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Vescovo E, Cardellicchio P, Tomassini A, Fadiga L, D'Ausilio A. Excitatory/inhibitory motor balance reflects individual differences during joint action coordination. Eur J Neurosci 2024; 59:3403-3421. [PMID: 38666628 DOI: 10.1111/ejn.16365] [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: 11/03/2023] [Revised: 03/07/2024] [Accepted: 04/06/2024] [Indexed: 06/15/2024]
Abstract
Joint action (JA) is a continuous process of motor co-regulation based on the integration of contextual (top-down) and kinematic (bottom-up) cues from partners. The fine equilibrium between excitation and inhibition in sensorimotor circuits is, thus, central to such a dynamic process of action selection and execution. In a bimanual task adapted to become a unimanual JA task, the participant held a bottle (JA), while a confederate had to reach and unscrew either that bottle or another stabilized by a mechanical clamp (No_JA). Prior knowledge was manipulated in each trial such that the participant knew (K) or not (No_K) the target bottle in advance. Online transcranial magnetic stimulation (TMS) was administered at action-relevant landmarks to explore corticospinal excitability (CSE) and inhibition (cortical silent period [cSP]). CSE was modulated early on before the action started if prior information was available. In contrast, cSP modulation emerged later during the reaching action, regardless of prior information. These two indexes could thus reflect the concurrent elaboration of contextual priors (top-down) and the online sampling of partner's kinematic cues (bottom-up). Furthermore, participants selected either one of two possible behavioural strategies, preferring early or late force exertion on the bottle. One translates into a reduced risk of motor coordination failure and the other into reduced metabolic expenditure. Each strategy was characterised by a specific excitatory/inhibitory profile. In conclusion, the study of excitatory/inhibitory balance paves the way for the neurophysiological determination of individual differences in the combination of top-down and bottom-up processing during JA coordination.
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Affiliation(s)
- Enrico Vescovo
- Center for Translational Neurophysiology of Speech and Communication, Istituto Italiano di Tecnologia, Ferrara, Italy
- Department of Neuroscience and Rehabilitation, Section of Physiology, University of Ferrara, Ferrara, Italy
| | - Pasquale Cardellicchio
- Department of Neuroscience and Rehabilitation, Section of Physiology, University of Ferrara, Ferrara, Italy
- Physical Medicine and Rehabilitation Unit, IRCCS Istituto Giannina Gaslini, Genoa, Italy
| | - Alice Tomassini
- Center for Translational Neurophysiology of Speech and Communication, Istituto Italiano di Tecnologia, Ferrara, Italy
| | - Luciano Fadiga
- Center for Translational Neurophysiology of Speech and Communication, Istituto Italiano di Tecnologia, Ferrara, Italy
- Department of Neuroscience and Rehabilitation, Section of Physiology, University of Ferrara, Ferrara, Italy
| | - Alessandro D'Ausilio
- Center for Translational Neurophysiology of Speech and Communication, Istituto Italiano di Tecnologia, Ferrara, Italy
- Department of Neuroscience and Rehabilitation, Section of Physiology, University of Ferrara, Ferrara, Italy
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2
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Eysel UT, Jancke D. Induction of excitatory brain state governs plastic functional changes in visual cortical topology. Brain Struct Funct 2024; 229:531-547. [PMID: 38041743 PMCID: PMC10978694 DOI: 10.1007/s00429-023-02730-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: 08/09/2023] [Accepted: 11/03/2023] [Indexed: 12/03/2023]
Abstract
Adult visual plasticity underlying local remodeling of the cortical circuitry in vivo appears to be associated with a spatiotemporal pattern of strongly increased spontaneous and evoked activity of populations of cells. Here we review and discuss pioneering work by us and others about principles of plasticity in the adult visual cortex, starting with our study which showed that a confined lesion in the cat retina causes increased excitability in the affected region in the primary visual cortex accompanied by fine-tuned restructuring of neuronal function. The underlying remodeling processes was further visualized with voltage-sensitive dye (VSD) imaging that allowed a direct tracking of retinal lesion-induced reorganization across horizontal cortical circuitries. Nowadays, application of noninvasive stimulation methods pursues the idea further of increased cortical excitability along with decreased inhibition as key factors for the induction of adult cortical plasticity. We used high-frequency transcranial magnetic stimulation (TMS), for the first time in combination with VSD optical imaging, and provided evidence that TMS-amplified excitability across large pools of neurons forms the basis for noninvasively targeting reorganization of orientation maps in the visual cortex. Our review has been compiled on the basis of these four own studies, which we discuss in the context of historical developments in the field of visual cortical plasticity and the current state of the literature. Overall, we suggest markers of LTP-like cortical changes at mesoscopic population level as a main driving force for the induction of visual plasticity in the adult. Elevations in excitability that predispose towards cortical plasticity are most likely a common property of all cortical modalities. Thus, interventions that increase cortical excitability are a promising starting point to drive perceptual and potentially motor learning in therapeutic applications.
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Affiliation(s)
- Ulf T Eysel
- Department of Neurophysiology, Ruhr University Bochum, 44780, Bochum, Germany.
| | - Dirk Jancke
- Optical Imaging Group, Institut für Neuroinformatik, Ruhr University Bochum, 44780, Bochum, Germany.
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3
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Paparella I, Vanderwalle G, Stagg CJ, Maquet P. An integrated measure of GABA to characterize post-stroke plasticity. Neuroimage Clin 2023; 39:103463. [PMID: 37406594 PMCID: PMC10339061 DOI: 10.1016/j.nicl.2023.103463] [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: 03/31/2023] [Revised: 06/19/2023] [Accepted: 06/24/2023] [Indexed: 07/07/2023]
Abstract
Stroke is a major cause of death and chronic neurological disability. Despite the improvements in stroke care, the number of patients affected by stroke keeps increasing and many stroke survivors are left permanently disabled. Current therapies are limited in efficacy. Understanding the neurobiological mechanisms underlying post-stroke recovery is therefore crucial to find new therapeutic options to address this medical burden. Long-lasting and widespread alterations of γ-aminobutyric acid (GABA) neurotransmission seem to play a key role in stroke recovery. In this review we first discuss a possible model of GABAergic modulation of post-stroke plasticity. We then overview the techniques currently available to non-invasively assess GABA in patients and the conclusions drawn from this limited body of work. Finally, we address the remaining open questions to clarify GABAergic changes underlying post-stroke recovery, we briefly review possible ways to modulate GABA post stroke and propose a novel approach to thoroughly quantify GABA in stroke patients, by integrating its concentration, the activity of its receptors and its link with microstructural changes.
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Affiliation(s)
- Ilenia Paparella
- GIGA-Research, Cyclotron Research Center-In Vivo Imaging Unit, 8 allée du Six Août, Batiment B30, University of Liège, 4000 Liège, Belgium.
| | - Gilles Vanderwalle
- GIGA-Research, Cyclotron Research Center-In Vivo Imaging Unit, 8 allée du Six Août, Batiment B30, University of Liège, 4000 Liège, Belgium
| | - Charlotte J Stagg
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Medical Research Council Brain Network Dynamics Unit, Oxford, UK
| | - Pierre Maquet
- GIGA-Research, Cyclotron Research Center-In Vivo Imaging Unit, 8 allée du Six Août, Batiment B30, University of Liège, 4000 Liège, Belgium; Department of Neurology, Domaine Universitaire du Sart Tilman, Bâtiment B35, CHU de Liège, 4000 Liège, Belgium
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4
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Vucic S, Stanley Chen KH, Kiernan MC, Hallett M, Benninger DH, Di Lazzaro V, Rossini PM, Benussi A, Berardelli A, Currà A, Krieg SM, Lefaucheur JP, Long Lo Y, Macdonell RA, Massimini M, Rosanova M, Picht T, Stinear CM, Paulus W, Ugawa Y, Ziemann U, Chen R. Clinical diagnostic utility of transcranial magnetic stimulation in neurological disorders. Updated report of an IFCN committee. Clin Neurophysiol 2023; 150:131-175. [PMID: 37068329 PMCID: PMC10192339 DOI: 10.1016/j.clinph.2023.03.010] [Citation(s) in RCA: 44] [Impact Index Per Article: 44.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 02/28/2023] [Accepted: 03/09/2023] [Indexed: 03/31/2023]
Abstract
The review provides a comprehensive update (previous report: Chen R, Cros D, Curra A, Di Lazzaro V, Lefaucheur JP, Magistris MR, et al. The clinical diagnostic utility of transcranial magnetic stimulation: report of an IFCN committee. Clin Neurophysiol 2008;119(3):504-32) on clinical diagnostic utility of transcranial magnetic stimulation (TMS) in neurological diseases. Most TMS measures rely on stimulation of motor cortex and recording of motor evoked potentials. Paired-pulse TMS techniques, incorporating conventional amplitude-based and threshold tracking, have established clinical utility in neurodegenerative, movement, episodic (epilepsy, migraines), chronic pain and functional diseases. Cortical hyperexcitability has emerged as a diagnostic aid in amyotrophic lateral sclerosis. Single-pulse TMS measures are of utility in stroke, and myelopathy even in the absence of radiological changes. Short-latency afferent inhibition, related to central cholinergic transmission, is reduced in Alzheimer's disease. The triple stimulation technique (TST) may enhance diagnostic utility of conventional TMS measures to detect upper motor neuron involvement. The recording of motor evoked potentials can be used to perform functional mapping of the motor cortex or in preoperative assessment of eloquent brain regions before surgical resection of brain tumors. TMS exhibits utility in assessing lumbosacral/cervical nerve root function, especially in demyelinating neuropathies, and may be of utility in localizing the site of facial nerve palsies. TMS measures also have high sensitivity in detecting subclinical corticospinal lesions in multiple sclerosis. Abnormalities in central motor conduction time or TST correlate with motor impairment and disability in MS. Cerebellar stimulation may detect lesions in the cerebellum or cerebello-dentato-thalamo-motor cortical pathways. Combining TMS with electroencephalography, provides a novel method to measure parameters altered in neurological disorders, including cortical excitability, effective connectivity, and response complexity.
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Affiliation(s)
- Steve Vucic
- Brain, Nerve Research Center, The University of Sydney, Sydney, Australia.
| | - Kai-Hsiang Stanley Chen
- Department of Neurology, National Taiwan University Hospital Hsin-Chu Branch, Hsin-Chu, Taiwan
| | - Matthew C Kiernan
- Brain and Mind Centre, The University of Sydney; and Department of Neurology, Royal Prince Alfred Hospital, Australia
| | - Mark Hallett
- Human Motor Control Section, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health, Bethesda, Maryland, United States
| | - David H Benninger
- Department of Neurology, University Hospital of Lausanne (CHUV), Switzerland
| | - Vincenzo Di Lazzaro
- Unit of Neurology, Neurophysiology, Neurobiology, Department of Medicine, University Campus Bio-Medico of Rome, Rome, Italy
| | - Paolo M Rossini
- Department of Neurosci & Neurorehab IRCCS San Raffaele-Rome, Italy
| | - Alberto Benussi
- Centre for Neurodegenerative Disorders, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
| | - Alfredo Berardelli
- IRCCS Neuromed, Pozzilli; Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy
| | - Antonio Currà
- Department of Medico-Surgical Sciences and Biotechnologies, Alfredo Fiorini Hospital, Sapienza University of Rome, Terracina, LT, Italy
| | - Sandro M Krieg
- Department of Neurosurgery, Technical University Munich, School of Medicine, Klinikum rechts der Isar, Munich, Germany
| | - Jean-Pascal Lefaucheur
- Univ Paris Est Creteil, EA4391, ENT, Créteil, France; Clinical Neurophysiology Unit, Henri Mondor Hospital, AP-HP, Créteil, France
| | - Yew Long Lo
- Department of Neurology, National Neuroscience Institute, Singapore General Hospital, Singapore, and Duke-NUS Medical School, Singapore
| | | | - Marcello Massimini
- Dipartimento di Scienze Biomediche e Cliniche, Università degli Studi di Milano, Milan, Italy; Istituto Di Ricovero e Cura a Carattere Scientifico, Fondazione Don Carlo Gnocchi, Milan, Italy
| | - Mario Rosanova
- Department of Biomedical and Clinical Sciences University of Milan, Milan, Italy
| | - Thomas Picht
- Department of Neurosurgery, Charité-Universitätsmedizin Berlin, Cluster of Excellence: "Matters of Activity. Image Space Material," Humboldt University, Berlin Simulation and Training Center (BeST), Charité-Universitätsmedizin Berlin, Germany
| | - Cathy M Stinear
- Department of Medicine Waipapa Taumata Rau, University of Auckland, Auckland, Aotearoa, New Zealand
| | - Walter Paulus
- Department of Neurology, Ludwig-Maximilians-Universität München, München, Germany
| | - Yoshikazu Ugawa
- Department of Human Neurophysiology, School of Medicine, Fukushima Medical University, Japan
| | - Ulf Ziemann
- Department of Neurology and Stroke, Eberhard Karls University of Tübingen, Hoppe-Seyler-Str. 3, 72076, Tübingen, Germany; Hertie Institute for Clinical Brain Research, Eberhard Karls University of Tübingen, Otfried-Müller-Straße 27, 72076 Tübingen, Germany
| | - Robert Chen
- Edmond J. Safra Program in Parkinson's Disease, Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital-UHN, Division of Neurology-University of Toronto, Toronto Canada
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Lacroix A, Proteau-Lemieux M, Côté S, Near J, Hui SC, Edden RA, Lippé S, Çaku A, Corbin F, Lepage JF. Multimodal assessment of the GABA system in patients with fragile-X syndrome and neurofibromatosis of type 1. Neurobiol Dis 2022; 174:105881. [DOI: 10.1016/j.nbd.2022.105881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 09/12/2022] [Accepted: 10/02/2022] [Indexed: 11/24/2022] Open
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6
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Zeng Z, Koponen LM, Hamdan R, Li Z, Goetz SM, Peterchev AV. Modular multilevel TMS device with wide output range and ultrabrief pulse capability for sound reduction. J Neural Eng 2022; 19:10.1088/1741-2552/ac572c. [PMID: 35189604 PMCID: PMC9425059 DOI: 10.1088/1741-2552/ac572c] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 02/21/2022] [Indexed: 11/12/2022]
Abstract
Objective.This article presents a novel transcranial magnetic stimulation (TMS) pulse generator with a wide range of pulse shape, amplitude, and width.Approach.Based on a modular multilevel TMS (MM-TMS) topology we had proposed previously, we realized the first such device operating at full TMS energy levels. It consists of ten cascaded H-bridge modules, each implemented with insulated-gate bipolar transistors, enabling both novel high-amplitude ultrabrief pulses as well as pulses with conventional amplitude and duration. The MM-TMS device can output pulses including up to 21 voltage levels with a step size of up to 1100 V, allowing relatively flexible generation of various pulse waveforms and sequences. The circuit further allows charging the energy storage capacitor on each of the ten cascaded modules with a conventional TMS power supply.Main results. The MM-TMS device can output peak coil voltages and currents of 11 kV and 10 kA, respectively, enabling suprathreshold ultrabrief pulses (>8.25μs active electric field phase). Further, the MM-TMS device can generate a wide range of near-rectangular monophasic and biphasic pulses, as well as more complex staircase-approximated sinusoidal, polyphasic, and amplitude-modulated pulses. At matched estimated stimulation strength, briefer pulses emit less sound, which could enable quieter TMS. Finally, the MM-TMS device can instantaneously increase or decrease the amplitude from one pulse to the next in discrete steps by adding or removing modules in series, which enables rapid pulse sequences and paired-pulse protocols with variable pulse shapes and amplitudes.Significance.The MM-TMS device allows unprecedented control of the pulse characteristics which could enable novel protocols and quieter pulses.
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Affiliation(s)
- Zhiyong Zeng
- Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC, 27710, United States of America
| | - Lari M Koponen
- Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC, 27710, United States of America
| | - Rena Hamdan
- Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC, 27710, United States of America
| | - Zhongxi Li
- Department of Electrical and Computer Engineering, Duke University, Durham, NC, 27708, United States of America
| | - Stefan M Goetz
- Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC, 27710, United States of America.,Department of Electrical and Computer Engineering, Duke University, Durham, NC, 27708, United States of America.,Duke Institute for Brain Sciences, Duke University, Durham, NC, 27708, United States of America.,Department of Neurosurgery, Duke University, Durham, NC, 27710, United States of America
| | - Angel V Peterchev
- Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC, 27710, United States of America.,Department of Electrical and Computer Engineering, Duke University, Durham, NC, 27708, United States of America.,Duke Institute for Brain Sciences, Duke University, Durham, NC, 27708, United States of America.,Department of Neurosurgery, Duke University, Durham, NC, 27710, United States of America.,Department of Biomedical Engineering, Duke University, Durham, NC, 27708, United States of America
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7
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Diao X, Lu Q, Qiao L, Gong Y, Lu X, Feng M, Su P, Shen Y, Yuan TF, He C. Cortical Inhibition State-Dependent iTBS Induced Neural Plasticity. Front Neurosci 2022; 16:788538. [PMID: 35250445 PMCID: PMC8891511 DOI: 10.3389/fnins.2022.788538] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Accepted: 01/11/2022] [Indexed: 11/13/2022] Open
Abstract
Background Intermittent theta burst stimulation (iTBS) is an effective stimulus for long-term potentiation (LTP)-like plasticity. However, iTBS-induced effects varied greatly between individuals. Ample evidence suggested that an initial decrease in local γ-aminobutyric acid (GABA) or enhancement in N-methyl-D-aspartate (NMDA) facilitation neurotransmission is of vital importance for allowing LTP-like plasticity to occur. Therefore, we aimed to investigate whether the individual level of GABA or NMDA receptor-mediated activity before stimulation is correlated with the after-effect in cortical excitability induced by iTBS. Methods Fifteen healthy volunteers were recruited for the present study. We measured short-interval intracortical inhibitory (SICI), long-interval intracortical inhibitory (LICI), and intracortical facilitation (ICF), which index GABAA receptor-, GABAB receptor-, and glutamate receptor-mediated activity, respectively, in the cortex before conducting iTBS. After iTBS intervention, the changes of motor-evoked potential (MEP) amplitude were taken as a measure for cortical excitability in response to iTBS protocol. Results There was a significant negative correlation between the amount of SICI measured before iTBS and the after-effect of iTBS-induced LTP-like plasticity at the time points of 5, 10, and 15 min after inducing iTBS. A multiple linear regression model indicated that SICI was a good predictor of the after-effect in cortical excitability induced by iTBS at 5, 10, and 15 min following stimulation. Conclusion The present study found that GABAA receptor-mediated activity measured before stimulation is negatively correlated with the after-effect of cortical excitability induced by iTBS. SICI, as the index of GABAA receptor-mediated activity measured before stimulation, might be a good predictor of iTBS-induced LTP-like plasticity for a period lasting 15 min following stimulation.
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Affiliation(s)
- Xiaoying Diao
- Department of Rehabilitation Medicine, The Affiliated Jiangsu Shengze Hospital of Nanjing Medical University, Suzhou, China
- Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Qian Lu
- Department of Rehabilitation Medicine, The Affiliated Jiangsu Shengze Hospital of Nanjing Medical University, Suzhou, China
| | - Lei Qiao
- Jiangsu Zhongshan Geriatric Rehabilitation Hospital, Nanjing, China
| | - Youhui Gong
- Department of Rehabilitation Medicine, The Affiliated Jiangsu Shengze Hospital of Nanjing Medical University, Suzhou, China
| | - Xiao Lu
- Department of Rehabilitation Medicine, The Affiliated Jiangsu Shengze Hospital of Nanjing Medical University, Suzhou, China
| | - Min Feng
- Department of Rehabilitation Medicine, The Affiliated Jiangsu Shengze Hospital of Nanjing Medical University, Suzhou, China
| | - Panpan Su
- Department of Rehabilitation Medicine, The Affiliated Jiangsu Shengze Hospital of Nanjing Medical University, Suzhou, China
| | - Ying Shen
- Rehabilitation Medicine Center, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
- *Correspondence: Ying Shen,
| | - Ti-Fei Yuan
- Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
- Translational Research Institute of Brain and Brain-Like Intelligence, Shanghai Fourth People’s Hospital Affiliated to Tongji University School of Medicine, Shanghai, China
- Ti-Fei Yuan,
| | - Chuan He
- Department of Rehabilitation Medicine, The Affiliated Jiangsu Shengze Hospital of Nanjing Medical University, Suzhou, China
- Chuan He,
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Zhang BBB, Kan RLD, Giron CG, Lin TTZ, Yau SY, Kranz GS. Dose-response relationship between iTBS and prefrontal activation during executive functioning: A fNIRS study. Front Psychiatry 2022; 13:1049130. [PMID: 36606127 PMCID: PMC9807664 DOI: 10.3389/fpsyt.2022.1049130] [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: 09/22/2022] [Accepted: 12/05/2022] [Indexed: 12/24/2022] Open
Abstract
INTRODUCTION Intermittent theta-burst stimulation (iTBS) is a non-invasive brain stimulation paradigm that has demonstrated promising therapeutic benefits for a variety of neuropsychiatric disorders. It has recently garnered widespread favor among researchers and clinicians, owing to its comparable potentiation effects as conventional high-frequency repetitive transcranial magnetic stimulation (rTMS), but administered in a much shorter time frame. However, there is still a lack of agreement over the optimal stimulation intensity, particularly when targeting the prefrontal regions. The objective of this study was to systematically investigate the influence of different stimulation intensities of iTBS, applied over the left dorsolateral prefrontal cortex (DLPFC), on brain activity and executive function in healthy adults. METHODS Twenty young healthy adults were enrolled in this randomized cross-over experiment. All participants received a single session iTBS over the left DLPFC at intensities of 50, 70, or 100% of their individual resting motor threshold (RMT), each on separate visits. Functional near-infrared spectroscopy (fNIRS) was used to measure changes of hemoglobin concentrations in prefrontal areas during the verbal fluency task (VFT) before and after stimulation. RESULTS After stimulation, iTBS to the left DLPFC with 70% RMT maintained the concentration change of oxyhemoglobin (HbO) in the target area during the VFT. In contrast, 50% [t (17) = 2.203, P = 0.042, d = 0.523] and 100% iTBS [t (17) = 2.947, P = 0.009, d = 0.547] significantly decreased change of HbO concentration, indicating an inverse U-shape relationship between stimulation intensity and prefrontal hemodynamic response in healthy young adults. Notably, improved VFT performance was only observed after 70% RMT stimulation [t (17) = 2.511, P = 0.022, d = 0.592]. Moreover, a significant positive correlation was observed between task performance and the difference in HbO concentration change in the targeted area after 70% RMT stimulation (r = 0.496, P = 0.036) but not after 50 or 100% RMT stimulation. CONCLUSION The linear relationship between stimulation intensity and behavioral outcomes reported in previous conventional rTMS studies may not be translated to iTBS. Instead, iTBS at 70% RMT may be more efficacious than 100% RMT.
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Affiliation(s)
- Bella B B Zhang
- Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hung Hom, Hong Kong SAR, China
| | - Rebecca L D Kan
- Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hung Hom, Hong Kong SAR, China
| | - Cristian G Giron
- Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hung Hom, Hong Kong SAR, China
| | - Tim T Z Lin
- Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hung Hom, Hong Kong SAR, China
| | - Suk-Yu Yau
- Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hung Hom, Hong Kong SAR, China.,Mental Health Research Center (MHRC), The Hong Kong Polytechnic University, Hung Hom, Hong Kong SAR, China
| | - Georg S Kranz
- Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hung Hom, Hong Kong SAR, China.,Mental Health Research Center (MHRC), The Hong Kong Polytechnic University, Hung Hom, Hong Kong SAR, China.,Department of Psychiatry and Psychotherapy, Comprehensive Center for Clinical Neurosciences and Mental Health (C3NMH), Medical University of Vienna, Vienna, Austria.,The State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hung Hom, Hong Kong SAR, China
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9
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Rothwell J, Antal A, Burke D, Carlsen A, Georgiev D, Jahanshahi M, Sternad D, Valls-Solé J, Ziemann U. Central nervous system physiology. Clin Neurophysiol 2021; 132:3043-3083. [PMID: 34717225 PMCID: PMC8863401 DOI: 10.1016/j.clinph.2021.09.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 09/13/2021] [Accepted: 09/20/2021] [Indexed: 12/15/2022]
Abstract
This is the second chapter of the series on the use of clinical neurophysiology for the study of movement disorders. It focusses on methods that can be used to probe neural circuits in brain and spinal cord. These include use of spinal and supraspinal reflexes to probe the integrity of transmission in specific pathways; transcranial methods of brain stimulation such as transcranial magnetic stimulation and transcranial direct current stimulation, which activate or modulate (respectively) the activity of populations of central neurones; EEG methods, both in conjunction with brain stimulation or with behavioural measures that record the activity of populations of central neurones; and pure behavioural measures that allow us to build conceptual models of motor control. The methods are discussed mainly in relation to work on healthy individuals. Later chapters will focus specifically on changes caused by pathology.
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Affiliation(s)
- John Rothwell
- Department of Clinical and Movement Neuroscience, UCL Queen Square Institute of Neurology, London, UK,Corresponding author at: Department of Clinical and Movement Neuroscience, UCL Queen Square Institute of Neurology, London WC1N 3BG, UK, (J. Rothwell)
| | - Andrea Antal
- Department of Neurology, University Medical Center Göttingen, Germany
| | - David Burke
- Department of Neurology, Royal Prince Alfred Hospital, University of Sydney, Sydney 2050, Australia
| | - Antony Carlsen
- School of Human Kinetics, University of Ottawa, Ottawa, Canada
| | - Dejan Georgiev
- Department of Neurology, University Medical Centre Ljubljana, Slovenia
| | - Marjan Jahanshahi
- Department of Clinical and Movement Neuroscience, UCL Queen Square Institute of Neurology, London, UK
| | - Dagmar Sternad
- Departments of Biology, Electrical & Computer Engineering, and Physics, Northeastern University, Boston, MA 02115, USA
| | - Josep Valls-Solé
- Institut d’Investigació Biomèdica August Pi I Sunyer, Villarroel, 170, Barcelona, Spain
| | - Ulf Ziemann
- Department of Neurology and Stroke, and Hertie Institute for Clinical Brain Research, Eberhard Karls University, Tübingen, Germany
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10
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Age-related changes in motor cortex plasticity assessed with non-invasive brain stimulation: an update and new perspectives. Exp Brain Res 2021; 239:2661-2678. [PMID: 34269850 DOI: 10.1007/s00221-021-06163-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 06/22/2021] [Indexed: 12/24/2022]
Abstract
It is commonly accepted that the brains capacity to change, known as plasticity, declines into old age. Recent studies have used a variety of non-invasive brain stimulation (NIBS) techniques to examine this age-related decline in plasticity in the primary motor cortex (M1), but the effects seem inconsistent and difficult to unravel. The purpose of this review is to provide an update on studies that have used different NIBS techniques to assess M1 plasticity with advancing age and offer some new perspective on NIBS strategies to boost plasticity in the ageing brain. We find that early studies show clear differences in M1 plasticity between young and older adults, but many recent studies with motor training show no decline in use-dependent M1 plasticity with age. For NIBS-induced plasticity in M1, some protocols show more convincing differences with advancing age than others. Therefore, our view from the NIBS literature is that it should not be automatically assumed that M1 plasticity declines with age. Instead, the effects of age are likely to depend on how M1 plasticity is measured, and the characteristics of the elderly population tested. We also suggest that NIBS performed concurrently with motor training is likely to be most effective at producing improvements in M1 plasticity and motor skill learning in older adults. Proposed NIBS techniques for future studies include combining multiple NIBS protocols in a co-stimulation approach, or NIBS strategies to modulate intracortical inhibitory mechanisms, in an effort to more effectively boost M1 plasticity and improve motor skill learning in older adults.
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11
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Grigoras IF, Stagg CJ. Recent advances in the role of excitation-inhibition balance in motor recovery post-stroke. Fac Rev 2021; 10:58. [PMID: 34308424 PMCID: PMC8265564 DOI: 10.12703/r/10-58] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Stroke affects millions of people worldwide each year, and stroke survivors are often left with motor deficits. Current therapies to improve these functional deficits are limited, making it a priority to better understand the pathophysiology of stroke recovery and find novel adjuvant options. The excitation-inhibition balance undergoes significant changes post-stroke, and the inhibitory neurotransmitter γ-aminobutyric acid (GABA) appears to play an important role in stroke recovery. In this review, we summarise the most recent studies investigating GABAergic inhibition at different stages of stroke. We discuss the proposed role of GABA in counteracting glutamate-mediated excitotoxicity in hyperacute stroke as well as the evidence linking decreased GABAergic inhibition to increased neuronal plasticity in early stroke. Then, we discuss two types of interventions that aim to modulate the excitation-inhibition balance to improve functional outcomes in stroke survivors: non-invasive brain stimulation (NIBS) and pharmacological interventions. Finding the optimal NIBS administration or adjuvant pharmacological therapies would represent an important contribution to the currently scarce therapy options.
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Affiliation(s)
- Ioana-Florentina Grigoras
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford; Medical Research Council Brain Network Dynamics Unit, University of Oxford, Oxford, UK
| | - Charlotte J Stagg
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford; Medical Research Council Brain Network Dynamics Unit, University of Oxford, Oxford, UK
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12
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Caux-Dedeystère A, Allart E, Morel P, Kreisler A, Derambure P, Devanne H. Late cortical disinhibition in focal hand dystonia. Eur J Neurosci 2021; 54:4712-4720. [PMID: 34061422 DOI: 10.1111/ejn.15333] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 05/20/2021] [Accepted: 05/23/2021] [Indexed: 11/30/2022]
Abstract
In writer's cramp (WC), a form of focal hand dystonia, cortical GABAergic inhibitory mechanisms are altered and may cause involuntary tonic contractions while writing. The objective of this study was to explore the time course of long-interval intracortical inhibition (LICI) that involves gamma-amino butyric acid (GABA)-B transmission and late cortical disinhibition (LCD) (that combines GABA-A and GABA-B mechanisms) in patients with WC and in control subjects. A double pulse transcranial magnetic stimulation protocol was used to evoke LICI and LCD while the subjects either gripped a cylinder between their thumb and index fingers or relaxed all their upper limb muscles. We measured the ratio between primed and unprimed motor evoked potential in the first dorsal interosseous at interstimulus intervals ranging between 60 and 300 ms. Though the cortical silent period was not different between the groups, LICI lasted longer in patients with WC, that is, LCD was delayed for more than 30 ms and reached a higher level. In addition to the alteration of inhibitory mechanism mediated by GABA-B transmission, LCD which probably involves presynaptic inhibition is also modified in patients with WC with possible consequences on the activity of primary motor cortex inhibitory and excitatory circuits which control the hand muscles.caus.
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Affiliation(s)
- Alexandre Caux-Dedeystère
- ULR 7369 - URePSSS - Unité de Recherche Pluridisciplinaire Sport Santé Société, Univ Littoral Côte d'Opale, Univ Lille, Univ Artois, Calais, France
| | - Etienne Allart
- Rééducation Neurologique Cérébrolésion, CHU de Lille, Hôpital Pierre Swynghedauw, Lille, France.,univ Lille, UMR-S-1172 lilncog, Lille, France
| | - Pierre Morel
- ULR 7369 - URePSSS - Unité de Recherche Pluridisciplinaire Sport Santé Société, Univ Littoral Côte d'Opale, Univ Lille, Univ Artois, Calais, France
| | - Alexandre Kreisler
- Neurologie & Pathologie du Mouvement, CHU de Lille, Hôpital Roger Salengro, Lille, France
| | - Philippe Derambure
- univ Lille, UMR-S-1172 lilncog, Lille, France.,Neurophysiologie Clinique, CHU de Lille, Hôpital Roger Salengro, Lille, France
| | - Hervé Devanne
- ULR 7369 - URePSSS - Unité de Recherche Pluridisciplinaire Sport Santé Société, Univ Littoral Côte d'Opale, Univ Lille, Univ Artois, Calais, France.,Neurophysiologie Clinique, CHU de Lille, Hôpital Roger Salengro, Lille, France
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13
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Fatih P, Kucuker MU, Vande Voort JL, Doruk Camsari D, Farzan F, Croarkin PE. A Systematic Review of Long-Interval Intracortical Inhibition as a Biomarker in Neuropsychiatric Disorders. Front Psychiatry 2021; 12:678088. [PMID: 34149483 PMCID: PMC8206493 DOI: 10.3389/fpsyt.2021.678088] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 05/06/2021] [Indexed: 12/23/2022] Open
Abstract
Long-interval intracortical inhibition (LICI) is a paired-pulse transcranial magnetic stimulation (TMS) paradigm mediated in part by gamma-aminobutyric acid receptor B (GABAB) inhibition. Prior work has examined LICI as a putative biomarker in an array of neuropsychiatric disorders. This review conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) sought to examine existing literature focused on LICI as a biomarker in neuropsychiatric disorders. There were 113 articles that met the inclusion criteria. Existing literature suggests that LICI may have utility as a biomarker of GABAB functioning but more research with increased methodologic rigor is needed. The extant LICI literature has heterogenous methodology and inconsistencies in findings. Existing findings to date are also non-specific to disease. Future research should carefully consider existing methodological weaknesses and implement high-quality test-retest reliability studies.
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Affiliation(s)
- Parmis Fatih
- Mayo Clinic Department of Psychiatry and Psychology, Mayo Clinic, Rochester, MN, United States
| | - M Utku Kucuker
- Mayo Clinic Department of Psychiatry and Psychology, Mayo Clinic, Rochester, MN, United States
| | - Jennifer L Vande Voort
- Mayo Clinic Department of Psychiatry and Psychology, Mayo Clinic, Rochester, MN, United States
| | - Deniz Doruk Camsari
- Mayo Clinic Department of Psychiatry and Psychology, Mayo Clinic, Rochester, MN, United States
| | - Faranak Farzan
- School of Mechatronic Systems Engineering, Centre for Engineering-Led Brain Research, Simon Fraser University, Surrey, BC, Canada
| | - Paul E Croarkin
- Mayo Clinic Department of Psychiatry and Psychology, Mayo Clinic, Rochester, MN, United States
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Cortical Excitability in Temporal Lobe Epilepsy with Bilateral Tonic-Clonic Seizures. Can J Neurol Sci 2020; 48:648-654. [PMID: 33308332 DOI: 10.1017/cjn.2020.267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVE We investigated motor cortical excitability (CE) in unilateral temporal lobe epilepsy (TLE) and its relationship to bilateral tonic-clonic seizure (BTCS) using paired-pulse transcranial magnetic stimulation (TMS). METHODS In this cross-sectional study, we enrolled 46 unilateral TLE patients and 16 age-and sex-matched healthy controls. Resting motor thresholds (RMT); short-interval intracortical inhibition (SICI, GABAA receptor-mediated); facilitation (ICF, glutamatergic-mediated) with interstimulus intervals (ISIs) of 2, 5, 10, and 15 ms; and long-interval intracortical inhibition (LICI, GABAB receptor-mediated) with ISIs of 200-400 ms were measured via paired-pulse TMS. Comparisons were made between controls and patients with TLE, and then among the TLE subgroups (no BTCS, infrequent BTCS and frequent BTCS subgroup). RESULTS Compared with controls, TLE patients had higher RMT, lower SICI and higher LICI in both hemispheres, and higher ICF in the ipsilateral hemisphere. In patients with frequent BTCS, cortical hyperexcitability in the ipsilateral hemisphere was found in a parameter-dependent manner (SICI decreased at a stimulation interval of 5 ms, and ICF increased at a stimulation interval of 15 ms) compared with patients with infrequent or no BTCS. CONCLUSIONS Our results demonstrate that motor cortical hyper-excitability in the ipsilateral hemisphere underlies the epileptogenic network of patients with active BTCS, which is more extensive than those with infrequent or no BTCS.
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Cardellicchio P, Dolfini E, Fadiga L, D'Ausilio A. Parallel fast and slow motor inhibition processes in Joint Action coordination. Cortex 2020; 133:346-357. [DOI: 10.1016/j.cortex.2020.09.029] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 07/22/2020] [Accepted: 09/17/2020] [Indexed: 11/30/2022]
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16
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Yu F, Tang X, Hu R, Liang S, Wang W, Tian S, Wu Y, Yuan TF, Zhu Y. The After-Effect of Accelerated Intermittent Theta Burst Stimulation at Different Session Intervals. Front Neurosci 2020; 14:576. [PMID: 32670006 PMCID: PMC7330092 DOI: 10.3389/fnins.2020.00576] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 05/11/2020] [Indexed: 01/10/2023] Open
Abstract
OBJECTIVE The study aims to investigate the after-effect of three sessions of intermittent theta-burst stimulation (iTBS) on motor cortical excitability. The iTBS was induced over the primary motor cortex (M1) at different time intervals. METHODS The study has a crossover design. Sixteen participants were assigned to three groups and received different accelerated iTBS (aiTBS) protocols during each visit: (1) three continuous sessions with no interval (iTBS18000); (2) three iTBS sessions with 10-min intervals (iTBS600 × 3∗10); and (3) three iTBS sessions with 30-min intervals (iTBS600 × 3∗30). As washout period, each visit is separated by at least 7 days. We measured the motor cortical excitability changes and intracortical inhibition. RESULTS A dose of 1,800 pulses of aiTBS per day is tolerable. The iTBS1800 led to a reduced cortical excitability; whereas iTBS600 × 3∗10 and iTBS600 × 3∗30 enhanced cortical excitability to a differential extent. After a total dose of 1,800 pulses, iTBS600 × 3∗30 exhibited the longer effect and highest percentage of individuals with enhanced cortical excitability. CONCLUSION The results suggest that aiTBS protocols at different time intervals result in different motor cortical excitability after-effects.
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Affiliation(s)
- Fengyun Yu
- Department of Rehabilitation Medicine, Huashan Hospital, Fudan University, Shanghai, China
- School of Kinesiology, Shanghai University of Sport, Shanghai, China
| | - Xinwei Tang
- Department of Rehabilitation Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Ruiping Hu
- Department of Rehabilitation Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Sijie Liang
- School of Kinesiology, Shanghai University of Sport, Shanghai, China
| | - Weining Wang
- School of Kinesiology, Shanghai University of Sport, Shanghai, China
| | - Shan Tian
- Department of Rehabilitation Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Yi Wu
- Department of Rehabilitation Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Ti-Fei Yuan
- Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Yulian Zhu
- Department of Rehabilitation Medicine, Huashan Hospital, Fudan University, Shanghai, China
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17
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Gamboa OL, Brito A, Abzug Z, D'Arbeloff T, Beynel L, Wing EA, Dannhauer M, Palmer H, Hilbig SA, Crowell CA, Liu S, Donaldson R, Cabeza R, Davis SW, Peterchev AV, Sommer MA, Appelbaum LG. Application of long-interval paired-pulse transcranial magnetic stimulation to motion-sensitive visual cortex does not lead to changes in motion discrimination. Neurosci Lett 2020; 730:135022. [PMID: 32413540 DOI: 10.1016/j.neulet.2020.135022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 04/24/2020] [Accepted: 04/27/2020] [Indexed: 12/29/2022]
Abstract
The perception of visual motion is dependent on a set of occipitotemporal regions that are readily accessible to neuromodulation. The current study tested if paired-pulse Transcranial Magnetic Stimulation (ppTMS) could modulate motion perception by stimulating the occipital cortex as participants viewed near-threshold motion dot stimuli. In this sham-controlled study, fifteen subjects completed two sessions. On the first visit, resting motor threshold (RMT) was assessed, and participants performed an adaptive direction discrimination task to determine individual motion sensitivity. During the second visit, subjects performed the task with three difficulty levels as TMS pulses were delivered 150 and 50 ms prior to motion stimulus onset at 120% RMT, under the logic that the cumulative inhibitory effect of these pulses would alter motion sensitivity. ppTMS was delivered at one of two locations: 3 cm dorsal and 5 cm lateral to inion (scalp-based coordinate), or at the site of peak activation for "motion" according to the NeuroSynth fMRI database (meta-analytic coordinate). Sham stimulation was delivered on one-third of trials by tilting the coil 90°. Analyses showed no significant active-versus-sham effects of ppTMS when stimulation was delivered to the meta-analytic (p = 0.15) or scalp-based coordinates (p = 0.17), which were separated by 29 mm on average. Active-versus-sham stimulation differences did not interact with either stimulation location (p = 0.12) or difficulty (p = 0.33). These findings fail to support the hypothesis that long-interval ppTMS recruits inhibitory processes in motion-sensitive cortex but must be considered within the limited parameters used in this design.
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Affiliation(s)
- Olga Lucia Gamboa
- Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, United States
| | - Alexandra Brito
- Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, United States
| | - Zachary Abzug
- Department of Biomedical Engineering, Duke University, United States
| | - Tracy D'Arbeloff
- Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, United States; Department of Psychology & Neuroscience, Duke University, United States
| | - Lysianne Beynel
- Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, United States
| | - Erik A Wing
- Department of Psychology & Neuroscience, Duke University, United States
| | - Moritz Dannhauer
- Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, United States
| | - Hannah Palmer
- Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, United States
| | - Susan A Hilbig
- Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, United States
| | - Courtney A Crowell
- Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, United States
| | - Sicong Liu
- Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, United States
| | - Rachel Donaldson
- Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, United States
| | - Roberto Cabeza
- Department of Psychology & Neuroscience, Duke University, United States; Center for Cognitive Neuroscience, Duke University, United States
| | - Simon W Davis
- Center for Cognitive Neuroscience, Duke University, United States; Department of Neurology, Duke University School of Medicine, United States
| | - Angel V Peterchev
- Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, United States; Department of Biomedical Engineering, Duke University, United States; Department of Electrical & Computer Engineering, Duke University, United States; Department of Neurosurgery, Duke University School of Medicine, United States
| | - Marc A Sommer
- Department of Biomedical Engineering, Duke University, United States; Department of Psychology & Neuroscience, Duke University, United States; Center for Cognitive Neuroscience, Duke University, United States; Department of Neurobiology, Duke University School of Medicine, United States
| | - Lawrence G Appelbaum
- Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, United States; Center for Cognitive Neuroscience, Duke University, United States.
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18
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Cirillo J, Mooney RA, Ackerley SJ, Barber PA, Borges VM, Clarkson AN, Mangold C, Ren A, Smith MC, Stinear CM, Byblow WD. Neurochemical balance and inhibition at the subacute stage after stroke. J Neurophysiol 2020; 123:1775-1790. [PMID: 32186435 DOI: 10.1152/jn.00561.2019] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Stroke is a leading cause of death and disability worldwide with many people left with impaired motor function. Evidence from experimental animal models of stroke indicates that reducing motor cortex inhibition may facilitate neural plasticity and motor recovery. This study compared primary motor cortex (M1) inhibition measures over the first 12 wk after stroke with a cohort of age-similar healthy controls. The excitation-inhibition ratio and gamma-aminobutyric acid (GABA) neurotransmission within M1 were assessed using magnetic resonance spectroscopy and threshold hunting paired-pulse transcranial magnetic stimulation respectively. Upper limb impairment and function were assessed with the Fugl-Meyer Upper Extremity Scale and Action Research Arm Test. Patients with a functional corticospinal pathway had motor-evoked potentials on the paretic side and exhibited better recovery from upper limb impairment and recovery of function than patients without a functional corticospinal pathway. Compared with age-similar controls, the neurochemical balance in terms of the excitation-inhibition ratio was greater within contralesional M1 in patients with a functional corticospinal pathway. There was evidence for elevated long-interval inhibition in both ipsilesional and contralesional M1 compared with controls. Short-interval inhibition measures differed between the first and second phases, with evidence for elevation of the former only in ipsilesional M1 and no evidence of disinhibition for the latter. Overall, findings from transcranial magnetic stimulation indicate an upregulation of GABA-mediated tonic inhibition in M1 early after stroke. Therapeutic approaches that aim to normalize inhibitory tone during the subacute period warrant further investigation.NEW & NOTEWORTHY Magnetic resonance spectroscopy indicated higher excitation-inhibition ratios within motor cortex during subacute recovery than age-similar healthy controls. Measures obtained from adaptive threshold hunting paired-pulse transcranial magnetic stimulation indicated greater tonic inhibition in patients compared with controls. Therapeutic approaches that aim to normalize motor cortex inhibition during the subacute stage of recovery should be explored.
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Affiliation(s)
- John Cirillo
- Department of Exercise Sciences, University of Auckland, Auckland, New Zealand.,Centre for Brain Research, University of Auckland, Auckland, New Zealand
| | - Ronan A Mooney
- Department of Exercise Sciences, University of Auckland, Auckland, New Zealand.,Centre for Brain Research, University of Auckland, Auckland, New Zealand
| | - Suzanne J Ackerley
- Centre for Brain Research, University of Auckland, Auckland, New Zealand.,Department of Medicine, University of Auckland, Auckland, New Zealand
| | - P Alan Barber
- Centre for Brain Research, University of Auckland, Auckland, New Zealand.,Department of Medicine, University of Auckland, Auckland, New Zealand
| | - Victor M Borges
- Department of Exercise Sciences, University of Auckland, Auckland, New Zealand.,Centre for Brain Research, University of Auckland, Auckland, New Zealand
| | | | - Christine Mangold
- Centre for Brain Research, University of Auckland, Auckland, New Zealand
| | - April Ren
- Department of Exercise Sciences, University of Auckland, Auckland, New Zealand
| | - Marie-Claire Smith
- Centre for Brain Research, University of Auckland, Auckland, New Zealand.,Department of Medicine, University of Auckland, Auckland, New Zealand
| | - Cathy M Stinear
- Centre for Brain Research, University of Auckland, Auckland, New Zealand.,Department of Medicine, University of Auckland, Auckland, New Zealand
| | - Winston D Byblow
- Department of Exercise Sciences, University of Auckland, Auckland, New Zealand.,Centre for Brain Research, University of Auckland, Auckland, New Zealand
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Hyperexcitability and impaired intracortical inhibition in patients with fragile-X syndrome. Transl Psychiatry 2019; 9:312. [PMID: 31748507 PMCID: PMC6868148 DOI: 10.1038/s41398-019-0650-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 10/08/2019] [Accepted: 11/01/2019] [Indexed: 01/10/2023] Open
Abstract
Fragile-X syndrome (FXS) is characterized by neurological and psychiatric problems symptomatic of cortical hyperexcitability. Recent animal studies identified deficient γ-aminobutyricacid (GABA) inhibition as a key mechanism for hyperexcitability in FXS, but the GABA system remains largely unexplored in humans with the disorder. The primary objective of this study was to assess GABA-mediated inhibition and its relationship with hyperexcitability in patients with FXS. Transcranial magnetic stimulation (TMS) was used to assess cortical and corticospinal inhibitory and excitatory mechanisms in 18 patients with a molecular diagnosis of FXS and 18 healthy controls. GABA-mediated inhibition was measured with short-interval intracortical inhibition (GABAA), long-interval intracortical inhibition (GABAB), and the corticospinal silent period (GABAA+B). Net intracortical facilitation involving glutamate was assessed with intracortical facilitation, and corticospinal excitability was measured with the resting motor threshold. Results showed that FXS patients had significantly reduced short-interval intracortical inhibition, increased long-interval intracortical inhibition, and increased intracortical facilitation compared to healthy controls. In the FXS group, reduced short-interval intracortical inhibition was associated with heightened intracortical facilitation. Taken together, these results suggest that reduced GABAA inhibition is a plausible mechanism underlying cortical hyperexcitability in patients with FXS. These findings closely match those observed in animal models, supporting the translational validity of these markers for clinical research.
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20
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Mooney RA, Ackerley SJ, Rajeswaran DK, Cirillo J, Barber PA, Stinear CM, Byblow WD. The Influence of Primary Motor Cortex Inhibition on Upper Limb Impairment and Function in Chronic Stroke: A Multimodal Study. Neurorehabil Neural Repair 2019; 33:130-140. [PMID: 30744527 DOI: 10.1177/1545968319826052] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
BACKGROUND Stroke is a leading cause of adult disability owing largely to motor impairment and loss of function. After stroke, there may be abnormalities in γ-aminobutyric acid (GABA)-mediated inhibitory function within primary motor cortex (M1), which may have implications for residual motor impairment and the potential for functional improvements at the chronic stage. OBJECTIVE To quantify GABA neurotransmission and concentration within ipsilesional and contralesional M1 and determine if they relate to upper limb impairment and function at the chronic stage of stroke. METHODS Twelve chronic stroke patients and 16 age-similar controls were recruited for the study. Upper limb impairment and function were assessed with the Fugl-Meyer Upper Extremity Scale and Action Research Arm Test. Threshold tracking paired-pulse transcranial magnetic stimulation protocols were used to examine short- and long-interval intracortical inhibition and late cortical disinhibition. Magnetic resonance spectroscopy was used to evaluate GABA concentration. RESULTS Short-interval intracortical inhibition was similar between patients and controls ( P = .10). Long-interval intracortical inhibition was greater in ipsilesional M1 compared with controls ( P < .001). Patients who did not exhibit late cortical disinhibition in ipsilesional M1 were those with greater upper limb impairment and worse function ( P = .002 and P = .017). GABA concentration was lower within ipsilesional ( P = .009) and contralesional ( P = .021) M1 compared with controls, resulting in an elevated excitation-inhibition ratio for patients. CONCLUSION These findings indicate that ipsilesional and contralesional M1 GABAergic inhibition are altered in this small cohort of chronic stroke patients. Further study is warranted to determine how M1 inhibitory networks might be targeted to improve motor function.
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Affiliation(s)
| | | | | | - John Cirillo
- 1 The University of Auckland, Auckland, New Zealand
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21
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Rossini P, Di Iorio R, Bentivoglio M, Bertini G, Ferreri F, Gerloff C, Ilmoniemi R, Miraglia F, Nitsche M, Pestilli F, Rosanova M, Shirota Y, Tesoriero C, Ugawa Y, Vecchio F, Ziemann U, Hallett M. Methods for analysis of brain connectivity: An IFCN-sponsored review. Clin Neurophysiol 2019; 130:1833-1858. [DOI: 10.1016/j.clinph.2019.06.006] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 05/08/2019] [Accepted: 06/18/2019] [Indexed: 01/05/2023]
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Combined endogenous and exogenous disinhibition of intracortical circuits augments plasticity induction in the human motor cortex. Brain Stimul 2019; 12:1027-1040. [PMID: 30894281 DOI: 10.1016/j.brs.2019.03.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 02/03/2019] [Accepted: 03/08/2019] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Motor imagery (MI) engages cortical areas in the human brain similar to motor practice. Corticospinal excitability (CSE) is facilitated during but not after MI practice. We hypothesized that lasting CSE changes could be achieved by associatively pairing this endogenous modulation with exogenous stimulation of the same intracortical circuits. METHODS We combined MI with a disinhibition protocol (DIS) targeting intracortical circuits by paired-pulse repetitive transcranial magnetic stimulation in one main and three subsequent experiments. The follow-up experiments were applied to increase effects, e.g., by individualizing inter-stimulus intervals, adding neuromuscular stimulation and expanding the intervention period. CSE was captured during (online) and after (offline) the interventions via input-output changes and cortical maps of motor evoked potentials. A total of 35 healthy subjects (mean age 26.1 ± 2.6 years, 20 females) participated in this study. RESULTS A short intervention (48 stimuli within ∼90s) increased CSE. This plasticity developed rapidly, was associative (with MIon, but not MIoff or REST) and persisted beyond the intervention period. Follow-up experiments revealed the relevance of individualizing inter-stimulus intervals and of consistent inter-burst periods for online and offline effects, respectively. Expanding this combined MI/DIS intervention to 480 stimuli amplified the sustainability of CSE changes. When concurrent neuromuscular electrical stimulation was applied, the plasticity induction was cancelled. CONCLUSIONS This novel associative stimulation protocol augmented plasticity induction in the human motor cortex within a remarkably short period of time and in the absence of active movements. The combination of endogenous and exogenous disinhibition of intracortical circuits may provide a therapeutic backdoor when active movements are no longer possible, e.g., for hand paralysis after stroke.
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24
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Jordan HT, Stinear CM. Effects of bilateral priming on motor cortex function in healthy adults. J Neurophysiol 2018; 120:2858-2867. [PMID: 30281376 DOI: 10.1152/jn.00472.2018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Bilateral priming is a rehabilitation adjuvant that can improve upper limb motor recovery poststroke. It uses a table-top device to couple the upper limbs together such that active flexion and extension of one wrist leads to passive movement of the opposite wrist in a mirror symmetric pattern. Bilateral priming increases corticomotor excitability (CME) in the primary motor cortex (M1) of the passively driven wrist; however, the neurophysiological mechanisms underlying this increase remain unclear. This study explored these mechanisms by using transcranial magnetic stimulation over the right M1 and recording motor-evoked potentials from the passively driven left extensor carpi radialis of healthy adults. Intracortical measures were recorded before and 5 and 35 min after a single 15-min session of priming. One-millisecond short-interval intracortical inhibition, long-interval intracortical inhibition, late cortical disinhibition (LCD), and intracortical facilitation were recorded with a posterior-anterior (PA) intracortical current, whereas CME and short-interval intracortical facilitation (SICF) were recorded with both PA and anterior-posterior (AP) currents. CME with PA stimulation was also recorded ~1 h postpriming. PA CME was elevated 35 min postpriming and remained elevated ~1 h postpriming. LCD decreased, and AP SICF increased at both 5 and 35 min postpriming. However, these changes in LCD and AP SICF are unlikely to be the cause of the increased PA CME because of the differing timelines of their effects and AP and PA currents activating separate interneuron circuits. These results suggest that bilateral priming does not increase CME through alterations of the intracortical circuits investigated here. NEW & NOTEWORTHY This is the first study to measure how bilateral priming modulates corticomotor excitability with posterior-anterior and anterior-posterior intracortical currents, 1-ms short-interval intracortical inhibition, late cortical disinhibition, intracortical facilitation, and short-interval intracortical facilitation. We found corticomotor excitability with a posterior-anterior current increased by 35 min until ~1 h postpriming. Short-interval intracortical facilitation with an anterior-posterior current was greater for at least 35 min postpriming. This provides further insight into the neurophysiological mechanisms underlying bilateral priming.
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Affiliation(s)
- Harry T Jordan
- Department of Medicine, University of Auckland , Auckland , New Zealand
| | - Cathy M Stinear
- Department of Medicine, University of Auckland , Auckland , New Zealand
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25
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Ruddy K, Balsters J, Mantini D, Liu Q, Kassraian-Fard P, Enz N, Mihelj E, Subhash Chander B, Soekadar SR, Wenderoth N. Neural activity related to volitional regulation of cortical excitability. eLife 2018; 7:e40843. [PMID: 30489255 PMCID: PMC6294548 DOI: 10.7554/elife.40843] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 11/26/2018] [Indexed: 12/26/2022] Open
Abstract
To date there exists no reliable method to non-invasively upregulate or downregulate the state of the resting human motor system over a large dynamic range. Here we show that an operant conditioning paradigm which provides neurofeedback of the size of motor evoked potentials (MEPs) in response to transcranial magnetic stimulation (TMS), enables participants to self-modulate their own brain state. Following training, participants were able to robustly increase (by 83.8%) and decrease (by 30.6%) their MEP amplitudes. This volitional up-versus down-regulation of corticomotor excitability caused an increase of late-cortical disinhibition (LCD), a TMS derived read-out of presynaptic GABAB disinhibition, which was accompanied by an increase of gamma and a decrease of alpha oscillations in the trained hemisphere. This approach paves the way for future investigations into how altered brain state influences motor neurophysiology and recovery of function in a neurorehabilitation context.
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Affiliation(s)
- Kathy Ruddy
- Neural Control of Movement LabETH ZürichZürichSwitzerland
- Institute of NeuroscienceTrinity College DublinDublinIreland
| | - Joshua Balsters
- Neural Control of Movement LabETH ZürichZürichSwitzerland
- Department of PsychologyRoyal Holloway University of LondonLondonUnited Kingdom
| | - Dante Mantini
- Neural Control of Movement LabETH ZürichZürichSwitzerland
- Movement Control and Neuroplasticity Research GroupKU LeuvenLeuvenBelgium
| | - Quanying Liu
- Neural Control of Movement LabETH ZürichZürichSwitzerland
- Movement Control and Neuroplasticity Research GroupKU LeuvenLeuvenBelgium
| | | | - Nadja Enz
- Neural Control of Movement LabETH ZürichZürichSwitzerland
| | - Ernest Mihelj
- Neural Control of Movement LabETH ZürichZürichSwitzerland
| | | | - Surjo R Soekadar
- Applied Neurotechnology LaboratoryUniversity of TübingenTübingenGermany
- Clinical Neurotechnology Laboratory, Neuroscience Research Center (NWFZ), Department of Psychiatry and PsychotherapyCharité – University Medicine BerlinBerlinGermany
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26
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Chung SW, Sullivan CM, Rogasch NC, Hoy KE, Bailey NW, Cash RFH, Fitzgerald PB. The effects of individualised intermittent theta burst stimulation in the prefrontal cortex: A TMS-EEG study. Hum Brain Mapp 2018; 40:608-627. [PMID: 30251765 DOI: 10.1002/hbm.24398] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2018] [Revised: 08/08/2018] [Accepted: 09/04/2018] [Indexed: 01/08/2023] Open
Abstract
Recent studies have highlighted variability in response to theta burst stimulation (TBS) in humans. TBS paradigm was originally developed in rodents to mimic gamma bursts coupled with theta rhythms, and was shown to elicit long-term potentiation. The protocol was subsequently adapted for humans using standardised frequencies of stimulation. However, each individual has different rhythmic firing pattern. The present study sought to explore whether individualised intermittent TBS (Ind iTBS) could outperform the effects of two other iTBS variants. Twenty healthy volunteers received iTBS over left prefrontal cortex using 30 Hz at 6 Hz, 50 Hz at 5 Hz, or individualised frequency in separate sessions. Ind iTBS was determined using theta-gamma coupling during the 3-back task. Concurrent use of transcranial magnetic stimulation and electroencephalography (TMS-EEG) was used to track changes in cortical plasticity. We also utilised mood ratings using a visual analogue scale and assessed working memory via the 3-back task before and after stimulation. No group-level effect was observed following either 30 or 50 Hz iTBS in TMS-EEG. Ind iTBS significantly increased the amplitude of the TMS-evoked P60, and decreased N100 and P200 amplitudes. A significant positive correlation between neurophysiological change and change in mood rating was also observed. Improved accuracy in the 3-back task was observed following both 50 Hz and Ind iTBS conditions. These findings highlight the critical importance of frequency in the parameter space of iTBS. Tailored stimulation parameters appear more efficacious than standard paradigms in neurophysiological and mood changes. This novel approach presents a promising option and benefits may extend to clinical applications.
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Affiliation(s)
- Sung Wook Chung
- Monash Alfred Psychiatry Research Centre, Monash University, Central Clinical School and The Alfred, Melbourne, Australia
| | - Caley M Sullivan
- Monash Alfred Psychiatry Research Centre, Monash University, Central Clinical School and The Alfred, Melbourne, Australia
| | - Nigel C Rogasch
- Brain and Mental Health Laboratory, School of Psychological Sciences and Monash Biomedical Imaging, Monash Institute of Cognitive and Clinical Neuroscience, Monash University, Melbourne, Australia
| | - Kate E Hoy
- Monash Alfred Psychiatry Research Centre, Monash University, Central Clinical School and The Alfred, Melbourne, Australia
| | - Neil W Bailey
- Monash Alfred Psychiatry Research Centre, Monash University, Central Clinical School and The Alfred, Melbourne, Australia
| | - Robin F H Cash
- Monash Alfred Psychiatry Research Centre, Monash University, Central Clinical School and The Alfred, Melbourne, Australia
| | - Paul B Fitzgerald
- Monash Alfred Psychiatry Research Centre, Monash University, Central Clinical School and The Alfred, Melbourne, Australia.,Epworth Clinic, Epworth Healthcare, Melbourne, Australia
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27
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Lewis CP, Nakonezny PA, Blacker CJ, Vande Voort JL, Port JD, Worrell GA, Jo HJ, Daskalakis ZJ, Croarkin PE. Cortical inhibitory markers of lifetime suicidal behavior in depressed adolescents. Neuropsychopharmacology 2018; 43:1822-1831. [PMID: 29703993 PMCID: PMC6046050 DOI: 10.1038/s41386-018-0040-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Revised: 01/05/2018] [Accepted: 02/26/2018] [Indexed: 11/09/2022]
Abstract
Although suicide is the second-leading cause of death in adolescents and young adults worldwide, little progress has been made in developing reliable biological markers of suicide risk and suicidal behavior. Converging evidence suggests that excitatory and inhibitory cortical processes mediated by the neurotransmitters glutamate and γ-aminobutyric acid (GABA) are dysregulated in suicidal individuals. This study utilized single- and paired-pulse transcranial magnetic stimulation (TMS) to assess excitatory and inhibitory cortical functioning in healthy control adolescents (n = 20), depressed adolescents without any history of suicidal behavior ("Depressed", n = 37), and depressed adolescents with lifetime history of suicidal behavior ("Depressed+SB", n = 17). In a fixed-effects general linear model analysis, with age, sex, and depression severity as covariates, no significant group main effects emerged for resting motor threshold, intracortical facilitation, short-interval intracortical inhibition, or cortical silent period. However, group main effects were significant for long-interval intracortical inhibition (LICI) at interstimulus intervals (ISIs) of 100 ms and 150 ms, but not 200 ms. Depressed+SB adolescents demonstrated impaired LICI compared to healthy control and Depressed adolescents, while healthy control and Depressed participants did not differ in LICI. Multiple linear robust regression revealed significant positive linear relationships between lifetime suicidal behavior severity and impairment in LICI at 100-ms and 150-ms ISIs. In a post hoc receiver operating characteristic analysis, LICI significantly discriminated Depressed from Depressed+SB youth in 100-ms and 150-ms paradigms. These findings suggest that GABAB receptor-mediated inhibition is distinctly dysregulated in depressed adolescents with histories of suicidal behavior. Further research is warranted to establish the utility of cortical inhibition in the assessment of suicide risk and as a target for treatment interventions.
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Affiliation(s)
- Charles P Lewis
- Department of Psychiatry and Psychology, Mayo Clinic, Rochester, MN, USA
| | - Paul A Nakonezny
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Clinical Sciences, Division of Biostatistics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Caren J Blacker
- Department of Psychiatry and Psychology, Mayo Clinic, Rochester, MN, USA
| | | | - John D Port
- Department of Psychiatry and Psychology, Mayo Clinic, Rochester, MN, USA
- Department of Radiology, Mayo Clinic, Rochester, MN, USA
| | | | - Hang Joon Jo
- Department of Neurologic Surgery, Neural Engineering Lab, Mayo Clinic, Rochester, MN, USA
| | - Zafiris J Daskalakis
- Department of Psychiatry, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
- Temerty Centre for Therapeutic Brain Intervention, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, University of Toronto, Toronto, ON, Canada
| | - Paul E Croarkin
- Department of Psychiatry and Psychology, Mayo Clinic, Rochester, MN, USA.
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28
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Abstract
Transcranial magnetic stimulation (TMS) holds promise as a tool for noninvasively facilitating plastic changes in cortical networks. However, highly resolved visualization of its modulatory effects remains elusive because current neuroimaging techniques applicable in humans are limited in spatiotemporal resolution. Here we used an imaging approach with voltage-sensitive dye and tracked, at submillimeter range, TMS-induced plastic changes across cat primary visual cortex. We show that high-frequency 10-Hz TMS induces a state where visual cortical maps are transiently “destabilized.” In turn, the cortex was sensitized to a bias in input—here imposed by prolonged exposure to a single visual orientation—and primed to relearn connectivity patterns. These findings implicate an early post-TMS time window for promising therapeutic interventions through TMS. Transcranial magnetic stimulation (TMS) has become a popular clinical method to modify cortical processing. The events underlying TMS-induced functional changes remain, however, largely unknown because current noninvasive recording methods lack spatiotemporal resolution or are incompatible with the strong TMS-associated electrical field. In particular, an answer to the question of how the relatively unspecific nature of TMS stimulation leads to specific neuronal reorganization, as well as a detailed picture of TMS-triggered reorganization of functional brain modules, is missing. Here we used real-time optical imaging in an animal experimental setting to track, at submillimeter range, TMS-induced functional changes in visual feature maps over several square millimeters of the brain’s surface. We show that high-frequency TMS creates a transient cortical state with increased excitability and increased response variability, which opens a time window for enhanced plasticity. Visual stimulation (i.e., 30 min of passive exposure) with a single orientation applied during this TMS-induced permissive period led to enlarged imprinting of the chosen orientation on the visual map across visual cortex. This reorganization was stable for hours and was characterized by a systematic shift in orientation preference toward the trained orientation. Thus, TMS can noninvasively trigger a targeted large-scale remodeling of fundamentally mature functional architecture in early sensory cortex.
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29
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Bauer PR, de Goede AA, Stern WM, Pawley AD, Chowdhury FA, Helling RM, Bouet R, Kalitzin SN, Visser GH, Sisodiya SM, Rothwell JC, Richardson MP, van Putten MJAM, Sander JW. Long-interval intracortical inhibition as biomarker for epilepsy: a transcranial magnetic stimulation study. Brain 2018; 141:409-421. [PMID: 29340584 PMCID: PMC5837684 DOI: 10.1093/brain/awx343] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 10/08/2017] [Accepted: 10/24/2017] [Indexed: 11/13/2022] Open
Abstract
Cortical excitability, as measured by transcranial magnetic stimulation combined with electromyography, is a potential biomarker for the diagnosis and follow-up of epilepsy. We report on long-interval intracortical inhibition data measured in four different centres in healthy controls (n = 95), subjects with refractory genetic generalized epilepsy (n = 40) and with refractory focal epilepsy (n = 69). Long-interval intracortical inhibition was measured by applying two supra-threshold stimuli with an interstimulus interval of 50, 100, 150, 200 and 250 ms and calculating the ratio between the response to the second (test stimulus) and to the first (conditioning stimulus). In all subjects, the median response ratio showed inhibition at all interstimulus intervals. Using a mixed linear-effects model, we compared the long-interval intracortical inhibition response ratios between the different subject types. We conducted two analyses; one including data from the four centres and one excluding data from Centre 2, as the methods in this centre differed from the others. In the first analysis, we found no differences in long-interval intracortical inhibition between the different subject types. In all subjects, the response ratios at interstimulus intervals 100 and 150 ms showed significantly more inhibition than the response ratios at 50, 200 and 250 ms. Our second analysis showed a significant interaction between interstimulus interval and subject type (P = 0.0003). Post hoc testing showed significant differences between controls and refractory focal epilepsy at interstimulus intervals of 100 ms (P = 0.02) and 200 ms (P = 0.04). There were no significant differences between controls and refractory generalized epilepsy groups or between the refractory generalized and focal epilepsy groups. Our results do not support the body of previous work that suggests that long-interval intracortical inhibition is significantly reduced in refractory focal and genetic generalized epilepsy. Results from the second analysis are even in sharper contrast with previous work, showing inhibition in refractory focal epilepsy at 200 ms instead of facilitation previously reported. Methodological differences, especially shorter intervals between the pulse pairs, may have contributed to our inability to reproduce previous findings. Based on our results, we suggest that long-interval intracortical inhibition as measured by transcranial magnetic stimulation and electromyography is unlikely to have clinical use as a biomarker of epilepsy.
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Affiliation(s)
- Prisca R Bauer
- NIHR University College London Hospitals Biomedical Research Centre, UCL Institute of Neurology, Queen Square, London, WC1N 3BG, UK
- Stichting Epilepsie Instellingen Nederland (SEIN), Achterweg 5, 2103 SW Heemstede, The Netherlands
| | - Annika A de Goede
- Department of Clinical Neurophysiology, MIRA – Institute for Biomedical Technology and Technical Medicine, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - William M Stern
- NIHR University College London Hospitals Biomedical Research Centre, UCL Institute of Neurology, Queen Square, London, WC1N 3BG, UK
- Chalfont Centre for Epilepsy, Chalfont St Peter, SL9 0RJ, UK
| | - Adam D Pawley
- Institute of Psychiatry, Psychology and Neuroscience, King’s College London 16 De Crespigny Park, London, SE5 8AF, UK
| | - Fahmida A Chowdhury
- NIHR University College London Hospitals Biomedical Research Centre, UCL Institute of Neurology, Queen Square, London, WC1N 3BG, UK
- Institute of Psychiatry, Psychology and Neuroscience, King’s College London 16 De Crespigny Park, London, SE5 8AF, UK
| | - Robert M Helling
- Stichting Epilepsie Instellingen Nederland (SEIN), Achterweg 5, 2103 SW Heemstede, The Netherlands
- Image Sciences Institute, University Medical Centre Utrecht, P.O. Box 85500, 3508 GA Utrecht, The Netherlands
| | - Romain Bouet
- Lyon Neuroscience Research Center, INSERM U1028 - CNRS UMR5292, Université Claude Bernard Lyon1, Brain Dynamics and Cognition Team, Centre Hospitalier Le Vinatier (Bât. 452), 95 Bd Pinel, 69500 Bron, France
| | - Stiliyan N Kalitzin
- Stichting Epilepsie Instellingen Nederland (SEIN), Achterweg 5, 2103 SW Heemstede, The Netherlands
- Image Sciences Institute, University Medical Centre Utrecht, P.O. Box 85500, 3508 GA Utrecht, The Netherlands
| | - Gerhard H Visser
- Stichting Epilepsie Instellingen Nederland (SEIN), Achterweg 5, 2103 SW Heemstede, The Netherlands
| | - Sanjay M Sisodiya
- NIHR University College London Hospitals Biomedical Research Centre, UCL Institute of Neurology, Queen Square, London, WC1N 3BG, UK
- Chalfont Centre for Epilepsy, Chalfont St Peter, SL9 0RJ, UK
| | - John C Rothwell
- NIHR University College London Hospitals Biomedical Research Centre, UCL Institute of Neurology, Queen Square, London, WC1N 3BG, UK
| | - Mark P Richardson
- Institute of Psychiatry, Psychology and Neuroscience, King’s College London 16 De Crespigny Park, London, SE5 8AF, UK
| | - Michel J A M van Putten
- Department of Clinical Neurophysiology, MIRA – Institute for Biomedical Technology and Technical Medicine, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
- Department of Clinical Neurophysiology and Neurology, Medisch Spectrum Twente, Koningsplein 1, 7512 KZ Enschede, The Netherlands
| | - Josemir W Sander
- NIHR University College London Hospitals Biomedical Research Centre, UCL Institute of Neurology, Queen Square, London, WC1N 3BG, UK
- Stichting Epilepsie Instellingen Nederland (SEIN), Achterweg 5, 2103 SW Heemstede, The Netherlands
- Chalfont Centre for Epilepsy, Chalfont St Peter, SL9 0RJ, UK
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30
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Coxon JP, Cash RFH, Hendrikse JJ, Rogasch NC, Stavrinos E, Suo C, Yücel M. GABA concentration in sensorimotor cortex following high-intensity exercise and relationship to lactate levels. J Physiol 2017; 596:691-702. [PMID: 29159914 DOI: 10.1113/jp274660] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Accepted: 11/06/2017] [Indexed: 12/13/2022] Open
Abstract
KEY POINTS Magnetic resonance spectroscopy was conducted before and after high-intensity interval exercise. Sensorimotor cortex GABA concentration increased by 20%. The increase was positively correlated with the increase in blood lactate. There was no change in dorsolateral prefrontal cortex. There were no changes in the glutamate-glutamine-glutathione peak. ABSTRACT High-intensity exercise increases the concentration of circulating lactate. Cortical uptake of blood borne lactate increases during and after exercise; however, the potential relationship with changes in the concentration of neurometabolites remains unclear. Although changes in neurometabolite concentration have previously been demonstrated in primary visual cortex after exercise, it remains unknown whether these changes extend to regions such as the sensorimotor cortex (SM) or executive regions such as the dorsolateral prefrontal cortex (DLPFC). In the present study, we explored the acute after-effects of high-intensity interval training (HIIT) on the concentration of gamma-Aminobutyric acid (GABA) and the combined glutamate-glutamine-glutathione (Glx) spectral peak in the SM and DLPFC, as well as the relationship with blood lactate levels. Following HIIT, there was a robust increase in GABA concentration in the SM, as evident across the majority of participants. This change was not observed in the DLPFC. Furthermore, the increase in SM GABA was positively correlated with an increase in blood lactate. There were no changes in Glx concentration in either region. The observed increase in SM GABA concentration implies functional relevance, whereas the correlation with lactate levels may relate to the metabolic fate of exercise-derived lactate that crosses the blood-brain barrier.
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Affiliation(s)
- James P Coxon
- School of Psychological Sciences and Monash Institute of Cognitive and Clinical Neurosciences (MICCN), Monash University, Clayton, VIC, Australia
| | - Robin F H Cash
- Monash Alfred Psychiatry Research Centre, Monash University Central Clinical School and The Alfred, Melbourne, VIC, Australia
| | - Joshua J Hendrikse
- School of Psychological Sciences and Monash Institute of Cognitive and Clinical Neurosciences (MICCN), Monash University, Clayton, VIC, Australia
| | - Nigel C Rogasch
- School of Psychological Sciences and Monash Institute of Cognitive and Clinical Neurosciences (MICCN), Monash University, Clayton, VIC, Australia
| | - Ellen Stavrinos
- School of Psychological Sciences and Monash Institute of Cognitive and Clinical Neurosciences (MICCN), Monash University, Clayton, VIC, Australia
| | - Chao Suo
- School of Psychological Sciences and Monash Institute of Cognitive and Clinical Neurosciences (MICCN), Monash University, Clayton, VIC, Australia
| | - Murat Yücel
- School of Psychological Sciences and Monash Institute of Cognitive and Clinical Neurosciences (MICCN), Monash University, Clayton, VIC, Australia
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31
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Chung SW, Rogasch NC, Hoy KE, Sullivan CM, Cash RFH, Fitzgerald PB. Impact of different intensities of intermittent theta burst stimulation on the cortical properties during TMS-EEG and working memory performance. Hum Brain Mapp 2017; 39:783-802. [PMID: 29124791 DOI: 10.1002/hbm.23882] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Revised: 10/09/2017] [Accepted: 11/02/2017] [Indexed: 02/06/2023] Open
Abstract
Intermittent theta burst stimulation (iTBS) is a noninvasive brain stimulation technique capable of increasing cortical excitability beyond the stimulation period. Due to the rapid induction of modulatory effects, prefrontal application of iTBS is gaining popularity as a therapeutic tool for psychiatric disorders such as depression. In an attempt to increase efficacy, higher than conventional intensities are currently being applied. The assumption that this increases neuromodulatory may be mechanistically false for iTBS. This study examined the influence of intensity on the neurophysiological and behavioural effects of iTBS in the prefrontal cortex. Sixteen healthy participants received iTBS over prefrontal cortex at either 50, 75 or 100% resting motor threshold in separate sessions. Single-pulse TMS and concurrent electroencephalography (EEG) was used to assess changes in cortical reactivity measured as TMS-evoked potentials and oscillations. The n-back task was used to assess changes in working memory performance. The data can be summarised as an inverse U-shape relationship between intensity and iTBS plastic effects, where 75% iTBS yielded the largest neurophysiological changes. Improvement in reaction time in the 3-back task was supported by the change in alpha power, however, comparison between conditions revealed no significant differences. The assumption that higher intensity results in greater neuromodulatory effects may be false, at least in healthy individuals, and should be carefully considered for clinical populations. Neurophysiological changes associated with working memory following iTBS suggest functional relevance. However, the effects of different intensities on behavioural performance remain elusive in the present healthy sample.
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Affiliation(s)
- Sung Wook Chung
- Monash Alfred Psychiatry Research Centre, Monash University, Central Clinical School and The Alfred, Melbourne, Australia
| | - Nigel C Rogasch
- Brain and Mental Health Laboratory, School of Psychological Sciences and Monash Biomedical Imaging, Monash Institute of Cognitive and Clinical Neuroscience, Monash University, Melbourne, Australia
| | - Kate E Hoy
- Monash Alfred Psychiatry Research Centre, Monash University, Central Clinical School and The Alfred, Melbourne, Australia
| | - Caley M Sullivan
- Monash Alfred Psychiatry Research Centre, Monash University, Central Clinical School and The Alfred, Melbourne, Australia
| | - Robin F H Cash
- Monash Alfred Psychiatry Research Centre, Monash University, Central Clinical School and The Alfred, Melbourne, Australia
| | - Paul B Fitzgerald
- Monash Alfred Psychiatry Research Centre, Monash University, Central Clinical School and The Alfred, Melbourne, Australia.,Epworth Clinic, Epworth Healthcare, Camberwell, VIC, Australia
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32
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Di Lazzaro V, Rothwell J, Capogna M. Noninvasive Stimulation of the Human Brain: Activation of Multiple Cortical Circuits. Neuroscientist 2017; 24:246-260. [DOI: 10.1177/1073858417717660] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Noninvasive brain stimulation methods, such as transcranial electric stimulation and transcranial magnetic stimulation are widely used tools for both basic research and clinical applications. However, the cortical circuits underlying their effects are poorly defined. Here we review the current knowledge based on data mostly coming from experiments performed on human subjects, and also to a lesser extent on rodent or primate models. The data suggest that multiple mechanisms are likely to be involved, such as the direct activation of layer V pyramidal neurons, but also of different types of GABAergic interneurons. In this regard, we propose a key role for a specific type of interneuron known as neurogliaform cell.
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Affiliation(s)
- Vincenzo Di Lazzaro
- Unit of Neurology, Neurophysiology, Neurobiology, Department of Medicine, Università Campus Bio-Medico di Roma, Rome, Italy
- Fondazione Alberto Sordi–Research Institute for Ageing, Rome, Italy
| | - John Rothwell
- Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, Queen Square, London, UK
| | - Marco Capogna
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
- The Danish Research Institute of Translational Neuroscience–DANDRITE, Nordic EMBL Partnership for Molecular Medicine, Department of Biomedicine, Aarhus University, Aarhus, Denmark
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33
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Burns E, Chipchase LS, Schabrun SM. Temporal and spatial characteristics of post-silent period electromyographic bursting in low back muscles: comparison between persons with and without low back pain. Int J Neurosci 2017; 127:1074-1081. [DOI: 10.1080/00207454.2017.1326036] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Emma Burns
- Brain Rehabilitation and Neuroplasticity Unit, School of Science and Health, Western Sydney University, Penrith, Australia
| | - Lucy S. Chipchase
- Brain Rehabilitation and Neuroplasticity Unit, School of Science and Health, Western Sydney University, Penrith, Australia
| | - Siobhan M. Schabrun
- Brain Rehabilitation and Neuroplasticity Unit, School of Science and Health, Western Sydney University, Penrith, Australia
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34
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Cash RF, Dar A, Hui J, De Ruiter L, Baarbé J, Fettes P, Peters S, Fitzgerald PB, Downar J, Chen R. Influence of inter-train interval on the plastic effects of rTMS. Brain Stimul 2017; 10:630-636. [DOI: 10.1016/j.brs.2017.02.012] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 02/14/2017] [Accepted: 02/28/2017] [Indexed: 01/16/2023] Open
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35
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Mooney RA, Cirillo J, Byblow WD. GABA and primary motor cortex inhibition in young and older adults: a multimodal reliability study. J Neurophysiol 2017; 118:425-433. [PMID: 28424294 DOI: 10.1152/jn.00199.2017] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Revised: 04/19/2017] [Accepted: 04/19/2017] [Indexed: 12/14/2022] Open
Abstract
The effects of healthy aging on γ-aminobutyric acid (GABA) within primary motor cortex (M1) remain poorly understood. Studies have reported contrasting results, potentially due to limitations with the common assessment technique. The aim of the present study was to investigate the effect of healthy aging on M1 GABA concentration and neurotransmission using a multimodal approach. Fifteen young and sixteen older adults participated in this study. Magnetic resonance spectroscopy (MRS) was used to measure M1 GABA concentration. Single-pulse and threshold-tracking paired-pulse transcranial magnetic stimulation (TMS) protocols were used to examine cortical silent period duration, short- and long-interval intracortical inhibition (SICI and LICI), and late cortical disinhibition (LCD). The reliability of TMS measures was examined with intraclass correlation coefficient analyses. SICI at 1 ms was reduced in older adults (15.13 ± 2.59%) compared with young (25.66 ± 1.44%; P = 0.002). However, there was no age-related effect for cortical silent period duration, SICI at 3 ms, LICI, or LCD (all P > 0.66). The intersession reliability of threshold-tracking measures was good to excellent for both young (range 0.75-0.96) and older adults (range 0.88-0.93). Our findings indicate that extrasynaptic inhibition may be reduced with advancing age, whereas GABA concentration and synaptic inhibition are maintained. Furthermore, MRS and threshold-tracking TMS provide valid and reliable assessment of M1 GABA concentration and neurotransmission, respectively, in young and older adults.NEW & NOTEWORTHY γ-Aminobutyric acid (GABA) in primary motor cortex was assessed in young and older adults using magnetic resonance spectroscopy and threshold-tracking paired-pulse transcranial magnetic stimulation. Older adults exhibited reduced extrasynaptic inhibition (short-interval intracortical inhibition at 1 ms) compared with young, whereas GABA concentration and synaptic inhibition were similar between age groups. We demonstrate that magnetic resonance spectroscopy and threshold-tracking provide valid and reliable assessments of primary motor cortex GABA concentration and neurotransmission, respectively.
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Affiliation(s)
- Ronan A Mooney
- Movement Neuroscience Laboratory, Department of Exercise Sciences, The University of Auckland, New Zealand; and.,Centre for Brain Research, The University of Auckland, New Zealand
| | - John Cirillo
- Movement Neuroscience Laboratory, Department of Exercise Sciences, The University of Auckland, New Zealand; and.,Centre for Brain Research, The University of Auckland, New Zealand
| | - Winston D Byblow
- Movement Neuroscience Laboratory, Department of Exercise Sciences, The University of Auckland, New Zealand; and .,Centre for Brain Research, The University of Auckland, New Zealand
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Chong BWX, Stinear CM. Modulation of motor cortex inhibition during motor imagery. J Neurophysiol 2017; 117:1776-1784. [PMID: 28123007 DOI: 10.1152/jn.00549.2016] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Revised: 01/23/2017] [Accepted: 01/23/2017] [Indexed: 11/22/2022] Open
Abstract
Motor imagery (MI) is similar to overt movement, engaging common neural substrates and facilitating the corticomotor pathway; however, it does not result in excitatory descending motor output. Transcranial magnetic stimulation (TMS) can be used to assess inhibitory networks in the primary motor cortex via measures of 1-ms short-interval intracortical inhibition (SICI), long-interval intracortical inhibition (LICI), and late cortical disinhibition (LCD). These measures are thought to reflect extrasynaptic GABAA tonic inhibition, postsynaptic GABAB inhibition, and presynaptic GABAB disinhibition, respectively. The behavior of 1-ms SICI, LICI, and LCD during MI has not yet been explored. This study aimed to investigate how 1-ms SICI, LICI, and LCD are modulated during MI and voluntary relaxation (VR) of a target muscle. Twenty-five healthy young adults participated. TMS was used to assess nonconditioned motor evoked potential (MEP) amplitude, 1-ms SICI, 100- (LICI100) and 150-ms LICI, and LCD in the right abductor pollicis brevis (APB) and right abductor digiti minimi during rest, MI, and VR of the hand. Compared with rest, MEP amplitudes were facilitated in APB during MI. SICI was not affected by task or muscle. LICI100 decreased in both muscles during VR but not MI, whereas LCD was recruited in both muscles during both tasks. This indicates that VR modulates postsynaptic GABAB inhibition, whereas both tasks modulate presynaptic GABAB inhibition in a non-muscle-specific way. This study highlights further neurophysiological parallels between actual and imagined movement, which may extend to voluntary relaxation.NEW & NOTEWORTHY This is the first study to investigate how 1-ms short-interval intracortical inhibition, long-interval intracortical inhibition, and late cortical disinhibition are modulated during motor imagery and voluntary muscle relaxation. We present novel findings of decreased 100-ms long-interval intracortical inhibition during voluntary muscle relaxation and increased late cortical disinhibition during both motor imagery and voluntary muscle relaxation.
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Affiliation(s)
| | - Cathy M Stinear
- Department of Medicine, University of Auckland, Auckland, New Zealand
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37
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Opie GM, Rogasch NC, Goldsworthy MR, Ridding MC, Semmler JG. Investigating TMS–EEG Indices of Long-Interval Intracortical Inhibition at Different Interstimulus Intervals. Brain Stimul 2017; 10:65-74. [DOI: 10.1016/j.brs.2016.08.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 08/02/2016] [Accepted: 08/06/2016] [Indexed: 10/21/2022] Open
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38
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Modulation of the Direction and Magnitude of Hebbian Plasticity in Human Motor Cortex by Stimulus Intensity and Concurrent Inhibition. Brain Stimul 2017; 10:83-90. [DOI: 10.1016/j.brs.2016.08.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Revised: 08/09/2016] [Accepted: 08/10/2016] [Indexed: 11/18/2022] Open
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39
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Shafi MM, Whitfield-Gabrieli S, Chu CJ, Pascual-Leone A, Chang BS. A Multimodal Imaging- and Stimulation-based Method of Evaluating Connectivity-related Brain Excitability in Patients with Epilepsy. J Vis Exp 2016. [PMID: 27911366 DOI: 10.3791/53727] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Resting-state functional connectivity MRI (rs-fcMRI) is a technique that identifies connectivity between different brain regions based on correlations over time in the blood-oxygenation level dependent signal. rs-fcMRI has been applied extensively to identify abnormalities in brain connectivity in different neurologic and psychiatric diseases. However, the relationship among rs-fcMRI connectivity abnormalities, brain electrophysiology and disease state is unknown, in part because the causal significance of alterations in functional connectivity in disease pathophysiology has not been established. Transcranial Magnetic Stimulation (TMS) is a technique that uses electromagnetic induction to noninvasively produce focal changes in cortical activity. When combined with electroencephalography (EEG), TMS can be used to assess the brain's response to external perturbations. Here we provide a protocol for combining rs-fcMRI, TMS and EEG to assess the physiologic significance of alterations in functional connectivity in patients with neuropsychiatric disease. We provide representative results from a previously published study in which rs-fcMRI was used to identify regions with abnormal connectivity in patients with epilepsy due to a malformation of cortical development, periventricular nodular heterotopia (PNH). Stimulation in patients with epilepsy resulted in abnormal TMS-evoked EEG activity relative to stimulation of the same sites in matched healthy control patients, with an abnormal increase in the late component of the TMS-evoked potential, consistent with cortical hyperexcitability. This abnormality was specific to regions with abnormal resting-state functional connectivity. Electrical source analysis in a subject with previously recorded seizures demonstrated that the origin of the abnormal TMS-evoked activity co-localized with the seizure-onset zone, suggesting the presence of an epileptogenic circuit. These results demonstrate how rs-fcMRI, TMS and EEG can be utilized together to identify and understand the physiological significance of abnormal brain connectivity in human diseases.
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Affiliation(s)
- Mouhsin M Shafi
- Department of Neurology, Harvard Medical School; Department of Neurology, Beth Israel Deaconess Medical Center; Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center;
| | | | - Catherine J Chu
- Department of Neurology, Harvard Medical School; Department of Neurology, Massachusetts General Hospital
| | - Alvaro Pascual-Leone
- Department of Neurology, Harvard Medical School; Department of Neurology, Beth Israel Deaconess Medical Center; Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center
| | - Bernard S Chang
- Department of Neurology, Harvard Medical School; Department of Neurology, Beth Israel Deaconess Medical Center
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Mooney RA, Coxon JP, Cirillo J, Glenny H, Gant N, Byblow WD. Acute aerobic exercise modulates primary motor cortex inhibition. Exp Brain Res 2016; 234:3669-3676. [PMID: 27590480 DOI: 10.1007/s00221-016-4767-5] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2016] [Accepted: 08/27/2016] [Indexed: 11/30/2022]
Abstract
Aerobic exercise can enhance neuroplasticity although presently the neural mechanisms underpinning these benefits remain unclear. One possible mechanism is through effects on primary motor cortex (M1) function via down-regulation of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA). The aim of the present study was to examine how corticomotor excitability (CME) and M1 intracortical inhibition are modulated in response to a single bout of moderate intensity aerobic exercise. Ten healthy right-handed adults were participants. Single- and paired-pulse transcranial magnetic stimulation was applied over left M1 to obtain motor-evoked potentials in the right flexor pollicis brevis. We examined CME, cortical silent period (SP) duration, short- and long-interval intracortical inhibition (SICI, LICI), and late cortical disinhibition (LCD), before and after acute aerobic exercise (exercise session) or an equivalent duration without exercise (control session). Aerobic exercise was performed on a cycle ergometer for 30 min at a workload equivalent to 60 % of maximal cardiorespiratory fitness (VO2 peak; heart rate reserve = 75 ± 3 %, perceived exertion = 13.5 ± 0.7). LICI was reduced at 10 (52 ± 17 %, P = 0.03) and 20 min (27 ± 8 %, P = 0.03) post-exercise compared to baseline (13 ± 4 %). No significant changes in CME, SP duration, SICI or LCD were observed. The present study shows that GABAB-mediated intracortical inhibition may be down-regulated after acute aerobic exercise. The potential effects this may have on M1 plasticity remain to be determined.
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Affiliation(s)
- Ronan A Mooney
- Movement Neuroscience Laboratory, The University of Auckland, Auckland, New Zealand.,Centre for Brain Research, The University of Auckland, Auckland, New Zealand
| | - James P Coxon
- School of Psychological Sciences and Monash Institute of Cognitive and Clinical Neurosciences, Monash University, Melbourne, VIC, Australia.,Centre for Brain Research, The University of Auckland, Auckland, New Zealand
| | - John Cirillo
- Movement Neuroscience Laboratory, The University of Auckland, Auckland, New Zealand.,Centre for Brain Research, The University of Auckland, Auckland, New Zealand
| | - Helen Glenny
- Movement Neuroscience Laboratory, The University of Auckland, Auckland, New Zealand.,Centre for Brain Research, The University of Auckland, Auckland, New Zealand
| | - Nicholas Gant
- Exercise Neurometabolism Laboratory, Department of Exercise Sciences, The University of Auckland, Auckland, New Zealand.,Centre for Brain Research, The University of Auckland, Auckland, New Zealand
| | - Winston D Byblow
- Movement Neuroscience Laboratory, The University of Auckland, Auckland, New Zealand. .,Centre for Brain Research, The University of Auckland, Auckland, New Zealand.
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41
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Cirillo J, Byblow WD. Threshold tracking primary motor cortex inhibition: the influence of current direction. Eur J Neurosci 2016; 44:2614-2621. [DOI: 10.1111/ejn.13369] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Revised: 07/25/2016] [Accepted: 08/05/2016] [Indexed: 01/09/2023]
Affiliation(s)
- John Cirillo
- Movement Neuroscience Laboratory; Department of Exercise Sciences and Centre for Brain Research; University of Auckland; Private Bag 92019 Auckland 1142 New Zealand
| | - Winston D. Byblow
- Movement Neuroscience Laboratory; Department of Exercise Sciences and Centre for Brain Research; University of Auckland; Private Bag 92019 Auckland 1142 New Zealand
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42
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Fedele T, Blagovechtchenski E, Nazarova M, Iscan Z, Moiseeva V, Nikulin VV. Long-Range Temporal Correlations in the amplitude of alpha oscillations predict and reflect strength of intracortical facilitation: Combined TMS and EEG study. Neuroscience 2016; 331:109-19. [DOI: 10.1016/j.neuroscience.2016.06.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Revised: 06/03/2016] [Accepted: 06/09/2016] [Indexed: 12/01/2022]
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43
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Shirota Y, Sommer M, Paulus W. Strength-Duration Relationship in Paired-pulse Transcranial Magnetic Stimulation (TMS) and Its Implications for Repetitive TMS. Brain Stimul 2016; 9:755-761. [PMID: 27234142 DOI: 10.1016/j.brs.2016.04.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 04/25/2016] [Accepted: 04/27/2016] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Paired-pulse protocols have played a pivotal role in neuroscience research using transcranial magnetic stimulation (TMS). Stimulus parameters have been optimized over the years. More recently, pulse width (PW) has been introduced to this field as a new parameter, which may further fine-tune paired-pulse protocols. The relationship between the PW and effectiveness of a stimulus is known as the "strength-duration relationship". OBJECTIVE To test the "strength-duration relationship", so as to improve paired-pulse TMS protocols, and to apply the results to develop new repetitive TMS (rTMS) methods. METHODS Four protocols were investigated separately: short-interval intracortical inhibition (SICI), intracortical facilitation (ICF), short-interval intracortical facilitation (SICF) and long-interval intracortical inhibition (LICI). First, various stimulus parameters were tested to identify those yielding the largest facilitation or inhibition of the motor evoked potential (MEP) in each participant. Using these parameters, paired-pulse stimulations were repeated every five seconds for 30 minutes (repetitive paired-pulse stimulation, rPPS). The after-effects of rPPS were measured using MEP amplitude as an index of motor-cortical excitability. RESULTS Altogether, the effect of changing PW was similar to that of changing the stimulus intensity in the conventional settings. The best parameters were different for each participant. When these parameters were used, rPPS based on either SICF or ICF induced an increase in MEP amplitude. CONCLUSIONS PW was introduced as a new parameter in paired-pulse TMS. Modulation of PW influenced the results of paired-pulse protocols. rPPS using facilitatory protocols can be a good candidate to induce enhancement of motor-cortical excitability.
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Affiliation(s)
- Yuichiro Shirota
- Department of Clinical Neurophysiology, University Medical Center Göttingen, Robert-Koch Straße 40, Göttingen 37075, Germany.
| | - Martin Sommer
- Department of Clinical Neurophysiology, University Medical Center Göttingen, Robert-Koch Straße 40, Göttingen 37075, Germany
| | - Walter Paulus
- Department of Clinical Neurophysiology, University Medical Center Göttingen, Robert-Koch Straße 40, Göttingen 37075, Germany
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44
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Age-related Differences in Pre- and Post-synaptic Motor Cortex Inhibition are Task Dependent. Brain Stimul 2015; 8:926-36. [DOI: 10.1016/j.brs.2015.04.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Revised: 03/23/2015] [Accepted: 04/07/2015] [Indexed: 11/22/2022] Open
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45
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Bocci T, Barloscio D, Vergari M, Di Rollo A, Rossi S, Priori A, Sartucci F. Spinal Direct Current Stimulation Modulates Short Intracortical Inhibition. Neuromodulation 2015; 18:686-93. [DOI: 10.1111/ner.12298] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Revised: 02/09/2015] [Accepted: 02/25/2015] [Indexed: 11/28/2022]
Affiliation(s)
- Tommaso Bocci
- Department of Clinical and Experimental Medicine, Unit of Neurology; Pisa University Medical School; Pisa Italy
- Department of Neurological and Neurosensorial Sciences, Neurology and Clinical Neurophysiology Section, Brain Investigation and Neuromodulation Lab.; Azienda Ospedaliera Universitaria Senese; Siena Italy
| | - Davide Barloscio
- Department of Clinical and Experimental Medicine, Unit of Neurology; Pisa University Medical School; Pisa Italy
| | - Maurizio Vergari
- Department of Neurological Sciences; University of Milan, Fondazione IRCCS Ospedale Maggiore Policlinico; Milan Italy
| | - Andrea Di Rollo
- Department of Clinical and Experimental Medicine, Cisanello Neurology Unit; Azienda Ospedaliera Universitaria Pisana; Pisa Italy
| | - Simone Rossi
- Department of Neurological and Neurosensorial Sciences, Neurology and Clinical Neurophysiology Section, Brain Investigation and Neuromodulation Lab.; Azienda Ospedaliera Universitaria Senese; Siena Italy
| | - Alberto Priori
- Department of Neurological Sciences; University of Milan, Fondazione IRCCS Ospedale Maggiore Policlinico; Milan Italy
| | - Ferdinando Sartucci
- Department of Clinical and Experimental Medicine, Unit of Neurology; Pisa University Medical School; Pisa Italy
- Department of Clinical and Experimental Medicine, Cisanello Neurology Unit; Azienda Ospedaliera Universitaria Pisana; Pisa Italy
- CNR Neuroscience Institute; Pisa Italy
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46
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Caux-Dedeystère A, Derambure P, Devanne H. Late cortical disinhibition in relaxed versus active hand muscles. Neuroscience 2015; 298:52-62. [PMID: 25888934 DOI: 10.1016/j.neuroscience.2015.04.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2015] [Revised: 04/08/2015] [Accepted: 04/09/2015] [Indexed: 10/23/2022]
Abstract
Recent research suggests that long-interval intracortical inhibition (LICI) is followed by a transitory period of late cortical disinhibition (LCD) that can even lead to a net increase in cortical excitability. The relationship between LICI/LCD and voluntary drive remains poorly understood. Our study aims at investigating the influence of index abduction on LICI and LCD in an actively engaged muscle and a neighboring muscle, while varying the intensity of the conditioning stimulus (CS). Motor-evoked potentials (MEPs) were recorded from the first dorsal interosseus (FDI) and abductor digiti minimi (ADM) muscles in 13 subjects. Paired-pulses were delivered with 10 different interstimulus intervals (ranging from 60 to 290 ms). Whatever the condition (relaxed or active FDI), the test stimulus was set to evoke an MEP of 1mV. The time course of conditioned MEP amplitude was compared for relaxed and active conditions when the CS intensity was set to (i) 130% of the rest motor threshold (RMT) or (ii) to evoke the same size of MEP under both conditions. LICI lasted longer (i.e. disinhibition occurred later) at rest than during abduction when evoked either by similar or matched conditioning stimuli. No post-LICI facilitation was observed at rest - even when the CS intensity was set to 160% RMT. In contrast, long-interval intracortical facilitation (LICF) was observed in the quiescent ADM when FDI was active. LICF may then be associated with voluntary activity albeit with lack of topographic specificity.
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Affiliation(s)
- A Caux-Dedeystère
- Université de Lille, Centre Hospitalier Régional Universitaire de Lille, Neurophysiologie Clinique, F-59037 Lille Cedex, France
| | - P Derambure
- Université de Lille, Centre Hospitalier Régional Universitaire de Lille, Neurophysiologie Clinique, F-59037 Lille Cedex, France
| | - H Devanne
- Université de Lille, Centre Hospitalier Régional Universitaire de Lille, Neurophysiologie Clinique, F-59037 Lille Cedex, France; Université du Littoral Côte d'Opale, F-62228 Calais Cedex, France.
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47
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Cash RFH, Isayama R, Gunraj CA, Ni Z, Chen R. The influence of sensory afferent input on local motor cortical excitatory circuitry in humans. J Physiol 2015; 593:1667-84. [PMID: 25832926 PMCID: PMC4386965 DOI: 10.1113/jphysiol.2014.286245] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Accepted: 12/21/2014] [Indexed: 11/08/2022] Open
Abstract
In human, sensorimotor integration can be investigated by combining sensory input and transcranial magnetic stimulation (TMS). Short latency afferent inhibition (SAI) refers to motor cortical inhibition 20-25 ms after median nerve stimulation. We investigated the interaction between SAI and short-interval intracortical facilitation (SICF), an excitatory motor cortical circuit. Seven experiments were performed. Contrary to expectations, SICF was facilitated in the presence of SAI (SICF(SAI)). This effect is specific to SICF since there was no effect at SICF trough 1 when SICF was absent. Furthermore, the facilitatory SICF(SAI) interaction increased with stronger SICF or SAI. SAI and SICF correlated between individuals, and this relationship was maintained when SICF was delivered in the presence of SAI, suggesting an intrinsic relationship between SAI and SICF in sensorimotor integration. The interaction was present at rest and during muscle contraction, had a broad degree of somatotopic influence and was present in different interneuronal SICF circuits induced by posterior-anterior and anterior-posterior current directions. Our results are compatible with the finding that projections from sensory to motor cortex terminate in both superficial layers where late indirect (I-) waves are thought to originate, as well as deeper layers with more direct effect on pyramidal output. This interaction is likely to be relevant to sensorimotor integration and motor control.
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Affiliation(s)
- Robin F H Cash
- Division of Neurology, Department of Medicine, University of Toronto, Division of Brain, Imaging and Behaviour – Systems Neuroscience, Toronto Western Research Institute, University Health NetworkToronto, Ontario, Canada
| | - Reina Isayama
- Division of Neurology, Department of Medicine, University of Toronto, Division of Brain, Imaging and Behaviour – Systems Neuroscience, Toronto Western Research Institute, University Health NetworkToronto, Ontario, Canada
| | - Carolyn A Gunraj
- Division of Neurology, Department of Medicine, University of Toronto, Division of Brain, Imaging and Behaviour – Systems Neuroscience, Toronto Western Research Institute, University Health NetworkToronto, Ontario, Canada
| | - Zhen Ni
- Division of Neurology, Department of Medicine, University of Toronto, Division of Brain, Imaging and Behaviour – Systems Neuroscience, Toronto Western Research Institute, University Health NetworkToronto, Ontario, Canada
| | - Robert Chen
- Division of Neurology, Department of Medicine, University of Toronto, Division of Brain, Imaging and Behaviour – Systems Neuroscience, Toronto Western Research Institute, University Health NetworkToronto, Ontario, Canada
- Corresponding author R. Chen: 13MP-304, 399 Bathurst Street, Toronto, Ontario, M5T 2S8, Canada.
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48
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Opie GM, Ridding MC, Semmler JG. Task-related changes in intracortical inhibition assessed with paired- and triple-pulse transcranial magnetic stimulation. J Neurophysiol 2015; 113:1470-9. [DOI: 10.1152/jn.00651.2014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Recent research has demonstrated a task-related modulation of postsynaptic intracortical inhibition within primary motor cortex for tasks requiring isolated (abduction) or synergistic (precision grip) muscle activation. The current study sought to investigate task-related changes in pre- and postsynaptic intracortical inhibition in motor cortex. In 13 young adults (22.5 ± 3.5 yr), paired-pulse transcranial magnetic stimulation (TMS) was used to measure short (SICI)- and long-interval intracortical inhibition (LICI) (i.e., postsynaptic motor cortex inhibition) in first dorsal interosseous muscle, and triple-pulse TMS was used to investigate changes in SICI-LICI interactions (i.e., presynaptic motor cortex inhibition). These measurements were obtained at rest and during muscle activation involving isolated abduction of the index finger and during a precision grip using the index finger and thumb. SICI was reduced during abduction and precision grip compared with rest, with greater reductions during precision grip. The modulation of LICI during muscle activation depended on the interstimulus interval (ISI; 100 and 150 ms) but was not different between abduction and precision grip. For triple-pulse TMS, SICI was reduced in the presence of LICI at both ISIs in resting muscle (reflecting presynaptic motor cortex inhibition) but was only modulated at the 150-ms ISI during index finger abduction. Results suggest that synergistic contractions are accompanied by greater reductions in postsynaptic motor cortex inhibition than isolated contractions, but the contribution of presynaptic mechanisms to this disinhibition is limited. Furthermore, timing-dependent variations in LICI provide additional evidence that measurements using different ISIs may not represent activation of the same cortical process.
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Affiliation(s)
- George M. Opie
- Discipline of Physiology, School of Medical Sciences, The University of Adelaide, Adelaide, Australia; and
| | - Michael C. Ridding
- Robinson Research Institute, School of Paediatrics and Reproductive Health, The University of Adelaide, Adelaide, Australia
| | - John G. Semmler
- Discipline of Physiology, School of Medical Sciences, The University of Adelaide, Adelaide, Australia; and
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Rogasch NC, Daskalakis ZJ, Fitzgerald PB. Cortical inhibition of distinct mechanisms in the dorsolateral prefrontal cortex is related to working memory performance: A TMS–EEG study. Cortex 2015; 64:68-77. [DOI: 10.1016/j.cortex.2014.10.003] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Revised: 08/23/2014] [Accepted: 10/07/2014] [Indexed: 10/24/2022]
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50
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Rossini PM, Burke D, Chen R, Cohen LG, Daskalakis Z, Di Iorio R, Di Lazzaro V, Ferreri F, Fitzgerald PB, George MS, Hallett M, Lefaucheur JP, Langguth B, Matsumoto H, Miniussi C, Nitsche MA, Pascual-Leone A, Paulus W, Rossi S, Rothwell JC, Siebner HR, Ugawa Y, Walsh V, Ziemann U. Non-invasive electrical and magnetic stimulation of the brain, spinal cord, roots and peripheral nerves: Basic principles and procedures for routine clinical and research application. An updated report from an I.F.C.N. Committee. Clin Neurophysiol 2015; 126:1071-1107. [PMID: 25797650 PMCID: PMC6350257 DOI: 10.1016/j.clinph.2015.02.001] [Citation(s) in RCA: 1736] [Impact Index Per Article: 192.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Revised: 01/22/2015] [Accepted: 02/01/2015] [Indexed: 12/14/2022]
Abstract
These guidelines provide an up-date of previous IFCN report on “Non-invasive electrical and magnetic stimulation of the brain, spinal cord and roots: basic principles and procedures for routine clinical application” (Rossini et al., 1994). A new Committee, composed of international experts, some of whom were in the panel of the 1994 “Report”, was selected to produce a current state-of-the-art review of non-invasive stimulation both for clinical application and research in neuroscience. Since 1994, the international scientific community has seen a rapid increase in non-invasive brain stimulation in studying cognition, brain–behavior relationship and pathophysiology of various neurologic and psychiatric disorders. New paradigms of stimulation and new techniques have been developed. Furthermore, a large number of studies and clinical trials have demonstrated potential therapeutic applications of non-invasive brain stimulation, especially for TMS. Recent guidelines can be found in the literature covering specific aspects of non-invasive brain stimulation, such as safety (Rossi et al., 2009), methodology (Groppa et al., 2012) and therapeutic applications (Lefaucheur et al., 2014). This up-dated review covers theoretical, physiological and practical aspects of non-invasive stimulation of brain, spinal cord, nerve roots and peripheral nerves in the light of more updated knowledge, and include some recent extensions and developments.
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Affiliation(s)
- P M Rossini
- Institute of Neurology, Department of Geriatrics, Neuroscience and Orthopedics, Catholic University, Policlinic A. Gemelli, Rome, Italy
| | - D Burke
- Department of Neurology, Royal Prince Alfred Hospital, University of Sydney, Sydney, Australia
| | - R Chen
- Division of Neurology, Toronto Western Research Institute, University of Toronto, Toronto, Ontario, Canada
| | - L G Cohen
- Human Cortical Physiology and Neurorehabilitation Section, NINDS, NIH, Bethesda, MD, USA
| | - Z Daskalakis
- Temerty Centre for Therapeutic Brain Intervention, Centre for Addiction and Mental Health, University of Toronto, Toronto, Ontario, Canada
| | - R Di Iorio
- Institute of Neurology, Department of Geriatrics, Neuroscience and Orthopedics, Catholic University, Policlinic A. Gemelli, Rome, Italy.
| | - V Di Lazzaro
- Department of Neurology, University Campus Bio-medico, Rome, Italy
| | - F Ferreri
- Department of Neurology, University Campus Bio-medico, Rome, Italy; Department of Clinical Neurophysiology, University of Eastern Finland, Kuopio, Finland
| | - P B Fitzgerald
- Monash Alfred Psychiatry Research Centre, Monash University Central Clinical School and The Alfred, Melbourne, Australia
| | - M S George
- Medical University of South Carolina, Ralph H. Johnson VA Medical Center, Charleston, SC, USA
| | - M Hallett
- Human Motor Control Section, Medical Neurology Branch, NINDS, NIH, Bethesda, MD, USA
| | - J P Lefaucheur
- Department of Physiology, Henri Mondor Hospital, Assistance Publique - Hôpitaux de Paris, Créteil, France; EA 4391, Nerve Excitability and Therapeutic Team, Faculty of Medicine, Paris Est Créteil University, Créteil, France
| | - B Langguth
- Department of Psychiatry and Psychotherapy, University of Regensburg, Regensburg, Germany
| | - H Matsumoto
- Department of Neurology, Japanese Red Cross Medical Center, Tokyo, Japan
| | - C Miniussi
- Department of Clinical and Experimental Sciences University of Brescia, Brescia, Italy; IRCCS Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy
| | - M A Nitsche
- Department of Clinical Neurophysiology, University Medical Center Göttingen, Georg-August-University, Göttingen, Germany
| | - A Pascual-Leone
- Berenson-Allen Center for Non-invasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - W Paulus
- Department of Clinical Neurophysiology, Georg-August University, Göttingen, Germany
| | - S Rossi
- Brain Investigation & Neuromodulation Lab, Unit of Neurology and Clinical Neurophysiology, Department of Neuroscience, University of Siena, Siena, Italy
| | - J C Rothwell
- Institute of Neurology, University College London, London, United Kingdom
| | - H R Siebner
- Department of Neurology, Copenhagen University Hospital Bispebjerg, Copenhagen, Denmark; Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark
| | - Y Ugawa
- Department of Neurology, School of Medicine, Fukushima Medical University, Fukushima, Japan
| | - V Walsh
- Institute of Cognitive Neuroscience, University College London, London, United Kingdom
| | - U Ziemann
- Department of Neurology & Stroke, and Hertie Institute for Clinical Brain Research, Eberhard Karls University, Tübingen, Germany
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