Skeletal muscle interaction synergetic effects during a complex acyclic motor action performing

2021 ◽  
Author(s):  
S.A. Moiseev ◽  
S.M. Ivanov ◽  
R.V. Shamilov ◽  
I.Yu. Dolgova
Keyword(s):  
Skeletal Muscle ◽  
Temporal Structure ◽  
Muscle Synergies ◽  
Reliable Control ◽  
Motor Action ◽  
Synergetic Effects ◽  
Pca Method ◽  
The Individual ◽  
Complex Movement ◽  
Key Words Muscle

The study showed the sambo wrestlers’ muscle synergies’ spatial-temporal structure, extracted using the PCA method. We considered the individual periods of the "leg grabbing" throw coordination structure. It was revealed the electrical activity of extensive synergies changes depending on registered muscular efforts values, typical for different periods of the performed movement. The synergetic effects of skeletal muscle interaction demonstrate plasticity, manifested in typical patterns of spatial and temporal activation of revealed muscle synergies, which ensures reliable control of motor function in various periods of complex movement coordination performing. Key words: muscle synergies; synergetic effects; intermuscular coordination; motion control, skeletal muscle.

scholarly journals Confounding Roles of ER Stress and the Unfolded Protein Response in Skeletal Muscle Atrophy

2021 ◽  
Vol 22 (5) ◽  
pp. 2567
Author(s):  
Yann S. Gallot ◽  
Kyle R. Bohnert
Keyword(s):  
Skeletal Muscle ◽  
Er Stress ◽  
Unfolded Protein Response ◽  
Smooth Endoplasmic Reticulum ◽  
Skeletal Muscle Atrophy ◽  
Unfolded Protein ◽  
The Individual ◽  
The Unfolded Protein Response ◽  
Protein Response

Skeletal muscle is an essential organ, responsible for many physiological functions such as breathing, locomotion, postural maintenance, thermoregulation, and metabolism. Interestingly, skeletal muscle is a highly plastic tissue, capable of adapting to anabolic and catabolic stimuli. Skeletal muscle contains a specialized smooth endoplasmic reticulum (ER), known as the sarcoplasmic reticulum, composed of an extensive network of tubules. In addition to the role of folding and trafficking proteins within the cell, this specialized organelle is responsible for the regulated release of calcium ions (Ca2+) into the cytoplasm to trigger a muscle contraction. Under various stimuli, such as exercise, hypoxia, imbalances in calcium levels, ER homeostasis is disturbed and the amount of misfolded and/or unfolded proteins accumulates in the ER. This accumulation of misfolded/unfolded protein causes ER stress and leads to the activation of the unfolded protein response (UPR). Interestingly, the role of the UPR in skeletal muscle has only just begun to be elucidated. Accumulating evidence suggests that ER stress and UPR markers are drastically induced in various catabolic stimuli including cachexia, denervation, nutrient deprivation, aging, and disease. Evidence indicates some of these molecules appear to be aiding the skeletal muscle in regaining homeostasis whereas others demonstrate the ability to drive the atrophy. Continued investigations into the individual molecules of this complex pathway are necessary to fully understand the mechanisms.

The KATP channel Kir6.2 subunit content is higher in glycolytic than oxidative skeletal muscle fibers

2011 ◽  
Vol 301 (4) ◽  
pp. R916-R925 ◽  
Author(s):  
Krystyna Banas ◽  
Charlene Clow ◽  
Bernard J. Jasmin ◽  
Jean-Marc Renaud
Keyword(s):  
Skeletal Muscle ◽  
Cross Sections ◽  
Fiber Type ◽  
Energy Levels ◽  
Muscle Fibers ◽  
Metabolic Stress ◽  
Oxidative Capacity ◽  
Fiber Types ◽  
Fiber Damage ◽  
The Individual

It has long been suggested that in skeletal muscle, the ATP-sensitive K+ channel (KATP) channel is important in protecting energy levels and that abolishing its activity causes fiber damage and severely impairs function. The responses to a lack of KATP channel activity vary between muscles and fibers, with the severity of the impairment being the highest in the most glycolytic muscle fibers. Furthermore, glycolytic muscle fibers are also expected to face metabolic stress more often than oxidative ones. The objective of this study was to determine whether the t-tubular KATP channel content differs between muscles and fiber types. KATP channel content was estimated using a semiquantitative immunofluorescence approach by staining cross sections from soleus, extensor digitorum longus (EDL), and flexor digitorum brevis (FDB) muscles with anti-Kir6.2 antibody. Fiber types were determined using serial cross sections stained with specific antimyosin I, IIA, IIB, and IIX antibodies. Changes in Kir6.2 content were compared with changes in CaV1.1 content, as this Ca2+ channel is responsible for triggering Ca2+ release from sarcoplasmic reticulum. The Kir6.2 content was the lowest in the oxidative soleus and the highest in the glycolytic EDL and FDB. At the individual fiber level, the Kir6.2 content within a muscle was in the order of type IIB > IIX > IIA ≥ I. Interestingly, the Kir6.2 content for a given fiber type was significantly different between soleus, EDL, and FDB, and highest in FDB. Correlations of relative fluorescence intensities from the Kir6.2 and CaV1.1 antibodies were significant for all three muscles. However, the variability in content between the three muscles or individual fibers was much greater for Kir6.2 than for CaV1.1. It is suggested that the t-tubular KATP channel content increases as the glycolytic capacity increases and as the oxidative capacity decreases and that the expression of KATP channels may be linked to how often muscles/fibers face metabolic stress.

scholarly journals BIOMECHANICAL ASSESSMENT OF THE MOTOR ACTION OF THE TECHNIQUE SEOI NAGE IN THE JUDO SPORT

2019 ◽  
Vol 17 (Suppl.1) ◽  
pp. 717-722
Author(s):  
Nikolina Dimitrova
Keyword(s):  
Point Of View ◽  
Training Process ◽  
Motor Action ◽  
Basic Technique ◽  
Legal Principles ◽  
Biomechanical Assessment ◽  
Is Research ◽  
Active Experiment ◽  
The Individual

An “active” experiment has been realized for cinematic and dynamographic analyses of the motor action with one of the basic judo techniques of Kyu-dan system Seoi nage. From one hand the general common and legal principles assuring the success of the technique are respected and the individual particularities demonstrated during the performance of elite sportsman. The aim of the present work is research and realization of complex biomechanical analyses of the technique Seoi nage. The cinematic characteristics are assessed from quantity point of view with the help of videocomputing methods and the dynamic ones by using measurement of the supporting reactions on the dynamograhic platform. Two elite competitors for whom Seoi nage represents the basic technique are taking part in the research. The results followed the performance are common biomechanical regularities and important individual particularities in the sport technical mastership. The obtained results are followed by questions to the training process concerning the measurement between the standards and the individualization of the sport technical mastership.

Androgen cytosol binding during compensatory overload-induced skeletal muscle hypertrophy

1985 ◽  
Vol 63 (5) ◽  
pp. 348-354 ◽  
Author(s):  
R. C. Hickson ◽  
T. T. Kurowski ◽  
T. M. Galassi ◽  
D. G. Daniels ◽  
R. J. Chatterton Jr.
Keyword(s):  
Skeletal Muscle ◽  
Muscle Hypertrophy ◽  
Glucocorticoid Receptors ◽  
Male Rats ◽  
Control Group ◽  
Binding Model ◽  
Sequence Of Events ◽  
Skeletal Muscle Hypertrophy ◽  
High Concentrations ◽  
The Individual

This study was undertaken to evaluate whether the increased androgen cytosol binding is an early or later event in the sequence of skeletal muscle hypertrophy induced by surgical overload. Following removal of the synergistic gastrocnemius and soleus muscles, plantaris muscle weights of overloaded hypophysectomized male rats were heavier than those in the controls by 29% at 2 days, 41% at 7 days, 38% at 14 days, and 47% at 35 days. Androgen cytosol receptor binding capacities (femtomoles per milligram protein), determined using a synthetic androgen, [3H]methyltrienolone (R1881), were higher than observed in muscles of controls at all points of muscle enlargement. At high concentrations of labeled ligand, Scatchard analyses became nonlinear and were resolved using a two-component binding model. Receptor capacity of the higher affinity "androgenic component" for methyltrienolone binding in plantaris muscles was lower at 2 days but 60–80% higher at 7, 14, and 35 days in the hypertrophied group than in the control group. The lower affinity "glucocorticoid component" was higher in the overloaded group at all points following surgery. Several glucocorticoids and estradiol-17β competed equally with androgens for methyltrienolone binding. However, when cytosol s were incubated with triamcinolone acetonide to block methyltrienolone binding to glucocorticoid receptors, the androgenic component was highly specific for androgens. These results show that total [3H]methyltrienolone cytosol concentrations increased in parallel with the muscle hypertrophy, yet the individual components of methyltrienolone binding attained greater concentrations in overloaded muscles by an apparently different sequence of events.

Interactions of Perceived Intensity, Duration, and Pitch in Pure Tone Sequences

1997 ◽  
Vol 14 (3) ◽  
pp. 281-294 ◽  
Author(s):  
Hasan Gürkan Tekman
Keyword(s):  
Pure Tone ◽  
Temporal Structure ◽  
One Dimension ◽  
Perceptual Object ◽  
Perceived Intensity ◽  
Pitch Structure ◽  
The Individual ◽  
Rhythmic Organization

If one dimension of sound is manipulated in a way that suggests a particular rhythmic organization, does perception of other dimensions change in ways that are consistent with the same rhythmic organization? When subjects were asked to judge or adjust intensities of tones, rhythmic manipulations of pitch structure changed the perception of intensity. When subjects were asked to judge timing, rhythmic manipulations of intensity had a similar effect. Timing manipulations did not have an effect on judgments of pitch. The results indicate that temporal structure as a whole is more accessible than the individual physical manipulations that give rise to that structure. It may be concluded that the temporal structure itself, rather than pitches, intensities, and durations in isolation, is a perceptual object.

Sample Size Required for the Accurate Determination of Fiber Area and Capillarity of Human Skeletal Muscle

1998 ◽  
Vol 23 (6) ◽  
pp. 594-599 ◽  
Author(s):  
Gary E. Mccall ◽  
William C. Byrnes ◽  
Arthur L. Dickinson ◽  
Steven J. Fleck
Keyword(s):  
Skeletal Muscle ◽  
Sample Size ◽  
Biceps Brachii ◽  
Accurate Determination ◽  
Sequential Estimation ◽  
Type I ◽  
College Age ◽  
Fiber Area ◽  
Key Words Muscle

This study aimed to determine the skeletal muscle fiber sample size required for a reliable, valid representation of an individual's average fiber area and capillary contacts (CC) per fiber. Biopsies were obtained from the biceps brachii of 11 college-age, recreational resistance-trained men in conjunction with a study investigating how muscle morphology changed after 12 weeks of resistance training. The effect of additional measurements on the rolling cumulative means for fiber area and CC per fiber was evaluated using sequential estimation analysis. Results showed that group cumulative mean and standard deviation had stabilized by 50 fiber measurements per individual for type I and II fibers and CC per fiber. Significant correlations (.96-.99; p < .05) existed between the 50th and 95th/100th cumulative individual means. These results indicate that a typical skeletal muscle needle biopsy would be sufficient to characterize type I and II fiber areas and CC per fiber of an individual in most subject populations, although the required sample size for characterizing fiber subtypes might be different. Key words: muscle biopsy; sequential estimation analysis

Differential Effects of Sevoflurane, Isoflurane, and Halothane on Ca (2+) Release from the Sarcoplasmic Reticulum of Skeletal Muscle 

1999 ◽  
Vol 91 (1) ◽  
pp. 179-186 ◽  
Author(s):  
Gudrun Kunst ◽  
Bernhard M. Graf ◽  
Rupert Schreiner ◽  
Eike Martin ◽  
Rainer H. A. Fink
Keyword(s):  
Skeletal Muscle ◽  
Sarcoplasmic Reticulum ◽  
Muscle Fibers ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Maximal Force ◽  
Skinned Muscle ◽  
Skeletal Muscle Fibers ◽  
Force Relation ◽  
The Individual

Background Although malignant hyperthermia after application of sevoflurane has been reported, little is known about its action on intracellular calcium homeostasis of skeletal muscle. The authors compared the effect of sevoflurane with that of isoflurane and halothane on Ca2+ release of mammalian sarcoplasmic reticulum and applied a novel method to quantify Ca2+ turnover in permeabilized skeletal muscle fibers. Methods Liquid sevoflurane, isoflurane, and halothane at 0.6 mM, 3.5 mM, and 7.6 mm were diluted either in weakly calcium buffered solutions with no added Ca2+ (to monitor Ca2+ release) or in strongly Ca2+ buffered solutions with [Ca2+] values between 3 nM and 24.9 microm for [Ca+]-force relations. Measurements were taken on single saponin skinned muscle fiber preparations of BALB/c mice. Individual [Ca2+]force relations were characterized by the Ca2+ concentration at half-maximal force that indicates the sensitivity of the contractile proteins and by the steepness. Each force transient was transformed directly into a Ca2+ transient with respect to the individual [Ca2+]-force relation of the fiber. Results At 0.6 mM, single force transients induced by sevoflurane were lower compared with equimolar concentrations of isoflurane and halothane (P &lt; 0.05). Similarly, calculated peak Ca2+ transients of sevoflurane were lower than those induced by equimolar halothane (P &lt; 0.05). The Ca2+ concentrations at half maximal force were decreased after the addition of sevoflurane, isoflurane, and halothane in a concentration-dependent manner (P &lt; 0.05). Conclusion Whereas sevoflurane, isoflurane, and halothane similarly increase the Ca2+ sensitivity of the contractile apparatus in skeletal muscle fibers, 0.6 mM sevoflurane induces smaller Ca2+ releases from the sarcoplasmic reticulum than does equimolar halothane.

Subject, Space, Time: How to Read Ancient Chinese Text

2020 ◽  
Vol 12 (3-1) ◽  
pp. 17-35
Author(s):  
Andrey Krushinskiy ◽  
Keyword(s):  
Chinese Text ◽  
Temporal Structure ◽  
Special Kind ◽  
General Characteristic ◽  
Linear Ordering ◽  
Hieroglyphic Writing ◽  
The Subject ◽  
The Individual ◽  
Person Game ◽  
The Ancient Chinese

The epoch-making discovery of the phenomenon of non-linear organization of the ancient Chinese text by the remarkable Leningrad sinologist-philosopher V.S. Spirin (1929–2002) radically expanded the horizons of our perception of the written heritage of Ancient China, outlining the way to overcome the prejudice about linear reading of the ancient Chinese classics as supposedly the only acceptable. At the same time, Spirin’s discovery of the multidimensionality of the ancient Chinese text seriously challenges the concept of the subject in the context of ancient Chinese discourse. After all, a break with the linear ordering of the text is tantamount to destroying the unity of the speech intention and the subjectivity of the speaker corresponding to it, constituted by his speaking. Accordingly, the figure of a storyteller telling a story should either disappear, leaving behind a void of subjectlessness, or give way to a completely different subjectivity. The proposed article raises the question of the nature and character of this subjectivity, which is fundamentally different from the narrator’s figure. It is shown that the synchronous integrity of the multidimensional image (Xiang 象), which distinguishes the Chinese hieroglyphic writing, has its own temporality, which allows it to be an alternative to the diachronic unity of the narrative. It is argued that the temporality of the image-xiang extends to gestaltic multidimensionality of hexagram graphics, endowing the latter with the corresponding multidimensional temporal structure. It is the hexagram time (guashi 卦時) that assumes the functions of a narrative for the temporal unification of the past and the future, thereby providing the necessary prerequisites for the emergence of a special kind of subjectivity. The guashi-hexagram time is determined by the graphic structure of the hexagram. This is the most general characteristic of the meaning of a particular hexagram as an era, providing space for the game between the era and the individual. As a result, we have a two-person game, constituting a game subjectivity, consisting of the game interaction of an individual and a hexagram time. It is argued that it is precisely the subordination of the line of discourse to the course of the game that sometimes makes it loop, and then the text lining up along this line requires its reader to read it backward, so to speak.

scholarly journals Physiological and histological changes in skeletal muscle following in vivo gene transfer by electroporation

2011 ◽  
Vol 301 (5) ◽  
pp. C1239-C1250 ◽  
Author(s):  
Joseph A. Roche ◽  
Diana L. Ford-Speelman ◽  
Lisa W. Ru ◽  
Allison L. Densmore ◽  
Renuka Roche ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Green Fluorescent Protein ◽  
Intramuscular Injection ◽  
Fluorescent Protein ◽  
Contractile Function ◽  
Complete Recovery ◽  
Secondary Damage ◽  
The Individual ◽  
Green Fluorescent

Electroporation (EP) is used to transfect skeletal muscle fibers in vivo, but its effects on the structure and function of skeletal muscle tissue have not yet been documented in detail. We studied the changes in contractile function and histology after EP and the influence of the individual steps involved to determine the mechanism of recovery, the extent of myofiber damage, and the efficiency of expression of a green fluorescent protein (GFP) transgene in the tibialis anterior (TA) muscle of adult male C57Bl/6J mice. Immediately after EP, contractile torque decreased by ∼80% from pre-EP levels. Within 3 h, torque recovered to ∼50% but stayed low until day 3. Functional recovery progressed slowly and was complete at day 28. In muscles that were depleted of satellite cells by X-irradiation, torque remained low after day 3, suggesting that myogenesis is necessary for complete recovery. In unirradiated muscle, myogenic activity after EP was confirmed by an increase in fibers with central nuclei or developmental myosin. Damage after EP was confirmed by the presence of necrotic myofibers infiltrated by CD68+ macrophages, which persisted in electroporated muscle for 42 days. Expression of GFP was detected at day 3 after EP and peaked on day 7, with ∼25% of fibers transfected. The number of fibers expressing green fluorescent protein (GFP), the distribution of GFP+ fibers, and the intensity of fluorescence in GFP+ fibers were highly variable. After intramuscular injection alone, or application of the electroporating current without injection, torque decreased by ∼20% and ∼70%, respectively, but secondary damage at D3 and later was minimal. We conclude that EP of murine TA muscles produces variable and modest levels of transgene expression, causes myofiber damage due to the interaction of intramuscular injection with the permeabilizing current, and that full recovery requires myogenesis.

ELECTROMYOGRAPHY, NERVE ACTION POTENTIAL, AND COMPOUND MOTOR ACTION POTENTIALS IN OBSTETRIC BRACHIAL PLEXUS LESIONS

Neurosurgery ◽  
2009 ◽  
Vol 65 (suppl_4) ◽  
pp. A153-A159 ◽  
Author(s):  
Martijn J.A. Malessy ◽  
Willem Pondaag ◽  
J. Gert van Dijk
Keyword(s):  
Action Potential ◽  
Brachial Plexus ◽  
Action Potentials ◽  
Typical Feature ◽  
Clinical Findings ◽  
Motor Action ◽  
Compound Motor Action Potential ◽  
Nerve Action ◽  
Obstetric Brachial Plexus ◽  
The Individual

Abstract OBJECTIVE Obstetric brachial plexus lesions (OBPLs) are caused by traction to the brachial plexus during labor. Typically, in these lesions, the nerves are usually not completely ruptured but form a “neuroma-in-continuity.” Even in the most severe OBPL lesions, at least some axons will pass through this neuroma-in-continuity and reach the tubes distal to the lesion site. These axons may be particularly prone to abnormal branching and misrouting, which may explain the typical feature of co-contraction. An additional factor that may reduce functional regeneration is that improper central motor programming may occur. Surgery should be restricted to severe cases in which spontaneous restoration of function will not occur, i.e., in neurotmesis or root avulsions. A major problem is how to predict whether function will be best after spontaneous nerve outgrowth or after nerve reconstructive surgery. When a decision has been made to perform an early surgical exploration, what to do with the neuroma-in-continuity can be a problem. The intraoperative appraisal is difficult and depends on experience, but even in experienced hands, misjudgment can be made. METHODS We performed an observational study to assess whether early electromyography (at the age of 1 month) is able to predict severe lesions. Additionally, the value of intraoperative nerve action potential and compound motor action potentials was investigated. RESULTS Severe cases of OBPL can be identified at 1 month of age on the basis of clinical findings and needle electromyography of the biceps. This outcome needs independent validation, which is currently in progress. Nerve action potential and compound motor action potential recordings show statistically significant differences on the group level between avulsion, neurotmesis, axonotmesis, and normal. For the individual patient, a clinically useful cutoff point could not be found. Intraoperative nerve action potential and compound motor action potential recordings do not add to the decision making during surgery. CONCLUSION The absence of a “gold standard” for the assessment of the severity of the OBPL lesion makes prognostic studies of OBPL complex. The currently available assessment strategies used to obtain the best possible solutions are discussed.

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