Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
3.9
3.3
Journals
Brain Sciences
Special Issues
Acute and Chronic Changes in Neural Excitability During Physical Activity...
share announcement

Acute and Chronic Changes in Neural Excitability During Physical Activity in Non-Pathological States

A special issue of Brain Sciences (ISSN 2076-3425). This special issue belongs to the section "Systems Neuroscience".

Deadline for manuscript submissions: closed (9 December 2019) | Viewed by 25062

Printed Edition Available!
A printed edition of this Special Issue is available here.

Special Issue Editor

Dr. Kevin Power

E-Mail Website
Guest Editor
CSEP-CEP School of Human Kinetics and Recreation ,Cross-Appointment, Biomedical Sciences, Faculty of Medicine Memorial University of Newfoundland, St. John’s, Newfoundland, A1C 5S7, Physical Education Building, Room PE 2022A
Interests: neurophysiology; neuroplasticity;cortical excitability;spinal excitabilty; exercise; fatigue

Special Issue Information

Dear Colleagues,

The neural control of human motor output and how it is modified by alterations in physical activity levels is complex and multidimensional. The use of various experimental designs has vastly increased our knowledge of how the nervous system integrates descending, segmental, and ascending information to produce motor outputs, yet there is still much to learn. A more complete picture of how the neurophysiology underlying the control of human motor outputs may prove useful in guiding rehabilitation programs aimed at reducing motor impairments following disease or injury is emerging.

The purpose of this Special Issue is to collect original articles that explore neural excitability in various states. Studies examining neural excitability on a moment-to-moment basis (acute) or following prolonged periods of exercise or skill training and disuse (chronic) are encouraged. Original research studies using various experimental measures (e.g., transcranial magnetic stimulation, transmastoid electrical stimulation, single motor unit recordings, electroencephalography, and measures of spinal reflexes), in various states (e.g., fatigued, non-fatigued, and resting) during different types of motor outputs (tonic or dynamic) are encouraged. Experimental studies and literature reviews are welcome.

Dr. Kevin Power
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Brain Sciences is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2200 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Neurophysiology
  • Neuroplasticity
  • Cortical excitability
  • Spinal excitability
  • Exercise
  • Fatigue

Published Papers (7 papers)

Download All Papers
Order results
Result details
Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:

Research

16 pages, 1830 KiB  
Article
Neuromuscular Mechanisms Underlying Changes in Force Production during an Attentional Focus Task
by Shawn Wiseman, Shahab Alizadeh, Israel Halperin, Behzad Lahouti, Nicholas J. Snow, Kevin E. Power and Duane C. Button
Brain Sci. 2020, 10(1), 33; https://doi.org/10.3390/brainsci10010033 - 07 Jan 2020
Cited by 8 | Viewed by 4739
Abstract
We examined the effects of attentional focus cues on maximal voluntary force output of the elbow flexors and the underlying physiological mechanisms. Eleven males participated in two randomized experimental sessions. In each session, four randomized blocks of three maximal voluntary contractions (MVC) were [...] Read more.
We examined the effects of attentional focus cues on maximal voluntary force output of the elbow flexors and the underlying physiological mechanisms. Eleven males participated in two randomized experimental sessions. In each session, four randomized blocks of three maximal voluntary contractions (MVC) were performed. The blocks consisted of two externally and two internally attentional focus cued blocks. In one of the sessions, corticospinal excitability (CSE) was measured. During the stimulation session transcranial magnetic, transmastoid and Erb’s point stimulations were used to induce motor evoked potentials (MEPs), cervicomedullary MEP (CMEPs) and maximal muscle action potential (Mmax), respectively in the biceps brachii. Across both sessions forces were lower (p = 0.024) under the internal (282.4 ± 60.3 N) compared to the external condition (310.7 ± 11.3 N). Muscle co-activation was greater (p = 0.016) under the internal (26.3 ± 11.5%) compared with the external condition (21.5 ± 9.4%). There was no change in CSE. Across both sessions, force measurements were lower (p = 0.033) during the stimulation (279.0 ± 47.1 N) compared with the no-stimulation session (314.1 ± 57.5 N). In conclusion, external focus increased force, likely due to reduced co-activation. Stimulating the corticospinal pathway may confound attentional focus. The stimulations may distract participants from the cues and/or disrupt areas of the cortex responsible for attention and focus. Full article
(This article belongs to the Special Issue Acute and Chronic Changes in Neural Excitability During Physical Activity in Non-Pathological States)
►▼ Show Figures

Figure 1

11 pages, 1965 KiB  
Article
The Inhibitory Tendon-Evoked Reflex Is Increased in the Torque-Enhanced State Following Active Lengthening Compared to a Purely Isometric Contraction
by Vincenzo S. Contento, Brian H. Dalton and Geoffrey A. Power
Brain Sci. 2020, 10(1), 13; https://doi.org/10.3390/brainsci10010013 - 23 Dec 2019
Cited by 11 | Viewed by 3733
Abstract
Residual torque enhancement (rTE) is a history-dependent property of muscle, which results in an increase in steady-state isometric torque production following an active lengthening contraction as compared to a purely isometric (ISO) contraction at the same muscle length and level of activation. Once [...] Read more.
Residual torque enhancement (rTE) is a history-dependent property of muscle, which results in an increase in steady-state isometric torque production following an active lengthening contraction as compared to a purely isometric (ISO) contraction at the same muscle length and level of activation. Once thought to be only an intrinsic property of muscle, recent evidence during voluntary contractions indicates a neuromechanical coupling between motor neuron excitability and the contractile state of the muscle. However, the mechanism by which this occurs has yet to be elucidated. The purpose of this study was to investigate inhibition arising from tendon-mediated feedback (e.g., Golgi tendon organ; GTO) through tendon electrical stimulation (TStim) in the ISO and rTE states during activation-matching and torque-matching tasks. Fourteen male participants (22 ± 2 years) performed 10 activation-matching contractions at 40% of their maximum tibialis anterior electromyography amplitude (5 ISO/5 rTE) and 10 torque-matching contractions at 40% of their maximum dorsiflexion torque (5 ISO/5 rTE). During both tasks, 10 TStim were delivered during the isometric steady state of all contractions, and the resulting tendon-evoked inhibitory reflexes were averaged and analyzed. Reflex amplitude increased by ~23% in the rTE state compared to the ISO state for the activation-matching task, and no differences were detected for the torque-matching task. The current data indicate an important relationship between afferent feedback in the torque-enhanced state and voluntary control of submaximal contractions. The history-dependent properties of muscle is likely to alter motor neuron excitability through modifications in tension- or torque-mediated afferent feedback arising from the tendon. Full article
(This article belongs to the Special Issue Acute and Chronic Changes in Neural Excitability During Physical Activity in Non-Pathological States)
►▼ Show Figures

Figure 1

18 pages, 2527 KiB  
Article
The Task at Hand: Fatigue-Associated Changes in Cortical Excitability During Writing
by Kezia T. M. Cinelli, Lara A. Green and Jayne M. Kalmar
Brain Sci. 2019, 9(12), 353; https://doi.org/10.3390/brainsci9120353 - 02 Dec 2019
Cited by 4 | Viewed by 2868
Abstract
Measures of corticospinal excitability (CSE) made via transcranial magnetic stimulation (TMS) depend on the task performed during stimulation. Our purpose was to determine whether fatigue-induced changes in CSE made during a conventional laboratory task (isometric finger abduction) reflect the changes measured during a [...] Read more.
Measures of corticospinal excitability (CSE) made via transcranial magnetic stimulation (TMS) depend on the task performed during stimulation. Our purpose was to determine whether fatigue-induced changes in CSE made during a conventional laboratory task (isometric finger abduction) reflect the changes measured during a natural motor task (writing). We assessed single-and paired-pulse motor evoked potentials (MEPs) recorded from the first dorsal interosseous (FDI) of 19 participants before and after a fatigue protocol (submaximal isometric contractions) on two randomized days. The fatigue protocol was identical on the two days, but the tasks used to assess CSE before and after fatigue differed. Specifically, MEPs were evoked during a writing task on one day and during isometric finger abduction to a low-level target that matched muscle activation during writing on the other day. There was greater variability in MEP amplitude (F (1,18) = 13.55, p < 0.01) during writing compared to abduction. When participants were divided into groups according to writing style (printers, n = 8; cursive writers, n = 8), a task x fatigue x style interaction was revealed for intracortical facilitation (F (1,14) = 9.90, p < 0.01), which increased by 28% after fatigue in printers but did not change in cursive writers nor during the abduction task. This study is the first to assess CSE during hand-writing. Our finding that fatigue-induced changes in intracortical facilitation depend on the motor task used during TMS, highlights the need to consider the task-dependent nature of CSE when applying results to movement outside of the laboratory. Full article
(This article belongs to the Special Issue Acute and Chronic Changes in Neural Excitability During Physical Activity in Non-Pathological States)
►▼ Show Figures

Graphical abstract

13 pages, 1101 KiB  
Article
The Impact of Glucose on Corticospinal and Intracortical Excitability
by Stephen L. Toepp, Claudia V. Turco, Mitchell B. Locke, Chiara Nicolini, Roshni Ravi and Aimee J. Nelson
Brain Sci. 2019, 9(12), 339; https://doi.org/10.3390/brainsci9120339 - 25 Nov 2019
Cited by 8 | Viewed by 2365
Abstract
Neurotransmission is highly dependent on the availability of glucose-derived energy, although it is unclear how glucose availability modulates corticospinal and intracortical excitability as assessed via transcranial magnetic stimulation (TMS). In this double-blinded placebo-controlled study, we tested the effect of acute glucose intake on [...] Read more.
Neurotransmission is highly dependent on the availability of glucose-derived energy, although it is unclear how glucose availability modulates corticospinal and intracortical excitability as assessed via transcranial magnetic stimulation (TMS). In this double-blinded placebo-controlled study, we tested the effect of acute glucose intake on motor-evoked potential (MEP) recruitment curves, short-interval intracortical inhibition (SICI), short-latency afferent inhibition (SAI) and long-latency afferent inhibition (LAI). Eighteen healthy males participated in four sessions. Session 1 involved acquisition of an individualized blood glucose response curve. This allowed measurements to be time-locked to an individualized glucose peak after consuming one of three drinks during the subsequent three sessions. Participants were administered a 300 mL concealed solution containing 75 g of glucose, sucralose, or water in separate sessions. Dependent measures were assessed at baseline and twice after drinking the solution. Secondary measures included blood glucose and mean arterial pressure. Corticospinal excitability and blood pressure increased following the drink across all treatments. No changes were observed in SICI, SAI or LAI. There was no rise in corticospinal excitability that was specific to the glucose drink, suggesting that acute changes in glucose levels do not necessarily alter TMS measures of corticospinal or intracortical excitability. Full article
(This article belongs to the Special Issue Acute and Chronic Changes in Neural Excitability During Physical Activity in Non-Pathological States)
►▼ Show Figures

Figure 1

15 pages, 2498 KiB  
Article
Exercise-Induced Fatigue in One Leg Does Not Impair the Neuromuscular Performance in the Contralateral Leg but Improves the Excitability of the Ipsilateral Corticospinal Pathway
by Saied Jalal Aboodarda, Cindy Xin Yu Zhang, Ruva Sharara, Madeleine Cline and Guillaume Y Millet
Brain Sci. 2019, 9(10), 250; https://doi.org/10.3390/brainsci9100250 - 25 Sep 2019
Cited by 13 | Viewed by 4181
Abstract
To investigate the influence of pre-induced fatigue in one leg on neuromuscular performance and corticospinal responses of the contralateral homologous muscles, three experiments were conducted with different exercise protocols; A (n = 12): a 60 s rest vs. time-matched sustained left leg knee [...] Read more.
To investigate the influence of pre-induced fatigue in one leg on neuromuscular performance and corticospinal responses of the contralateral homologous muscles, three experiments were conducted with different exercise protocols; A (n = 12): a 60 s rest vs. time-matched sustained left leg knee extension maximum voluntary contraction (MVC), B (n = 12): a 60 s rest vs. time-matched left leg MVC immediately followed by 60 s right leg MVC, and C (n = 9): a similar protocol to experiment B, but with blood flow occluded in the left leg while the right leg was performing the 60 s MVC. The neuromuscular assessment included 5 s knee extensions at 100%, 75%, and 50% of MVC. At each force level, transcranial magnetic and peripheral nerve stimuli were elicited to investigate the influence of different protocols on the right (tested) knee extensors’ maximal force output, voluntary activation, corticospinal excitability, and inhibition. The pre-induced fatigue in the left leg did not alter the performance nor the neuromuscular responses recorded from the right leg in the three experiments (all p > 0.3). However, enhanced corticospinal pathway excitability was evident in the tested knee extensors (p = 0.002). These results suggest that the pre-induced fatigue and muscle ischemia in one leg did not compromise the central and peripheral components of the neuromuscular function in the tested contralateral leg. Full article
(This article belongs to the Special Issue Acute and Chronic Changes in Neural Excitability During Physical Activity in Non-Pathological States)
►▼ Show Figures

Figure 1

15 pages, 1835 KiB  
Article
Corticospinal-Evoked Responses from the Biceps Brachii during Arm Cycling across Multiple Power Outputs
by Evan J. Lockyer, Katarina Hosel, Anna P. Nippard, Duane C. Button and Kevin E. Power
Brain Sci. 2019, 9(8), 205; https://doi.org/10.3390/brainsci9080205 - 19 Aug 2019
Cited by 8 | Viewed by 3076
Abstract
Background: We examined corticospinal and spinal excitability across multiple power outputs during arm cycling using a weak and strong stimulus intensity. Methods: We elicited motor evoked potentials (MEPs) and cervicomedullary motor evoked potentials (CMEPs) in the biceps brachii using magnetic stimulation [...] Read more.
Background: We examined corticospinal and spinal excitability across multiple power outputs during arm cycling using a weak and strong stimulus intensity. Methods: We elicited motor evoked potentials (MEPs) and cervicomedullary motor evoked potentials (CMEPs) in the biceps brachii using magnetic stimulation over the motor cortex and electrical stimulation of corticospinal axons during arm cycling at six different power outputs (i.e., 25, 50, 100, 150, 200 and 250 W) and two stimulation intensities (i.e., weak vs. strong). Results: In general, biceps brachii MEP and CMEP amplitudes (normalized to maximal M-wave (Mmax)) followed a similar pattern of modulation with increases in cycling intensity at both stimulation strengths. Specifically, MEP and CMEP amplitudes increased up until ~150 W and ~100 W when the weak and strong stimulations were used, respectively. Further increases in cycling intensity revealed no changes on MEP or CMEP amplitudes for either stimulation strength. Conclusions: In general, MEPs and CMEPs changed in a similar manner, suggesting that increases and subsequent plateaus in overall excitability are likely mediated by spinal factors. Interestingly, however, MEP amplitudes were disproportionately larger than CMEP amplitudes as power output increased, despite being initially matched in amplitude, particularly with strong stimulation. This suggests that supraspinal excitability is enhanced to a larger degree than spinal excitability as the power output of arm cycling increases. Full article
(This article belongs to the Special Issue Acute and Chronic Changes in Neural Excitability During Physical Activity in Non-Pathological States)
►▼ Show Figures

Figure 1

8 pages, 772 KiB  
Communication
Modulating Observation-Execution-Related Motor Cortex Activity by Cathodal Transcranial Direct Current Stimulation
by Fengxue Qi, Michael A. Nitsche and Volker R. Zschorlich
Brain Sci. 2019, 9(5), 121; https://doi.org/10.3390/brainsci9050121 - 26 May 2019
Cited by 6 | Viewed by 3738
Abstract
The aim of this randomized sham-controlled study was to examine the impact of cathodal transcranial direct current stimulation (ctDCS) of the primary motor cortex (M1) during movement observation on subsequent execution-related motor cortex activity. Thirty healthy participants received sham or real ctDCS (1 [...] Read more.
The aim of this randomized sham-controlled study was to examine the impact of cathodal transcranial direct current stimulation (ctDCS) of the primary motor cortex (M1) during movement observation on subsequent execution-related motor cortex activity. Thirty healthy participants received sham or real ctDCS (1 mA) over the left M1 for 10 minutes, respectively. The participants observed a video showing repeated button pressing tasks of the right hand during the sham or real ctDCS, followed by performance of these tasks by the right hand. Motor-evoked potentials (MEP) were recorded from the resting right first dorsal interosseous muscle before movement observation during the sham or real ctDCS, immediately after observation of actions, and after subsequent movement execution. The results of the ANOVA showed a significant main effect on the group (F1,28 = 4.60, p = 0.041) and a significant interaction between time and the group (F2,56 = 5.34, p = 0.008). As revealed by respective post hoc tests, ctDCS induced a significant reduction of MEP amplitudes in connection with movement observation (p = 0.026, Cohen’s d = 0.861) and after subsequent movement execution (p = 0.018, Cohen’s d = 0.914) in comparison with the sham stimulation. It is concluded that ctDCS during movement observation was effective in terms of modulating motor cortex excitability. Moreover, it subsequently influenced execution-related motor cortex activity. This indicates a possible application for rehabilitative treatment in syndromes with pathologically enhanced cortical activity. Full article
(This article belongs to the Special Issue Acute and Chronic Changes in Neural Excitability During Physical Activity in Non-Pathological States)
►▼ Show Figures

Figure 1

Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:
 
Displaying articles 1-7
Back to TopTop