Muscle-Twitch Cognition

1967 ◽  
Vol 12 (10) ◽  
pp. 506, 508
Author(s):  
PAUL A. KOLERS
Keyword(s):  
Muscle Twitch

Muscle–twitch Correlates of Piagetian Cognitions

1975 ◽  
Vol 20 (5) ◽  
pp. 426-427
Author(s):  
DAVID ZEAMAN
Keyword(s):  
Muscle Twitch

The priority of the heat production in a muscle twitch

1958 ◽  
Vol 148 (932) ◽  
pp. 397-402 ◽  
Keyword(s):  
Chemical Reactions ◽  
Heat Production ◽  
Mechanical Response ◽  
Substantial Part ◽  
Hypertonic Solution ◽  
Isotonic Solution ◽  
Muscle Twitch ◽  
Previous Conclusion

When a muscle has been soaked in a moderately hypertonic solution its mechanical response to a shock is delayed, but its heat production is almost normal and starts considerably earlier than its shortening. After a more hypertonic solution the mechanical response is abolished, but a substantial part of the heat production remains. These effects are rapidly reversed by soaking in a normal isotonic solution. They strengthen the previous conclusion that chemical reactions triggered by a stimulus precede the mechanical response.

Weakfish sonic muscle: influence of size, temperature and season

2002 ◽  
Vol 205 (15) ◽  
pp. 2183-2188 ◽  
Author(s):  
M. A. Connaughton ◽  
M. L. Fine ◽  
M. H. Taylor
Keyword(s):  
Natural Frequency ◽  
Pulse Duration ◽  
Dominant Frequency ◽  
Forced Response ◽  
Acoustic Energy ◽  
Honest Signal ◽  
Muscle Twitch ◽  
Cross Sectional ◽  
Fish Size ◽  
Sonic Muscle

SUMMARYThe influence of temperature, size and season on the sounds produced by the sonic muscles of the weakfish Cynoscion regalis are categorized and used to formulate a hypothesis about the mechanism of sound generation by the sonic muscle and swimbladder. Sounds produced by male weakfish occur at the time and location of spawning and have been observed in courtship in captivity. Each call includes a series of 6-10 sound pulses, and each pulse expresses a damped, 2-3 cycle acoustic waveform generated by single simultaneous twitches of the bilateral sonic muscles. The sonic muscles triple in mass during the spawning season, and this hypertrophy is initiated by rising testosterone levels that trigger increases in myofibrillar and sarcoplasmic cross-sectional area of sonic muscle fibers. In response to increasing temperature, sound pressure level (SPL), dominant frequency and repetition rate increase, and pulse duration decreases. Likewise, SPL and pulse duration increase and dominant frequency decreases with fish size. Changes in acoustic parameters with fish size suggest the possibility that drumming sounds act as an `honest' signal of male fitness during courtship. These parameters also correlate with seasonally increasing sonic muscle mass. We hypothesize that sonic muscle twitch duration rather than the resonant frequency of the swimbladder determines dominant frequency. The brief (3.5 ms), rapidly decaying acoustic pulses reflect a low-Q, broadly tuned resonator, suggesting that dominant frequency is determined by the forced response of the swimbladder to sonic muscle contractions. The changing dominant frequency with temperature in fish of the same size further suggests that frequency is not determined by the natural frequency of the bladder because temperature is unlikely to affect resonance. Finally, dominant frequency correlates with pulse duration (reflecting muscle twitch duration),and the inverse of the period of the second cycle of acoustic energy approximates the recorded frequency. This paper demonstrates for the first time that the dominant frequency of a fish sound produced by a single muscle twitch is apparently determined by the velocity of the muscle twitch rather than the natural frequency of the swimbladder.

Long-Lasting Changes in Muscle Twitch Force During Simulated Work While Standing or Walking

2016 ◽  
Vol 58 (8) ◽  
pp. 1117-1127 ◽  
Author(s):  
Maria-Gabriela Garcia ◽  
Rudolf Wall ◽  
Benjamin Steinhilber ◽  
Thomas Läubli ◽  
Bernard J. Martin
Keyword(s):  
Muscle Function ◽  
Signal Amplitude ◽  
Lower Leg ◽  
Muscle Twitch ◽  
Prolonged Standing ◽  
Twitch Force ◽  
Slow Pace ◽  
Leg Muscles ◽  
Ergonomic Interventions ◽  
Hard Floor

Objective: The aim of this study was to evaluate the long-lasting effects of prolonged standing work on a hard floor or floor mat and slow-pace walking on muscle twitch force (MTF) elicited by electrical stimulation. Background: Prolonged standing work may alter lower-leg muscle function, which can be quantified by changes in the MTF amplitude and duration related to muscle fatigue. Ergonomic interventions have been proposed to mitigate fatigue and discomfort; however, their influences remain controversial. Method: Ten men and eight women simulated standing work in 320-min experiments with three conditions: standing on a hard floor or an antifatigue mat and walking on a treadmill, each including three seated rest breaks. MTF in the gastrocnemius-soleus muscles was evaluated through changes in signal amplitude and duration. Results: The significant decrease of MTF amplitude and an increase of duration after standing work on a hard floor and on a mat persisted beyond 1 hr postwork. During walking, significant MTF metrics changes appeared 30 min postwork. MTF amplitude decrease was not significant after the first 110 min in any of the conditions; however, MTF duration was significantly higher than baseline in the standing conditions. Conclusion: Similar long-lasting weakening of MTF was induced by standing on a hard floor and on an antifatigue mat. However, walking partially attenuated this phenomenon. Application: Mostly static standing is likely to contribute to alterations of MTF in lower-leg muscles and potentially to musculoskeletal disorders regardless of the flooring characteristics. Occupational activities including slow-pace walking may reduce such deterioration in muscle function.

Body Temperature and Singing in the Bladder Cicada, Cystosoma Saundersii

1979 ◽  
Vol 80 (1) ◽  
pp. 69-81 ◽  
Author(s):  
R. K. JOSEPHSON ◽  
D. YOUNG
Keyword(s):  
Heat Production ◽  
Cell Biology ◽  
Sound Production ◽  
Marked Decrease ◽  
Cooling Curve ◽  
Muscle Twitch ◽  
Temperature Excess ◽  
Air Mixing ◽  
Artificial Heat ◽  
Sound Pulses

1. Body temperatures during singing were measured in the cicada, Cystosoma saundersii Westwood, both in the field and in tethered animals indoors. 2. The temperature of the sound-producing tymbal muscle rises rapidly during singing to reach a plateau approximately 12°C above ambient. This produces a temperature gradient in the abdominal air sac which surrounds the muscle. When singing stops, the tymbal muscle cools exponentially. 3. Heat production during singing, estimated from the cooling curve, is 4.82 cal min−1 g muscle−1. Generation of the same temperature excess in the air sac by an artificial heat source yields an estimated heat production of 54.4 cal min−1 g muscle−1. This discrepancy may be caused by air mixing in the air sac during singing. 4. As temperature rises, tymbal muscle twitch contractions become faster and stronger. This and heat transfer to the thorax cause changes in the song pattern: a marked decrease in the interval between the two sound pulses produced by a single tymbal buckling and a lesser decrease in the interval between bucklings. The fundamental sound period remains unaltered. These effects are consistent with earlier data on sound production. Note: Present address: Department of Developmental and Cell Biology, University of California, Irvine, California 92717, U.S.A.

scholarly journals Cysteine Reversal of the Novel Neuromuscular Blocking Drug CW002 in Dogs

2010 ◽  
Vol 112 (4) ◽  
pp. 900-909 ◽  
Author(s):  
Hiroshi Sunaga ◽  
Jaideep K. Malhotra ◽  
Edward Yoon ◽  
John J. Savarese ◽  
Paul M. Heerdt
Keyword(s):  
Heart Rate ◽  
Dose Range ◽  
Cardiovascular Effects ◽  
Neuromuscular Blocking ◽  
Dependent Manner ◽  
Blocking Drug ◽  
Muscle Twitch ◽  
Organ Toxicity ◽  
Neuromuscular Blocking Drug ◽  
Additional Group

Background CW002 is a neuromuscular blocking drug that is inactivated by endogenous L-cysteine. This study determined the exogenous L-cysteine dose-response relationship for CW002 reversal along with acute cardiovascular effects and organ toxicity in dogs. Methods Six dogs were each studied four times during isoflurane-nitrous oxide anesthesia and recording of muscle twitch, arterial pressure, and heart rate. CW002 (0.08 mg/kg or 9 x ED95) was injected, and the time to spontaneous muscle recovery was determined. CW002 was then administered again followed 1 min later by 10, 20, 50, or 100 mg/kg L-cysteine (1 dose/experiment). After twitch recovery, CW002 was given a third time to determine whether residual L-cysteine influenced duration. Preliminary toxicology was performed in an additional group of dogs that received CW002 followed by vehicle (n = 8) or 200 mg/kg L-cysteine (n = 8). Animals were awakened and observed for 2 or 14 days before sacrificing and anatomic, biochemical, and histopathologic analyses. Results L-cysteine at all doses accelerated recovery from CW002, with both 50 and 100 mg/kg decreasing median duration from more than 70 min to less than 5 min. After reversal, duration of a subsequent CW002 dose was also decreased in a dose-dependent manner. Over the studied dose range, L-cysteine had less than 10% effect on blood pressure and heart rate. Animals receiving a single 200-mg/kg dose of L-cysteine showed no clinical, anatomic, biochemical, or histologic evidence of organ toxicity. Conclusion The optimal L-cysteine dose for rapidly reversing the neuromuscular blockade produced by a large dose of CW002 in dogs is approximately 50 mg/kg, which has no concomitant hemodynamic effect. A dose of 200 mg/kg had no evident organ toxicity.

Response to sudden torques about ankle in man: V effects of peripheral ischemia

1983 ◽  
Vol 50 (1) ◽  
pp. 297-312 ◽  
Author(s):  
G. L. Gottlieb ◽  
G. C. Agarwal ◽  
R. J. Jaeger
Keyword(s):  
Motor Response ◽  
Muscle Tone ◽  
H Reflex ◽  
Original Position ◽  
Muscle Twitch ◽  
Peripheral Ischemia ◽  
Below The Knee ◽  
Triggered Reactions ◽  
Anterior Tibial ◽  
Reflex Arc

Sudden dorsiflexions and plantar flexions of the foot were imposed by a torque motor while blood flow to the lower leg was occluded by a sphygmomanometer cuff. Seated subjects were instructed to resist the torques and restore the foot to its original position as rapidly as possible. Measurements of the first two electromyographic (EMG) responses were made in the soleus (SOL) and anterior tibial (TA) muscles. These are the myotatic reflex at about 40 ms and the postmyotatic response at about 120 ms. In the anterior tibial muscle, the myotatic component often occurs at 60- to 90-ms latency and is continuous with the postmyotatic component. After about 20 min of ischemia, there is a rapid and eventually complete loss of the myotatic component of the response in the stretched muscle. Concurrent with the loss of the myotatic reflex there is usually a reduction of the postmyotatic component. The latency of postmyotatic component remains unchanged, even after the myotatic reflex is abolished. Voluntary restoration of the foot to its original position in opposition to the motor torque is delayed and slowed by the time that the myotatic reflex has vanished. By measuring electromyographic responses to visually triggered reactions, we demonstrate that the reduction of the postmyotatic response is not due to failure of the efferent pathway. On this basis we discuss the possible contributions made by myotatic mechanisms to the tasks of load compensation and maintenance of muscle tone. Hoffmann reflexes were evoked in similar experiments with stimulation of the posterior tibial nerve at the popliteal fossa, distal to the cuff. The maximal direct motor response and muscle twitch are unaffected by loss of the H-reflex. Myotatic and Hoffmann reflexes were both evoked with torque perturbations and with a stimulating electrode proximal to a below-the-knee cuff. In this case, the myotatic reflex failed while the maximal H-reflex was slightly facilitated. The loss of the myotatic reflex was accompanied by a modest reduction in the direct motor response to electrical stimulation and a somewhat greater reduction in the postmyotatic response to torque perturbation. The data are interpreted to support a dual role for the primary afferent pathway in the control of voluntary movements. It provides the fastest path for the activation of a stretched muscle to initiate a load-compensating contraction. It also provides a form of servo assistance in modulating descending control signals. The degree of this assistance is estimated. In this simple experimental paradigm, functional contributions of the reflex arc are demonstrated.

Anatomic and physiological characteristics of the ferret lateral rectus muscle and abducens nucleus

2007 ◽  
Vol 103 (5) ◽  
pp. 1706-1714 ◽  
Author(s):  
Keith N. Bishop ◽  
J. Ross McClung ◽  
Stephen J. Goldberg ◽  
Mary S. Shall
Keyword(s):  
Motor Units ◽  
Lateral Rectus ◽  
Contraction Time ◽  
Fatigue Index ◽  
Muscle Twitch ◽  
Abducens Nucleus ◽  
Single Motor Unit ◽  
Twitch Contraction ◽  
Whole Muscle ◽  
Individual Motor

The ferret has become a popular model for physiological and neurodevelopmental research in the visual system. We believed it important, therefore, to study extraocular whole muscle as well as single motor unit physiology in the ferret. Using extracellular stimulation, 62 individual motor units in the ferret abducens nucleus were evaluated for their contractile characteristics. Of these motor units, 56 innervated the lateral rectus (LR) muscle alone, while 6 were split between the LR and retractor bulbi (RB) muscle slips. In addition to individual motor units, the whole LR muscle was evaluated for twitch, tetanic peak force, and fatigue. The abducens nucleus motor units showed a twitch contraction time of 15.4 ms, a mean twitch tension of 30.2 mg, and an average fusion frequency of 154 Hz. Single-unit fatigue index averaged 0.634. Whole muscle twitch contraction time was 16.7 ms with a mean twitch tension of 3.32 g. The average fatigue index of whole muscle was 0.408. The abducens nucleus was examined with horseradish peroxidase conjugated with the subunit B of cholera toxin histochemistry and found to contain an average of 183 motoneurons. Samples of LR were found to contain an average of 4,687 fibers, indicating an LR innervation ratio of 25.6:1. Compared with cat and squirrel monkeys, the ferret LR motor units contract more slowly yet more powerfully. The functional visual requirements of the ferret may explain these fundamental differences.

Metabolic fluctuation during a muscle contraction cycle

1998 ◽  
Vol 274 (3) ◽  
pp. C846-C852 ◽  
Author(s):  
Youngran Chung ◽  
Robert Sharman ◽  
Richard Carlsen ◽  
Steven W. Unger ◽  
Douglas Larson ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Steady State ◽  
Magnetic Resonance ◽  
Muscle Contraction ◽  
Gastrocnemius Muscle ◽  
Reference State ◽  
Maximum Force ◽  
Muscle Twitch ◽  
Energy Fluctuation ◽  
Contraction Cycle

Gated31P-nuclear magnetic resonance followed the metabolic fluctuation in rat gastrocnemius muscle during a contraction cycle. Within 16 ms after stimulation, the phosphocreatine (PCr) level drops 11.3% from its reference state. The PCr minimum corresponds closely to the time of maximum force contraction. Pi increases stoichiometrically, while ATP remains constant. During a twitch, PCr hydrolysis produces 3.1 μmol ATP/g tissue, which is substantially higher than the reported 0.3 μmol ATP ⋅ twitch−1 ⋅ g tissue−1 derived from steady-state experiments. The results reveal that a substantial energy fluctuation accompanies a muscle twitch.

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