scholarly journals Conduction Velocity of Muscle Action Potential of Knee Extensor Muscle During Evoked and Voluntary Contractions After Exhaustive Leg Pedaling Exercise

2020 ◽  
Vol 11 ◽  
Author(s):  
Kohei Watanabe ◽  
Taiki Sakai ◽  
Shosaku Kato ◽  
Natsuka Hashizume ◽  
Naoki Horii ◽  
...  
Keyword(s):  
Action Potential ◽  
Conduction Velocity ◽  
Knee Extensor ◽  
Extensor Muscle ◽  
Muscle Action ◽  
Muscle Action Potential ◽  
Voluntary Contractions

Elbow flexor fatigue modulates central excitability of the knee extensors

2015 ◽  
Vol 40 (9) ◽  
pp. 924-930 ◽  
Author(s):  
Saied Jalal Aboodarda ◽  
David B. Copithorne ◽  
Kevin E. Power ◽  
Eric Drinkwater ◽  
David G. Behm
Keyword(s):  
Action Potential ◽  
Compound Muscle Action Potential ◽  
Knee Extensor ◽  
Elbow Flexion ◽  
Elbow Flexor ◽  
Emg Activity ◽  
Muscle Action ◽  
Muscle Action Potential ◽  
Extensor Muscles ◽  
Knee Extensor Muscles

The present study investigated the effects of exercise-induced elbow flexor fatigue on voluntary force output, electromyographic (EMG) activity and motoneurone excitability of the nonexercised knee extensor muscles. Eleven participants attended 3 testing sessions: (i) control, (ii) unilateral fatiguing elbow flexion and (iii) bilateral fatiguing elbow flexion (BiFlex). The nonfatigued knee extensor muscles were assessed with thoracic motor evoked potentials (TMEPs), maximal compound muscle action potential (Mmax), knee extensor maximal voluntary contractions (MVCs), and normalized EMG activity before and at 30 s, 3 min, and 5 min postexercise. BiFlex showed significantly lower (Δ = −18%, p = 0.03) vastus lateralis (VL) normalized EMG activity compared with the control session whereas knee extension MVC force did not show any statistical difference between the 3 conditions (p = 0.12). The TMEP·Mmax−1 ratio measured at the VL showed a significantly higher value (Δ = +46%, p = 0.003) following BiFlex compared with the control condition at 30 s postexercise. The results suggest that the lower VL normalized EMG following BiFlex might have been due to a reduction in supraspinal motor output because spinal motoneuronal responses demonstrated substantially higher value (30 s postexercise) and peripheral excitability (compound muscle action potential) showed no change following BiFelex than control condition.

scholarly journals Optical recording of action potential initiation and propagation in mouse skeletal muscle fibers

2018 ◽  
Author(s):  
Q. Banks ◽  
S.J.P. Pratt ◽  
S.R. Iyer ◽  
R.M. Lovering ◽  
E.O. Hernández-Ochoa ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Action Potential ◽  
Conduction Velocity ◽  
Muscle Fibers ◽  
Extracellular Potassium ◽  
Bipolar Electrode ◽  
Muscle Action ◽  
Action Potential Propagation ◽  
Skeletal Muscle Fibers ◽  
Muscle Action Potential

ABSTRACTIndividual skeletal muscle fibers have been used to examine a wide variety of cellular functions and pathologies. Among other parameters, skeletal muscle action potential propagation has been measured to assess the integrity and function of skeletal muscle. In this paper, we utilize Di-8-ANEPPS, a potentiometric dye and mag-fluo-4, a low-affinity intracellular calcium indicator to non-invasively and reliably measure action potential conduction velocity in skeletal muscle. We used an extracellular bipolar electrode to generate an electric field that will initiate an action potential at one end of the fiber or the other. Using enzymatically dissociated flexor digitorum brevis (FDB) fibers, we demonstrate the strength and applicability of this technique. Using high-speed line scans, we estimate the conduction velocity to be approximately 0.4 m/s. In addition to measuring the conduction velocity, we can also measure the passive electrotonic potentials elicited by pulses by either applying tetrodotoxin (TTX) or reducing the bath sodium levels. We applied these methodologies to FDB fibers under elevated extracellular potassium conditions, and found that the conduction velocity is significantly reduced compared to our control concentration. Lastly, we have constructed a circuit model of a skeletal muscle in order to predict passive polarization of the fiber by the field stimuli. Our predictions from the model fiber closely resemble the recordings acquired from in vitro assays. With these techniques, we can examine how many different pathologies and mutations affect skeletal muscle action potential propagation. Our work demonstrates the utility of using Di-8-ANEPPS or mag-fluo-4 to non-invasively measure action potential conduction velocity.

Influence of Atracurium on the Diaphragm Mean Action Potential Conduction Velocity in Canines 

1999 ◽  
Vol 90 (3) ◽  
pp. 855-862 ◽  
Author(s):  
Ernesto Goldman ◽  
Christer Sinderby ◽  
Lars Lindstrom ◽  
Alex Grassino
Keyword(s):  
Action Potential ◽  
Conduction Velocity ◽  
Compound Muscle Action Potential ◽  
Motor Units ◽  
Muscle Action ◽  
Muscle Action Potential ◽  
Frequency Domains ◽  
Muscle Shortening ◽  
Supramaximal Stimulation ◽  
The Mean

Background It has been shown that progressive neuromuscular blockade (NMB) affects the electromyogram power spectrum and compound muscle action potential duration in skeletal muscle. These measures are linked to the mean muscle action potential conduction velocity (APCV), but no studies have confirmed a relation between the mean APCV and NMB. The aim of this study was to determine whether diaphragm mean APCV is affected by NMB. Methods The effects of NMB on diaphragm mean APCV were evaluated in five mongrel dogs. Progressive NMB was induced by slow intravenous infusion of atracurium. During spontaneous breathing, the diaphragm mean APCV was determined by electromyogram signals, in the time and frequency domains. The magnitude of NMB was quantified by the amplitude of the compound muscle action potential and by changes in muscle shortening during supramaximal stimulation of the phrenic nerve. Results Progressive NMB was associated with a decrease in diaphragm mean APCV. At approximately 70% reduction in the compound muscle action potential amplitude, diaphragm mean APCV had decreased more than 20%. Recovery after NMB was characterized by a restoration of the mean APCV to control values. Conclusion This study shows that progressive NMB paralyzes motor units within the diaphragm in an orderly manner, and the blockade first affects muscle fibers with high APCV before it affects fibers with lower APCV.

scholarly journals Impact of stimulus duration on motor unit thresholds and alternation in compound muscle action potential scans

2020 ◽  
Author(s):  
Boudewijn T.H.M. Sleutjes ◽  
Janna Ruisch ◽  
Thijs E. Nassi ◽  
Jan R. Buitenweg ◽  
Leonard J. van Schelven ◽  
...  
Keyword(s):  
Action Potential ◽  
Motor Unit ◽  
Stimulus Duration ◽  
Compound Muscle Action Potential ◽  
Muscle Action ◽  
Muscle Action Potential

Intrinsic Reinnervation—Myth or Reality?

1993 ◽  
Vol 18 (4) ◽  
pp. 454-460 ◽  
Author(s):  
R. L. LESTER ◽  
P. J. SMITH ◽  
G. MOTT ◽  
R. M. R. McALLISTER
Keyword(s):  
Action Potential ◽  
Muscle Power ◽  
Muscle Action ◽  
Intrinsic Muscle ◽  
Clinical Recovery ◽  
Muscle Action Potential ◽  
Intrinsic Muscles

A clinical and electromyographic study of major nerve transections at the wrist in 22 patients has shown that electrical recovery nearly always occurs in the intrinsic muscles, despite the absence of clinically detectable function. There appears to be a level of electrical reinnervation above which clinically detectable intrinsic muscle power is usually present. This level would appear to be 50% of the contralateral maximum evoked muscle action potential; above this the “myth” of clinical recovery becomes a reality.

Determination of the best electrode position for recording of the diaphragm compound muscle action potential

2009 ◽  
Vol 40 (1) ◽  
pp. 37-41 ◽  
Author(s):  
Annie Dionne ◽  
Anthony Parkes ◽  
Beata Engler ◽  
Bradley V. Watson ◽  
Michael W. Nicolle
Keyword(s):  
Action Potential ◽  
Compound Muscle Action Potential ◽  
Electrode Position ◽  
Muscle Action ◽  
Muscle Action Potential

Regulation of breathing at beginning of exercise

1963 ◽  
Vol 18 (6) ◽  
pp. 1183-1187 ◽  
Author(s):  
F. N. Craig ◽  
E. G. Cummings ◽  
W. V. Blevins
Keyword(s):  
Action Potential ◽  
Cycle Ergometer ◽  
Respiratory Drive ◽  
Muscle Action ◽  
Work Situation ◽  
Muscle Action Potential ◽  
Regulation Of Breathing ◽  
The Subject ◽  
Leg Movement

In initial 20-sec periods of running on the treadmill, raising the slope to 12% increased by 50% the integrated muscle action potential, recorded from the under side of the thigh, without affecting the ventilation in four men. Five men worked for 1 min at four tasks, two on the treadmill and two on the horizontal cycle ergometer. Each pair of tasks consisted of slow and rapid leg movement at the same rate of work. Ventilation often continued at about the resting rate for the first few seconds of work, unaffected in any significant way by frequency of leg movement. In the subject responding to the onset of exercise by a sudden sharp involuntary increase in ventilation, the nature of the nervous respiratory drive is not clear. Whatever drive arises from the work itself may be strongly modified by training or by complexities in the work situation. leg movement; muscle action potential; nervous respiratory drive Submitted on May 16, 1963

Correlation between distal motor latency and compound muscle action potential in amyotrophic lateral sclerosis

2007 ◽  
Vol 29 (5) ◽  
pp. 425-428 ◽  
Author(s):  
Bahram Mohammadi ◽  
Klaus Krampfl ◽  
Katja Kollewe ◽  
Amir Seyfadini ◽  
Johannes Bufler ◽  
...  
Keyword(s):  
Amyotrophic Lateral Sclerosis ◽  
Action Potential ◽  
Compound Muscle Action Potential ◽  
Muscle Action ◽  
Distal Motor Latency ◽  
Motor Latency ◽  
Muscle Action Potential ◽  
Lateral Sclerosis
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