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Olarogba OB, Lockyer EJ, Antolinez AK, Button DC. Sex-related differences in corticospinal excitability outcome measures of the biceps brachii during a submaximal elbow flexor contraction. Physiol Rep 2024; 12:e16102. [PMID: 39095333 PMCID: PMC11296885 DOI: 10.14814/phy2.16102] [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: 04/08/2024] [Revised: 05/24/2024] [Accepted: 05/24/2024] [Indexed: 08/04/2024] Open
Abstract
The purpose of this study was to investigate the effects of sex, muscle thickness, and subcutaneous fat thickness (SFT) on corticospinal excitability outcome measures of the biceps brachii. Eighteen participants (10 males and 8 females) completed this study. Ultrasound was used to assess biceps brachii muscle thickness and the overlying SFT. Transcranial magnetic stimulation (TMS) was used to determine corticospinal excitability by inducing motor-evoked potentials (MEPs) at eight different TMS intensities from 90% to 160% of active motor threshold (AMT) from the biceps brachii during an isometric contraction of the elbow flexors at 10% of maximum voluntary contraction (MVC). Biceps brachii maximal compound muscle action potential (Mmax) was also recorded prior to and after TMS. Males had higher (p < 0.001) biceps brachii muscle thickness and lower SFT, produced higher levels of MVC force and had, on average, higher (p < 0.001) MEP amplitudes at lower (p < 0.05) percentages of maximal stimulator output than females during the 10% elbow flexion MVC. Multiple linear regression modeling revealed that sex was not associated with any of the neurophysiological parameters examined, while SFT showed a positive association with the stimulation intensity required at AMT (p = 0.035) and a negative association with biceps brachii pre-stimulus electromyography (EMG) activity (p = 0.021). Additionally, there was a small positive association between muscle thickness and biceps brachii pre-stimulus EMG activity (p = 0.049). Overall, this study suggests that some measures of corticospinal excitability may be different between the sexes and influenced by SFT and muscle thickness.
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Affiliation(s)
- Olalekan B. Olarogba
- Human Neurophysiology LabSchool of Human Kinetics and RecreationSt. John'sNewfoundlandCanada
| | - Evan J. Lockyer
- Human Neurophysiology LabSchool of Human Kinetics and RecreationSt. John'sNewfoundlandCanada
- Faculty of MedicineMemorial University of NewfoundlandSt. John'sNewfoundlandCanada
| | - Angie K. Antolinez
- Human Neurophysiology LabSchool of Human Kinetics and RecreationSt. John'sNewfoundlandCanada
| | - Duane C. Button
- Human Neurophysiology LabSchool of Human Kinetics and RecreationSt. John'sNewfoundlandCanada
- Faculty of MedicineMemorial University of NewfoundlandSt. John'sNewfoundlandCanada
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2
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Keriven H, Sánchez Sierra A, González de-la-Flor Á, García-Arrabé M, Bravo-Aguilar M, de la Plaza San Frutos M, Garcia-Perez-de-Sevilla G, Tornero-Aguilera JF, Clemente-Suarez VJ, Domínguez-Balmaseda D. Effects of combined treatment with transcranial and peripheral electromagnetic stimulation on performance and pain recovery from delayed onset muscle soreness induced by eccentric exercise in young athletes. A randomized clinical trial. Front Physiol 2023; 14:1267315. [PMID: 37900951 PMCID: PMC10603222 DOI: 10.3389/fphys.2023.1267315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Accepted: 09/19/2023] [Indexed: 10/31/2023] Open
Abstract
Background: There is a common interest in finding a common consensus in the approach of athletes suffering from DOMS with the aim of accelerating recovery and thereby enhancing performance. The objective of this study was to observe the effects of a paired-associative transcranial and peripheral electromagnetic stimulation on young athletes suffering from DOMS, induced by 1 h of eccentric and plyometric exercises. Methods: Forty-eight young athletes participated in this randomized control trial: 13 were assigned to the peripheral group (P); 12 were in the control group (Cont); 11 were assigned to the transcranial group (T) and 12 were included in the paired-associative group (Comb). The Visual Analogue Scale (VAS) of pain perception and the mechanical Pressure Pain Threshold (PPT) were the tools used to analyze the symptoms of DOMS. On the other hand, the Half Squat (HS) test evaluated with an accelerometer, and the 30 m sprint velocity (30-mSP) test were used to observe the evolution of the sports performance of the lower limbs. All evaluations were performed before and after the eccentric exercise session that caused DOMS, as well as at 24-48, and 72 h afterward. Results: The AS group improved the symptoms of the induced DOMS, since significant positive differences were observed in the VAS and PPT compared to the other groups (p < 0.001). In addition, the AS group showed a significant improvement in the HS and the 30-mSP tests (p < 0.001). Based on the results a treatment with both peripheral and transcranial electromagnetic stimulation improves recovery and performance in athletes at 72 h, although these data would need to be verified in future research with a larger sample size. Conclusion: Paired-associative electromagnetic stimulation improved DOMS symptomatology, velocity, and sports performance in the lower limbs.
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Affiliation(s)
- Hugo Keriven
- Department of Physiotherapy, Faculty of Sports Sciences, Therapeutic Exercise and Fucntional Rehabiltiation Research Group, Universidad Europea de Madrid, Villaviciosa de Odón, Madrid, Spain
| | - Alberto Sánchez Sierra
- Department of Physiotherapy, Faculty of Sports Sciences, Therapeutic Exercise and Fucntional Rehabiltiation Research Group, Universidad Europea de Madrid, Villaviciosa de Odón, Madrid, Spain
- Faculty of Phisioterapy and Nursing, Universidad de Castilla-La Mancha, Toledo, Spain
- Toledo Physiotherapy Research Group (GIFTO), Madrid, Spain
| | - Ángel González de-la-Flor
- Department of Physiotherapy, Faculty of Sports Sciences, Therapeutic Exercise and Fucntional Rehabiltiation Research Group, Universidad Europea de Madrid, Villaviciosa de Odón, Madrid, Spain
| | - María García-Arrabé
- Department of Physiotherapy, Faculty of Sports Sciences, Therapeutic Exercise and Fucntional Rehabiltiation Research Group, Universidad Europea de Madrid, Villaviciosa de Odón, Madrid, Spain
| | - María Bravo-Aguilar
- Department of Physiotherapy, Faculty of Sports Sciences, Therapeutic Exercise and Fucntional Rehabiltiation Research Group, Universidad Europea de Madrid, Villaviciosa de Odón, Madrid, Spain
| | - Marta de la Plaza San Frutos
- Department of Physiotherapy, Faculty of Sports Sciences, Therapeutic Exercise and Fucntional Rehabiltiation Research Group, Universidad Europea de Madrid, Villaviciosa de Odón, Madrid, Spain
- Research Group on Exercise Therapy and Functional Rehabilitation, Faculty of Health Sciences, Universidad Europea de Madrid, Madrid, Spain
| | - Guillermo Garcia-Perez-de-Sevilla
- Department of Physiotherapy, Faculty of Sports Sciences, Therapeutic Exercise and Fucntional Rehabiltiation Research Group, Universidad Europea de Madrid, Villaviciosa de Odón, Madrid, Spain
| | - Jose Francisco Tornero-Aguilera
- Department of Physiotherapy, Faculty of Sports Sciences, Therapeutic Exercise and Fucntional Rehabiltiation Research Group, Universidad Europea de Madrid, Villaviciosa de Odón, Madrid, Spain
| | - Vicente Javier Clemente-Suarez
- Department of Physiotherapy, Faculty of Sports Sciences, Therapeutic Exercise and Fucntional Rehabiltiation Research Group, Universidad Europea de Madrid, Villaviciosa de Odón, Madrid, Spain
| | - Diego Domínguez-Balmaseda
- Department of Physiotherapy, Faculty of Sports Sciences, Therapeutic Exercise and Fucntional Rehabiltiation Research Group, Universidad Europea de Madrid, Villaviciosa de Odón, Madrid, Spain
- Masmicrobiota Group, Faculty of Health Sciences, Universidad Europea de Madrid, Madrid, Spain
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3
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Talebian Nia M, Leclerc C, Glazebrook C, Chopek J, Giesbrecht GG. Corticospinal and spinal excitability during peripheral or central cooling in humans. J Therm Biol 2023; 112:103489. [PMID: 36796930 DOI: 10.1016/j.jtherbio.2023.103489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 01/24/2023] [Accepted: 01/25/2023] [Indexed: 01/30/2023]
Abstract
Cold exposure can impair fine and gross motor control and threaten survival. Most motor task decrement is due to peripheral neuromuscular factors. Less is known about cooling on central neural factors. Corticospinal and spinal excitability were determined during cooling of the skin (Tsk) and core (Tco). Eight subjects (four female) were actively cooled in a liquid perfused suit for 90 min (2 °C inflow temperature), passively cooled for 7 min, and then rewarmed for 30 min (41 °C inflow temperature). Stimulation blocks included 10 transcranial magnetic stimulations [eliciting motor evoked potentials (MEPs) which indicate corticospinal excitability], 8 trans-mastoid electrical stimulations [eliciting cervicomedullary evoked potentials (CMEPs) which indicate spinal excitability] and 2 brachial plexus electrical stimulations [eliciting maximal compound motor action potentials (Mmax)]. These stimulations were delivered every 30 min. Cooling for 90 min reduced Tsk to 18.2 °C while Tco did not change. At the end of rewarming Tsk returned to baseline while Tco decreased by 0.8 °C (afterdrop) (P < 0.001). Metabolic heat production was higher than baseline at the end of passive cooling (P = 0.01), and 7 min into rewarming (P = 0.04). MEP/Mmax remained unchanged throughout. CMEP/Mmax increased by 38% at end cooling (although increased variability at this time rendered the increase insignificant, P = 0.23) and 58% at end warming when Tco was 0.8 °C below baseline (P = 0.02). Cooling increased spinal excitability but not corticospinal excitability. Cooling may decrease cortical and/or supraspinal excitability which is compensated for by increased spinal excitability. This compensation is key to providing a motor task and survival advantage.
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Affiliation(s)
- M Talebian Nia
- Faculty of Kinesiology and Recreational Management, University of Manitoba, Canada
| | - C Leclerc
- Faculty of Kinesiology and Recreational Management, University of Manitoba, Canada
| | - C Glazebrook
- Faculty of Kinesiology and Recreational Management, University of Manitoba, Canada
| | - J Chopek
- Dept. of Physiology and Pathophysiology, University of Manitoba, Canada
| | - G G Giesbrecht
- Faculty of Kinesiology and Recreational Management, University of Manitoba, Canada; Faculty of Medicine, Depts. of Anesthesia and Emergency Medicine, University of Manitoba, Canada.
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4
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Stinson RJ, Morice AH, Sadofsky LR. Modulation of transient receptor potential (TRP) channels by plant derived substances used in over-the-counter cough and cold remedies. Respir Res 2023; 24:45. [PMID: 36755306 PMCID: PMC9907891 DOI: 10.1186/s12931-023-02347-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Accepted: 01/27/2023] [Indexed: 02/10/2023] Open
Abstract
BACKGROUND Upper respiratory tract infections (URTIs) impact all age groups and have a significant economic and social burden on society, worldwide. Most URTIs are mild and self-limiting, but due to the wide range of possible causative agents, including Rhinovirus (hRV), Adenovirus, Respiratory Syncytial Virus (RSV), Coronavirus and Influenza, there is no single and effective treatment. Over-the-counter (OTC) remedies, including traditional medicines and those containing plant derived substances, help to alleviate symptoms including inflammation, pain, fever and cough. PURPOSE This systematic review focuses on the role of the major plant derived substances in several OTC remedies used to treat cold symptoms, with a particular focus on the transient receptor potential (TRP) channels involved in pain and cough. METHODS Literature searches were done using Pubmed and Web of Science, with no date limitations, using the principles of the PRISMA statement. The search terms used were 'TRP channel AND plant compound', 'cough AND plant compound', 'cough AND TRP channels AND plant compound', 'cough AND P2X3 AND plant compound' and 'P2X3 AND plant compound' where plant compound represents menthol or camphor or eucalyptus or turpentine or thymol. RESULTS The literature reviewed showed that menthol activates TRPM8 and may inhibit respiratory reflexes reducing irritation and cough. Menthol has a bimodal action on TRPA1, but inhibition may have an analgesic effect. Eucalyptus also activates TRPM8 and inhibits TRPA1 whilst down regulating P2X3, aiding in the reduction of cough, pain and airway irritation. Camphor inhibits TRPA1 and the activation of TRPM8 may add to the effects of menthol. Activation of TRPV1 by camphor, may also have an analgesic effect. CONCLUSIONS The literature suggests that these plant derived substances have multifaceted actions and can interact with the TRP 'cough' receptors. The plant derived substances used in cough and cold medicines have the potential to target multiple symptoms experienced during a cold.
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Affiliation(s)
- Rebecca J. Stinson
- grid.9481.40000 0004 0412 8669Centre for Biomedicine, Hull York Medical School, The University of Hull, Cottingham Road, Hull, HU6 7RX UK
| | - Alyn H. Morice
- grid.413631.20000 0000 9468 0801Clinical Sciences Centre, Hull York Medical School, Castle Hill Hospital, Cottingham, Hull, HU16 5JQ UK
| | - Laura R. Sadofsky
- grid.9481.40000 0004 0412 8669Centre for Biomedicine, Hull York Medical School, The University of Hull, Cottingham Road, Hull, HU6 7RX UK
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5
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Li Z, Zhang H, Wang Y, Li Y, Li Q, Zhang L. The distinctive role of menthol in pain and analgesia: Mechanisms, practices, and advances. Front Mol Neurosci 2022; 15:1006908. [PMID: 36277488 PMCID: PMC9580369 DOI: 10.3389/fnmol.2022.1006908] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 09/13/2022] [Indexed: 11/13/2022] Open
Abstract
Menthol is an important flavoring additive that triggers a cooling sensation. Under physiological condition, low to moderate concentrations of menthol activate transient receptor potential cation channel subfamily M member 8 (TRPM8) in the primary nociceptors, such as dorsal root ganglion (DRG) and trigeminal ganglion, generating a cooling sensation, whereas menthol at higher concentration could induce cold allodynia, and cold hyperalgesia mediated by TRPM8 sensitization. In addition, the paradoxical irritating properties of high concentrations of menthol is associated with its activation of transient receptor potential cation channel subfamily A member 1 (TRPA1). Under pathological situation, menthol activates TRPM8 to attenuate mechanical allodynia and thermal hyperalgesia following nerve injury or chemical stimuli. Recent reports have recapitulated the requirement of central group II/III metabotropic glutamate receptors (mGluR) with endogenous κ-opioid signaling pathways for menthol analgesia. Additionally, blockage of sodium channels and calcium influx is a determinant step after menthol exposure, suggesting the possibility of menthol for pain management. In this review, we will also discuss and summarize the advances in menthol-related drugs for pathological pain treatment in clinical trials, especially in neuropathic pain, musculoskeletal pain, cancer pain and postoperative pain, with the aim to find the promising therapeutic candidates for the resolution of pain to better manage patients with pain in clinics.
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Affiliation(s)
- Ziping Li
- The Graduate School, Tianjin Medical University, Tianjin, China
| | - Haoyue Zhang
- The Graduate School, Tianjin Medical University, Tianjin, China
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, China
| | - Yigang Wang
- The Graduate School, Tianjin Medical University, Tianjin, China
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, China
| | - Yize Li
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, China
| | - Qing Li
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, China
- Qing Li,
| | - Linlin Zhang
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, China
- *Correspondence: Linlin Zhang,
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6
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Hurrie DMG, Talebian Nia M, Power KE, Stecina K, Gardiner P, Lockyer EJ, Giesbrecht GG. Spinal and corticospinal excitability in response to reductions in skin and core temperature via whole-body cooling. Appl Physiol Nutr Metab 2021; 47:195-205. [PMID: 34582724 DOI: 10.1139/apnm-2021-0370] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cold stress impairs fine and gross motor movements. Although peripheral effects of muscle cooling on performance are well understood, less is known about central mechanisms. This study characterized corticospinal and spinal excitability during surface cooling, reducing skin (Tsk) and core (Tes) temperature. Ten subjects (3 female) wore a liquid-perfused suit and were cooled (9°C perfusate, 90 min) and rewarmed (41°C perfusate, 30 min). Transcranial magnetic stimulation [eliciting motor evoked potentials (MEPs)], as well as transmastoid [eliciting cervicomedullary evoked potentials (CMEPs)] and brachial plexus [eliciting maximal compound motor action potentials (Mmax)] electrical stimulation, were applied at baseline, every 20 min during cooling, and following rewarming. Sixty minutes of cooling, reduced Tsk by 9.6°C (P<0.001) but Tes remained unchanged (P=0.92). Tes then decreased ~0.6℃ in the next 30 minutes of cooling (P<0.001). Eight subjects shivered. During rewarming, shivering was abolished, and Tsk returned to baseline while Tes did not increase. During cooling and rewarming, Mmax, MEP, and MEP/Mmax were unchanged from baseline. However, CMEP and CMEP/Mmax increased during cooling by ~85% and 79% (P<0.001) respectively, and remained elevated post-rewarming. Results suggest that spinal excitability is facilitated by reduced Tsk during cooling, and reduced Tes during warming, while corticospinal excitability remains unchanged. ClinicalTrials.gov ID NCT04253730 Novelty: • This is the first study to characterize corticospinal, and spinal excitability during whole body cooling, and rewarming in humans. • Whole body cooling did not affect corticospinal excitability. • Spinal excitability was facilitated during reductions in both skin and core temperatures.
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Affiliation(s)
- Daryl Michael George Hurrie
- University of Manitoba, 8664, Kinesiology and Recreation Management, 102 Frank Kennedy Centre, University of Manitoba, Winnipeg, Manitoba, Canada, R3T 2N2;
| | - Morteza Talebian Nia
- University of Manitoba, 8664, Kinesiology and recreation management, 87 Radcliffe Rd, Winnipeg, Manitoba, Canada, R3T 3H2;
| | - Kevin E Power
- Memorial University of Newfoundland, Human Kinetics, Physical Education Building, Room 2022a, St. John's, Newfoundland and Labrador, Canada, A1C 5S7;
| | - Katinka Stecina
- University of Manitoba, 8664, Kinesiology and Recreation Management, Winnipeg, Manitoba, Canada;
| | - Phillip Gardiner
- University of Manitoba College of Medicine, 12359, Physiology, 745 Bannatyne, Winnipeg, Manitoba, Canada, R3E 3P5;
| | - Evan J Lockyer
- Memorial University of Newfoundland, Human Kinetics, 230 Elizabeth Avenue, Physical Education Building, St. John's, Newfoundland and Labrador, Canada, A1C5S7;
| | - Gordon G Giesbrecht
- University of Manitoba, KRM, 102 Frank Kennedy Centre, U of Man, R3T 2N2, Winnipeg, Manitoba, Canada, R3T 2N2;
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7
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Menthol-Based Topical Analgesic Induces Similar Upper and Lower Body Pain Pressure Threshold Values: A Randomized Trial. J Sport Rehabil 2021; 31:24-30. [PMID: 34552033 DOI: 10.1123/jsr.2021-0144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 06/23/2021] [Indexed: 11/18/2022]
Abstract
CONTEXT Both health professionals and consumers use menthol-based topical analgesics extensively for the temporary relief of pain from musculoskeletal ailments or injury. However, there are no reports of differences in the pain pressure threshold (PPT) or the relative effectiveness of topical analgesics to reduce pain in the upper and lower body muscles and tendons. The objective of this study was to investigate whether differences existed in PPT and relative pain attenuation associated with a menthol-based topical analgesic over a variety of upper and lower body muscles and tendons. DESIGN Randomized allocation, controlled, intervention study. METHODS Sixteen participants (10 females and 6 males) were tested on their dominant or nondominant side. The order of specific muscle/tendon testing was also randomized, which included upper body (middle deltoid, biceps brachii, and lateral epicondylar tendon) and lower body locations (quadriceps, hamstrings, gastrocnemius, lumbosacral erector spinae muscles, and patellar and Achilles tendons). The PPT was monitored before and 15 minutes following the application of a menthol-based topical analgesic. RESULTS A menthol-based topical analgesic increased PPT (decreased pain sensitivity) overall (P = .05; 11.6% [2.4%]; d = 1.05) and PPT was higher (P < .0001; 31.5%-44.2%; d = 1.03-1.8) for lower versus upper body locations. CONCLUSIONS Health professionals and the public can be assured of similar reductions in pain sensitivity independent of the location of application of a menthol-based topical analgesic.
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8
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Lockyer EJ, Compton CT, Forman DA, Pearcey GE, Button DC, Power KE. Moving forward: methodological considerations for assessing corticospinal excitability during rhythmic motor output in humans. J Neurophysiol 2021; 126:181-194. [PMID: 34133230 DOI: 10.1152/jn.00027.2021] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The use of transcranial magnetic stimulation to assess the excitability of the central nervous system to further understand the neural control of human movement is expansive. The majority of the work performed to-date has assessed corticospinal excitability either at rest or during relatively simple isometric contractions. The results from this work are not easily extrapolated to rhythmic, dynamic motor outputs, given that corticospinal excitability is task-, phase-, intensity-, direction-, and muscle-dependent (Power KE, Lockyer EJ, Forman DA, Button DC. Appl Physiol Nutr Metab 43: 1176-1185, 2018). Assessing corticospinal excitability during rhythmic motor output, however, involves technical challenges that are to be overcome, or at the minimum considered, when attempting to design experiments and interpret the physiological relevance of the results. The purpose of this narrative review is to highlight the research examining corticospinal excitability during a rhythmic motor output and, importantly, to provide recommendations regarding the many factors that must be considered when designing and interpreting findings from studies that involve limb movement. To do so, the majority of work described herein refers to work performed using arm cycling (arm pedaling or arm cranking) as a model of a rhythmic motor output used to examine the neural control of human locomotion.
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Affiliation(s)
- Evan J Lockyer
- Human Neurophysiology Lab, School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John's, Newfoundland, Canada.,Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland, Canada
| | - Chris T Compton
- Human Neurophysiology Lab, School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John's, Newfoundland, Canada.,Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland, Canada
| | - Davis A Forman
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Gregory E Pearcey
- Department of Physical Medicine and Rehabilitation, Feinberg School of Medicine, Northwestern University, Chicago, Illinois.,Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois.,Shirley Ryan Ability Lab, Chicago, Illinois
| | - Duane C Button
- Human Neurophysiology Lab, School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John's, Newfoundland, Canada.,Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland, Canada
| | - Kevin E Power
- Human Neurophysiology Lab, School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John's, Newfoundland, Canada.,Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland, Canada
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9
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Clark BC, Carson RG. Sarcopenia and Neuroscience: Learning to Communicate. J Gerontol A Biol Sci Med Sci 2021; 76:1882-1890. [PMID: 33824986 DOI: 10.1093/gerona/glab098] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Indexed: 12/11/2022] Open
Abstract
In the 1990s and early 2000s, the common definition for sarcopenia was age-related loss of skeletal muscle, and low levels of muscle mass were central to sarcopenia diagnosis. In more recent consensus definitions, however, low muscle strength displaces low muscle mass as a defining feature of sarcopenia. The change stems from growing evidence that muscle weakness is a better predictor of adverse health outcomes (e.g., mobility limitations) than muscle mass. This evidence accompanies an emerging recognition that central neural mechanisms are critical determinants of age-related changes in strength and mobility that can occur independently of variations in muscle mass. However, strikingly little practical attention is typically given to the potential role of the central nervous system in the aetiology or remediation of sarcopenia (i.e., low muscle function). In this article, we provide an overview of some mechanisms that mediate neural regulation of muscle contraction and control, and highlight the specific contributions of neural hypoexcitability, dopaminergic dysfunction, and degradation of functional and structural brain connectivity in relation to sarcopenia. We aim to enhance the lines of communication between the domains of sarcopenia and neuroscience. We believe that appreciation of the neural regulation of muscle contraction and control is fundamental to understanding sarcopenia and to developing targeted therapeutic strategies for its treatment.
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Affiliation(s)
- Brian C Clark
- Ohio Musculoskeletal & Neurological Institute and the Department of Biomedical Sciences, Ohio University, Athens, Ohio, USA
| | - Richard G Carson
- Trinity College Institute of Neuroscience and School of Psychology, Trinity College Dublin, Dublin, Ireland.,School of Psychology, Queen's University Belfast, Belfast, Northern Ireland, UK.,School of Human Movement and Nutrition Sciences, The University of Queensland, Australia
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10
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Clark LA, Manini TM, Wages NP, Simon JE, Russ DW, Clark BC. Reduced Neural Excitability and Activation Contribute to Clinically Meaningful Weakness in Older Adults. J Gerontol A Biol Sci Med Sci 2021; 76:692-702. [PMID: 32588058 PMCID: PMC8011705 DOI: 10.1093/gerona/glaa157] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Weakness is a risk factor for physical limitations and death in older adults (OAs). We sought to determine whether OAs with clinically meaningful leg extensor weakness exhibit differences in voluntary inactivation (VIA) and measures of corticospinal excitability when compared to young adults (YAs) and OAs without clinically meaningful weakness. We also sought to estimate the relative contribution of indices of neural excitability and thigh lean mass in explaining the between-subject variability in OAs leg extensor strength. METHODS In 66 OAs (75.1 ± 7.0 years) and 20 YAs (22.0 ± 1.9 years), we quantified leg extensor strength, thigh lean mass, VIA, and motor evoked potential (MEP) amplitude and silent period (SP) duration. OAs were classified into weakness groups based on previously established strength/body weight (BW) cut points (Weak, Modestly Weak, or Not Weak). RESULTS The OAs had 63% less strength/BW when compared to YAs. Weak OAs exhibited higher levels of leg extensor VIA than Not Weak OAs (14.2 ± 7.5% vs 6.1 ± 7.5%). Weak OAs exhibited 24% longer SPs compared to Not Weak OAs, although this difference was insignificant (p = .06). The Weak OAs MEPs were half the amplitude of the Not Weak OAs. Regression analysis indicated that MEP amplitude, SP duration, and thigh lean mass explained ~62% of the variance in strength, with the neural excitability variables explaining ~33% of the variance and thigh lean mass explaining ~29%. CONCLUSION These findings suggest that neurotherapeutic interventions targeting excitability could be a viable approach to increase muscle strength in order to reduce the risk of physical impairments in late life.
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Affiliation(s)
- Leatha A Clark
- Ohio Musculoskeletal and Neurological Institute (OMNI), Ohio University, Athens
- Department of Biomedical Sciences, Ohio University, Athens
| | - Todd M Manini
- Department of Aging and Geriatric Research, University of Florida, Gainesville
| | - Nathan P Wages
- Ohio Musculoskeletal and Neurological Institute (OMNI), Ohio University, Athens
- Department of Biomedical Sciences, Ohio University, Athens
| | - Janet E Simon
- Ohio Musculoskeletal and Neurological Institute (OMNI), Ohio University, Athens
- School of Applied Health Sciences and Wellness, Ohio University, Athens
| | - David W Russ
- School of Physical Therapy & Rehabilitation Sciences, University of South Florida, Tampa
| | - Brian C Clark
- Ohio Musculoskeletal and Neurological Institute (OMNI), Ohio University, Athens
- Department of Biomedical Sciences, Ohio University, Athens
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Neuromuscular Mechanisms Underlying Changes in Force Production during an Attentional Focus Task. Brain Sci 2020; 10:brainsci10010033. [PMID: 31936030 PMCID: PMC7016702 DOI: 10.3390/brainsci10010033] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 12/20/2019] [Accepted: 01/03/2020] [Indexed: 11/18/2022] Open
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 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.
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