Review of muscle activity and action potentials as they are related to movement. (AAF AMC Aero Medical Lab. Memo Rept. TSEAA 694-2E, 1947; Pub. Bd. No. M 81423.).

1947 ◽  
Author(s):  
Glen Finch
Keyword(s):  
Muscle Activity ◽  
Action Potentials

EMG Feedback and Recovery of Facial and Speech Gestures Following Neural Anastomosis

1978 ◽  
Vol 43 (1) ◽  
pp. 9-20 ◽  
Author(s):  
Billie Daniel ◽  
Barry Guitar
Keyword(s):  
Muscle Activity ◽  
Action Potentials ◽  
Substantial Improvement ◽  
Upper Lip ◽  
Lower Lip ◽  
Feedback Training ◽  
The Face ◽  
The Subject ◽  
The Right ◽  
Lifting Task

A case report is presented of an attempt to increase muscle activity during non-speech and speech activities through surface electromyographic feedback. The subject, a 25-year-old male, had a surgical anastomosis of the seventh cranial to the twelfth cranial nerve five years prior to the initiation of this therapy. The right side of the face was immobile. Frequency analogs of muscle action potentials from the right lower lip during pressing, retraction, eversion, and speech were presented to the subject. His task was to increase the frequency of the tone thereby increasing muscle activity. The subject made substantial improvement in the gestures listed above. Electrodes also were placed in various infraorbital positions for an upper lip lifting task. This gesture was unimproved. Pre- and posttherapy independence of facial gestures from conscious tongue contraction was found. Possible explanations were proposed for (1) increases of muscle activity in the lower lip, (2) lack of change of MAPs in the upper lip, (3) independence of the facial muscle activity from conscious tongue contraction, and (4) effectiveness of this feedback training.

Comparable patterns of muscle facilitation evoked by individual corticomotoneuronal (CM) cells and by single intracortical microstimuli in primates: evidence for functional groups of CM cells

1985 ◽  
Vol 53 (3) ◽  
pp. 786-804 ◽  
Author(s):  
P. D. Cheney ◽  
E. E. Fetz
Keyword(s):  
Motor Cortex ◽  
Muscle Activity ◽  
Action Potentials ◽  
Relative Strength ◽  
Emg Activity ◽  
Base Line ◽  
Onset Latency ◽  
Wrist Flexion ◽  
Forelimb Muscles ◽  
The Mean

We compared the averaged responses of forelimb muscles to action potentials of single motor cortex cells and to single intracortical microstimuli (S-ICMS). Activity of precentral neurons and 12 identified forelimb muscles (6 flexors and 6 extensors of wrist and fingers) was recorded in macaques while they performed alternating ramp-and-hold wrist movements. Action potentials of cells that covaried reliably with wrist flexion or extension were used to compile spike-triggered averages (spike-TAs) of rectified electromyographic (EMG) activity of six synergistically coactivated muscles. Cells whose spikes were followed by a clear postspike facilitation (PSF) of rectified muscle activity were designated corticomotoneuronal (CM) cells. CM cells typically facilitated a subset of the coactivated muscles called the cell's target muscles. The relative strength of the PSF in different target muscles ranged from clear increases above base-line fluctuations to weak but significant effects. For each CM cell we characterized the "PSF profile" of facilitation across different muscles, defined as the relative strength of PSF in each of the coactivated agonist muscles. After identifying the CM cell's target muscles, we delivered S-ICMS through the microelectrode at the same site. Biphasic stimuli were delivered during the same wrist movements in which the recorded CM cell had been active. Stimulus intensities were too weak (typically 5-10 microA) and their repetition rate too slow (5-15 Hz) to evoke muscle excitation evident in the raw EMG record. However, stimulus-triggered averages (stimulus-TAs) of the rectified EMGs of coactivated muscles revealed consistent patterns of poststimulus facilitation (PStimF). In most cases the muscles facilitated by the CM cell in spike-TAs (n = 60) were also facilitated by S-ICMS in stimulus-TAs. At sites of CM cells the threshold stimulus intensities for evoking a statistically significant effect were between 0.5 and 2 microA. S-ICMS of 5 microA evoked PStimF that was, on the average, six times stronger than the PSF of the CM cell. The height of the facilitation peak relative to base-line fluctuations was 5-60 times greater for the stimuli than the spikes of the CM cell. The average onset latency of PStimF (8.0 +/- 1.2 ms) was 1.3 ms longer than the mean latency of PSF (6.7 +/- 1.4 ms). At two-thirds of the cortical sites where both spike- and stimulus-TAs were computed (n = 30), the PStimF profile exactly matched the PSF profile.(ABSTRACT TRUNCATED AT 400 WORDS)

Activity of circular muscle of rat uterus at different times in pregnancy

1984 ◽  
Vol 246 (3) ◽  
pp. C216-C223 ◽  
Author(s):  
B. Bengtsson ◽  
E. M. Chow ◽  
J. M. Marshall
Keyword(s):  
Membrane Potential ◽  
Electrical Activity ◽  
Spontaneous Activity ◽  
Muscle Activity ◽  
Action Potentials ◽  
Circular Muscle ◽  
Spike Trains ◽  
Plateau Potentials ◽  
Rat Uterus ◽  
In Pregnancy

During pregnancy, circular muscle activity changes from weak irregular contractions at midterm to strong regular contractions at term. The present study was designed to determine if this change is related to contractile ability or to membrane electrical events. Myometrial segments were taken from rats on days 16–17, 18–19, 20, and 21 (term) of gestation. Contractile ability was estimated as the maximum force elicited by 121 mM KCl or 0.6 mM acetylcholine. The K- and acetylcholine-induced contractions were significantly greater than spontaneous and no different at midterm and term. Electrical activity was measured with intracellular electrodes. Between days 16 and 21, action potentials evolved from single, plateau-type to repetitive spike trains. Plateau potentials were associated with small contractions and repetitive spikes with larger contractions. On day 21, there was a transient increase in membrane potential and cessation of spontaneous activity. Before delivery, the membrane potential declined and spontaneous spike trains appeared and triggered large contractions. Conclusion: the change in circular muscle activity during pregnancy is related to electrical events and not to contractile ability.

Behavior of uterine muscle in Na-deficient solutions; effects of oxytocin

1963 ◽  
Vol 204 (4) ◽  
pp. 732-738 ◽  
Author(s):  
Jean M. Marshall
Keyword(s):  
Muscle Activity ◽  
Action Potentials ◽  
External Solution ◽  
Isometric Tension ◽  
Normal Muscle ◽  
Stimulatory Action ◽  
Uterine Muscle ◽  
White Rats ◽  
Relationship Of ◽  
The Relationship

Myometrial strips, from parturient or 21-day pregnant white rats, were exposed to Na-deficient solutions, and membrane potentials were recorded from single muscle fibers, isometric tension from the entire muscle strip. Reduction of [Na+]0 to 50% of normal had no observable effect on muscle activity. At [Na+]0 below this level, the amplitude and rising velocity of the action potentials declined and, below 10% of normal, muscle activity was abolished. The stimulatory action of oxytocin on the myometrium was unaffected by reductions in [Na+]0 down to 50% of the normal level. Oxytocin (50 µU/ml) stimulated the production of action potentials in muscles previously depressed by exposure to solutions containing 25% and 10% of normal [Na+]0. The data indicate that although the presence of sodium ions in the external solution is necessary for the production and maintenance of activity in uterine smooth muscle, certain quantitative differences exist between uterine muscle and skeletal or cardiac muscle regarding the relationship of membrane activity to [Na+]0.

Metabolic Rates Related to Muscle Activity in Bumblebees

1974 ◽  
Vol 61 (1) ◽  
pp. 219-227 ◽  
Author(s):  
ANN E. KAMMER ◽  
BERND HEINRICH
Keyword(s):  
Oxygen Consumption ◽  
Muscle Activity ◽  
Action Potentials ◽  
Adaptive Significance ◽  
Oxygen Debt ◽  
Temperature Sensitive ◽  
Metabolic Rates ◽  
Warm Up ◽  
Similar Activity ◽  
Single Spike

1. Oxygen consumption, thoracic temperature, and action potentials from the fibrillar muscles were concurrently recorded in queens and workers of Bombus vosnesenskii. 2. The oxygen consumption of ‘inactive’ bees (quiescent and/or producing fewer than 0.3 spikes/sec) was markedly temperature-sensitive, with a Q10 of 3.4 for thoracic temperatures of 25-35 °C. 3. The oxygen consumption of bees with active fibrillar muscles was directly correlated with spike frequency; a single spike was associated with the consumption of 2.3-2.6 µl O2/gth. No oxygen debt was observed. 4. The oxygen consumption per spike during flight was similar to that during warm-up. 5. Oxygen consumption per gram thorax was similar in queens and workers engaging in similar activity. 6. The results are compared with those from other insects and their adaptive significance is discussed.

Sign in / Sign up

Export Citation Format

Share Document