependent control of non-spatial attention in human prefrontal cortex. Nat Hum Behav 2024; 8:743-757. [PMID: 38366104 PMCID: PMC11045450 DOI: 10.1038/s41562-024-01820-z] [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: 03/13/2023] [Accepted: 01/08/2024] [Indexed: 02/18/2024]
Abstract
Non-spatial attention is a fundamental cognitive mechanism that allows organisms to orient the focus of conscious awareness towards sensory information that is relevant to a behavioural goal while shifting it away from irrelevant stimuli. It has been suggested that attention is regulated by the ongoing phase of slow excitability fluctuations of neural activity in the prefrontal cortex, a hypothesis that has been challenged with no consensus. Here we developed a behavioural and non-invasive stimulation paradigm aiming at modulating slow excitability fluctuations of the inferior frontal junction. Using this approach, we show that non-spatial attention can be selectively modulated as a function of the ongoing phase of exogenously modulated excitability states of this brain structure. These results demonstrate that non-spatial attention relies on ongoing prefrontal excitability states, which are probably regulated by slow oscillatory dynamics, that orchestrate goal-oriented behaviour.
Collapse
Affiliation(s)
- Jeroen Brus
- Decision Neuroscience Lab, Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland.
- Neuroscience Center Zurich, Zurich, Switzerland.
| | - Joseph A Heng
- Decision Neuroscience Lab, Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland
- Neuroscience Center Zurich, Zurich, Switzerland
| | - Valeriia Beliaeva
- Decision Neuroscience Lab, Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland
- Neuroscience Center Zurich, Zurich, Switzerland
| | - Fabian Gonzalez Pinto
- Decision Neuroscience Lab, Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland
- Neuroscience Center Zurich, Zurich, Switzerland
| | - Antonino Mario Cassarà
- Foundation for Research on Information Technologies in Society (IT'IS), Zurich, Switzerland
| | - Esra Neufeld
- Foundation for Research on Information Technologies in Society (IT'IS), Zurich, Switzerland
| | - Marcus Grueschow
- Zurich Center for Neuroeconomics, Department of Economics, University of Zurich, Zurich, Switzerland
| | - Lukas Imbach
- Swiss Epilepsy Center (Klinik Lengg), Zurich, Switzerland
| | - Rafael Polanía
- Decision Neuroscience Lab, Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland.
- Neuroscience Center Zurich, Zurich, Switzerland.
| |
Collapse
|
41
|
Yang D, Kang MK, Huang G, Eggebrecht AT, Hong KS. Repetitive Transcranial Alternating Current Stimulation to Improve Working Memory: An EEG-fNIRS Study. IEEE Trans Neural Syst Rehabil Eng 2024; 32:1257-1266. [PMID: 38498739 DOI: 10.1109/tnsre.2024.3377138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/20/2024]
Abstract
Transcranial electrical stimulation has demonstrated the potential to enhance cognitive functions such as working memory, learning capacity, and attentional allocation. Recently, it was shown that periodic stimulation within a specific duration could augment the human brain's neuroplasticity. This study investigates the effects of repetitive transcranial alternating current stimulation (tACS; 1 mA, 5 Hz, 2 min duration) on cognitive function, functional connectivity, and topographic changes using both electroencephalography (EEG) and functional near-infrared spectroscopy (fNIRS). Fifteen healthy subjects were recruited to measure brain activity in the pre-, during-, and post-stimulation sessions under tACS and sham stimulation conditions. Fourteen trials of working memory tasks and eight repetitions of tACS/sham stimulation with a 1-minute intersession interval were applied to the frontal cortex of the participants. The working memory score, EEG band-wise powers, EEG topography, concentration changes of oxygenated hemoglobin, and functional connectivity (FC) were individually analyzed to quantify the behavioral and neurophysiological effects of tACS. Our results indicate that tACS increases: i) behavioral scores (i.e., 15.08, ) and EEG band-wise powers (i.e., theta and beta bands) compared to the sham stimulation condition, ii) FC of both EEG-fNIRS signals, especially in the large-scale brain network communication and interhemispheric connections, and iii) the hemodynamic response in comparison to the pre-stimulation session and the sham condition. Conclusively, the repetitive theta-band tACS stimulation improves the working memory capacity regarding behavioral and neuroplasticity perspectives. Additionally, the proposed fNIRS biomarkers (mean, slope), EEG band-wise powers, and FC can be used as neuro-feedback indices for closed-loop brain stimulation.
Collapse
|
42
|
Manippa V, Palmisano A, Nitsche MA, Filardi M, Vilella D, Logroscino G, Rivolta D. Cognitive and Neuropathophysiological Outcomes of Gamma-tACS in Dementia: A Systematic Review. Neuropsychol Rev 2024; 34:338-361. [PMID: 36877327 PMCID: PMC10920470 DOI: 10.1007/s11065-023-09589-0] [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: 05/03/2022] [Accepted: 01/23/2023] [Indexed: 03/07/2023]
Abstract
Despite the numerous pharmacological interventions targeting dementia, no disease-modifying therapy is available, and the prognosis remains unfavorable. A promising perspective involves tackling high-frequency gamma-band (> 30 Hz) oscillations involved in hippocampal-mediated memory processes, which are impaired from the early stages of typical Alzheimer's Disease (AD). Particularly, the positive effects of gamma-band entrainment on mouse models of AD have prompted researchers to translate such findings into humans using transcranial alternating current stimulation (tACS), a methodology that allows the entrainment of endogenous cortical oscillations in a frequency-specific manner. This systematic review examines the state-of-the-art on the use of gamma-tACS in Mild Cognitive Impairment (MCI) and dementia patients to shed light on its feasibility, therapeutic impact, and clinical effectiveness. A systematic search from two databases yielded 499 records resulting in 10 included studies and a total of 273 patients. The results were arranged in single-session and multi-session protocols. Most of the studies demonstrated cognitive improvement following gamma-tACS, and some studies showed promising effects of gamma-tACS on neuropathological markers, suggesting the feasibility of gamma-tACS in these patients anyhow far from the strong evidence available for mouse models. Nonetheless, the small number of studies and their wide variability in terms of aims, parameters, and measures, make it difficult to draw firm conclusions. We discuss results and methodological limitations of the studies, proposing possible solutions and future avenues to improve research on the effects of gamma-tACS on dementia.
Collapse
Affiliation(s)
- Valerio Manippa
- Department of Education, Psychology and Communication, University of Bari "Aldo Moro", Bari, Italy.
| | - Annalisa Palmisano
- Department of Education, Psychology and Communication, University of Bari "Aldo Moro", Bari, Italy
| | - Michael A Nitsche
- Department of Psychology and Neurosciences, Leibniz Research Centre for Working Environment and Human Factors, Dortmund, Germany
- Department of Neurology, University Medical Hospital Bergmannsheil, Bochum, Germany
| | - Marco Filardi
- Center for Neurodegenerative Diseases and the Aging Brain, University of Bari "Aldo Moro" at Pia Fondazione "Cardinale G. Panico", Tricase, Lecce, Italy
- Department of Basic Medicine, Neuroscience and Sense Organs, University of Bari "Aldo Moro", Bari, Italy
| | - Davide Vilella
- Center for Neurodegenerative Diseases and the Aging Brain, University of Bari "Aldo Moro" at Pia Fondazione "Cardinale G. Panico", Tricase, Lecce, Italy
| | - Giancarlo Logroscino
- Center for Neurodegenerative Diseases and the Aging Brain, University of Bari "Aldo Moro" at Pia Fondazione "Cardinale G. Panico", Tricase, Lecce, Italy
- Department of Basic Medicine, Neuroscience and Sense Organs, University of Bari "Aldo Moro", Bari, Italy
| | - Davide Rivolta
- Department of Education, Psychology and Communication, University of Bari "Aldo Moro", Bari, Italy
| |
Collapse
|
43
|
Huang X, Wei X, Wang J, Yi G. Frequency-dependent membrane polarization across neocortical cell types and subcellular elements by transcranial alternating current stimulation. J Neural Eng 2024; 21:016034. [PMID: 38382101 DOI: 10.1088/1741-2552/ad2b8a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Accepted: 02/21/2024] [Indexed: 02/23/2024]
Abstract
Objective.Transcranial alternating current stimulation (tACS) is a non-invasive brain stimulation technique that directly interacts with ongoing brain oscillations in a frequency-dependent manner. However, it remains largely unclear how the cellular effects of tACS vary between cell types and subcellular elements.Approach.In this study, we use a set of morphologically realistic models of neocortical neurons to simulate the cellular response to uniform oscillating electric fields (EFs). We systematically characterize the membrane polarization in the soma, axons, and dendrites with varying field directions, intensities, and frequencies.Main results.Pyramidal cells are more sensitive to axial EF that is roughly parallel to the cortical column, while interneurons are sensitive to axial EF and transverse EF that is tangent to the cortical surface. Membrane polarization in each subcellular element increases linearly with EF intensity, and its slope, i.e. polarization length, highly depends on the stimulation frequency. At each frequency, pyramidal cells are more polarized than interneurons. Axons usually experience the highest polarization, followed by the dendrites and soma. Moreover, a visible frequency resonance presents in the apical dendrites of pyramidal cells, while the other subcellular elements primarily exhibit low-pass filtering properties. In contrast, each subcellular element of interneurons exhibits complex frequency-dependent polarization. Polarization phase in each subcellular element of cortical neurons lags that of field and exhibits high-pass filtering properties. These results demonstrate that the membrane polarization is not only frequency-dependent, but also cell type- and subcellular element-specific. Through relating effective length and ion mechanism with polarization, we emphasize the crucial role of cell morphology and biophysics in determining the frequency-dependent membrane polarization.Significance.Our findings highlight the diverse polarization patterns across cell types as well as subcellular elements, which provide some insights into the tACS cellular effects and should be considered when understanding the neural spiking activity by tACS.
Collapse
Affiliation(s)
- Xuelin Huang
- School of Electrical and Information Engineering, Tianjin University, Tianjin 300072, People's Republic of China
| | - Xile Wei
- School of Electrical and Information Engineering, Tianjin University, Tianjin 300072, People's Republic of China
| | - Jiang Wang
- School of Electrical and Information Engineering, Tianjin University, Tianjin 300072, People's Republic of China
| | - Guosheng Yi
- School of Electrical and Information Engineering, Tianjin University, Tianjin 300072, People's Republic of China
| |
Collapse
|
44
|
Wischnewski M, Tran H, Zhao Z, Shirinpour S, Haigh ZJ, Rotteveel J, Perera ND, Alekseichuk I, Zimmermann J, Opitz A. Induced neural phase precession through exogenous electric fields. Nat Commun 2024; 15:1687. [PMID: 38402188 PMCID: PMC10894208 DOI: 10.1038/s41467-024-45898-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Accepted: 02/06/2024] [Indexed: 02/26/2024] Open
Abstract
The gradual shifting of preferred neural spiking relative to local field potentials (LFPs), known as phase precession, plays a prominent role in neural coding. Correlations between the phase precession and behavior have been observed throughout various brain regions. As such, phase precession is suggested to be a global neural mechanism that promotes local neuroplasticity. However, causal evidence and neuroplastic mechanisms of phase precession are lacking so far. Here we show a causal link between LFP dynamics and phase precession. In three experiments, we modulated LFPs in humans, a non-human primate, and computational models using alternating current stimulation. We show that continuous stimulation of motor cortex oscillations in humans lead to a gradual phase shift of maximal corticospinal excitability by ~90°. Further, exogenous alternating current stimulation induced phase precession in a subset of entrained neurons (~30%) in the non-human primate. Multiscale modeling of realistic neural circuits suggests that alternating current stimulation-induced phase precession is driven by NMDA-mediated synaptic plasticity. Altogether, the three experiments provide mechanistic and causal evidence for phase precession as a global neocortical process. Alternating current-induced phase precession and consequently synaptic plasticity is crucial for the development of novel therapeutic neuromodulation methods.
Collapse
Affiliation(s)
- Miles Wischnewski
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA.
| | - Harry Tran
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA
| | - Zhihe Zhao
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA
| | - Sina Shirinpour
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA
| | - Zachary J Haigh
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA
| | - Jonna Rotteveel
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA
| | - Nipun D Perera
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA
| | - Ivan Alekseichuk
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA
| | - Jan Zimmermann
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA
- Department of Neuroscience, University of Minnesota, Minneapolis, MN, USA
- Department of Radiology, Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, USA
| | - Alexander Opitz
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA.
| |
Collapse
|
45
|
Verma AK, Nandakumar B, Acedillo K, Yu Y, Marshall E, Schneck D, Fiecas M, Wang J, MacKinnon CD, Howell MJ, Vitek JL, Johnson LA. Slow-wave sleep dysfunction in mild parkinsonism is associated with excessive beta and reduced delta oscillations in motor cortex. Front Neurosci 2024; 18:1338624. [PMID: 38449736 PMCID: PMC10915200 DOI: 10.3389/fnins.2024.1338624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Accepted: 01/17/2024] [Indexed: 03/08/2024] Open
Abstract
Increasing evidence suggests slow-wave sleep (SWS) dysfunction in Parkinson's disease (PD) is associated with faster disease progression, cognitive impairment, and excessive daytime sleepiness. Beta oscillations (8-35 Hz) in the basal ganglia thalamocortical (BGTC) network are thought to play a role in the development of cardinal motor signs of PD. The role cortical beta oscillations play in SWS dysfunction in the early stage of parkinsonism is not understood, however. To address this question, we used a within-subject design in a nonhuman primate (NHP) model of PD to record local field potentials from the primary motor cortex (MC) during sleep across normal and mild parkinsonian states. The MC is a critical node in the BGTC network, exhibits pathological oscillations with depletion in dopamine tone, and displays high amplitude slow oscillations during SWS. The MC is therefore an appropriate recording site to understand the neurophysiology of SWS dysfunction in parkinsonism. We observed a reduction in SWS quantity (p = 0.027) in the parkinsonian state compared to normal. The cortical delta (0.5-3 Hz) power was reduced (p = 0.038) whereas beta (8-35 Hz) power was elevated (p = 0.001) during SWS in the parkinsonian state compared to normal. Furthermore, SWS quantity positively correlated with delta power (r = 0.43, p = 0.037) and negatively correlated with beta power (r = -0.65, p < 0.001). Our findings support excessive beta oscillations as a mechanism for SWS dysfunction in mild parkinsonism and could inform the development of neuromodulation therapies for enhancing SWS in people with PD.
Collapse
Affiliation(s)
- Ajay K. Verma
- Department of Neurology, University of Minnesota, Minneapolis, MN, United States
| | - Bharadwaj Nandakumar
- Department of Neurology, University of Minnesota, Minneapolis, MN, United States
| | - Kit Acedillo
- Department of Neurology, University of Minnesota, Minneapolis, MN, United States
| | - Ying Yu
- Department of Neurology, University of Minnesota, Minneapolis, MN, United States
| | - Ethan Marshall
- Department of Neurology, University of Minnesota, Minneapolis, MN, United States
| | - David Schneck
- Masonic Institute for the Developing Brain, University of Minnesota, Minneapolis, MN, United States
| | - Mark Fiecas
- Division of Biostatistics, University of Minnesota, Minneapolis, MN, United States
| | - Jing Wang
- Department of Neurology, University of Minnesota, Minneapolis, MN, United States
| | - Colum D. MacKinnon
- Department of Neurology, University of Minnesota, Minneapolis, MN, United States
| | - Michael J. Howell
- Department of Neurology, University of Minnesota, Minneapolis, MN, United States
| | - Jerrold L. Vitek
- Department of Neurology, University of Minnesota, Minneapolis, MN, United States
| | - Luke A. Johnson
- Department of Neurology, University of Minnesota, Minneapolis, MN, United States
| |
Collapse
|
46
|
Shtoots L, Nadler A, Partouche R, Sharir D, Rothstein A, Shati L, Levy DA. Frontal midline theta transcranial alternating current stimulation enhances early consolidation of episodic memory. NPJ SCIENCE OF LEARNING 2024; 9:8. [PMID: 38365886 PMCID: PMC10873319 DOI: 10.1038/s41539-024-00222-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Accepted: 02/02/2024] [Indexed: 02/18/2024]
Abstract
Evidence implicating theta rhythms in declarative memory encoding and retrieval, together with the notion that both retrieval and consolidation involve memory reinstatement or replay, suggests that post-learning theta rhythm modulation can promote early consolidation of newly formed memories. Building on earlier work employing theta neurofeedback, we examined whether theta-frequency transcranial alternating stimulation (tACS) can engender effective consolidation of newly formed episodic memories, compared with beta frequency stimulation or sham control conditions. We compared midline frontal and posterior parietal theta stimulation montages and examined whether benefits to memory of theta upregulation are attributable to consolidation rather than to retrieval processes by using a washout period to eliminate tACS after-effects between stimulation and memory assessment. Four groups of participants viewed object pictures followed by a free recall test during three study-test cycles. They then engaged in tACS (frontal theta montage/parietal theta montage/frontal beta montage/sham) for a period of 20 min, followed by a 2-h break. Free recall assessments were conducted after the break, 24 h later, and 7 days later. Frontal midline theta-tACS induced significant off-line retrieval gains at all assessment time points relative to all other conditions. This indicates that theta upregulation provides optimal conditions for the consolidation of episodic memory, independent of mental-state strategies.
Collapse
Affiliation(s)
- Limor Shtoots
- Baruch Ivcher School of Psychology, Reichman University, Herzliya, 4610101, Israel
| | - Asher Nadler
- Baruch Ivcher School of Psychology, Reichman University, Herzliya, 4610101, Israel
| | - Roni Partouche
- Baruch Ivcher School of Psychology, Reichman University, Herzliya, 4610101, Israel
| | - Dorin Sharir
- Baruch Ivcher School of Psychology, Reichman University, Herzliya, 4610101, Israel
| | - Aryeh Rothstein
- Baruch Ivcher School of Psychology, Reichman University, Herzliya, 4610101, Israel
| | - Liran Shati
- Baruch Ivcher School of Psychology, Reichman University, Herzliya, 4610101, Israel
| | - Daniel A Levy
- Baruch Ivcher School of Psychology, Reichman University, Herzliya, 4610101, Israel.
- Department of Psychology, Palo Alto University, Palo Alto, CA, 94304, USA.
| |
Collapse
|
47
|
Soto-Icaza P, Soto-Fernández P, Kausel L, Márquez-Rodríguez V, Carvajal-Paredes P, Martínez-Molina MP, Figueroa-Vargas A, Billeke P. Oscillatory activity underlying cognitive performance in children and adolescents with autism: a systematic review. Front Hum Neurosci 2024; 18:1320761. [PMID: 38384334 PMCID: PMC10879575 DOI: 10.3389/fnhum.2024.1320761] [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: 10/12/2023] [Accepted: 01/15/2024] [Indexed: 02/23/2024] Open
Abstract
Autism spectrum disorder (ASD) is a neurodevelopmental condition that exhibits a widely heterogeneous range of social and cognitive symptoms. This feature has challenged a broad comprehension of this neurodevelopmental disorder and therapeutic efforts to address its difficulties. Current therapeutic strategies have focused primarily on treating behavioral symptoms rather than on brain psychophysiology. During the past years, the emergence of non-invasive brain stimulation techniques (NIBS) has opened alternatives to the design of potential combined treatments focused on the neurophysiopathology of neuropsychiatric disorders like ASD. Such interventions require identifying the key brain mechanisms underlying the symptomatology and cognitive features. Evidence has shown alterations in oscillatory features of the neural ensembles associated with cognitive functions in ASD. In this line, we elaborated a systematic revision of the evidence of alterations in brain oscillations that underlie key cognitive processes that have been shown to be affected in ASD during childhood and adolescence, namely, social cognition, attention, working memory, inhibitory control, and cognitive flexibility. This knowledge could contribute to developing therapies based on NIBS to improve these processes in populations with ASD.
Collapse
Affiliation(s)
- Patricia Soto-Icaza
- Laboratorio de Neurociencia Social y Neuromodulación, Centro de Investigación en Complejidad Social, (neuroCICS), Facultad de Gobierno, Universidad del Desarrollo, Santiago, Chile
| | | | - Leonie Kausel
- Centro de Estudios en Neurociencia Humana y Neuropsicología (CENHN), Facultad de Psicología, Universidad Diego Portales, Santiago, Chile
| | - Víctor Márquez-Rodríguez
- Laboratorio de Neurociencia Social y Neuromodulación, Centro de Investigación en Complejidad Social, (neuroCICS), Facultad de Gobierno, Universidad del Desarrollo, Santiago, Chile
| | - Patricio Carvajal-Paredes
- Laboratorio de Neurociencia Social y Neuromodulación, Centro de Investigación en Complejidad Social, (neuroCICS), Facultad de Gobierno, Universidad del Desarrollo, Santiago, Chile
| | - María Paz Martínez-Molina
- Laboratorio de Neurociencia Social y Neuromodulación, Centro de Investigación en Complejidad Social, (neuroCICS), Facultad de Gobierno, Universidad del Desarrollo, Santiago, Chile
| | - Alejandra Figueroa-Vargas
- Laboratorio de Neurociencia Social y Neuromodulación, Centro de Investigación en Complejidad Social, (neuroCICS), Facultad de Gobierno, Universidad del Desarrollo, Santiago, Chile
- Laboratory for Cognitive and Evolutionary Neuroscience (LaNCE), Centro Interdisciplinario de Neurociencia, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Pablo Billeke
- Laboratorio de Neurociencia Social y Neuromodulación, Centro de Investigación en Complejidad Social, (neuroCICS), Facultad de Gobierno, Universidad del Desarrollo, Santiago, Chile
| |
Collapse
|
48
|
Guerra A, Paparella G, Passaretti M, Costa D, Birreci D, De Biase A, Colella D, Angelini L, Cannavacciuolo A, Berardelli A, Bologna M. Theta-tACS modulates cerebellar-related motor functions and cerebellar-cortical connectivity. Clin Neurophysiol 2024; 158:159-169. [PMID: 38219405 DOI: 10.1016/j.clinph.2023.12.129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 11/21/2023] [Accepted: 12/11/2023] [Indexed: 01/16/2024]
Abstract
OBJECTIVE To evaluate the effects of cerebellar transcranial alternating current stimulation (tACS) delivered at cerebellar-resonant frequencies, i.e., theta (θ) and gamma (γ), on upper limb motor performance and cerebellum-primary motor cortex (M1) connectivity, as assessed by cerebellar-brain inhibition (CBI), in healthy subjects. METHODS Participants underwent cerebellar-tACS while performing three cerebellar-dependent motor tasks: (i) rhythmic finger-tapping, (ii) arm reaching-to-grasp ('grasping') and (iii) arm reaching-to-point ('pointing') an object. Also, we evaluated possible changes in CBI during cerebellar-tACS. RESULTS θ-tACS decreased movement regularity during the tapping task and increased the duration of the pointing task compared to sham- and γ-tACS. Additionally, θ-tACS increased the CBI effectiveness (greater inhibition). The effect of θ-tACS on movement rhythm correlated with CBI changes and less tapping regularity corresponded to greater CBI. CONCLUSIONS Cerebellar-tACS delivered at the θ frequency modulates cerebellar-related motor behavior and this effect is, at least in part, mediated by changes in the cerebellar inhibitory output onto M1. The effects of θ-tACS may be due to the modulation of cerebellar neurons that resonate to the θ rhythm. SIGNIFICANCE These findings contribute to a better understanding of the physiological mechanisms of motor control and provide new evidence on cerebellar non-invasive brain stimulation.
Collapse
Affiliation(s)
- Andrea Guerra
- Parkinson and Movement Disorders Unit, Study Center on Neurodegeneration (CESNE), Department of Neuroscience, University of Padua, Padua, Italy; Padova Neuroscience Center (PNC), University of Padua, Padua, Italy
| | - Giulia Paparella
- IRCCS Neuromed, Pozzilli (IS) 86077, Italy; Department of Human Neurosciences, Sapienza University of Rome, Rome 00185, Italy
| | | | - Davide Costa
- Department of Human Neurosciences, Sapienza University of Rome, Rome 00185, Italy
| | - Daniele Birreci
- Department of Human Neurosciences, Sapienza University of Rome, Rome 00185, Italy
| | - Alessandro De Biase
- Department of Human Neurosciences, Sapienza University of Rome, Rome 00185, Italy
| | - Donato Colella
- Department of Human Neurosciences, Sapienza University of Rome, Rome 00185, Italy
| | | | | | - Alfredo Berardelli
- IRCCS Neuromed, Pozzilli (IS) 86077, Italy; Department of Human Neurosciences, Sapienza University of Rome, Rome 00185, Italy
| | - Matteo Bologna
- IRCCS Neuromed, Pozzilli (IS) 86077, Italy; Department of Human Neurosciences, Sapienza University of Rome, Rome 00185, Italy.
| |
Collapse
|
49
|
Cabral-Calderin Y, van Hinsberg D, Thielscher A, Henry MJ. Behavioral entrainment to rhythmic auditory stimulation can be modulated by tACS depending on the electrical stimulation field properties. eLife 2024; 12:RP87820. [PMID: 38289225 PMCID: PMC10945705 DOI: 10.7554/elife.87820] [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] [Indexed: 02/01/2024] Open
Abstract
Synchronization between auditory stimuli and brain rhythms is beneficial for perception. In principle, auditory perception could be improved by facilitating neural entrainment to sounds via brain stimulation. However, high inter-individual variability of brain stimulation effects questions the usefulness of this approach. Here we aimed to modulate auditory perception by modulating neural entrainment to frequency modulated (FM) sounds using transcranial alternating current stimulation (tACS). In addition, we evaluated the advantage of using tACS montages spatially optimized for each individual's anatomy and functional data compared to a standard montage applied to all participants. Across two different sessions, 2 Hz tACS was applied targeting auditory brain regions. Concurrent with tACS, participants listened to FM stimuli with modulation rate matching the tACS frequency but with different phase lags relative to the tACS, and detected silent gaps embedded in the FM sound. We observed that tACS modulated the strength of behavioral entrainment to the FM sound in a phase-lag specific manner. Both the optimal tACS lag and the magnitude of the tACS effect were variable across participants and sessions. Inter-individual variability of tACS effects was best explained by the strength of the inward electric field, depending on the field focality and proximity to the target brain region. Although additional evidence is necessary, our results also provided suggestive insights that spatially optimizing the electrode montage could be a promising tool to reduce inter-individual variability of tACS effects. This work demonstrates that tACS effectively modulates entrainment to sounds depending on the optimality of the electric field. However, the lack of reliability on optimal tACS lags calls for caution when planning tACS experiments based on separate sessions.
Collapse
Affiliation(s)
| | | | - Axel Thielscher
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Amager and HvidovreCopenhagenDenmark
- Section for Magnetic Resonance, DTU Health Tech, Technical University of DenmarkCopenhagenDenmark
| | - Molly J Henry
- Max Planck Institute for Empirical AestheticsFrankfurtGermany
- Toronto Metropolitan UniversityTorontoCanada
| |
Collapse
|
50
|
Wang J, Choi KY, Thompson B, Chan HHL, Cheong AMY. The effect of montages of transcranial alternating current stimulation on occipital responses-a sham-controlled pilot study. Front Psychiatry 2024; 14:1273044. [PMID: 38328519 PMCID: PMC10849049 DOI: 10.3389/fpsyt.2023.1273044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2023] [Accepted: 12/13/2023] [Indexed: 02/09/2024] Open
Abstract
Background Transcranial alternative current stimulation (tACS) refers to a promising non-invasive technique to improve brain functions. However, owing to various stimulation parameters in the literature, optimization of the stimulation is warranted. In this study, the authors aimed to compare the effect of tACS electrode montages on occipital responses. Methods In three montage sessions (i.e., Oz-Cz, Oz-cheek, and sham), 10 healthy young adults participated, receiving 20-min 2-mA alpha-tACS. Pattern-reversal visual evoked potentials (VEPs) were measured before tACS (T0), immediately after (T20), and 20 min (T40) after tACS. Normalized changes in time-domain features (i.e., N75, P100 amplitudes, and P100 latency) and frequency-domain features [i.e., power spectral density in alpha (PSDα) and beta (PSDβ) bands] were evaluated. Results In contrast to our hypothesis, the occipital response decreased immediately (T20) after receiving the 20-min tACS in all montages in terms of P100 amplitude (p = 0.01). This reduction returned to baseline level (T0) in Oz-cheek and sham conditions but sustained in the Oz-Cz condition (T40, p = 0.03) after 20 min of tACS. The effects on N75 amplitude and P100 latency were statistically insignificant. For spectral analysis, both PSDα and PSDβ were significantly increased after tACS at T20, in which the effect sustained until T40. However, there was no differential effect by montages. There was no significant difference in the occurrence of sensations across the montages. The effectiveness of the blinding is supported by the participants' rate of guessing correctly. Conclusion This study revealed an immediate inhibitory effect of tACS, regardless of the montages. This inhibitory effect sustained in the Oz-Cz montage but faded out in other montages after 20 min.
Collapse
Affiliation(s)
- Jingying Wang
- School of Optometry, The Hong Kong Polytechnic University, Hong Kong, Hong Kong SAR, China
- College of Health and Human Performance, University of Florida, Gainesville, FL, United States
| | - Kai Yip Choi
- School of Optometry, The Hong Kong Polytechnic University, Hong Kong, Hong Kong SAR, China
| | - Benjamin Thompson
- School of Optometry and Vision Science, University of Waterloo, Waterloo, ON, Canada
- Centre for Eye and Vision Research, Hong Kong Science Park, Hong Kong, Hong Kong SAR, China
| | - Henry Ho Lung Chan
- School of Optometry, The Hong Kong Polytechnic University, Hong Kong, Hong Kong SAR, China
- Centre for Eye and Vision Research, Hong Kong Science Park, Hong Kong, Hong Kong SAR, China
| | - Allen Ming Yan Cheong
- School of Optometry, The Hong Kong Polytechnic University, Hong Kong, Hong Kong SAR, China
- Centre for Eye and Vision Research, Hong Kong Science Park, Hong Kong, Hong Kong SAR, China
| |
Collapse
|