Background: Paired associative stimulation (PAS) is widely used to induce plasticity in the human motor cortex. Although reciprocal inhibition of antagonist muscles plays a fundamental role in human movements, change in cortical circuits for reciprocal muscles by PAS is unknown.
Methods: We investigated change in cortical plasticity for reciprocal muscles during PAS. PAS consisted of 200 pairs of peripheral electric stimulation of the right median nerve at the wrist at a frequency of 0.25 Hz followed by transcranial magnetic stimulation of the left M1 at the midpoint between the center of gravities of the flexor carpi radialis (FCR) and extensor carpi radialis (ECR) muscles. Measures of motor cortical excitability included resting motor threshold (RMT), GABAA-mediated short-interval intracortical inhibition (SICI), and GABAB-mediated long-interval intracortical inhibition (LICI).
Results: Motor evoked potential amplitude-conditioned LICI for the FCR muscle was significantly decreased after PAS (P = 0.020), whereas that for the ECR muscle was significantly increased (P = 0.033). Changes in RMT and SICI for the FCR and ECR muscles were not significantly different before and after PAS. Corticospinal excitability for both reciprocal muscles was increased during PAS, but GABAB-mediated cortical inhibitory functions for the agonist and antagonist muscles were reciprocally altered after PAS.
Conclusion: These results implied that the cortical excitability for reciprocal muscles including GABAB-ergic inhibitory systems within human M1 could be differently altered by PAS.
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http://dx.doi.org/10.1002/brb3.280 | DOI Listing |
Front Physiol
January 2025
Institute of Vegetative Physiology, University of Cologne, Köln, Germany.
Objective: Previous studies on muscle fibers, myofibrils, and myosin revealed that the release of inorganic phosphate (P) and the force-generating step(s) are reversible, with cross-bridges also cycling backward through these steps by reversing force-generating steps and rebinding P. The aim was to explore the significance of force redevelopment kinetics (rate constant ) in cardiac myofibrils for the coupling between the P binding induced force reversal and the rate-limiting transition for backward cycling of cross-bridges from force-generating to non-force-generating states.
Methods: and force generation of cardiac myofibrils from guinea pigs were investigated at 0.
Rheumatology (Oxford)
January 2025
Institute of Experimental Endocrinology, Biomedical Research Center, Slovak Academy of Sciences, Bratislava, Slovakia.
Objectives: Objective of this work was to examine myomiR levels in plasma, skeletal muscle, and skeletal muscle cells of patients with idiopathic inflammatory myopathy (IIM), their interrelations with the disease-related clinical phenotypes and with the effects of the disease-modifying 6-month training-intervention.
Methods: Samples of vastus lateralis muscle (n = 12/13) and plasma (n = 20/21) were obtained from IIM patients and healthy controls, respectively. Muscle and plasma were obtained before and after a 6-month training-intervention in 7 patients.
Biomimetics (Basel)
December 2024
School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200030, China.
This study develops biomimetic strategies for slip prevention in prosthetic hand grasps. The biomimetic system is driven by a novel slip sensor, followed by slip perception and preventive control. Here, we show that biologically inspired sensorimotor pathways can be restored between the prosthetic hand and users.
View Article and Find Full Text PDFJ Neurophysiol
January 2025
Department of Health Sciences and Research, College of Health Professions, Medical University of South Carolina, Charleston, South Carolina, United States.
Deep dry needling (DDN) is a method to treat muscle trigger points (TrPs) often found in persons with neuromuscular pain and spasticity. Currently, its neurophysiological actions are not well established. Thus, to understand how DDN affects spinal cord physiology, we investigated the effects of TrP DDN on spinal reflexes.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!