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Marciniak Dg Agra K, Dg Agra P. F = ma. Is the macaque brain Newtonian? Cogn Neuropsychol 2023; 39:376-408. [PMID: 37045793 DOI: 10.1080/02643294.2023.2191843] [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: 04/14/2023]
Abstract
Intuitive Physics, the ability to anticipate how the physical events involving mass objects unfold in time and space, is a central component of intelligent systems. Intuitive physics is a promising tool for gaining insight into mechanisms that generalize across species because both humans and non-human primates are subject to the same physical constraints when engaging with the environment. Physical reasoning abilities are widely present within the animal kingdom, but monkeys, with acute 3D vision and a high level of dexterity, appreciate and manipulate the physical world in much the same way humans do.
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Affiliation(s)
- Karolina Marciniak Dg Agra
- The Rockefeller University, Laboratory of Neural Circuits, New York, NY, USA
- Center for Brain, Minds and Machines, Cambridge, MA, USA
| | - Pedro Dg Agra
- The Rockefeller University, Laboratory of Neural Circuits, New York, NY, USA
- Center for Brain, Minds and Machines, Cambridge, MA, USA
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2
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Song H, Moradi H, Jiang B, Xu K, Wu Y, Taylor RH, Deguet A, Kang JU, Salcudean SE, Boctor EM. Real-time intraoperative surgical guidance system in the da Vinci surgical robot based on transrectal ultrasound/photoacoustic imaging with photoacoustic markers: an ex vivo demonstration. IEEE Robot Autom Lett 2023; 8:1287-1294. [PMID: 37997605 PMCID: PMC10664816 DOI: 10.1109/lra.2022.3191788] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2023]
Abstract
This paper introduces the first integrated real-time intraoperative surgical guidance system, in which an endoscope camera of da Vinci surgical robot and a transrectal ultrasound (TRUS) transducer are co-registered using photoacoustic markers that are detected in both fluorescence (FL) and photoacoustic (PA) imaging. The co-registered system enables the TRUS transducer to track the laser spot illuminated by a pulsed-laser-diode attached to the surgical instrument, providing both FL and PA images of the surgical region-of-interest (ROI). As a result, the generated photoacoustic marker is visualized and localized in the da Vinci endoscopic FL images, and the corresponding tracking can be conducted by rotating the TRUS transducer to display the PA image of the marker. A quantitative evaluation revealed that the average registration and tracking errors were 0.84 mm and 1.16°, respectively. This study shows that the co-registered photoacoustic marker tracking can be effectively deployed intraoperatively using TRUS+PA imaging providing functional guidance of the surgical ROI.
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Affiliation(s)
- Hyunwoo Song
- Department of Computer Science, Whiting School of Engineering, the Johns Hopkins University, Baltimore, MD 21218 USA
| | - Hamid Moradi
- Department of Electrical and Computer Engineering, the University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Baichuan Jiang
- Department of Computer Science, Whiting School of Engineering, the Johns Hopkins University, Baltimore, MD 21218 USA
| | - Keshuai Xu
- Department of Computer Science, Whiting School of Engineering, the Johns Hopkins University, Baltimore, MD 21218 USA
| | - Yixuan Wu
- Department of Computer Science, Whiting School of Engineering, the Johns Hopkins University, Baltimore, MD 21218 USA
| | - Russell H Taylor
- Department of Computer Science, Whiting School of Engineering, the Johns Hopkins University, Baltimore, MD 21218 USA
| | - Anton Deguet
- Department of Computer Science, Whiting School of Engineering, the Johns Hopkins University, Baltimore, MD 21218 USA
| | - Jin U Kang
- Department of Electrical and Computer Engineering, Whiting school of Engineering, the Johns Hopkins University, Baltimore, MD 21211 USA
| | - Septimiu E Salcudean
- Department of Electrical and Computer Engineering, the University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Emad M Boctor
- Department of Computer Science, Whiting School of Engineering, the Johns Hopkins University, Baltimore, MD 21218 USA
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3
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Tomassini A, Laroche J, Emanuele M, Nazzaro G, Petrone N, Fadiga L, D'Ausilio A. Interpersonal synchronization of movement intermittency. iScience 2022; 25:104096. [PMID: 35372806 PMCID: PMC8971945 DOI: 10.1016/j.isci.2022.104096] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 02/02/2022] [Accepted: 03/14/2022] [Indexed: 11/12/2022] Open
Abstract
Most animal species group together and coordinate their behavior in quite sophisticated manners for mating, hunting, or defense purposes. In humans, coordination at a macroscopic level (the pacing of movements) is evident both in daily life (e.g., walking) and skilled (e.g., music and dance) behaviors. By examining the fine structure of movement, we here show that interpersonal coordination is established also at a microscopic – submovement – level. Natural movements appear as marked by recurrent (2–3 Hz) speed breaks, i.e., submovements, that are traditionally considered the result of intermittency in (visuo)motor feedback-based control. In a series of interpersonal coordination tasks, we show that submovements produced by interacting partners are not independent but alternate tightly over time, reflecting online mutual adaptation. These findings unveil a potential core mechanism for behavioral coordination that is based on between-persons synchronization of the intrinsic dynamics of action-perception cycles. Movements show intermittent speed pulses occurring at 2–3 Hz, called submovements Submovements are actively coordinated in counter-phase by interacting partners Submovements coordination depends on spatial alignment but not movement congruency Behavioral coordination occurs both at macro- and microscopic movement scales
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Affiliation(s)
- Alice Tomassini
- Center for Translational Neurophysiology of Speech and Communication (CTNSC), Italian Institute of Technology (IIT), Via Fossato di Mortara, 17-19, 44121 Ferrara, Italy
| | - Julien Laroche
- Center for Translational Neurophysiology of Speech and Communication (CTNSC), Italian Institute of Technology (IIT), Via Fossato di Mortara, 17-19, 44121 Ferrara, Italy
| | - Marco Emanuele
- Center for Translational Neurophysiology of Speech and Communication (CTNSC), Italian Institute of Technology (IIT), Via Fossato di Mortara, 17-19, 44121 Ferrara, Italy.,Department of Neuroscience and Rehabilitation, University of Ferrara, Via Fossato di Mortara, 17-19, 44121 Ferrara, Italy
| | - Giovanni Nazzaro
- Center for Translational Neurophysiology of Speech and Communication (CTNSC), Italian Institute of Technology (IIT), Via Fossato di Mortara, 17-19, 44121 Ferrara, Italy.,Department of Neuroscience and Rehabilitation, University of Ferrara, Via Fossato di Mortara, 17-19, 44121 Ferrara, Italy
| | - Nicola Petrone
- Department of Neuroscience and Rehabilitation, University of Ferrara, Via Fossato di Mortara, 17-19, 44121 Ferrara, Italy
| | - Luciano Fadiga
- Center for Translational Neurophysiology of Speech and Communication (CTNSC), Italian Institute of Technology (IIT), Via Fossato di Mortara, 17-19, 44121 Ferrara, Italy.,Department of Neuroscience and Rehabilitation, University of Ferrara, Via Fossato di Mortara, 17-19, 44121 Ferrara, Italy
| | - Alessandro D'Ausilio
- Center for Translational Neurophysiology of Speech and Communication (CTNSC), Italian Institute of Technology (IIT), Via Fossato di Mortara, 17-19, 44121 Ferrara, Italy.,Department of Neuroscience and Rehabilitation, University of Ferrara, Via Fossato di Mortara, 17-19, 44121 Ferrara, Italy
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4
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Liu W, Fleming A, Lee IC, Huang HH. Direct Myoelectric Control Modifies Lower Limb Functional Connectivity: A Case Study. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2021; 2021:6573-6576. [PMID: 34892615 DOI: 10.1109/embc46164.2021.9630844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Prostheses with direct EMG control could restore amputee's biomechanics structure and residual muscle functions by using efferent signals to drive prosthetic ankle joint movements. Because only feedforward control is restored, it is unclear 1) what neuromuscular control mechanisms are used in coordinating residual and intact muscle activities and 2) how this mechanism changes over guided training with the prosthetic ankle. To address these questions, we applied functional connectivity analysis to an individual with unilateral lower-limb amputation during postural sway task. We built functional connectivity networks of surface EMGs from eleven lower-limb muscles during three sessions to investigate the coupling among different function modules. We observed that functional network was reshaped by training and we identified a stronger connection between residual and intact below knee modules with improved bilateral symmetry after amputee acquired skills to better control the powered prosthetic ankle. The evaluation session showed that functional connectivity was largely preserved even after nine months interval. This preliminary study might inform a unique way to unveil the potential neuromechanic changes that occur after extended training with direct EMG control of a powered prosthetic ankle.
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Lorentzen J, Willerslev-Olsen M, Hüche Larsen H, Farmer SF, Nielsen JB. Maturation of feedforward toe walking motor program is impaired in children with cerebral palsy. Brain 2020; 142:526-541. [PMID: 30726881 DOI: 10.1093/brain/awz002] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 11/02/2018] [Accepted: 11/26/2018] [Indexed: 11/13/2022] Open
Abstract
Voluntary toe walking in adults is characterized by feedforward control of ankle muscles in order to ensure optimal stability of the ankle joint at ground impact. Toe walking is frequently observed in children with cerebral palsy, but the mechanisms involved have not been clarified. Here, we investigated maturation of voluntary toe walking in typically-developing children and typically-developed adults and compared it to involuntary toe walking in children with cerebral palsy. Twenty-eight children with cerebral palsy (age 3-14 years), 24 typically-developing children (age 2-14 years) and 15 adults (mean age 30.7 years) participated in the study. EMG activity was measured from the tibialis anterior and soleus muscles together with knee and ankle joint position during treadmill walking. In typically-developed adults, low step-to-step variability of the drop of the heel after ground impact was correlated with low tibialis anterior and high soleus EMG with no significant coupling between the antagonist muscle EMGs. Typically-developing children showed a significant age-related decline in EMG amplitude reaching an adult level at 10-12 years of age. The youngest typically-developing children showed a broad peak EMG-EMG synchronization (>100 ms) associated with large 5-15 Hz coherence between antagonist muscle activities. EMG coherence declined with age and at the age of 10-12 years no correlation was observed similar to adults. This reduction in coherence was closely related to improved step-to-step stability of the ankle joint position. Children with cerebral palsy generally showed lower EMG levels than typically-developing children and larger step-to-step variability in ankle joint position. In contrast to typically-developing children, children with cerebral palsy showed no age-related decline in tibialis anterior EMG amplitude. Motor unit synchronization and 5-15 Hz coherence between antagonist EMGs was observed more frequently in children with cerebral palsy when compared to typically-developing children and in contrast to typically-developing participants there was no age-related decline. We conclude that typically-developing children develop mature feedforward control of ankle muscle activity as they age, such that at age 10-12 years there is little agonist-antagonist muscle co-contraction around the time of foot-ground contact during toe walking. Children with cerebral palsy, in contrast, continue to co-contract agonist and antagonist ankle muscles when toe walking. We speculate that children with cerebral palsy maintain a co-contraction activation pattern when toe walking due to weak muscles and insufficient motor and sensory signalling necessary for optimization of feedforward motor programs. These findings are important for understanding of the pathophysiology and treatment of toe walking.
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Affiliation(s)
- Jakob Lorentzen
- Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark.,Elsass Institute, Charlottenlund, Denmark
| | - Maria Willerslev-Olsen
- Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark.,Elsass Institute, Charlottenlund, Denmark
| | | | - Simon Francis Farmer
- Department of Clinical and Movement Neuroscience, Institute of Neurology, University College London, London, UK.,Department of Clinical Neurology, National Hospital for Neurology and Neurosurgery, UK
| | - Jens Bo Nielsen
- Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark.,Elsass Institute, Charlottenlund, Denmark
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6
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Coupling between human brain activity and body movements: Insights from non-invasive electromagnetic recordings. Neuroimage 2019; 203:116177. [DOI: 10.1016/j.neuroimage.2019.116177] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 08/28/2019] [Accepted: 09/06/2019] [Indexed: 01/11/2023] Open
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7
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Dione M, Wessberg J. Human 8- to 10-Hz pulsatile motor output during active exploration of textured surfaces reflects the textures’ frictional properties. J Neurophysiol 2019; 122:922-932. [DOI: 10.1152/jn.00756.2018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Active sensing in biological system consists of emitting/receiving a periodic signal to explore the environment. The signal can be emitted toward distant objects, as in echolocation, or in direct contact with the object, for example, whisking in rodents. We explored the hypothesis that a similar mechanism exists in humans. Humans generate periodic signals at ~10 Hz during voluntary finger movements, which reflects a pulsatile motor command in the central nervous system. In the present study, we tested whether the ~10-Hz signal persists during the active exploration of textures and whether the textures’ features can modulate the signal. Our results confirm our assumptions. The ~10-Hz signal persisted during active touch, and its amplitude increased with textures of higher friction. These findings support the idea that the ~10-Hz periodic signal generated during voluntary finger movements is part of an active sensing mechanism acting in a pulse-amplitude modulation fashion to convey relevant tactile information to the brain. NEW & NOTEWORTHY For the first time, we show that pulsatile motor output during voluntary movement of a finger persists during active exploration of a surface. We propose that this is part of an active sensing system in humans, with generation of an ~10-Hz signal during active touch that reinforces extraction of information about features of the touched surface.
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Affiliation(s)
- Mariama Dione
- Department of Physiology, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Johan Wessberg
- Department of Physiology, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
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8
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Guigon E, Chafik O, Jarrassé N, Roby-Brami A. Experimental and theoretical study of velocity fluctuations during slow movements in humans. J Neurophysiol 2019; 121:715-727. [PMID: 30649981 DOI: 10.1152/jn.00576.2018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Moving smoothly is generally considered as a higher-order goal of motor control and moving jerkily as a witness of clumsiness or pathology, yet many common and well-controlled movements (e.g., tracking movements) have irregular velocity profiles with widespread fluctuations. The origin and nature of these fluctuations have been associated with the operation of an intermittent process but in fact remain poorly understood. Here we studied velocity fluctuations during slow movements, using combined experimental and theoretical tools. We recorded arm movement trajectories in a group of healthy participants performing back-and-forth movements at different speeds, and we analyzed velocity profiles in terms of series of segments (portions of velocity between 2 minima). We found that most of the segments were smooth (i.e., corresponding to a biphasic acceleration) and had constant duration irrespective of movement speed and linearly increasing amplitude with movement speed. We accounted for these observations with an optimal feedback control model driven by a staircase goal position signal in the presence of sensory noise. Our study suggests that one and the same control process can explain the production of fast and slow movements, i.e., fast movements emerge from the immediate tracking of a global goal position and slow movements from the successive tracking of intermittently updated intermediate goal positions. NEW & NOTEWORTHY We show in experiments and modeling that slow movements could result from the brain tracking a sequence of via points regularly distributed in time and space. Accordingly, slow movements would differ from fast movement by the nature of the guidance and not by the nature of control. This result could help in understanding the origin and nature of slow and segmented movements frequently observed in brain disorders.
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Affiliation(s)
- Emmanuel Guigon
- Institut des Systèmes Intelligents et de Robotique, CNRS, Sorbonne Université , Paris , France
| | - Oussama Chafik
- Institut des Systèmes Intelligents et de Robotique, CNRS, Sorbonne Université , Paris , France
| | - Nathanaël Jarrassé
- Institut des Systèmes Intelligents et de Robotique, CNRS, Sorbonne Université , Paris , France
| | - Agnès Roby-Brami
- Institut des Systèmes Intelligents et de Robotique, CNRS, Sorbonne Université , Paris , France
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9
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Kerkman JN, Daffertshofer A, Gollo LL, Breakspear M, Boonstra TW. Network structure of the human musculoskeletal system shapes neural interactions on multiple time scales. SCIENCE ADVANCES 2018; 4:eaat0497. [PMID: 29963631 PMCID: PMC6021138 DOI: 10.1126/sciadv.aat0497] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 05/22/2018] [Indexed: 06/02/2023]
Abstract
Human motor control requires the coordination of muscle activity under the anatomical constraints imposed by the musculoskeletal system. Interactions within the central nervous system are fundamental to motor coordination, but the principles governing functional integration remain poorly understood. We used network analysis to investigate the relationship between anatomical and functional connectivity among 36 muscles. Anatomical networks were defined by the physical connections between muscles, and functional networks were based on intermuscular coherence assessed during postural tasks. We found a modular structure of functional networks that was strongly shaped by the anatomical constraints of the musculoskeletal system. Changes in postural tasks were associated with a frequency-dependent reconfiguration of the coupling between functional modules. These findings reveal distinct patterns of functional interactions between muscles involved in flexibly organizing muscle activity during postural control. Our network approach to the motor system offers a unique window into the neural circuitry driving the musculoskeletal system.
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Affiliation(s)
- Jennifer N. Kerkman
- Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam Movement Sciences and Institute for Brain and Behavior, Amsterdam, Netherlands
| | - Andreas Daffertshofer
- Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam Movement Sciences and Institute for Brain and Behavior, Amsterdam, Netherlands
| | - Leonardo L. Gollo
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
- The University of Queensland, St. Lucia, Queensland 4072, Australia
- Queensland University of Technology, 2 George Street, Brisbane, Queensland 4000, Australia
- National Institute for Dementia Research, QIMR Berghofer Medical Research Institute, 300 Herston Road, Brisbane, Queensland 4006, Australia
| | - Michael Breakspear
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
- Metro North Mental Health Service, Brisbane, Queensland, Australia
| | - Tjeerd W. Boonstra
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
- Black Dog Institute, University of New South Wales, Sydney, New South Wales, Australia
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10
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de Vries IEJ, Daffertshofer A, Stegeman DF, Boonstra TW. Functional connectivity in the neuromuscular system underlying bimanual coordination. J Neurophysiol 2016; 116:2576-2585. [PMID: 27628205 DOI: 10.1152/jn.00460.2016] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Accepted: 09/09/2016] [Indexed: 11/22/2022] Open
Abstract
Neural synchrony has been suggested as a mechanism for integrating distributed sensorimotor systems involved in coordinated movement. To test the role of corticomuscular and intermuscular coherence in bimanual coordination, we experimentally manipulated the degree of coordination between hand muscles by varying the sensitivity of the visual feedback to differences in bilateral force. In 16 healthy participants, cortical activity was measured using EEG and muscle activity of the flexor pollicis brevis of both hands using high-density electromyography (HDsEMG). Using the uncontrolled manifold framework, coordination between bilateral forces was quantified by the synergy index RV in the time and frequency domain. Functional connectivity was assessed using corticomuscular coherence between muscle activity and cortical source activity and intermuscular coherence between bilateral EMG activity. The synergy index increased in the high coordination condition. RV was higher in the high coordination condition in frequencies between 0 and 0.5 Hz; for the 0.5- to 2-Hz frequency band, this pattern was inverted. Corticomuscular coherence in the beta band (16-30 Hz) was maximal in the contralateral motor cortex and was reduced in the high coordination condition. In contrast, intermuscular coherence was observed at 5-12 Hz and increased with bimanual coordination. Within-subject comparisons revealed a negative correlation between RV and corticomuscular coherence and a positive correlation between RV and intermuscular coherence. Our findings suggest two distinct neural pathways: 1) corticomuscular coherence reflects direct corticospinal projections involved in controlling individual muscles; and 2) intermuscular coherence reflects diverging pathways involved in the coordination of multiple muscles.
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Affiliation(s)
- Ingmar E J de Vries
- Faculty of Behavioural and Movement Sciences, VU University, Amsterdam, The Netherlands
| | - Andreas Daffertshofer
- Faculty of Behavioural and Movement Sciences, VU University, Amsterdam, The Netherlands
| | - Dick F Stegeman
- Faculty of Behavioural and Movement Sciences, VU University, Amsterdam, The Netherlands.,Donders Institute for Brain, Cognition and Behavior, Radboud University, Nijmegen, The Netherlands
| | - Tjeerd W Boonstra
- Faculty of Behavioural and Movement Sciences, VU University, Amsterdam, The Netherlands; .,Black Dog Institute, University of New South Wales, Sydney, Australia; and.,Systems Neuroscience Group, QIMR Berghofer Medical Research Institute, Brisbane, Australia
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11
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Schmied A, Forget R, Vedel JP. Motor unit firing pattern, synchrony and coherence in a deafferented patient. Front Hum Neurosci 2014; 8:746. [PMID: 25346671 PMCID: PMC4191205 DOI: 10.3389/fnhum.2014.00746] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Accepted: 09/05/2014] [Indexed: 12/11/2022] Open
Abstract
The firing of spinal motoneurons (MNs) is controlled continuously by inputs from muscle, joint and skin receptors. Besides altering MN synaptic drive, the removal of these inputs is liable to alter the synaptic noise and, thus, the variability of their tonic activity. Sensory afferents, which are a major source of common and/or synchronized inputs shared by several MNs, may also contribute to the coupling in the time and frequency domains (synchrony and coherence, respectively) observed when cross-correlation and coherence analyses are applied to the discharges of MN pairs. Surprisingly, no consistent changes in firing frequency, nor in synchrony and coherence were reported to affect the activity of 3 pairs of motor units (MUs) tested in a case of sensory polyradiculoneuropathy (SPRNP), leading to an irreversible loss of large diameter sensory afferents (Farmer et al., 1993). Such a limited sample, however, precludes a definite conclusion about the actual impact that a chronic loss of muscle and cutaneous afferents may have on the firing properties of human MUs. To address this issue, the firing pattern of 92 MU pairs was analyzed at low contraction force in a case of SPRNP leading similarly to a permanent loss of proprioceptive inputs. Compared with 8 control subjects, MNs in this patient tended to discharge with slightly shorter inter-spike intervals but with greater variability. Synchronous firing tended to occur more frequently with a tighter coupling in the patient. There was no consistent change in coherence in the 15–30 Hz frequency range attributed to the MN corticospinal drive, but a greater coherence was observed below 5 Hz and between 30 and 60 Hz in the patient. The possible origins of the greater irregularity in MN tonic discharges, the tighter coupling of the synchronous firing and the changes in coherence observed in the absence of proprioceptive inputs are discussed.
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Affiliation(s)
- Annie Schmied
- National Center for Scientific Research (Centre National de la Recherche Scientifique), Plasticité et Pathophysiologie du Mouvement, Institut de Neuroscience de la Timone, University Aix Marseilles Marseille, France
| | - Robert Forget
- Faculté de Médecine, Ecole de Réadaptation, Centre de Recherche Interdisciplinaire en Réadaptation du Montréal Métropolitain, Institut de Réadaptation Gingras-Lindsay de Montréal, Université de Montréal Montréal, QC, Canada
| | - Jean-Pierre Vedel
- National Center for Scientific Research (Centre National de la Recherche Scientifique), Plasticité et Pathophysiologie du Mouvement, Institut de Neuroscience de la Timone, University Aix Marseilles Marseille, France
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12
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A common structure underlies low-frequency cortical dynamics in movement, sleep, and sedation. Neuron 2014; 83:1185-99. [PMID: 25132467 PMCID: PMC4157580 DOI: 10.1016/j.neuron.2014.07.022] [Citation(s) in RCA: 96] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/14/2014] [Indexed: 12/05/2022]
Abstract
Upper-limb movements are often composed of regular submovements, and neural correlates of submovement frequencies between 1 and 4 Hz have been found in the motor cortex. The temporal profile of movements is usually assumed to be determined by extrinsic factors such as limb biomechanics and feedback delays, but another possibility is that an intrinsic rhythmicity contributes to low frequencies in behavior. We used multielectrode recordings in monkeys performing an isometric movement task to reveal cyclic activity in primary motor cortex locked to submovements, and a distinct oscillation in premotor cortex. During ketamine sedation and natural sleep, cortical activity traversed similar cycles and became synchronized across areas. Because the same cortical dynamics are coupled to submovements and also observed in the absence of behavior, we conclude that the motor networks controlling the upper limb exhibit an intrinsic periodicity at submovement frequencies that is reflected in the speed profile of movements. Local field potentials (LFPs) and neural firing are phase locked to submovements Movement kinematics can be decoded from the areal velocity of LFP trajectories The same dynamic patterns are seen during free reaching, sleep, and sedation An intrinsic periodicity in motor circuits imposes temporal structure on behavior
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13
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Kinematic property of target motion conditions gaze behavior and eye-hand synergy during manual tracking. Hum Mov Sci 2013; 32:1253-69. [PMID: 24054436 DOI: 10.1016/j.humov.2013.03.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2011] [Revised: 12/17/2012] [Accepted: 03/22/2013] [Indexed: 11/22/2022]
Abstract
This study investigated how frequency demand and motion feedback influenced composite ocular movements and eye-hand synergy during manual tracking. Fourteen volunteers conducted slow and fast force-tracking in which targets were displayed in either line-mode or wave-mode to guide manual tracking with target movement of direct position or velocity nature. The results showed that eye-hand synergy was a selective response of spatiotemporal coupling conditional on target rate and feedback mode. Slow and line-mode tracking exhibited stronger eye-hand coupling than fast and wave-mode tracking. Both eye movement and manual action led the target signal during fast-tracking, while the latency of ocular navigation during slow-tracking depended on the feedback mode. Slow-tracking resulted in more saccadic responses and larger pursuit gains than fast-tracking. Line-mode tracking led to larger pursuit gains but fewer and shorter gaze fixations than wave-mode tracking. During slow-tracking, incidences of saccade and gaze fixation fluctuated across a target cycle, peaking at velocity maximum and the maximal curvature of target displacement, respectively. For line-mode tracking, the incidence of smooth pursuit was phase-dependent, peaking at velocity maximum as well. Manual behavior of slow or line-mode tracking was better predicted by composite eye movements than that of fast or wave-mode tracking. In conclusion, manual tracking relied on versatile visual strategies to perceive target movements of different kinematic properties, which suggested a flexible coordinative control for the ocular and manual sensorimotor systems.
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14
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Wells TS, Yang S, Maclachlan RA, Handa JT, Gehlbach P, Riviere C. Comparison of Baseline Tremor Under Various Microsurgical Conditions. CONFERENCE PROCEEDINGS. IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNETICS 2013:1482-1487. [PMID: 24752457 DOI: 10.1109/smc.2013.256] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
This paper presents the characterization and comparison of physiological tremor for pointing tasks in multiple environments, as a baseline for performance evaluation of microsurgical robotics. Previous studies have examined the characteristics of physiological tremor under laboratory settings as well as different operating conditions. However, different test methods make the comparison of results across trials and conditions difficult. Two vitroretinal microsurgeons were evaluated while performing a pointing task with no entry-point constraint, constrained by an artificial eye model, and constrained by a rabbit eye in vivo. For the three respective conditions the 3D RMS positioning error was 144 μm, 258 μm, and 285 μm, and maximum 3D error was 349 μm, 647 μm, and 696 μm. A spectral analysis was also performed, confirming a distinct peak near in the 6-12 Hz frequency range, characteristic of hand tremor during tasks in all three environments.
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Affiliation(s)
- Trent S Wells
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA
| | - Sungwook Yang
- The Robotics Institute, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA
| | - Robert A Maclachlan
- The Robotics Institute, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA
| | - James T Handa
- Wilmer Eye Institute, Johns Hopkins University, Baltimore, Maryland, USA
| | - Peter Gehlbach
- Wilmer Eye Institute, Johns Hopkins University, Baltimore, Maryland, USA
| | - Cameron Riviere
- The Robotics Institute, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA
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15
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Global effect on multi-segment physiological tremors due to localized fatiguing contraction. Eur J Appl Physiol 2011; 112:899-910. [DOI: 10.1007/s00421-011-2044-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2010] [Accepted: 06/07/2011] [Indexed: 10/18/2022]
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16
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Deutsch KM, Stephens JA, Farmer SF. Developmental profile of slow hand movement oscillation coupling in humans. J Neurophysiol 2011; 105:2204-12. [DOI: 10.1152/jn.00695.2010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In adults, slow hand and finger movements are characterized by 6- to 12-Hz discontinuities visible in the raw records and spectra of motion signals such as acceleration. This pulsitile behavior is correlated with motor unit synchronization at 6–12 Hz as shown by significant coherence at these frequencies between pairs of motor units and between the motor units and the acceleration recorded from the limb part controlled by the muscle, suggesting that it has a central origin. In this study, we examined the correlation between this 6- to 12-Hz pulsatile behavior and muscle activity as a function of childhood development. Sixty-eight participants (ages 4–25 yr) performed static wrist extensions against gravity or slow wrist extension and flexion movements while extensor carpi radialis muscle electromyographic (EMG) and wrist acceleration signals were simultaneously recorded. Coherence between EMG and acceleration within the 6- to 12-Hz frequency band was used as an index of the strength of the relation between central drive and the motor output. The main findings of the study are 1) EMG-acceleration coherence increased with increases in age, with the age differences being greater under movement conditions and the difference between conditions increasing with age; 2) the EMG signal showed increases in normalized power with increases in age under both conditions; and 3) coherence under movement conditions was moderately positively correlated with manual dexterity. These findings indicate that the strength of the 6- to 12-Hz central oscillatory drive to the motor output increases through childhood development and may contribute to age-related improvements in motor skills.
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Affiliation(s)
| | | | - Simon F. Farmer
- Department of Physiology, University College London and
- The National Hospital for Neurology and Neurosurgery, London, and
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17
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Bye RT, Neilson PD. The BUMP model of response planning: intermittent predictive control accounts for 10 Hz physiological tremor. Hum Mov Sci 2010; 29:713-36. [PMID: 20674054 DOI: 10.1016/j.humov.2010.01.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2009] [Revised: 12/27/2009] [Accepted: 01/21/2010] [Indexed: 11/25/2022]
Abstract
Physiological tremor during movement is characterized by ∼10 Hz oscillation observed both in the electromyogram activity and in the velocity profile. We propose that this particular rhythm occurs as the direct consequence of a movement response planning system that acts as an intermittent predictive controller operating at discrete intervals of ∼100 ms. The BUMP model of response planning describes such a system. It forms the kernel of Adaptive Model Theory which defines, in computational terms, a basic unit of motor production or BUMP. Each BUMP consists of three processes: (1) analyzing sensory information, (2) planning a desired optimal response, and (3) execution of that response. These processes operate in parallel across successive sequential BUMPs. The response planning process requires a discrete-time interval in which to generate a minimum acceleration trajectory to connect the actual response with the predicted future state of the target and compensate for executional error. We have shown previously that a response planning time of 100 ms accounts for the intermittency observed experimentally in visual tracking studies and for the psychological refractory period observed in double stimulation reaction time studies. We have also shown that simulations of aimed movement, using this same planning interval, reproduce experimentally observed speed-accuracy tradeoffs and movement velocity profiles. Here we show, by means of a simulation study of constant velocity tracking movements, that employing a 100 ms planning interval closely reproduces the measurement discontinuities and power spectra of electromyograms, joint-angles, and angular velocities of physiological tremor reported experimentally. We conclude that intermittent predictive control through sequential operation of BUMPs is a fundamental mechanism of 10 Hz physiological tremor in movement.
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Affiliation(s)
- Robin T Bye
- Neuroengineering Laboratory, School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney 2052, Australia.
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18
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Spinal interneuron circuits reduce approximately 10-Hz movement discontinuities by phase cancellation. Proc Natl Acad Sci U S A 2010; 107:11098-103. [PMID: 20534484 DOI: 10.1073/pnas.0913373107] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Tremor imposes an important limit to the accuracy of fine movements in healthy individuals and can be a disabling feature of neurological disease. Voluntary slow finger movements are not smooth but are characterized by large discontinuities (i.e., steps) in the tremor frequency range (approximately 10 Hz). Previous studies have shown that these discontinuities are coherent with activity in the primary motor cortex (M1), but that other brain areas are probably also involved. We investigated the contribution of three important subcortical areas in two macaque monkeys trained to perform slow finger movements. Local field potential and single-unit activity were recorded from the deep cerebellar nuclei (DCN), medial pontomedullary reticular formation, and the intermediate zone of the spinal cord (SC). Coherence between LFP and acceleration was significant at 6 to 13 Hz for all areas, confirming the highly distributed nature of the central network responsible for this activity. The coherence phase at 6 to 13 Hz for DCN and pontomedullary reticular formation was similar to our previous results in M1. By contrast, for SC the phase differed from M1 by approximately pi rad. Examination of single-unit discharge confirmed that this was a genuine difference in neural spiking and could not be explained by different properties of the local field potential. Convergence of antiphase oscillations from the SC with cortical and subcortical descending inputs will lead to cancellation of approximately 10 Hz oscillations at the motoneuronal level. This could appreciably limit drive to muscle at this frequency, thereby reducing tremor and improving movement precision.
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19
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Schroeder CE, Wilson DA, Radman T, Scharfman H, Lakatos P. Dynamics of Active Sensing and perceptual selection. Curr Opin Neurobiol 2010; 20:172-6. [PMID: 20307966 DOI: 10.1016/j.conb.2010.02.010] [Citation(s) in RCA: 390] [Impact Index Per Article: 27.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2010] [Accepted: 02/23/2010] [Indexed: 11/15/2022]
Abstract
Sensory processing is often regarded as a passive process in which biological receptors like photoreceptors and mechanoreceptors transduce physical energy into a neural code. Recent findings, however, suggest that: first, most sensory processing is active, and largely determined by motor/attentional sampling routines; second, owing to rhythmicity in the motor routine, as well as to its entrainment of ambient rhythms in sensory regions, sensory inflow tends to be rhythmic; third, attentional manipulation of rhythms in sensory pathways is instrumental to perceptual selection. These observations outline the essentials of an Active Sensing paradigm, and argue for increased emphasis on the study of sensory processes as specific to the dynamic motor/attentional context in which inputs are acquired.
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Affiliation(s)
- Charles E Schroeder
- Cognitive Neuroscience and Schizophrenia Program, Nathan Kline Institute for Psychiatric Research, USA.
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20
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21
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Corticomuscular and bilateral EMG coherence reflect distinct aspects of neural synchronization. Neurosci Lett 2009; 463:17-21. [PMID: 19619608 DOI: 10.1016/j.neulet.2009.07.043] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2009] [Revised: 07/01/2009] [Accepted: 07/14/2009] [Indexed: 11/24/2022]
Abstract
Using electroencephalography (EEG) and electromyography (EMG), corticomuscular and bilateral motor unit synchronization have been found in different frequency bands and under different task conditions. These different types of long-range synchrony are hypothesized to originate from distinct mechanisms. We tested this by comparing time-resolved EEG-EMG and EMG-EMG coherence in a bilateral precision-grip task. Bilateral EMG activity was synchronized between 7 and 13Hz for about 1s when force output from both hands changed from an increasing to a stable force production. In contrast, EEG-EMG coherence was statistically significant between 15 and 30Hz during stable force production. The disparities in their time-frequency profiles accord with the existence of distinct underlying processes for corticomuscular and bilateral motor unit synchronization. In addition, the absence of synchronization between cortical activity and common spinal input at 10Hz renders a cortical source unlikely.
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22
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Williams ER, Soteropoulos DS, Baker SN. Coherence between motor cortical activity and peripheral discontinuities during slow finger movements. J Neurophysiol 2009; 102:1296-309. [PMID: 19474171 DOI: 10.1152/jn.90996.2008] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Slow finger movements in man are not smooth, but are characterized by 8- to 12-Hz discontinuities in finger acceleration thought to have a central source. We trained two macaque monkeys to track a moving target by performing index finger flexion/extension movements and recorded local field potentials (LFPs) and spike activity from the primary motor cortex (M1); some cells were identified as pyramidal tract neurons by antidromic activation or as corticomotoneuronal cells by spike-triggered averaging. There was significant coherence between finger acceleration in the approximately 10-Hz range and both LFPs and spikes. LFP-acceleration coherence was similar for flexion and extension movements (0.094 at 9.8 Hz and 0.11 at 6.8 Hz, respectively), but substantially smaller during steady holding (0.0067 at 9.35 Hz). The coherence phase showed a significant linear relationship with frequency over the 6- to 13-Hz range, as expected for a constant conduction delay, but the slope indicated that LFP lagged acceleration by 18 +/- 14 or 36 +/- 8 ms for flexion and extension movements, respectively. Directed coherence analysis supported the conclusion that the dominant interaction was in the acceleration to LFP (i.e., sensory) direction. The phase relationships between finger acceleration and both LFPs and spikes shifted by about pi radians in flexion compared with extension trials. However, for a given trial type the phase relationship with acceleration was similar for cells that increased their firing during flexion or during extension trials. We conclude that movement discontinuities during slow finger movements arise from a reciprocally coupled network, which includes M1 and the periphery.
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Affiliation(s)
- Elizabeth R Williams
- Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, NE2 4HH, United Kingdom
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23
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Wu PS, Lin CCK, Wang CH, Hwang IS. Atypical task-invariant organization of multi-segment tremors in patients with Parkinson's disease during manual tracking. J Electromyogr Kinesiol 2008; 19:e144-53. [PMID: 18255314 DOI: 10.1016/j.jelekin.2007.12.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2007] [Revised: 11/22/2007] [Accepted: 12/16/2007] [Indexed: 10/22/2022] Open
Abstract
The objective of the study was to investigate the interplay between involuntary tremulous activities and task performance under volitional control for patients with Parkinson's disease (PD) during position tracking. A volunteer sample of nine untreated patients and nine age-matched healthy subjects participated in this study. They performed a sinusoidal tracking maneuver with a shoulder and a static pointing task; meanwhile, a position trace of the index and accelerometer data in the upper limb were recorded to characterize tracking performance and postural-kinetic tremors. In reference to postural tremor, the kinetic tremor of control subjects during tracking was considerably modulated, leading to a lower regularity and greater spectral deviation. In contrast, patients with PD demonstrated greater postural and kinetic tremors than control subjects, and tremulous movements of the patients were comparatively task-invariant. The prominent coherence peak, which occurred at 8-12 Hz in control subjects, was atypically presented at 5-8 Hz for PD patients with poorer tracking performance. Functionally, congruency of position tracking was related to amplitude of kinetic tremor after subtracting from amplitude of postural tremor. In conclusion, task-dependent organization of tremulous movements was impaired in patients with PD. The inferior tracking performance of the patients correlated implicitly with kinetic tremor, signifying some sharing of neural substrates for manual tracking and tremor generation.
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Affiliation(s)
- Pei-Shan Wu
- Department of Physical Therapy, Shu-Zen College of Medicine and Management, Lu Chu, Taiwan
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24
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Erimaki S, Christakos CN. Coherent Motor Unit Rhythms in the 6–10 Hz Range During Time-Varying Voluntary Muscle Contractions: Neural Mechanism and Relation to Rhythmical Motor Control. J Neurophysiol 2008; 99:473-83. [PMID: 18057114 DOI: 10.1152/jn.00341.2007] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In quasi-sinusoidal (0.5–3.0 Hz) voluntary muscle contractions, we studied the 6- to 10-Hz motor unit (MU) firing synchrony and muscle force oscillation with emphasis on their neural substrate and relation to rhythmical motor control. Our analyses were performed on data from 121 contractions of a finger muscle in 24 human subjects. They demonstrate that coherent 6- to 10-Hz components of MU discharges coexist with carrier components and coherent modulation components underlying the voluntary force variations. The 6- to 10-Hz synchrony has the frequency of the tremor synchrony in steady contractions and is also widespread and in-phase. Its strength ranges from very small to very large (MU/MU coherence >0.50) among contractions; moreover, it is not related to the contraction parameters, in accord with the notion of a distinct 6- to 10-Hz synaptic input to the MUs. Unlike the coherent MU modulations and the voluntary force variations, the in-phase 6- to 10-Hz MU components are suppressed or even eliminated during ischemia, while the respective force component is drastically reduced. These findings agree with the widely assumed supraspinal origin of the MU modulations, but they also strongly suggest a key role for muscle spindle feedback in the generation of the 6- to 10-Hz synaptic input. They therefore provide important information for the study of generators of the 6- to 10-Hz rhythm which subserves the postulated rhythmical control and is manifested as force and movement components. Moreover, they argue for a participation of oscillating spinal stretch reflex loops in the rhythm generation, possibly in interaction with supraspinal oscillators.
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25
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Serban MC, Dobrea DM. Central physiological tremor oscillators within a hemifield repetitive visual stimulation paradigm. CONFERENCE PROCEEDINGS : ... ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL CONFERENCE 2007; 2006:4478-81. [PMID: 17946247 DOI: 10.1109/iembs.2006.260579] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
In order to analyze the activation pattern of the two putative central tremor oscillators that independently control the right and left hands, two hemifield repetitive visual stimulation tests were employed. The dynamical evolution of the tremor spectral characteristics of both hands was tracked using coherence joint time-frequency analysis. To get reliable spectral estimators for the tremor stochastic process, two non-parametric methods were applied: a Welch periodogram-based method and a multitaper method. In both cases, the results were the same: none significant coherence value could indicate a potential central driving activity.
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26
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Jerbi K, Lachaux JP, N'Diaye K, Pantazis D, Leahy RM, Garnero L, Baillet S. Coherent neural representation of hand speed in humans revealed by MEG imaging. Proc Natl Acad Sci U S A 2007; 104:7676-81. [PMID: 17442753 PMCID: PMC1863498 DOI: 10.1073/pnas.0609632104] [Citation(s) in RCA: 203] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2006] [Indexed: 11/18/2022] Open
Abstract
The spiking activity of single neurons in the primate motor cortex is correlated with various limb movement parameters, including velocity. Recent findings obtained using local field potentials suggest that hand speed may also be encoded in the summed activity of neuronal populations. At this macroscopic level, the motor cortex has also been shown to display synchronized rhythmic activity modulated by motor behavior. Yet whether and how neural oscillations might be related to limb speed control is still poorly understood. Here, we applied magnetoencephalography (MEG) source imaging to the ongoing brain activity in subjects performing a continuous visuomotor (VM) task. We used coherence and phase synchronization to investigate the coupling between the estimated activity throughout the brain and the simultaneously recorded instantaneous hand speed. We found significant phase locking between slow (2- to 5-Hz) oscillatory activity in the contralateral primary motor cortex and time-varying hand speed. In addition, we report long-range task-related coupling between primary motor cortex and multiple brain regions in the same frequency band. The detected large-scale VM network spans several cortical and subcortical areas, including structures of the frontoparietal circuit and the cerebello-thalamo-cortical pathway. These findings suggest a role for slow coherent oscillations in mediating neural representations of hand kinematics in humans and provide further support for the putative role of long-range neural synchronization in large-scale VM integration. Our findings are discussed in the context of corticomotor communication, distributed motor encoding, and possible implications for brain-machine interfaces.
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Affiliation(s)
- Karim Jerbi
- Cognitive Neuroscience and Brain Imaging Laboratory, Centre National de la Recherche Scientifique, UPR-640 Lena, MEG Center, Université Pierre et Marie Curie (Paris 6), Hôpital de la Salpêtrière, 75013 Paris, France.
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27
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Hwang IS, Wu PS. The reorganization of tremulous movements in the upper limb due to finger tracking maneuvers. Eur J Appl Physiol 2006; 98:191-201. [PMID: 16896728 DOI: 10.1007/s00421-006-0262-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/22/2006] [Indexed: 10/24/2022]
Abstract
In light of the interplay between limb oscillatory outputs and the outcome performance of movement effectors, this study was undertaken to investigate neuromotor control in the upper limb during position tracking and posture holding. Sixteen volunteers conducted a postural pointing task and two index tracking maneuvers at 0.3 and 0.6 Hz with an outstretched arm. Limb acceleration in the index finger, hand, forearm, arm, and C7 spinal process were monitored to correlate functionally with the accuracy of index rhythmic displacements. The results showed that index oscillatory activity multiplied with tracking speed, but hand oscillatory activity declined during tracking movement. The tracking maneuvers also altered spectral distribution of the tremulous activities in the context of a lower spectral peak in the range of 8-12 Hz and suppression of spectral peaks at 2-4 Hz, in reference to that already presented in posture tremor. Consisting of three local maxima around 2-4, 8-12, and 18-22 Hz, the coherence of tremulous activity between the finger and hand during position tracking was nearly identical, but inferior to high coherence below 12 Hz during posture holding. Functionally, better tracking performance was associated with a smaller tremulous activity in the finger and hand, entailing sophisticated release of mechanical couplings in the finger-hand and hand-forearm. In conclusion, inversely related to tracking performance, limb tremulous movements were task-dependently organized, and speed-invariant coherence of limb tremulous movement specified an inter-segmental coordination, which is physiological evidence of the generalized motor program for position tracking.
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Affiliation(s)
- Ing-Shiou Hwang
- Department of Physical Therapy, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
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28
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Lang EJ, Sugihara I, Llinás R. Olivocerebellar modulation of motor cortex ability to generate vibrissal movements in rat. J Physiol 2005; 571:101-20. [PMID: 16357010 PMCID: PMC1805652 DOI: 10.1113/jphysiol.2005.102764] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
The vibrissal movements known as whisking are generated in a pulsatile, or non-continuous, fashion and comprise sequences of brief regularly spaced movements. These rhythmic timing sequences imply the existence of periodically issued motor commands. As inferior olivary (IO) neurones generate periodic synchronous discharges that could provide the underlying timing signal, this possibility was tested by determining whether the olivocerebellar system modulates motor cortex (MCtx)-triggered whisker movements in rats. Trains of current pulses were applied to MCtx, and the resulting whisker movements were recorded using a high speed video camera. The evoked movement patterns demonstrated properties consistent with the existence of an oscillatory motor driving rhythm. In particular, movement amplitude showed a bell-shaped dependence on stimulus frequency, with a peak at 11.5+/-2.3 Hz. Moreover, movement trajectories showed harmonic and subharmonic entrainment patterns within specific stimulus frequency ranges. By contrast, movements evoked by facial nerve stimulation showed no such frequency-dependent properties. To test whether the IO was the oscillator in question, IO neuronal properties were modified in vivo by intra-IO picrotoxin injection, which enhances synchronous oscillatory IO activity and reduces its natural frequency. The ensuing changes in the evoked whisker patterns were consistent with these pharmacological effects. Furthermore, in cerebellectomized rats, oscillatory modulation of MCtx-evoked movements was greatly reduced, and intra-IO picrotoxin injections did not affect the evoked movement patterns. Additionally, multielectrode recording of Purkinje cell complex spikes showed a temporal correlation of olivocerebellar activity during MCtx stimulus trains to evoked movement patterns. In sum, the results indicate that MCtx's ability to generate movements is modulated by an oscillatory signal arising in the olivocerebellar system.
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Affiliation(s)
- Eric J Lang
- Department of Physiology and Neuroscience, New York University Medical Center, 550 First Avenue, New York, NY 10016, USA.
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29
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Proudlock FA, Scott J. Tremor in the human hand following peripheral nerve transection and reinnervation. Brain Res 2004; 989:238-45. [PMID: 14556946 DOI: 10.1016/s0006-8993(03)03377-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Slow movements and position holding by the digits are both characterised by 8-10 Hz tremor which appears to be centrally generated. Denervation and subsequent reinnervation lead to significant alterations in peripheral connectivity and reflex organisation. We have tested the hypothesis that 8-10 Hz tremor is present in the digits of subjects following a complete nerve lesion. The frequency content of abduction and adduction movements was recorded in 12 index fingers and nine little fingers reinnervated subsequent to a complete ulnar nerve transection. An optical position laser transducer was used to measure digital movements, minimising mechanical interference to the system. Concurrently, surface electromyograms (EMG) were also recorded from first dorsal interosseus muscles (1DI) and abductor digiti minimi brevis (ADMB) muscles for index and little fingers, respectively. The maximal voluntary contraction (MVC) of the reinnervated muscles varied from 5.9% to 100% of those of the unimpaired, contralateral hands. The subjects performed abduction-adduction movements of the index and little fingers and a position holding task. Significant peaks in PSD curves of acceleration and rectified integrated EMG traces were identified. Tremor in the 8-10 Hz range was evident in both the acceleration and EMG signals for the majority of digits during both the slow movement and position holding tasks. These findings demonstrate the robust nature of these 8-10 Hz oscillations, even following the significant changes in peripheral connectivity of muscle and nerve resulting from nerve transection and reinnervation.
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Affiliation(s)
- Frank A Proudlock
- Department of Ophthalmology, Leicester Royal Infirmary, Leicester, UK
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30
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Evans CMB, Baker SN. Task-dependent intermanual coupling of 8-Hz discontinuities during slow finger movements. Eur J Neurosci 2003; 18:453-6. [PMID: 12887428 DOI: 10.1046/j.1460-9568.2003.02751.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
During slow finger movements, small discontinuities are visible at approximately 8-10 Hz. We have recorded from eight normal subjects whilst they performed index finger flexion-extension movements with the left and right hand. Movements were either performed in-phase (both fingers flexing or extending together), or anti-phase (flexion on one side coinciding with extension on the other). Coherence calculated between left and right finger velocity was significantly above zero at approximately 8 Hz for the in-phase condition, but was significantly smaller for anti-phase movements (mean coherence across all subjects at 8.7 Hz was 0.031 for in-phase, 0.010 for anti-phase). We also calculated a 'phase coherence' measure which, unlike conventional coherence analysis, was sensitive only to phase synchronization and not to amplitude co-variations. For the in-phase task, phase coherence values were smaller than coherence, but still significantly different from zero around 8 Hz; for the anti-phase task, phase coherence was not significant in this band. Measures calculated from EMG recordings yielded similar conclusions to those using finger velocity, indicating that the results were not simply due to mechanical cross-talk. Neural oscillators generating approximately 8-Hz movement discontinuities on each side of the body are therefore selectively coupled during the in-phase task. A wavelet-based analysis further suggested that intermanual coupling modulated during in-phase task performance; coupling was maximal at the start and the end of a movement. We conclude that the systems producing approximately 8-Hz movement discontinuities and those responsible for intermanual coupling are likely to share common neural elements.
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Affiliation(s)
- Clary M B Evans
- Department of Anatomy, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK
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31
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Elble RJ. Chapter 22 Physiologic and enhanced physiologic tremor. HANDBOOK OF CLINICAL NEUROPHYSIOLOGY 2003. [DOI: 10.1016/s1567-4231(09)70170-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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32
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Abstract
Despite the fact that Parkinson's disease (PD) is a relatively common neurological condition, the physiological derangements that result in its clinical features remain unclear. On combining findings from psychophysical, clinical and electrophysiological studies, an overriding theme is proposed that PD deficits are essentially quantitative rather than qualitative in nature. This may arise because the normal function of the basal ganglia is to activate neural processes selectively, providing appropriate diversion of "attentional" resources for decision-making aspects of motor tasks and appropriate "energising" of the executive aspects of such tasks. It is suggested that these concepts of attention, an idea stemming from psychophysical studies, and of energisation, which has derived from kinematic studies, may in fact reflect the same universal process of selective facilitation of particular processes and inhibition of others. In PD, without efficient facilitation, tasks may still be performed but less well than in normal individuals. Possible underlying mechanisms of basal ganglial function are discussed in the context of new findings on direct and indirect pathway actions and the role that oscillatory modulations may play in achieving selective facilitation is explored. Further investigation of disturbances of such mechanisms in PD may prove important in understanding the underlying pathophysiology of the condition.
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Affiliation(s)
- J H McAuley
- Department of Neurology, Royal London Hospital, Whitechapel, London E1 1BB, UK.
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33
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Collins DR, Korsak A, Gilbey MP. Cutaneous sympathetic motor rhythms during a fever-like response induced by prostaglandin E(1). Neuroscience 2002; 110:351-60. [PMID: 11958876 DOI: 10.1016/s0306-4522(01)00572-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Neuronal population discharges within the CNS and in somatic and sympathetic motor nerves often display oscillations. Peripheral oscillations may provide a window into central mechanisms, as they often show coherence with population activity of subsets of central neurones. The reduction in heat loss through the cutaneous circulation during fever may be mediated via sympathetic premotor neurones not utilised during normal temperature regulation. Consequently, here we assessed, in anaesthetised rats, whether the frequency signature of population sympathetic discharge observed in neurones innervating the tail (thermoregulatory) circulation changed during a fever-like response induced by intracerebroventricular injection of prostaglandin E(1). We found that when core temperature was raised to 38.8-40.5 degrees C sympathetic activity was abolished. Following administration of prostaglandin (400 ng or 1 microg per rat), activity was restored to levels seen prior to heating (154+/-53.5%; n=10). Injection of vehicle had no effect (n=7). Prior to heating when most animals were in central apnoea (14/18) two peaks were observed in autospectra of sympathetic activity: one at 0.68-0.93 Hz (T-peak) and another at the frequency of ventilation (2 Hz). Central respiratory drive was recruited during hyperthermia where it was 1:2 locked to the frequency of ventilation and following prostaglandin administration, an additional peak in sympathetic autospectra was seen at this frequency. Time-evolving spectra indicated that this peak resulted from the dynamic locking of the 'T-peak' to central respiratory drive. Our data show that during a fever-like response the dominant oscillations in sympathetic activity controlling a thermoregulatory circulation and their dynamic coupling to respiratory-related inputs are similar to those seen under normal conditions. Therefore, during this fever-like response, the neural substrate(s) underlying the oscillations is not reconfigured and remains capable of sculpturing the pattern of sympathetic neuronal discharge that may be regulated by several descending pathways.
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Affiliation(s)
- D R Collins
- Department of Physiology, Royal Free and University College Medical School, University College London, Royal Free Campus, London NW3 2PF, UK
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Gross J, Tass PA, Salenius S, Hari R, Freund HJ, Schnitzler A. Cortico-muscular synchronization during isometric muscle contraction in humans as revealed by magnetoencephalography. J Physiol 2000; 527 Pt 3:623-31. [PMID: 10990546 PMCID: PMC2270094 DOI: 10.1111/j.1469-7793.2000.00623.x] [Citation(s) in RCA: 233] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Magnetoencephalographic (MEG) and electromyographic (EMG) signals were recorded from six subjects during isometric contraction of four different muscles. Cortical sources were located from the MEG signal which was averaged time-locked to the onset of motor unit potentials. A spatial filtering algorithm was used to estimate the source activity. Sources were found in the primary motor cortex (M1) contralateral to the contracted muscle. Significant coherence between rectified EMG and M1 activity was seen in the 20 Hz frequency range in all subjects. Interactions between the motor cortex and spinal motoneuron pool were investigated by separately studying the non-stationary phase and amplitude dynamics of M1 and EMG signals. Delays between M1 and EMG signals, computed from their phase difference, were found to be in agreement with conduction times from the primary motor cortex to the respective muscle. The time-dependent cortico-muscular phase synchronization was found to be correlated with the time course of both M1 and EMG signals. The findings demonstrate that the coupling between the primary motor cortex and motoneuron pool is at least partly due to phase synchronization of 20 Hz oscillations which varies over time. Furthermore, the consistent phase lag between M1 and EMG signals, compatible with conduction time between M1 and the respective muscle with the M1 activity preceding EMG activity, supports the conjecture that the motor cortex drives the motoneuron pool.
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Affiliation(s)
- J Gross
- Department of Neurology, Heinrich-Heine-University, 40225 Dusseldorf, Germany
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Lakie M, Combes N. There is no simple temporal relationship between the initiation of rapid reactive hand movements and the phase of an enhanced physiological tremor in man. J Physiol 2000; 523 Pt 2:515-22. [PMID: 10699093 PMCID: PMC2269803 DOI: 10.1111/j.1469-7793.2000.t01-2-00515.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
1. A postural hand tremor of enhanced size was induced in eleven subjects. There was rhythmic activity in the posturally active extensor muscles synchronised to the tremor oscillation, which implied an oscillatory modulation of motor neurones. 2. The subjects executed single rapid wrist flexion movements in response to a flash of light. The light flash was presented at an instant when the wrist was spontaneously moving in the flexion direction, extension direction or at random. The time taken to generate a movement was not significantly different or more consistent in any of the conditions. 3. Inspection of individual and averaged acceleration and EMG records strongly suggests that the movement is made at a time that is independent of the tremor cycle at the time of stimulus presentation or at the moment of movement initiation. 4. These observations suggest that the central or spinal mechanism generating tremor does not gate the central mechanism that produces voluntary movement.
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Affiliation(s)
- M Lakie
- School of Sport and Exercise Sciences, University of Birmingham and Queen Elizabeth Hospital Neuroscience Centre, Birmingham, UK.
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Relationship of activity in the subthalamic nucleus-globus pallidus network to cortical electroencephalogram. J Neurosci 2000. [PMID: 10632612 DOI: 10.1523/jneurosci.20-02-00820.2000] [Citation(s) in RCA: 227] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
One of the functions of the excitatory subthalamic nucleus (STN) is to relay cortical activity to other basal ganglia structures. The response of the STN to cortical input is shaped by inhibition from the reciprocally connected globus pallidus (GP). To examine the activity in the STN-GP network in relation to cortical activity, we recorded single and multiple unit activity in STN and/or GP together with cortical electroencephalogram in anesthetized rats during various states of cortical activation. During cortical slow-wave activity (SWA), STN and GP neurons fired bursts of action potentials at frequencies that were similar to those of coincident slow ( approximately 1 Hz) and spindle (7-14 Hz) cortical oscillations. Spontaneous or sensory-driven global activation was associated with a reduction of SWA and a shift in STN-GP activity from burst- to tonic- or irregular-firing. Rhythmic activity in STN and GP neurons was lost when the cortex was inactivated by spreading depression and did not resume until SWA had recovered. Although rhythmic STN-GP activity was correlated with SWA, the phase relationships of activities of neurons within the STN and GP and between the nuclei were variable. Even when neurons displayed synchronous bursting activity, correlations on the millisecond time scale, which might indicate shared synaptic input, were not observed. These data indicate that (1) STN and GP activity is intimately related to cortical activity and hence the sleep-wake cycle; (2) rhythmic oscillatory activity in the STN-GP network in disease states may be driven by the cortex; and (3) activity of the STN-GP network is regulated in space in a complex manner.
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Magill PJ, Bolam JP, Bevan MD. Relationship of activity in the subthalamic nucleus-globus pallidus network to cortical electroencephalogram. J Neurosci 2000; 20:820-33. [PMID: 10632612 PMCID: PMC6772398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/1999] [Revised: 10/11/1999] [Accepted: 10/29/1999] [Indexed: 02/15/2023] Open
Abstract
One of the functions of the excitatory subthalamic nucleus (STN) is to relay cortical activity to other basal ganglia structures. The response of the STN to cortical input is shaped by inhibition from the reciprocally connected globus pallidus (GP). To examine the activity in the STN-GP network in relation to cortical activity, we recorded single and multiple unit activity in STN and/or GP together with cortical electroencephalogram in anesthetized rats during various states of cortical activation. During cortical slow-wave activity (SWA), STN and GP neurons fired bursts of action potentials at frequencies that were similar to those of coincident slow ( approximately 1 Hz) and spindle (7-14 Hz) cortical oscillations. Spontaneous or sensory-driven global activation was associated with a reduction of SWA and a shift in STN-GP activity from burst- to tonic- or irregular-firing. Rhythmic activity in STN and GP neurons was lost when the cortex was inactivated by spreading depression and did not resume until SWA had recovered. Although rhythmic STN-GP activity was correlated with SWA, the phase relationships of activities of neurons within the STN and GP and between the nuclei were variable. Even when neurons displayed synchronous bursting activity, correlations on the millisecond time scale, which might indicate shared synaptic input, were not observed. These data indicate that (1) STN and GP activity is intimately related to cortical activity and hence the sleep-wake cycle; (2) rhythmic oscillatory activity in the STN-GP network in disease states may be driven by the cortex; and (3) activity of the STN-GP network is regulated in space in a complex manner.
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Affiliation(s)
- P J Magill
- Medical Research Council Anatomical Neuropharmacology Unit, University Department of Pharmacology, Oxford, OX1 3TH, United Kingdom
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Kakuda N, Nagaoka M, Wessberg J. Common modulation of motor unit pairs during slow wrist movement in man. J Physiol 1999; 520 Pt 3:929-40. [PMID: 10545155 PMCID: PMC2269633 DOI: 10.1111/j.1469-7793.1999.00929.x] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
1. The activity of 36 pairs of single motor units were recorded with intramuscular wire electrodes from m. extensor carpi radialis while subjects performed slow wrist extension and flexion movements. Periods of steady position holding were interposed between movements. 2. The discharge trains from pairs of motor units were analysed statistically in the time and frequency domains. During extension movements, when the muscle recorded from was the agonist, coherence between motor units was significant below 12 Hz, with a peak at 6-12 Hz in 30 of 36 pairs (83 %). The magnitude of coherence decreased during position holding compared to movements in 26 pairs, while the difference in average firing rate was small. 3. During movements, but not during position holding, coherence estimates between single motor units and acceleration showed a significant peak at 6-12 Hz in 56 out of 62 motor units, suggesting that a modulation of motor unit discharge contributed to angular acceleration at these frequencies. Common motor unit modulation was present at 3 Hz as well, although the coupling between motor unit activity was weaker than at 6-12 Hz. 4. It is concluded that a 6-12 Hz common modulation of agonist motor units is a distinguishing feature of slow voluntary wrist movements, extending the previously established notion of an 8-10 Hz rhythmic organization of slow finger movements to more proximal limb segments. It is suggested that the 6-12 Hz input is specific for movements and is normally absent or much weaker during steady maintenance of position or force.
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Affiliation(s)
- N Kakuda
- Department of Neurology, National Rehabilitation Centre for the Disabled, Tokorozawa, Saitama, Japan.
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Abstract
Corticomuscular coherence measured between electroencephalography (EEG), magnetoencephalography, or local field potentials and electromyography (EMG) should be helpful in understanding the cortical control of movement. EEG-EMG coherence and phase spectra depend on the types of EEG derivation and current source density function of EEG appears to be the most appropriate for computation of EEG-EMG coherence. A new model for the interpretation of the phase spectra ("constant phase shift plus constant time lag model") shows that cortical surface negative potentials are phase-locked to EMG firing. There are functional differences of EEG-EMG coherence among the alpha, beta, and gamma bands suggesting differences in their possible generator mechanisms. Since corticomuscular coherence is a noninvasive measure of corticomotoneuronal function in a specific frequency range, clinical application of this method might be very fruitful in tremor research.
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Affiliation(s)
- T Mima
- Human Motor Control Section, Medical Neurology Branch, National Institutes of Neurological Disorders and Stroke, National Institutes of Health, Bethesda 20892-1428, Maryland, USA
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