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Blazevich AJ, Mesquita RNO, Pinto RS, Pulverenti T, Ratel S. Reduction and recovery of self-sustained muscle activity after fatiguing plantar flexor contractions. Eur J Appl Physiol 2024; 124:1781-1794. [PMID: 38340155 PMCID: PMC11130039 DOI: 10.1007/s00421-023-05403-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Accepted: 12/11/2023] [Indexed: 02/12/2024]
Abstract
PURPOSE Persistent inward calcium and sodium currents (PICs) are crucial for initiation and maintenance of motoneuron firing, and thus muscular force. However, there is a lack of data describing the effects of fatiguing exercise on PIC activity in humans. We simultaneously applied tendon vibration and neuromuscular electrical stimulation (VibStim) before and after fatiguing exercise. VibStim induces self-sustained muscle activity that is proposed to result from PIC activation. METHODS Twelve men performed 5-s maximal isometric plantar flexor contractions (MVC) with 5-s rests until joint torque was reduced to 70%MVC. VibStim trials consisted of five 2-s trains of neuromuscular electrical stimulation (20 Hz, evoking 10% MVC) of triceps surae with simultaneous Achilles tendon vibration (115 Hz) without voluntary muscle activation. VibStim was applied before (PRE), immediately (POST), 5-min (POST-5), and 10-min (POST-10) after exercise completion. RESULTS Sustained torque (Tsust) and soleus electromyogram amplitudes (EMG) measured 3 s after VibStim were reduced (Tsust: -59.0%, p < 0.001; soleus EMG: -38.4%, p < 0.001) but largely recovered by POST-5, and changes in MVC and Tsust were correlated across the four time points (r = 0.69; p < 0.001). After normalisation to values obtained at the end of the vibration phase to control for changes in fibre-specific force and EMG signal characteristics, decreases in Tsust (-42.9%) and soleus EMG (-22.6%) remained significant and were each correlated with loss and recovery of MVC (r = 0.41 and 0.46, respectively). CONCLUSION The parallel changes observed in evoked self-sustained muscle activity and force generation capacity provide motivation for future examinations on the potential influence of fatigue-induced PIC changes on motoneuron output.
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Affiliation(s)
- Anthony J Blazevich
- School of Medical and Health Sciences, Centre for Human Performance, Edith Cowan University, Joondalup, Australia.
| | - Ricardo N O Mesquita
- School of Medical and Health Sciences, Centre for Human Performance, Edith Cowan University, Joondalup, Australia
- Department of Electrical Engineering, Chalmers University of Technology, Gothenburg, Sweden
- Neuroscience Research Australia, Sydney, Australia
| | - Ronei S Pinto
- Exercise Research Laboratory, School of Physical Education, Physiotherapy and Dance, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Timothy Pulverenti
- Department of Physical Therapy, College of Staten Island, Staten Island, NY, USA
| | - Sébastien Ratel
- UFR STAPS - Laboratoire AME2P, Université Clermont Auvergne, Campus Universitaire des Cézeaux, 3 Rue de la Chebarde, 63170, Clermont-Ferrand, France
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2
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Morozumi K, Morishita K, Tojima M, Inomata T. Effect of repetitive peripheral magnetic stimulation of the common fibular nerve on the soleus muscle Hoffmann reflex. J Phys Ther Sci 2024; 36:278-283. [PMID: 38694014 PMCID: PMC11060763 DOI: 10.1589/jpts.36.278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Accepted: 02/08/2024] [Indexed: 05/03/2024] Open
Abstract
[Purpose] This study aimed to investigate the effects of repetitive peripheral magnetic stimulation of the common fibular nerve on the modification of neural circuit function as measured through the soleus muscle Hoffmann reflex. [Participants and Methods] Twenty-four healthy adult males were randomly and equally divided into the magnetic stimulation (experimental) and control groups. The Hoffmann reflex of the soleus muscle was analyzed before and after 10 min of repetitive peripheral magnetic stimulation for the experimental group and before and after 10 min of rest for the control group. The averages of the values for the maximum amplitude and latency of the Hoffman reflex across twenty repetitions were recorded and compared. [Results] The Hoffmann reflex amplitude decreased following stimulation in the experimental group, and significant variations were observed between the experimental and control groups. [Conclusion] The change in the Hoffmann reflex amplitude may have been caused by the magnetic stimulation to I-a sensory fibers on the common fibular nerve, suggesting that magnetic stimulation induces reciprocal inhibition of motor neurons through synapses in the spinal cord.
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Affiliation(s)
- Kazunori Morozumi
- Department of Physical Therapy, School of Health Sciences,
Tokyo International University: 1-13-1 Matobakita, Kawagoe-shi, Saitama 350-1197,
Japan
| | - Katsuyuki Morishita
- Department of Physical Therapy, Faculty of Social Work
Studies, Josai International University, Japan
| | - Michio Tojima
- Department of Physical Therapy, School of Health Sciences,
Tokyo International University: 1-13-1 Matobakita, Kawagoe-shi, Saitama 350-1197,
Japan
| | - Takashi Inomata
- Department of Physical Therapy, School of Health Sciences,
Tokyo International University: 1-13-1 Matobakita, Kawagoe-shi, Saitama 350-1197,
Japan
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Nakagawa K, Kakehata G, Kaneko N, Masugi Y, Osu R, Iso S, Kanosue K, Nakazawa K. Reciprocal inhibition of the thigh muscles in humans: A study using transcutaneous spinal cord stimulation. Physiol Rep 2024; 12:e16039. [PMID: 38740563 DOI: 10.14814/phy2.16039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Revised: 04/11/2024] [Accepted: 04/19/2024] [Indexed: 05/16/2024] Open
Abstract
Evaluating reciprocal inhibition of the thigh muscles is important to investigate the neural circuits of locomotor behaviors. However, measurements of reciprocal inhibition of thigh muscles using spinal reflex, such as H-reflex, have never been systematically established owing to methodological limitations. The present study aimed to clarify the existence of reciprocal inhibition in the thigh muscles using transcutaneous spinal cord stimulation (tSCS). Twenty able-bodied male individuals were enrolled. We evoked spinal reflex from the biceps femoris muscle (BF) by tSCS on the lumber posterior root. We examined whether the tSCS-evoked BF reflex was reciprocally inhibited by the following conditionings: (1) single-pulse electrical stimulation on the femoral nerve innervating the rectus femoris muscle (RF) at various inter-stimulus intervals in the resting condition; (2) voluntary contraction of the RF; and (3) vibration stimulus on the RF. The BF reflex was significantly inhibited when the conditioning electrical stimulation was delivered at 10 and 20 ms prior to tSCS, during voluntary contraction of the RF, and during vibration on the RF. These data suggested a piece of evidence of the existence of reciprocal inhibition from the RF to the BF muscle in humans and highlighted the utility of methods for evaluating reciprocal inhibition of the thigh muscles using tSCS.
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Affiliation(s)
- Kento Nakagawa
- Faculty of Sport Sciences, Waseda University, Tokorozawa, Saitama, Japan
- Faculty of Human Sciences, Waseda University, Tokorozawa, Saitama, Japan
- Department of Sports and Health Management, Faculty of Business and Information Sciences, Jobu University, Isesaki, Gunma, Japan
| | - Gaku Kakehata
- Faculty of Sport Sciences, Waseda University, Tokorozawa, Saitama, Japan
- Graduate School of Arts and Sciences, The University of Tokyo, Meguro-ku, Tokyo, Japan
- Japan Society for the Promotion of Science, Chiyoda-ku, Tokyo, Japan
| | - Naotsugu Kaneko
- Graduate School of Arts and Sciences, The University of Tokyo, Meguro-ku, Tokyo, Japan
| | - Yohei Masugi
- Graduate School of Arts and Sciences, The University of Tokyo, Meguro-ku, Tokyo, Japan
- Department of Physical Therapy, School of Health Sciences, Tokyo International University, Kawagoe, Saitama, Japan
| | - Rieko Osu
- Faculty of Human Sciences, Waseda University, Tokorozawa, Saitama, Japan
| | - Shigeo Iso
- Faculty of Sport Sciences, Waseda University, Tokorozawa, Saitama, Japan
| | - Kazuyuki Kanosue
- Faculty of Sport Sciences, Waseda University, Tokorozawa, Saitama, Japan
- Institute of Health and Sports Science and Medicine, Juntendo University, Inzai, Chiba, Japan
| | - Kimitaka Nakazawa
- Graduate School of Arts and Sciences, The University of Tokyo, Meguro-ku, Tokyo, Japan
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Desmons M, Cherif A, Rohel A, de Oliveira FCL, Mercier C, Massé-Alarie H. Corticomotor Control of Lumbar Erector Spinae in Postural and Voluntary Tasks: The Influence of Transcranial Magnetic Stimulation Current Direction. eNeuro 2024; 11:ENEURO.0454-22.2023. [PMID: 38167617 PMCID: PMC10883751 DOI: 10.1523/eneuro.0454-22.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 11/30/2023] [Accepted: 12/16/2023] [Indexed: 01/05/2024] Open
Abstract
Lumbar erector spinae (LES) contribute to spine postural and voluntary control. Transcranial magnetic stimulation (TMS) preferentially depolarizes different neural circuits depending on the direction of electrical currents evoked in the brain. Posteroanterior current (PA-TMS) and anteroposterior (AP-TMS) current would, respectively, depolarize neurons in the primary motor cortex (M1) and the premotor cortex. These regions may contribute differently to LES control. This study examined whether responses evoked by PA- and AP-TMS are different during the preparation and execution of LES voluntary and postural tasks. Participants performed a reaction time task. A Warning signal indicated to prepare to flex shoulders (postural; n = 15) or to tilt the pelvis (voluntary; n = 13) at the Go signal. Single- and paired-pulse TMS (short-interval intracortical inhibition-SICI) were applied using PA- and AP-TMS before the Warning signal (baseline), between the Warning and Go signals (preparation), or 30 ms before the LES onset (execution). Changes from baseline during preparation and execution were calculated in AP/PA-TMS. In the postural task, MEP amplitude was higher during the execution than that during preparation independently of the current direction (p = 0.0002). In the voluntary task, AP-MEP amplitude was higher during execution than that during preparation (p = 0.016). More PA inhibition (SICI) was observed in execution than that in preparation (p = 0.028). Different neural circuits are preferentially involved in the two motor tasks assessed, as suggested by different patterns of change in execution of the voluntary task (AP-TMS, increase; PA-TMS, no change). Considering that PA-TMS preferentially depolarize neurons in M1, it questions their importance in LES voluntary control.
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Affiliation(s)
- Mikaël Desmons
- Center for Interdisciplinary Research in Rehabilitation and Social Integration (Cirris), CIUSSS de la Capitale-Nationale, Quebec City, Quebec G1M 2S8, Canada
- Rehabilitation Department, University Laval, Quebec City, Quebec G1V 0A6, Canada, G1V 0A6
| | - Amira Cherif
- Center for Interdisciplinary Research in Rehabilitation and Social Integration (Cirris), CIUSSS de la Capitale-Nationale, Quebec City, Quebec G1M 2S8, Canada
- Rehabilitation Department, University Laval, Quebec City, Quebec G1V 0A6, Canada, G1V 0A6
| | - Antoine Rohel
- Center for Interdisciplinary Research in Rehabilitation and Social Integration (Cirris), CIUSSS de la Capitale-Nationale, Quebec City, Quebec G1M 2S8, Canada
- Rehabilitation Department, University Laval, Quebec City, Quebec G1V 0A6, Canada, G1V 0A6
| | - Fábio Carlos Lucas de Oliveira
- Center for Interdisciplinary Research in Rehabilitation and Social Integration (Cirris), CIUSSS de la Capitale-Nationale, Quebec City, Quebec G1M 2S8, Canada
- Rehabilitation Department, University Laval, Quebec City, Quebec G1V 0A6, Canada, G1V 0A6
| | - Catherine Mercier
- Center for Interdisciplinary Research in Rehabilitation and Social Integration (Cirris), CIUSSS de la Capitale-Nationale, Quebec City, Quebec G1M 2S8, Canada
- Rehabilitation Department, University Laval, Quebec City, Quebec G1V 0A6, Canada, G1V 0A6
| | - Hugo Massé-Alarie
- Center for Interdisciplinary Research in Rehabilitation and Social Integration (Cirris), CIUSSS de la Capitale-Nationale, Quebec City, Quebec G1M 2S8, Canada
- Rehabilitation Department, University Laval, Quebec City, Quebec G1V 0A6, Canada, G1V 0A6
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Chen B, Perez MA. Altered regulation of Ia afferent input during voluntary contraction in humans with spinal cord injury. eLife 2022; 11:e80089. [PMID: 36069767 PMCID: PMC9451536 DOI: 10.7554/elife.80089] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Accepted: 07/27/2022] [Indexed: 11/13/2022] Open
Abstract
Sensory input converging on the spinal cord contributes to the control of movement. Although sensory pathways reorganize following spinal cord injury (SCI), the extent to which sensory input from Ia afferents is regulated during voluntary contraction after the injury remains largely unknown. To address this question, the soleus H-reflex and conditioning of the H-reflex by stimulating homonymous [depression of the soleus H-reflex evoked by common peroneal nerve (CPN) stimulation, D1 inhibition] and heteronymous (d), [monosynaptic Ia facilitation of the soleus H-reflex evoked by femoral nerve stimulation (FN facilitation)] nerves were tested at rest, and during tonic voluntary contraction in humans with and without chronic incomplete SCI. The soleus H-reflex size increased in both groups during voluntary contraction compared with rest, but to a lesser extent in SCI participants. Compared with rest, the D1 inhibition decreased during voluntary contraction in controls but it was still present in SCI participants. Further, the FN facilitation increased in controls but remained unchanged in SCI participants during voluntary contraction compared with rest. Changes in the D1 inhibition and FN facilitation were correlated with changes in the H-reflex during voluntary contraction, suggesting an association between outcomes. These findings provide the first demonstration that the regulation of Ia afferent input from homonymous and heteronymous nerves is altered during voluntary contraction in humans with SCI, resulting in lesser facilitatory effect on motor neurons.
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Affiliation(s)
- Bing Chen
- Shirley Ryan AbilityLab, Northwestern University, and Edward Hines Jr., VA Medical CenterChicagoUnited States
| | - Monica A Perez
- Shirley Ryan AbilityLab, Northwestern University, and Edward Hines Jr., VA Medical CenterChicagoUnited States
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Takahashi Y, Kawakami M, Mikami R, Nakajima T, Nagumo T, Yamaguchi T, Honaga K, Kondo K, Ishii R, Fujiwara T, Liu M. Relationship between spinal reflexes and leg motor function in sub-acute and chronic stroke patients. Clin Neurophysiol 2022; 138:74-83. [DOI: 10.1016/j.clinph.2022.02.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 01/27/2022] [Accepted: 02/27/2022] [Indexed: 11/03/2022]
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7
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Effect of repetitive peripheral magnetic stimulation combined with motor imagery on the corticospinal excitability of antagonist muscles. Neuroreport 2021; 32:894-898. [PMID: 34029290 DOI: 10.1097/wnr.0000000000001673] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Repetitive peripheral magnetic stimulation (rPMS) combined with motor imagery facilitates the corticospinal excitability of the agonist muscles. However, the effects of rPMS combined with motor imagery on the corticospinal excitability of the antagonist muscles are unclear. This is an important aspect for applying rPMS in neurorehabilitation for sensorimotor dysfunction. Therefore, we investigated the real-time changes of corticospinal excitability of antagonist muscles during rPMS combined with motor imagery. METHODS Fourteen healthy volunteers underwent four different experimental conditions: rest, rPMS, motor imagery, and rPMS combined with motor imagery (rPMS + motor imagery). In the rPMS and rPMS + motor imagery conditions, rPMS (25 Hz, 1600 ms/train, 1.5× of the motor threshold) was delivered to the dorsal side of the forearm. In motor imagery and rPMS + motor imagery, the participant imagined wrist extension movements. Transcranial magnetic stimulation was delivered to record motor-evoked potentials of the antagonist muscle during experimental interventions. RESULTS The motor-evoked potential (normalized by rest condition) values indicated no difference between rPMS, motor imagery, and rPMS + motor imagery. CONCLUSION These results suggest that rPMS combined with motor imagery has no effect on the corticospinal excitability of the antagonist muscles and highlight the importance of investigating the effects of rPMS combined with motor imagery at the spinal level.
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8
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Interlimb conditioning of lumbosacral spinally evoked motor responses after spinal cord injury. Clin Neurophysiol 2020; 131:1519-1532. [PMID: 32403065 DOI: 10.1016/j.clinph.2020.03.021] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 02/11/2020] [Accepted: 03/06/2020] [Indexed: 11/24/2022]
Abstract
OBJECTIVE The importance of subcortical pathways to functional motor recovery after spinal cord injury (SCI) has been demonstrated in multiple animal models. The current study evaluated descending interlimb influence on lumbosacral motor excitability after chronic SCI in humans. METHODS Ulnar nerve stimulation and transcutaneous electrical spinal stimulation were used in a condition-test paradigm to evaluate the presence of interlimb connections linking the cervical and lumbosacral spinal segments in non-injured (n=15) and spinal cord injured (SCI) (n=18) participants. RESULTS Potentiation of spinally evoked motor responses (sEMRs) by ulnar nerve conditioning was observed in 7/7 SCI participants with volitional leg muscle activation, and in 6/11 SCI participants with no volitional activation. Of these six, conditioning of sEMRs was present only when the neurological level of injury was rostral to the ulnar innervation entry zones. CONCLUSIONS Descending modulation of lumbosacral motor pools via interlimb projections may exist in SCI participants despite the absence of volitional leg muscle activation. SIGNIFICANCE Evaluation of sub-clinical, spared pathways within the spinal cord after SCI may provide an improved understanding of both the contributions of different pathways to residual function, and the mechanisms of plasticity and functional motor recovery following rehabilitation..
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9
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Vasanthan LT, Nehrujee A, Solomon J, Tilak M. Electrical stimulation for people with spinal cord injury. Hippokratia 2019. [DOI: 10.1002/14651858.cd013481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Lenny T Vasanthan
- Christian Medical College; Physiotherapy Unit, Department of Physical Medicine and Rehabilitation; Vellore Tamil Nadu India
| | - Arun Nehrujee
- New York University; Department of Physical Therapy; New York USA
| | - John Solomon
- MCOAHS, Manipal University; Department of Physiotherapy; 2nd Floor, AHS building Madhav Nagar Manipal India 576104
| | - Merlyn Tilak
- Christian Medical College; Physiotherapy Unit, Department of Physical Medicine and Rehabilitation; Vellore Tamil Nadu India
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10
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Effects of repetitive passive movement on ankle joint on spinal reciprocal inhibition. Exp Brain Res 2019; 237:3409-3417. [DOI: 10.1007/s00221-019-05689-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Accepted: 11/07/2019] [Indexed: 10/25/2022]
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11
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Noble S, Pearcey GEP, Quartly C, Zehr EP. Robot controlled, continuous passive movement of the ankle reduces spinal cord excitability in participants with spasticity: a pilot study. Exp Brain Res 2019; 237:3207-3220. [PMID: 31599345 PMCID: PMC6882765 DOI: 10.1007/s00221-019-05662-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 09/28/2019] [Indexed: 02/06/2023]
Abstract
Spasticity of the ankle reduces quality of life by impeding walking and other activities of daily living. Robot-driven continuous passive movement (CPM) is a strategy for lower limb spasticity management but effects on spasticity, walking ability and spinal cord excitability (SCE) are unknown. The objectives of this experiment were to evaluate (1) acute changes in SCE induced by 30 min of CPM at the ankle joint, in individuals without neurological impairment and those with lower limb spasticity; and, (2) the effects of 6 weeks of CPM training on SCE, spasticity and walking ability in those with lower limb spasticity. SCE was assessed using soleus Hoffmann (H-) reflexes, collected prior to and immediately after CPM for acute assessments, whereas a multiple baseline repeated measures design assessed changes following 18 CPM sessions. Spasticity and walking ability were assessed using the Modified Ashworth Scale, the 10 m Walk test, and the Timed Up and Go test. Twenty-one neurologically intact and nine participants with spasticity (various neurological conditions) were recruited. In the neurologically intact group, CPM caused bi-directional modulation of H-reflexes creating 'facilitation' and 'suppression' groups. In contrast, amongst participants with spasticity, acute CPM facilitated H-reflexes. After CPM training, H-reflex excitability on both the more-affected and less-affected sides was reduced; on the more affected side H@Thres, H@50 and H@100 all significantly decreased following CPM training by 96.5 ± 7.7%, 90.9 ± 9.2%, and 62.9 ± 21.1%, respectively. After training there were modest improvements in walking and clinical measures of spasticity for some participants. We conclude that CPM of the ankle can significantly alter SCE. The use of CPM in those with spasticity can provide a temporary period of improved walking, but efficacy of treatment remains unknown.
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Affiliation(s)
- Steven Noble
- Rehabilitation Neuroscience Laboratory, University of Victoria, PO Box 3010 STN CSC, Victoria, BC, V8W 3P1, Canada.,Human Discovery Science, International Collaboration on Repair Discoveries (ICORD), Vancouver, BC, Canada.,Centre for Biomedical Research, University of Victoria, Victoria, BC, Canada
| | - Gregory E P Pearcey
- Rehabilitation Neuroscience Laboratory, University of Victoria, PO Box 3010 STN CSC, Victoria, BC, V8W 3P1, Canada.,Human Discovery Science, International Collaboration on Repair Discoveries (ICORD), Vancouver, BC, Canada.,Centre for Biomedical Research, University of Victoria, Victoria, BC, Canada
| | - Caroline Quartly
- Collaborative Spasticity Program, Queen Alexandra Hospital, Vancouver Island Health Authority, Victoria, BC, Canada
| | - E Paul Zehr
- Rehabilitation Neuroscience Laboratory, University of Victoria, PO Box 3010 STN CSC, Victoria, BC, V8W 3P1, Canada. .,Human Discovery Science, International Collaboration on Repair Discoveries (ICORD), Vancouver, BC, Canada. .,Centre for Biomedical Research, University of Victoria, Victoria, BC, Canada. .,Division of Medical Sciences, University of Victoria, Victoria, BC, Canada. .,Zanshin Consulting Inc., Victoria, BC, Canada.
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Kurz A, Leukel C. Excitability of Upper Layer Circuits Relates to Torque Output in Humans. Front Hum Neurosci 2019; 13:359. [PMID: 31649520 PMCID: PMC6794348 DOI: 10.3389/fnhum.2019.00359] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 09/26/2019] [Indexed: 01/08/2023] Open
Abstract
The relation between primary motor cortex (M1) activity and (muscular) force output has been studied extensively. Results from previous studies indicate that activity of a part of yet unidentified neurons in M1 are positively correlated with increased force levels. One considerable candidate causing this positive correlation could be circuits at supragranular layers. Here we tested this hypothesis and used the combination of H-reflexes with transcranial magnetic stimulation (TMS) to investigate laminar associations with force output in human subjects. Excitability of different M1 circuits were probed at movement onset and at peak torque while participants performed auxotonic contractions of the wrist with different torque levels. Only at peak torque we found a significant positive correlation between excitability of M1 circuits most likely involving neurons at supragranular layers and joint torque level. We argue that this finding may relate to the special role of upper layer circuits in integrating (force-related) afferent feedback and their connectivity with task-relevant pyramidal and also extrapyramidal pathways projecting to motoneurones in the spinal cord.
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Affiliation(s)
- Alexander Kurz
- Department of Sport Science, University of Freiburg, Freiburg, Germany.,Bernstein Center Freiburg, University of Freiburg, Freiburg, Germany
| | - Christian Leukel
- Department of Sport Science, University of Freiburg, Freiburg, Germany.,Bernstein Center Freiburg, University of Freiburg, Freiburg, Germany
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13
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Mason J, Howatson G, Frazer AK, Pearce AJ, Jaberzadeh S, Avela J, Kidgell DJ. Modulation of intracortical inhibition and excitation in agonist and antagonist muscles following acute strength training. Eur J Appl Physiol 2019; 119:2185-2199. [DOI: 10.1007/s00421-019-04203-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 07/31/2019] [Indexed: 10/26/2022]
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14
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Unilateral hamstrings static stretching can impair the affected and contralateral knee extension force but improve unilateral drop jump height. Eur J Appl Physiol 2019; 119:1943-1949. [DOI: 10.1007/s00421-019-04182-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Accepted: 06/19/2019] [Indexed: 10/26/2022]
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15
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Kurz A, Xu W, Wiegel P, Leukel C, N. Baker S. Non-invasive assessment of superficial and deep layer circuits in human motor cortex. J Physiol 2019; 597:2975-2991. [PMID: 31045242 PMCID: PMC6636705 DOI: 10.1113/jp277849] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 05/01/2019] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS The first indirect (I) corticospinal volley from stimulation of the motor cortex consists of two parts: one that originates from infragranular layer 5 and a subsequent part with a delay of 0.6 ms to which supragranular layers contribute. Non-invasive probing of these two parts was performed in humans using a refined electrophysiological method involving transcranial magnetic stimulation and peripheral nerve stimulation. Activity modulation of these two parts during a sensorimotor discrimination task was consistent with previous results in monkeys obtained with laminar recordings. ABSTRACT Circuits in superficial and deep layers play distinct roles in cortical computation, but current methods to study them in humans are limited. Here, we developed a novel approach for non-invasive assessment of layer-specific activity in the human motor cortex. We first conducted brain slice and in vivo experiments on monkey motor cortex to investigate the output timing from layer 5 (including corticospinal neurons) following extracellular stimulation. Neuron responses contained cyclical waves. The first wave was composed of two parts: the earliest part originated only from stimulation of layer 5; after 0.6 ms, stimuli to superficial layers 2/3 could also contribute. In healthy humans we then assessed different parts of the first corticospinal volley elicited by transcranial magnetic stimulation (TMS), by interacting TMS with stimulation of the median nerve generating an H-reflex. By adjusting the delay between stimuli, we could assess the earliest volley evoked by TMS, and the part 0.6 ms later. Measurements were made while subjects performed a visuo-motor discrimination task, which has been previously shown in monkey to modulate superficial motor cortical cells selectively depending on task difficulty. We showed a similar selective modulation of the later part of the TMS volley, as expected if this part of the volley is sensitive to superficial cortical excitability. We conclude that it is possible to segregate different cortical circuits which may refer to different motor cortex layers in humans, by exploiting small time differences in the corticospinal volleys evoked by non-invasive stimulation.
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Affiliation(s)
- Alexander Kurz
- Department of Sport ScienceUniversity of FreiburgFreiburg79117Germany
- Bernstein Center FreiburgUniversity of FreiburgFreiburg79104Germany
| | - Wei Xu
- Medical SchoolInstitute of NeuroscienceNewcastle UniversityNewcastle upon TyneNE2 4HHUK
| | - Patrick Wiegel
- Department of Sport ScienceUniversity of FreiburgFreiburg79117Germany
- Bernstein Center FreiburgUniversity of FreiburgFreiburg79104Germany
| | - Christian Leukel
- Department of Sport ScienceUniversity of FreiburgFreiburg79117Germany
- Bernstein Center FreiburgUniversity of FreiburgFreiburg79104Germany
| | - Stuart N. Baker
- Medical SchoolInstitute of NeuroscienceNewcastle UniversityNewcastle upon TyneNE2 4HHUK
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Spinal reciprocal inhibition in the co-contraction of the lower leg depends on muscle activity ratio. Exp Brain Res 2019; 237:1469-1478. [DOI: 10.1007/s00221-019-05523-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Accepted: 03/16/2019] [Indexed: 10/27/2022]
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17
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Takahashi Y, Kawakami M, Yamaguchi T, Idogawa Y, Tanabe S, Kondo K, Liu M. Effects of Leg Motor Imagery Combined With Electrical Stimulation on Plasticity of Corticospinal Excitability and Spinal Reciprocal Inhibition. Front Neurosci 2019; 13:149. [PMID: 30846928 PMCID: PMC6393385 DOI: 10.3389/fnins.2019.00149] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 02/08/2019] [Indexed: 12/14/2022] Open
Abstract
Motor imagery (MI) combined with electrical stimulation (ES) enhances upper-limb corticospinal excitability. However, its after-effects on both lower limb corticospinal excitability and spinal reciprocal inhibition remain unknown. We aimed to investigate the effects of MI combined with peripheral nerve ES (MI + ES) on the plasticity of lower limb corticospinal excitability and spinal reciprocal inhibition. Seventeen healthy individuals performed the following three tasks on different days, in a random order: (1) MI alone; (2) ES alone; and (3) MI + ES. The MI task consisted of repetitive right ankle dorsiflexion for 20 min. ES was percutaneously applied to the common peroneal nerve at a frequency of 100 Hz and intensity of 120% of the sensory threshold of the tibialis anterior (TA) muscle. We examined changes in motor-evoked potential (MEP) of the TA (task-related muscle) and soleus muscle (SOL; task-unrelated muscle). We also examined disynaptic reciprocal inhibition before, immediately after, and 10, 20, and 30 min after the task. MI + ES significantly increased TA MEPs immediately and 10 min after the task compared with baseline, but did not change the task-unrelated muscle (SOL) MEPs. MI + ES resulted in a significant increase in the magnitude of reciprocal inhibition immediately and 10 min after the task compared with baseline. MI and ES alone did not affect TA MEPs or reciprocal inhibition. MI combined with ES is effective in inducing plastic changes in lower limb corticospinal excitability and reciprocal Ia inhibition.
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Affiliation(s)
- Yoko Takahashi
- Department of Rehabilitation Medicine, Keio University School of Medicine, Tokyo, Japan.,Tokyo Bay Rehabilitation Hospital, Chiba, Japan
| | - Michiyuki Kawakami
- Department of Rehabilitation Medicine, Keio University School of Medicine, Tokyo, Japan
| | - Tomofumi Yamaguchi
- Department of Rehabilitation Medicine, Keio University School of Medicine, Tokyo, Japan.,Department of Physical Therapy, Yamagata Prefectural University of Health Sciences, Yamagata, Japan
| | | | - Shigeo Tanabe
- Faculty of Rehabilitation, School of Health Sciences, Fujita Health University, Toyoake, Japan
| | | | - Meigen Liu
- Department of Rehabilitation Medicine, Keio University School of Medicine, Tokyo, Japan
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18
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Hirabayashi R, Edama M, Kojima S, Nakamura M, Ito W, Nakamura E, Kikumoto T, Onishi H. Effects of Reciprocal Ia Inhibition on Contraction Intensity of Co-contraction. Front Hum Neurosci 2019; 12:527. [PMID: 30687045 PMCID: PMC6336824 DOI: 10.3389/fnhum.2018.00527] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Accepted: 12/13/2018] [Indexed: 11/13/2022] Open
Abstract
Introduction: Excessive co-contraction interferes with smooth joint movement. One mechanism is the failure of reciprocal inhibition against antagonists during joint movement. Reciprocal inhibition has been investigated using joint torque as an index of intensity during co-contraction. However, contraction intensity as an index of co-contraction intensity has not been investigated. In this study, we aimed to evaluate the influence of changes in contraction intensity during co-contraction on reciprocal inhibition. Methods: We established eight stimulus conditions in 20 healthy adult males to investigate the influence of changes in contraction intensity during co-contraction on reciprocal inhibition. These stimulus conditions comprised a conditioning stimulus-test stimulation interval (C–T interval) of -2, 0, 1, 2, 3, 4, or 5 ms plus a test stimulus without a conditioning stimulus (single). Co-contraction of the tibialis anterior and soleus muscles at the same as contraction intensity was examined at rest and at 5, 15, and 30% maximal voluntary contraction (MVC). Results: At 5 and 15% MVC in the co-contraction task, the H-reflex amplitude was significantly decreased compared with single stimulation at a 2-ms C–T interval. At 30% MVC, there was no significant difference compared with single stimulation at a 2-ms C–T interval. At a 5-ms C–T interval, the H-reflex amplitude at 30% MVC was significantly reduced compared with that at rest. Discussion: The findings indicated that during co-contraction, reciprocal Ia inhibition worked at 5 and 15% MVC. Contrary inhibition of reciprocal Ia inhibition did not apparently work at 30% MVC, and presynaptic inhibition (D1 inhibition) might work.
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Affiliation(s)
- Ryo Hirabayashi
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan
| | - Mutsuaki Edama
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan
| | - Sho Kojima
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan
| | - Masatoshi Nakamura
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan
| | - Wataru Ito
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan
| | - Emi Nakamura
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan
| | - Takanori Kikumoto
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan
| | - Hideaki Onishi
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan
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19
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Avrillon S, Hug F, Guilhem G. Between-muscle differences in coactivation assessed using elastography. J Electromyogr Kinesiol 2018; 43:88-94. [DOI: 10.1016/j.jelekin.2018.09.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 09/11/2018] [Accepted: 09/20/2018] [Indexed: 01/03/2023] Open
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20
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Impaired Ability to Suppress Excitability of Antagonist Motoneurons at Onset of Dorsiflexion in Adults with Cerebral Palsy. Neural Plast 2018; 2018:1265143. [PMID: 30402086 PMCID: PMC6198563 DOI: 10.1155/2018/1265143] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Revised: 09/14/2018] [Accepted: 09/19/2018] [Indexed: 11/17/2022] Open
Abstract
We recently showed that impaired gait function in adults with cerebral palsy (CP) is associated with reduced rate of force development in ankle dorsiflexors. Here, we explore potential mechanisms. We investigated the suppression of antagonist excitability, calculated as the amount of soleus H-reflex depression at the onset of ankle dorsiflexion compared to rest, in 24 adults with CP (34.3 years, range 18–57; GMFCS 1.95, range 1–3) and 15 healthy, age-matched controls. Furthermore, the central common drive to dorsiflexor motoneurons during a static contraction in the two groups was examined by coherence analyses. The H-reflex was significantly reduced by 37% at the onset of dorsiflexion compared to rest in healthy adults (P < 0.001) but unchanged in adults with CP (P = 0.91). Also, the adults with CP had significantly less coherence. These findings suggest that the ability to suppress antagonist motoneuronal excitability at movement onset is impaired and that the central common drive during static contractions is reduced in adults with CP.
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21
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Takahashi Y, Fujiwara T, Yamaguchi T, Matsunaga H, Kawakami M, Honaga K, Mizuno K, Liu M. Voluntary contraction enhances spinal reciprocal inhibition induced by patterned electrical stimulation in patients with stroke. Restor Neurol Neurosci 2018; 36:99-105. [PMID: 29439361 DOI: 10.3233/rnn-170759] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Reciprocal inhibition (RI) may be important for recovering locomotion after stroke. Patterned electrical stimulation (PES) can modulate RI in a manner that could be enhanced by voluntary muscle contraction (VC). OBJECTIVE To investigate whether VC enhances the PES-induced spinal RI in patients with stroke. METHODS Twelve patients with chronic stroke underwent three 20 min tasks, each on different days: (1) PES (10 pulses, 100 Hz every 2 s) applied to the common peroneal nerve; (2) VC consisting of isometric contraction of the affected-side tibialis anterior muscle; (3) PES combined with VC (PES + VC). RI from the tibialis anterior to the soleus muscle was assessed before, immediately after, and 10, 20, and 30 min after the task. RESULTS Compared to the baseline, PES + VC significantly increased the changes in reciprocal inhibition at immediately after and 10 min after the task. PES alone significantly increased this change immediately after the task, while VC alone showed no significant increase. CONCLUSION VC enhanced the PES-induced plastic changes in RI in patients with stroke. This effect can potentially increase the success rate of newer neurorehabilitative approaches in achieving functional recovery after stroke.
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Affiliation(s)
- Yoko Takahashi
- Department of Rehabilitation Medicine, Keio University School of Medicine, Tokyo, Japan.,Tokyo Bay Rehabilitation Hospital, Chiba, Japan
| | - Toshiyuki Fujiwara
- Department of Rehabilitation Medicine, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Tomofumi Yamaguchi
- Department of Rehabilitation Medicine, Keio University School of Medicine, Tokyo, Japan.,Department of Physical Therapy, Yamagata Prefectural University of Health Sciences, Yamagata, Japan.,JSPS Overseas Research Fellow.,Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark
| | | | - Michiyuki Kawakami
- Department of Rehabilitation Medicine, Keio University School of Medicine, Tokyo, Japan
| | - Kaoru Honaga
- Department of Rehabilitation Medicine, Keio University School of Medicine, Tokyo, Japan.,Tokyo Bay Rehabilitation Hospital, Chiba, Japan
| | - Katsuhiro Mizuno
- Department of Rehabilitation Medicine, Keio University School of Medicine, Tokyo, Japan
| | - Meigen Liu
- Department of Rehabilitation Medicine, Keio University School of Medicine, Tokyo, Japan
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22
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Acute whole-body vibration increases reciprocal inhibition. Hum Mov Sci 2018; 60:191-201. [DOI: 10.1016/j.humov.2018.06.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 06/12/2018] [Accepted: 06/14/2018] [Indexed: 11/23/2022]
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23
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Sun Y, Zehr EP. Effects of wrist position on reciprocal inhibition and cutaneous reflex amplitudes in forearm muscles. Neurosci Lett 2018; 677:37-43. [PMID: 29684529 DOI: 10.1016/j.neulet.2018.04.031] [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] [Received: 02/23/2018] [Revised: 04/03/2018] [Accepted: 04/16/2018] [Indexed: 01/03/2023]
Abstract
In the leg, amplitudes of cutaneous reflexes and reciprocal inhibition are significantly affected by joint and limb position. Comparatively little is known about such modulation in the arm. In this study, amplitudes of reciprocal inhibition (from median nerve stimulation near elbow) and cutaneous reflexes (from median or superficial radial nerve stimulation at the wrist) were measured in forearm muscle extensor carpi radialis with the hand pronated or neutral during graded voluntary activation. Significant correlations with muscle activation were found for reciprocal inhibition and cutaneous reflex amplitudes at both positions. Only cutaneous reflexes from superficial radial nerve were modulated by wrist position. This study reveals that effect of limb position is nerve-specific in cutaneous reflexes and not significant on reciprocal inhibition in the arm. This has implications for measurement and study design in those who have mobility and motor activation challenges (e.g. neurotrauma) that affect hand function.
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Affiliation(s)
- Yao Sun
- Rehabilitation Neuroscience Laboratory, University of Victoria, Victoria, BC, Canada; Human Discovery Science, International Collaboration on Repair Discoveries (ICORD), Vancouver, BC, Canada; Centre for Biomedical Research, University of Victoria, Victoria, BC, Canada
| | - E Paul Zehr
- Rehabilitation Neuroscience Laboratory, University of Victoria, Victoria, BC, Canada; Human Discovery Science, International Collaboration on Repair Discoveries (ICORD), Vancouver, BC, Canada; Centre for Biomedical Research, University of Victoria, Victoria, BC, Canada; Division of Medical Sciences, University of Victoria, Victoria, BC, Canada.
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24
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McComas A, deBruin H, Fu W. Quantitative input-output relationships between human soleus muscle spindle afferents and motoneurons. J Neurophysiol 2018; 119:887-893. [PMID: 29187549 DOI: 10.1152/jn.00273.2017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
A method is described that, for the first time, allows instantaneous estimation of the Ia fiber input to human soleus motoneurons following electrical stimulation of the tibial nerve. The basis of the method is to determine the thresholds of the most and least excitable 1a fibers to electrical stimulation, and to treat the intervening thresholds as having a normal distribution about the mean; the validity of this approach is discussed. It was found that, for the same Ia fiber input, the percentage of soleus motoneurons contributing to the H (Hoffmann)-reflex differed considerably among subjects; when the results were pooled, however, there was an approximately linear relationship between Ia input and motoneuron output. Weak extension of the great toe diminished the soleus motoneuron reflex discharge in all but 2 of 16 subjects; the results for weak ankle plantarflexion were less consistent, but overall, there was a reduction in soleus motoneuron output also. The methodology should provide new insights into disorders of movement and tone, especially as it permits estimates of motoneuron depolarization to be made. NEW & NOTEWORTHY Assuming a normal distribution of Ia fiber thresholds to electrical stimulation and using the H-reflex, we determined for the first time an Ia input-α-motoneuron output relationship for the human soleus muscle. The relationship varies greatly among subjects but, overall, is approximately linear. Minimal contraction of a toe muscle alters the relationship dramatically, probably due to presynaptic inhibition of Ia fibers. Drawing on the literature, we can calculate changes in α-motoneuron membrane potential.
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Affiliation(s)
- Alan McComas
- Department of Medicine, McMaster University , Hamilton, Ontario , Canada
| | - Hubert deBruin
- Department of Electrical and Computer Engineering, McMaster University , Hamilton, Ontario , Canada
| | - Winnie Fu
- Department of Electrical and Computer Engineering, McMaster University , Hamilton, Ontario , Canada
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25
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The effects of patterned electrical stimulation combined with voluntary contraction on spinal reciprocal inhibition in healthy individuals. Neuroreport 2018; 28:434-438. [PMID: 28383320 DOI: 10.1097/wnr.0000000000000777] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The aim of this study was to examine the effects of voluntary contraction (VC) on the modulation of reciprocal inhibition induced by patterned electrical stimulation (PES) in healthy individuals. Twelve healthy volunteers participated in this study. PES was applied to the common peroneal nerve with a train of 10 pulses at 100 Hz every 2 s for 20 min. VC comprised repetitive ankle dorsiflexion at a frequency of 0.5 Hz for 20 min. All participants performed the following three tasks: (i) VC alone, (ii) PES alone, and (iii) PES combined with VC (PES+VC). Reciprocal inhibition was assessed using a soleus H-reflex conditioning-test paradigm at the time points of before, immediately after, 10 min after, 20 min after, and 30 min after the tasks. PES+VC increased the amount of reciprocal inhibition, with after-effects lasting up to 20 min. PES alone increased reciprocal inhibition and maintained the after-effects on reciprocal inhibition for 10 min, whereas VC alone increased only immediately after the task. VC could modulate the plastic changes in spinal reciprocal inhibition induced by PES in healthy individuals. PES combined with VC has a potential to modulate impaired reciprocal inhibition and it may facilitate functional recovery and improve locomotion after central nervous system lesions.
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26
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Anticipatory Inhibition of EMG Activity of the Human M. Soleus at Voluntary Contraction of Its Antagonists. NEUROPHYSIOLOGY+ 2018. [DOI: 10.1007/s11062-018-9714-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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27
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How plastic are human spinal cord motor circuitries? Exp Brain Res 2017; 235:3243-3249. [PMID: 28776155 DOI: 10.1007/s00221-017-5037-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 07/17/2017] [Indexed: 12/27/2022]
Abstract
Human and animal studies have documented that neural circuitries in the spinal cord show adaptive changes caused by altered supraspinal and/or afferent input to the spinal circuitry in relation to learning, immobilization, injury and neurorehabilitation. Reversible adaptations following, e.g. the acquisition or refinement of a motor skill rely heavily on the functional integration between supraspinal and sensory inputs to the spinal cord networks. Accordingly, what is frequently conceived as a change in the spinal circuitry may be a change in either descending or afferent input or in the relative integration of these, i.e. a change in the neuronal weighting. This is evident from findings documenting only task-specific functional changes after periods of altered inputs whereas resting responses remain unaffected. In fact, the proximity of the spinal circuitry to the outer world may demand a more rigid organization compared to the highly flexible cortical circuits. The understanding of all of this is important for the planning and execution of neurorehabilitation.
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28
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Geertsen SS, Willerslev-Olsen M, Lorentzen J, Nielsen JB. Development and aging of human spinal cord circuitries. J Neurophysiol 2017; 118:1133-1140. [PMID: 28566459 DOI: 10.1152/jn.00103.2017] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Revised: 05/25/2017] [Accepted: 05/25/2017] [Indexed: 01/25/2023] Open
Abstract
The neural motor circuitries in the spinal cord receive information from our senses and the rest of the nervous system and translate it into purposeful movements, which allow us to interact with the rest of the world. In this review, we discuss how these circuitries are established during early development and the extent to which they are shaped according to the demands of the body that they control and the environment with which the body has to interact. We also discuss how aging processes and physiological changes in our body are reflected in adaptations of activity in the spinal cord motor circuitries. The complex, multifaceted connectivity of the spinal cord motor circuitries allows them to generate vastly different movements and to adapt their activity to meet new challenges imposed by bodily changes or a changing environment. There are thus plenty of possibilities for adaptive changes in the spinal motor circuitries both early and late in life.
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Affiliation(s)
- Svend Sparre Geertsen
- Neural Control of Movement Research Group, Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen N, Denmark.,Department of Nutrition, Exercise, and Sports, University of Copenhagen, Copenhagen N, Denmark; and
| | - Maria Willerslev-Olsen
- Neural Control of Movement Research Group, Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen N, Denmark.,Elsass Institute, Charlottenlund, Denmark
| | - Jakob Lorentzen
- Neural Control of Movement Research Group, Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen N, Denmark.,Elsass Institute, Charlottenlund, Denmark
| | - Jens Bo Nielsen
- Neural Control of Movement Research Group, Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen N, Denmark; .,Elsass Institute, Charlottenlund, Denmark
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29
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Wu R, Delahunt E, Ditroilo M, Lowery M, De Vito G. Effects of age and sex on neuromuscular-mechanical determinants of muscle strength. AGE (DORDRECHT, NETHERLANDS) 2016; 38:57. [PMID: 27189591 PMCID: PMC5005921 DOI: 10.1007/s11357-016-9921-2] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 05/08/2016] [Indexed: 05/20/2023]
Abstract
The aim of this study was to concurrently assess the effect of age on neuromuscular and mechanical properties in 24 young (23.6 ± 3.7 years) and 20 older (66.5 ± 3.8 years) healthy males and females. Maximal strength of knee extensors (KE) and flexors (KF), contractile rate of torque development (RTD) and neural activation of agonist-antagonist muscles (surface EMG) were examined during maximal voluntary isometric contraction (MVIC). Tissue stiffness (i.e. musculo-articular stiffness (MAS) and muscle stiffness (MS)) was examined via the free-oscillation technique, whereas muscle architecture (MA) of the vastus lateralis and subcutaneous fat were measured by ultrasonography. Males exhibited a greater age-related decline for KE (47.4 %) and KF (53.1 %) MVIC, and RTD (60.4 %) when compared to females (32.9, 42.6 and 34.0 %, respectively). Neural activation of agonist muscles during KE MVIC falls markedly with ageing; however, no age and sex effects were observed in the antagonist co-activation. MAS and MS were lower in elderly compared with young participants and in females compared with males. Regarding MA, main effects for age (young 23.0 ± 3.3 vs older 19.5 ± 2.0 mm) and sex (males 22.4 ± 3.5 vs females 20.4 ± 2.7 mm) were detected in muscle thickness. For fascicle length, there was an effect of age (young 104.6 ± 8.8 vs older 89.8 ± 10.5 mm), while for pennation angle, there was an effect of sex (males 13.3 ± 2.4 vs females 11.5 ± 1.7°). These findings suggest that both neuromuscular and mechanical declines are important contributors to the age-related loss of muscle strength/function but with some peculiar sex-related differences.
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Affiliation(s)
- Rui Wu
- School of Public Health, Physiotherapy and Sports Science, University College Dublin, Dublin, Republic of Ireland.
| | - Eamonn Delahunt
- School of Public Health, Physiotherapy and Sports Science, University College Dublin, Dublin, Republic of Ireland
- Institute for Sport and Health, University College Dublin, Dublin, Republic of Ireland
| | - Massimiliano Ditroilo
- School of Public Health, Physiotherapy and Sports Science, University College Dublin, Dublin, Republic of Ireland
- Institute for Sport and Health, University College Dublin, Dublin, Republic of Ireland
| | - Madeleine Lowery
- School of Electrical, Electronic and Communications Engineering, University College Dublin, Dublin, Republic of Ireland
| | - Giuseppe De Vito
- School of Public Health, Physiotherapy and Sports Science, University College Dublin, Dublin, Republic of Ireland
- Institute for Sport and Health, University College Dublin, Dublin, Republic of Ireland
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30
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Abstract
Human studies in the past three decades have provided us with an emerging understanding of how cortical and spinal networks collaborate to ensure the vast repertoire of human behaviors. Humans have direct cortical connections to spinal motoneurons, which bypass spinal interneurons and exert a direct (willful) muscle control with the aid of a context-dependent integration of somatosensory and visual information at cortical level. However, spinal networks also play an important role. Sensory feedback through spinal circuitries is integrated with central motor commands and contributes importantly to the muscle activity underlying voluntary movements. Regulation of spinal interneurons is used to switch between motor states such as locomotion (reciprocal innervation) and stance (coactivation pattern). Cortical regulation of presynaptic inhibition of sensory afferents may focus the central motor command by opening or closing sensory feedback pathways. In the future, human studies of spinal motor control, in close collaboration with animal studies on the molecular biology of the spinal cord, will continue to document the neural basis for human behavior.
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Affiliation(s)
- Jens Bo Nielsen
- Department of Neuroscience and Pharmacology and Department of Nutrition, Exercise and Sports, University of Copenhagen, DK-2200 Copenhagen N, Denmark;
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31
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Mori N, Horino H, Matsugi A, Kamata N, Hiraoka K. Tonic suppression of the soleus H-reflex during rhythmic movement of the contralateral ankle. J Phys Ther Sci 2015; 27:1287-90. [PMID: 26157202 PMCID: PMC4483380 DOI: 10.1589/jpts.27.1287] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 01/11/2015] [Indexed: 11/24/2022] Open
Abstract
[Purpose] We investigated the effect of rhythmic ankle movement on the contralateral
soleus H-reflex. The H-reflex was evoked from the right soleus muscle. [Subjects and
Methods] Healthy humans rhythmically moved the left ankle (movement condition) or held the
left ankle stationary (stationary condition) at one of three positions corresponding to
the ankle positions at which the H-reflex was evoked in the movement condition. The
background electromyographic amplitude in the right soleus muscle was maintained at 10% of
the maximum voluntary contraction level, and that in the right tibialis anterior muscle
was matched between the stationary and movement conditions. [Results] The soleus H-reflex
was suppressed throughout all phases of contralateral rhythmic ankle movement.
[Conclusion] Rhythmic movement of the contralateral joint suppresses the H-reflex in the
muscle that is the prime mover of the joint homologous to the rhythmically moving joint.
This inhibitory mechanism may be activated during unilateral rhythmic movement to isolate
the motor control of the moving ankle from that of the contralateral stationary ankle.
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Affiliation(s)
- Nobuhiko Mori
- Graduate School of Comprehensive Rehabilitation, Osaka Prefecture University, Japan
| | - Hiroshi Horino
- Graduate School of Comprehensive Rehabilitation, Osaka Prefecture University, Japan
| | - Akiyoshi Matsugi
- Graduate School of Comprehensive Rehabilitation, Osaka Prefecture University, Japan
| | - Noriyuki Kamata
- Graduate School of Comprehensive Rehabilitation, Osaka Prefecture University, Japan
| | - Koichi Hiraoka
- College of Health and Human Sciences, Osaka Prefecture University, Japan
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32
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Hanna-Boutros B, Sangari S, Giboin LS, El Mendili MM, Lackmy-Vallée A, Marchand-Pauvert V, Knikou M. Corticospinal and reciprocal inhibition actions on human soleus motoneuron activity during standing and walking. Physiol Rep 2015; 3:3/2/e12276. [PMID: 25825912 PMCID: PMC4393188 DOI: 10.14814/phy2.12276] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Reciprocal Ia inhibition constitutes a key segmental neuronal pathway for coordination of antagonist muscles. In this study, we investigated the soleus H-reflex and reciprocal inhibition exerted from flexor group Ia afferents on soleus motoneurons during standing and walking in 15 healthy subjects following transcranial magnetic stimulation (TMS). The effects of separate TMS or deep peroneal nerve (DPN) stimulation and the effects of combined (TMS + DPN) stimuli on the soleus H-reflex were assessed during standing and at mid- and late stance phases of walking. Subthreshold TMS induced short-latency facilitation on the soleus H-reflex that was present during standing and at midstance but not at late stance of walking. Reciprocal inhibition was increased during standing and at late stance but not at the midstance phase of walking. The effects of combined TMS and DPN stimuli on the soleus H-reflex significantly changed between tasks, resulting in an extra facilitation of the soleus H-reflex during standing and not during walking. Our findings indicate that corticospinal inputs and Ia inhibitory interneurons interact at the spinal level in a task-dependent manner, and that corticospinal modulation of reciprocal Ia inhibition is stronger during standing than during walking.
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Affiliation(s)
- Berthe Hanna-Boutros
- Sorbonne Universités, UPMC Univ Paris 06, UMR 7371, UMR_S 1146, LIB, Paris, France CNRS, UMR 7371, LIB, Paris, France INSERM, UMR_S 1146, LIB, Paris, France
| | - Sina Sangari
- Sorbonne Universités, UPMC Univ Paris 06, UMR 7371, UMR_S 1146, LIB, Paris, France CNRS, UMR 7371, LIB, Paris, France INSERM, UMR_S 1146, LIB, Paris, France
| | - Louis-Solal Giboin
- Sensorimotor Performance Laboratory, Konstanz University, Konstanz, Germany
| | - Mohamed-Mounir El Mendili
- Sorbonne Universités, UPMC Univ Paris 06, UMR 7371, UMR_S 1146, LIB, Paris, France CNRS, UMR 7371, LIB, Paris, France INSERM, UMR_S 1146, LIB, Paris, France
| | - Alexandra Lackmy-Vallée
- Sorbonne Universités, UPMC Univ Paris 06, UMR 7371, UMR_S 1146, LIB, Paris, France CNRS, UMR 7371, LIB, Paris, France INSERM, UMR_S 1146, LIB, Paris, France
| | - Véronique Marchand-Pauvert
- Sorbonne Universités, UPMC Univ Paris 06, UMR 7371, UMR_S 1146, LIB, Paris, France CNRS, UMR 7371, LIB, Paris, France INSERM, UMR_S 1146, LIB, Paris, France
| | - Maria Knikou
- The Graduate Center, City University of New York, New York, New York Sensory Motor Performance Program, Rehabilitation Institute of Chicago, Chicago, Illinois Department of Physical Medicine and Rehabilitation, Northwestern University Feinberg School of Medicine, Chicago, Illinois
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Holmes MR, Gould JR, Peña-González I, Enoka RM. Force steadiness during a co-contraction task can be improved with practice, but only by young adults and not by middle-aged or old adults. Exp Physiol 2015; 100:182-92. [PMID: 25398707 DOI: 10.1113/expphysiol.2014.083741] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Accepted: 11/04/2014] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS What is the central question of this study? Does the capacity to modulate afferent input to spinal motor neurons during steady submaximal contractions change with advancing age? What is the main finding and its importance? After practising a co-contraction task involving lower leg muscles, young subjects improved force steadiness by reducing the amount of Ia presynaptic inhibition as indexed by D1 inhibition. Middle-aged and old adults both found the task challenging, and force steadiness even worsened for old adults after practising the co-contraction task. Despite similar muscle strength for young and middle-aged adults, the capacity to modulate a spinal reflex pathway was reduced in middle-aged adults. This study compared the changes in steadiness and the modulation of presynaptic inhibition of soleus Ia afferents in young, middle-aged and old adults before and after a single session of practising a task that involved concurrent contraction of dorsiflexor and plantarflexor muscles. The hypothesis was that young subjects would be able to improve steadiness with practice by modulating Ia afferent feedback as indicated by changes in a measure of presynaptic inhibition (D1 inhibition), but that middle-aged and older subjects would exhibit a lesser ability to augment steadiness. There were no differences in steadiness between groups during an initial co-contraction trial (P = 0.713). Maximal voluntary contraction force for the plantarflexors was not significantly different between young and middle-aged subjects (P > 0.05), but it was significantly less in old subjects (P < 0.05). The main finding of the study was that young adults were able to improve steadiness by ∼19% (P < 0.001) during a co-contraction task after 50 min of practice, whereas there was no change for the middle-aged adults, and old adults became less steady by ∼15% (P < 0.05). The improvement in steadiness by young adults was accompanied by a significant reduction in the amount of Ia presynaptic inhibition as indexed by D1 inhibition (P < 0.01). Conversely, neither of the other two groups exhibited any change in D1 inhibition after practising the co-contraction task. In contrast to young subjects, middle-aged and old adults found the co-contraction task challenging and were not able to improve steadiness after practising the low-force isometric contraction.
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Affiliation(s)
- Matthew R Holmes
- Department of Integrative Physiology, University of Colorado, Boulder, CO, 80309, USA
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Nielsen JB, Willerslev-Olsen M, Christiansen L, Lundbye-Jensen J, Lorentzen J. Science-Based Neurorehabilitation: Recommendations for Neurorehabilitation From Basic Science. J Mot Behav 2015; 47:7-17. [DOI: 10.1080/00222895.2014.931273] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Behrens M, Mau-Moeller A, Wassermann F, Bader R, Bruhn S. Effect of balance training on neuromuscular function at rest and during isometric maximum voluntary contraction. Eur J Appl Physiol 2015; 115:1075-85. [DOI: 10.1007/s00421-014-3089-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Accepted: 12/17/2014] [Indexed: 10/24/2022]
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Effects of Vibration on Spasticity in Individuals with Spinal Cord Injury. Am J Phys Med Rehabil 2014; 93:995-1007. [DOI: 10.1097/phm.0000000000000098] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Duchateau J, Baudry S. The neural control of coactivation during fatiguing contractions revisited. J Electromyogr Kinesiol 2014; 24:780-8. [PMID: 25225169 DOI: 10.1016/j.jelekin.2014.08.006] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Accepted: 08/18/2014] [Indexed: 10/24/2022] Open
Abstract
In addition to the role of muscle coactivation, a major question in the field is how antagonist activation is controlled to minimize its opposing effect on agonist muscle performance. Muscle fatigue is an interesting condition to analyze the neural adjustments in antagonist muscle activity and to gain more insights into the control mechanisms of coactivation. In that context, previous studies have reported that although the EMG activity of agonists and antagonists increase in parallel, the ratio between EMG activities in the two sets of muscles during a fatiguing submaximal contraction decreased progressively and contributed to a reduction in the time to task failure. In contrast, more recent studies using a novel normalization procedure indicated that the agonist/antagonist ratio remained relatively constant, suggesting that the fatigue-related increase in coactivation does not impede performance. Current knowledge also indicates that peripheral mechanisms cannot by themselves mediate the intensity of antagonist coactivation during fatiguing contractions, implying that supraspinal mechanisms are involved. The unique modulation of the synaptic input from Ia afferents to the antagonist motor neurones during a fatiguing contraction of the agonist muscles further suggests a separate control of the two sets of muscles.
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Affiliation(s)
- Jacques Duchateau
- Laboratory of Applied Biology, ULB Neurosciences Institute, Université Libre de Bruxelles (ULB), Brussels, Belgium.
| | - Stéphane Baudry
- Laboratory of Applied Biology, ULB Neurosciences Institute, Université Libre de Bruxelles (ULB), Brussels, Belgium
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Goto Y, Jono Y, Hatanaka R, Nomura Y, Tani K, Chujo Y, Hiraoka K. Different corticospinal control between discrete and rhythmic movement of the ankle. Front Hum Neurosci 2014; 8:578. [PMID: 25126066 PMCID: PMC4115592 DOI: 10.3389/fnhum.2014.00578] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Accepted: 07/14/2014] [Indexed: 12/05/2022] Open
Abstract
We investigated differences in corticospinal and spinal control between discrete and rhythmic ankle movements. Motor evoked potentials (MEPs) in the tibialis anterior and soleus muscles and soleus H-reflex were elicited in the middle of the plantar flexion phase during discrete ankle movement or in the initial or later cycles of rhythmic ankle movement. The H-reflex was evoked at an intensity eliciting a small M-wave and MEPs were elicited at an intensity of 1.2 times the motor threshold of the soleus MEPs. Only trials in which background EMG level, ankle angle, and ankle velocity were similar among the movement conditions were included for data analysis. In addition, only trials with a similar M-wave were included for data analysis in the experiment evoking H-reflexes. Results showed that H reflex and MEP amplitudes in the soleus muscle during discrete movement were not significantly different from those during rhythmic movement. MEP amplitude in the tibialis anterior muscle during the later cycles of rhythmic movement was significantly larger than that during the initial cycle of the rhythmic movement or during discrete movement. Higher corticospinal excitability in the tibialis anterior muscle during the later cycles of rhythmic movement may reflect changes in corticospinal control from the initial cycle to the later cycles of rhythmic movement.
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Affiliation(s)
- Yumeno Goto
- Graduate School of Comprehensive Rehabilitation, Osaka Prefecture University Habikino, Japan
| | - Yasutomo Jono
- Graduate School of Comprehensive Rehabilitation, Osaka Prefecture University Habikino, Japan
| | - Ryota Hatanaka
- Graduate School of Comprehensive Rehabilitation, Osaka Prefecture University Habikino, Japan
| | - Yoshifumi Nomura
- Graduate School of Comprehensive Rehabilitation, Osaka Prefecture University Habikino, Japan
| | - Keisuke Tani
- Graduate School of Comprehensive Rehabilitation, Osaka Prefecture University Habikino, Japan
| | - Yuta Chujo
- Graduate School of Comprehensive Rehabilitation, Osaka Prefecture University Habikino, Japan
| | - Koichi Hiraoka
- College of Health and Human Sciences, Osaka Prefecture University Habikino, Japan
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Ivanchenko YZ. Anticipatory Changes in the Soleus H Reflex in Humans Related to the Movements of the Contralateral Foot in Upright Stance. NEUROPHYSIOLOGY+ 2014. [DOI: 10.1007/s11062-014-9419-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Geertsen SS, Kjær M, Pedersen KK, Petersen TH, Perez MA, Nielsen JB. Central common drive to antagonistic ankle muscles in relation to short-term cocontraction training in nondancers and professional ballet dancers. J Appl Physiol (1985) 2013; 115:1075-81. [PMID: 23869059 DOI: 10.1152/japplphysiol.00707.2012] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Optimization of cocontraction of antagonistic muscles around the ankle joint has been shown to involve plastic changes in spinal and cortical neural circuitries. Such changes may explain the ability of elite ballet dancers to maintain a steady balance during various ballet postures. Here we investigated whether short-term cocontraction training in ballet dancers and nondancers leads to changes in the coupling between antagonistic ankle motor units. Eleven ballet dancers and 10 nondancers were recruited for the study. Prior to training, ballet dancers and nondancers showed an equal amount of coherence in the 15- to 35-Hz frequency band and short-term synchronization between antagonistic tibialis anterior and soleus motor units. The ballet dancers tended to be better at maintaining a stable cocontraction of the antagonistic muscles, but this difference was not significant (P = 0.09). Following 27 min of cocontraction training, the nondancers improved their performance significantly, whereas no significant improvement was observed for the ballet dancers. The nondancers showed a significant increase in 15- to 35-Hz coherence following the training, whereas the ballet dancers did not show a significant change. A group of control subjects (n = 4), who performed cocontraction of the antagonistic muscles for an equal amount of time, but without any requirement to improve their performance, showed no change in coherence. We suggest that improved ability to maintain a stable cocontraction around the ankle joint is accompanied by short-term plastic changes in the neural drive to the involved muscles, but that such changes are not necessary for maintained high-level performance.
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Affiliation(s)
- S S Geertsen
- Department of Exercise and Sport Sciences, University of Copenhagen, and
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The representation of egocentric space in the posterior parietal cortex. Behav Brain Sci 2013; 15 Spec No 4:691-700. [PMID: 23842408 DOI: 10.1017/s0140525x00072605] [Citation(s) in RCA: 244] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The posterior parietal cortex (PPC) is the most likely site where egocentric spatial relationships are represented in the brain. PPC cells receive visual, auditory, somaesthetic, and vestibular sensory inputs; oculomotor, head, limb, and body motor signals; and strong motivational projections from the limbic system. Their discharge increases not only when an animal moves towards a sensory target, but also when it directs its attention to it. PPC lesions have the opposite effect: sensory inattention and neglect. The PPC does not seem to contain a "map" of the location of objects in space but a distributed neural network for transforming one set of sensory vectors into other sensory reference frames or into various motor coordinate systems. Which set of transformation rules is used probably depends on attention, which selectively enhances the synapses needed for making a particular sensory comparison or aiming a particular movement.
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Manella KJ, Roach KE, Field-Fote EC. Operant conditioning to increase ankle control or decrease reflex excitability improves reflex modulation and walking function in chronic spinal cord injury. J Neurophysiol 2013; 109:2666-79. [PMID: 23468393 DOI: 10.1152/jn.01039.2011] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Ankle clonus is common after spinal cord injury (SCI) and is attributed to loss of supraspinally mediated inhibition of soleus stretch reflexes and maladaptive reorganization of spinal reflex pathways. The maladaptive reorganization underlying ankle clonus is associated with other abnormalities, such as coactivation and reciprocal facilitation of tibialis anterior (TA) and soleus (SOL), which contribute to impaired walking ability in individuals with motor-incomplete SCI. Operant conditioning can increase muscle activation and decrease stretch reflexes in individuals with SCI. We compared two operant conditioning-based interventions in individuals with ankle clonus and impaired walking ability due to SCI. Training included either voluntary TA activation (TA↑) to enhance supraspinal drive or SOL H-reflex suppression (SOL↓) to modulate reflex pathways at the spinal cord level. We measured clonus duration, plantar flexor reflex threshold angle, timed toe tapping, dorsiflexion (DF) active range of motion, lower extremity motor scores (LEMS), walking foot clearance, speed and distance, SOL H-reflex amplitude modulation as an index of reciprocal inhibition, presynaptic inhibition, low-frequency depression, and SOL-to-TA clonus coactivation ratio. TA↑ decreased plantar flexor reflex threshold angle (-4.33°) and DF active range-of-motion angle (-4.32°) and increased LEMS of DF (+0.8 points), total LEMS of the training leg (+2.2 points), and nontraining leg (+0.8 points), and increased walking foot clearance (+ 4.8 mm) and distance (+12.09 m). SOL↓ decreased SOL-to-TA coactivation ratio (-0.21), increased nontraining leg LEMS (+1.8 points), walking speed (+0.02 m/s), and distance (+6.25 m). In sum, we found increased voluntary control associated with TA↑ outcomes and decreased reflex excitability associated with SOL↓ outcomes.
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Affiliation(s)
- Kathleen J Manella
- Department of Physical Therapy, Miller School of Medicine, University of Miami, Miami, Florida 33146, USA
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Activity-dependent plasticity of spinal circuits in the developing and mature spinal cord. Neural Plast 2012; 2012:964843. [PMID: 22900208 PMCID: PMC3415235 DOI: 10.1155/2012/964843] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Accepted: 06/12/2012] [Indexed: 01/29/2023] Open
Abstract
Part of the development and maturation of the central nervous system (CNS) occurs through interactions with the environment. Through physical activities and interactions with the world, an animal receives considerable sensory information from various sources. These sources can be internally (proprioceptive) or externally (such as touch and pressure) generated senses. Ample evidence exists to demonstrate that the sensory information originating from large diameter afferents (Ia fibers) have an important role in inducing essential functional and morphological changes for the maturation of both the brain and the spinal cord. The Ia fibers transmit sensory information generated by muscle activity and movement. Such use or activity-dependent plastic changes occur throughout life and are one reason for the ability to acquire new skills and learn new movements. However, the extent and particularly the mechanisms of activity-dependent changes are markedly different between a developing nervous system and a mature nervous system. Understanding these mechanisms is an important step to develop strategies for regaining motor function after different injuries to the CNS. Plastic changes induced by activity occur both in the brain and spinal cord. This paper reviews the activity-dependent changes in the spinal cord neural circuits during both the developmental stages of the CNS and in adulthood.
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Jessop T, DePaola A, Casaletto L, Englard C, Knikou M. Short-term plasticity of human spinal inhibitory circuits after isometric and isotonic ankle training. Eur J Appl Physiol 2012; 113:273-84. [DOI: 10.1007/s00421-012-2438-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Accepted: 05/29/2012] [Indexed: 12/18/2022]
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46
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Bhagchandani N, Schindler-Ivens S. Reciprocal inhibition post-stroke is related to reflex excitability and movement ability. Clin Neurophysiol 2012; 123:2239-46. [PMID: 22613030 DOI: 10.1016/j.clinph.2012.04.023] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2011] [Revised: 04/02/2012] [Accepted: 04/04/2012] [Indexed: 10/28/2022]
Abstract
OBJECTIVE Decreased reciprocal inhibition (RI) of motor neurons may contribute to spasticity after stroke. However, decreased RI is not a uniform observation among stroke survivors, suggesting that this spinal circuit may be influenced by other stroke-related characteristics. The purpose of this study was to measure RI post-stroke and to examine the relationship between RI and other features of stroke. METHODS RI was examined in 15 stroke survivors (PAR) and 10 control subjects by quantifying the effect of peroneal nerve stimulation on soleus H-reflex amplitude. The relationship between RI and age, time post-stroke, lesion side, walking velocity, Fugl-Meyer, Ashworth, and Achilles reflex scores was examined. RESULTS RI was absent and replaced by reciprocal facilitation in 10 of 15 PAR individuals. Reciprocal facilitation was associated with low Fugl-Meyer scores and slow walking velocities but not with hyperactive Achilles tendon reflexes. There was no relationship between RI or reciprocal facilitation and time post-stroke, lesion side, or Ashworth score. CONCLUSIONS Decreased RI is not a uniform finding post-stroke and is more closely related to walking ability and movement impairment than to spasticity. SIGNIFICANCE Phenomena other than decreased RI may contribute to post-stroke spasticity.
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Affiliation(s)
- Neha Bhagchandani
- Department of Physical Therapy, Marquette University, Milwaukee, WI 53201-1881, USA
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Blazevich AJ, Kay AD, Waugh C, Fath F, Miller S, Cannavan D. Plantarflexor stretch training increases reciprocal inhibition measured during voluntary dorsiflexion. J Neurophysiol 2012; 107:250-6. [DOI: 10.1152/jn.00407.2011] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Agonist-mediated reciprocal inhibition (RI) in distal skeletal muscles is an important neurophysiological phenomenon leading to improved movement coordination and efficiency. It has been shown to be reduced in aged and clinical populations, so the development of interventions augmenting RI is an important research goal. We examined the efficacy of using chronic passive muscle stretching to augment RI. The influence of 3 wk of plantarflexor stretching (4 × 30 s, two times/day) on RI of soleus and gastrocnemius initiated by tonic, voluntary dorsiflexion contractions [20% of maximum voluntary contraction (MVC)] was examined in 11 healthy men who performed stretch training and in nine nontraining controls. Hoffmann's reflexes (H-reflexes) were elicited by tibial nerve stimulation during both weak isometric (2% MVC) plantarflexions and dorsiflexion contractions at 20% MVC. Changes were examined at three joint angles, normalized to each subject's range of motion (ROM; plantarflexed = 10 ± 0°, neutral = −3.3 ± 2.9°, dorsiflexed = −16.5 ± 5.6°). No changes were detected in controls. A 20% increase in ROM in the stretch subjects was associated with a significant decrease in maximum H-reflex (Hmax): maximum evoked potential (Mmax), measured during 2% plantarflexion at the plantarflexed and neutral angles in soleus and at the plantarflexed angle in gastrocnemius ( P < 0.05–0.01). By contrast, decreases in Hmax:Mmax during 20% dorsiflexion contract were also seen at each angle in soleus and at the dorsiflexed angle in gastrocnemius. However, a greater decrease in Hmax:Mmax measured during voluntary dorsiflexion rather than during plantarflexion, which indicates a specific change in RI, was detected only at the dorsiflexed angle (−30.7 ± 9.4% and −35.8 ± 6.8% for soleus and gastrocnemius, respectively). These results demonstrate the efficacy of soleus-gastrocnemius stretch training in increasing agonist-mediated RI from tibialis anterior onto soleus-gastrocnemius in young, healthy individuals at dorsiflexed, but not plantarflexed, joint angles.
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Affiliation(s)
- A. J. Blazevich
- Centre for Exercise and Sports Science Research, School of Exercise and Health Sciences, Edith Cowan University, Australia
- Centre for Sports Medicine and Human Performance, Brunel University; and
| | - A. D. Kay
- Sport Exercise and Life Sciences, The University of Northampton
| | - C. Waugh
- Centre for Sports Medicine and Human Performance, Brunel University; and
| | - F. Fath
- Centre for Sports Medicine and Human Performance, Brunel University; and
| | - S. Miller
- Centre for Sports Medicine and Human Performance, Brunel University; and
- School of Health and Social Science, Middlesex University, United Kingdom; and
| | - D. Cannavan
- Department of Physical Education and Exercise Science, Seattle Pacific University, Seattle, Washington
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Vila-Chã C, Hassanlouei H, Farina D, Falla D. Eccentric exercise and delayed onset muscle soreness of the quadriceps induce adjustments in agonist-antagonist activity, which are dependent on the motor task. Exp Brain Res 2011; 216:385-95. [PMID: 22094715 PMCID: PMC3262141 DOI: 10.1007/s00221-011-2942-2] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2011] [Accepted: 11/04/2011] [Indexed: 12/01/2022]
Abstract
This study investigates the effects of eccentric exercise and delayed onset muscle soreness (DOMS) of the quadriceps on agonist–antagonist activity during a range of motor tasks. Ten healthy volunteers (age, mean ± SD, 24.9 ± 3.2 years) performed maximum voluntary contractions (MVC) and explosive isometric contractions of the knee extensors followed by isometric contractions at 2.5, 5, 10, 15, 20, and 30% MVC at baseline, immediately after and 24 h after eccentric exercise of the quadriceps. During each task, force of the knee extensors and surface EMG of the vasti and hamstrings muscles were recorded concurrently. Rate of force development (RFD) was computed from the explosive isometric contraction, and the coefficient of variation of the force (CoV) signal was estimated from the submaximal contractions. Twenty-four hours after exercise, the subjects rated their perceived pain intensity as 4.1 ± 1.2 (score out of 10). The maximum RFD and MVC of the knee extensors was reduced immediately post- and 24 h after eccentric exercise compared to baseline (average across both time points: 19.1 ± 17.1% and 11.9 ± 9.8% lower, respectively, P < 0.05). The CoV for force during the submaximal contractions was greater immediately after eccentric exercise (up to 66% higher than baseline, P < 0.001) and remained higher 24 h post-exercise during the presence of DOMS (P < 0.01). For the explosive and MVC tasks, the EMG amplitude of the vasti muscles decreased immediately after exercise and was accompanied by increased antagonist EMG for the explosive contraction only. On the contrary, reduced force steadiness was accompanied by a general increase in EMG amplitude of the vasti muscles and was accompanied by increased antagonist activity, but only at higher force levels (>15% MVC). This study shows that eccentric exercise and subsequent DOMS of the quadriceps reduce the maximal force, rate of force development and force steadiness of the knee extensors, and is accompanied by different adjustments of agonist and antagonist muscle activities.
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Affiliation(s)
- C Vila-Chã
- Polytechnic Institute of Bragança, Bragança, Portugal
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Geertsen SS, van de Ruit M, Grey MJ, Nielsen JB. Spinal inhibition of descending command to soleus motoneurons is removed prior to dorsiflexion. J Physiol 2011; 589:5819-31. [PMID: 21986208 DOI: 10.1113/jphysiol.2011.214387] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
It has recently been demonstrated that soleus motor-evoked potentials (MEPs) are facilitated prior to the onset of dorsiflexion. The purpose of this study was to examine if this could be explained by removal of spinal inhibition of the descending command to soleus motoneurons. To test this, we investigated how afferent inputs from the tibialis anterior muscle modulate the corticospinal activation of soleus spinal motoneurons at rest, during static contraction and prior to movement. MEPs activated by transcranial magnetic stimulation (TMS) and Hoffmann reflexes (H-reflexes), activated by electrical stimulation of the posterior tibial nerve (PTN), were conditioned by prior stimulation of the common peroneal nerve (CPN) at a variety of conditioning-test (CT) intervals. MEPs in the precontracted soleus muscle were inhibited when the TMS pulse was preceded by CPN stimulation with a CT interval of 35 ms, and they were facilitated for CT intervals of 50-55 ms. A similar inhibition of the soleus H-reflex was not observed. To investigate which descending pathways might be responsible for the afferent-evoked inhibition and facilitation, we examined the effect of CPN stimulation on short-latency facilitation (SLF) and long-latency facilitation (LLF) of the soleus H-reflex induced by a subthreshold TMS pulse at different CT intervals. SLF is known to reflect the excitability of the fastest conducting, corticomotoneuronal cells whereas LLF is believed to be caused by more indirect descending pathways. At CT intervals of 40-45 ms, the LLF was significantly more inhibited compared to the SLF when taking the effect on the H-reflex into account. Finally, we investigated how the CPN-induced inhibition and facilitation of the soleus MEP were modulated prior to dorsiflexion. Whereas the late facilitation (CT interval: 55 ms) was similar prior to dorsiflexion and at rest, no inhibition could be evoked at the earlier latency (CT interval: 35 ms) prior to onset of dorsiflexion. The observation that the CPN-induced inhibition of soleus MEPs disappears prior to onset of dorsiflexion may explain why soleus MEPs are facilitated prior to onset of dorsiflexion contraction. A possible mechanism involves the removal of inhibition of the descending command to the motoneurons at a spinal interneuronal level because the inhibition was seen in LLF and not in SLF, and the MEP inhibition was not observed in the H-reflex. The data illustrate that spinal interneuronal pathways modify descending commands to human spinal motoneurons and influence the size of MEPs elicited by TMS.
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Affiliation(s)
- Svend S Geertsen
- Copenhagen Neural Control of Movement (CPH-NCM) laboratory at the Panum Institute, the University of Copenhagen, Copenhagen, Denmark.
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Costa J, Guzmán J, Valldeoriola F, Rumià J, Tolosa E, Casanova-Molla J, Valls-Solé J. Modulation of the soleus H reflex by electrical subcortical stimuli in humans. Exp Brain Res 2011; 212:439-48. [DOI: 10.1007/s00221-011-2750-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2011] [Accepted: 05/20/2011] [Indexed: 12/19/2022]
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