scholarly journals Spatial variation in fast muscle function of the rainbow troutOncorhynchus mykissduring fast-starts and sprinting

2001 ◽  
Vol 204 (13) ◽  
pp. 2239-2250 ◽  
Author(s):  
D. J. Ellerby ◽  
J. D. Altringham
Keyword(s):  
Muscle Power ◽  
Fork Length ◽  
The Body ◽  
Fast Muscle ◽  
Emg Activity ◽  
Muscle Fibres ◽  
Muscle Recruitment ◽  
Axial Shift ◽  
Stage 1 ◽  
Sprint Swimming

SUMMARYFish fast-starts and sprints are rapid kinematic events powered by the lateral myotomal musculature. A distinction can be made between fast-starts and sprint-swimming activity. Fast-starts are kinematic events involving rapid, asymmetrical movements. Sprints involve a series of symmetrical, high-frequency tailbeats that are kinematically similar to lower-frequency, sustained swimming. The patterns of muscle recruitment and strain associated with these swimming behaviours were determined using electromyography and sonomicrometry. Axial patterns of fast muscle recruitment during sprints were similar to those in slow muscle in that the duration of electromyograhic (EMG) activity decreased in a rostro-caudal direction. There was also an axial shift in activity relative to the strain cycle so that activity occurred relatively earlier in the caudal region. This may result in caudal muscle performing a greater proportion of negative work and acting as a power transmitter as well as a power producer. The threshold tailbeat frequency for recruitment of fast muscle differed with location in the myotome. Superficial muscle fibres were recruited at lower tailbeat frequencies and shortening velocities than those deeper in the musculature. During sprints, fast muscle strain ranged from ±3.4%l0 (where l0 is muscle resting length) at 0.35FL (where FL is fork length) to ±6.3%l0 at 0.65FL. Fast-starts involved a prestretch of up to 2.5%l0 followed by shortening of up to 11.3%l0. Stage 1 EMG activity began simultaneously, during muscle lengthening, at all axial locations. Stage 2 EMG activity associated with the major contralateral contraction also commenced during lengthening and proceeded along the body as a wave. Onset of muscle activity during lengthening may enhance muscle power output.

Muscle dynamics in skipjack tuna: timing of red muscle shortening in relation to activation and body curvature during steady swimming

1999 ◽  
Vol 202 (16) ◽  
pp. 2139-2150 ◽  
Author(s):  
R.E. Shadwick ◽  
S.L. Katz ◽  
K.E. Korsmeyer ◽  
T. Knower ◽  
J.W. Covell
Keyword(s):  
Fork Length ◽  
Muscle Length ◽  
The Body ◽  
Emg Activity ◽  
Skipjack Tuna ◽  
Force Transmission ◽  
Muscle Strain ◽  
Muscle Shortening ◽  
Red Muscle ◽  
Length Changes

Cyclic length changes in the internal red muscle of skipjack tuna (Katsuwonus pelamis) were measured using sonomicrometry while the fish swam in a water tunnel at steady speeds of 1.1-2.3 L s(−)(1), where L is fork length. These data were coupled with simultaneous electromyographic (EMG) recordings. The onset of EMG activity occurred at virtually the same phase of the strain cycle for muscle at axial locations between approximately 0.4L and 0.74L, where the majority of the internal red muscle is located. Furthermore, EMG activity always began during muscle lengthening, 40–50 prior to peak length, suggesting that force enhancement by stretching and net positive work probably occur in red muscle all along the body. Our results support the idea that positive contractile power is derived from all the aerobic swimming muscle in tunas, while force transmission is provided primarily by connective tissue structures, such as skin and tendons, rather than by muscles performing negative work. We also compared measured muscle length changes with midline curvature (as a potential index of muscle strain) calculated from synchronised video image analysis. Unlike contraction of the superficial red muscle in other fish, the shortening of internal red muscle in skipjack tuna substantially lags behind changes in the local midline curvature. The temporal separation of red muscle shortening and local curvature is so pronounced that, in the mid-body region, muscle shortening at each location is synchronous with midline curvature at locations that are 7–8 cm (i.e. 8–10 vertebral segments) more posterior. These results suggest that contraction of the internal red muscle causes deformation of the body at more posterior locations, rather than locally. This situation represents a unique departure from the model of a homogeneous bending beam, which describes red muscle strain in other fish during steady swimming, but is consistent with the idea that tunas produce thrust by motion of the caudal fin rather than by undulation of segments along the body.

MYOTOMAL MUSCLE FUNCTION AT DIFFERENT LOCATIONS IN THE BODY OF A SWIMMING FISH

1993 ◽  
Vol 182 (1) ◽  
pp. 191-206 ◽  
Author(s):  
J. D. Altringham ◽  
C. S. Wardle ◽  
C. I. Smith
Keyword(s):  
Power Output ◽  
Muscle Function ◽  
Muscle Activation ◽  
Muscle Power ◽  
Travelling Waves ◽  
The Body ◽  
Muscle Fibres ◽  
Cycle Frequency ◽  
Lateral Muscle

We describe experiments on isolated, live muscle fibres which simulate their in vivo activity in a swimming saithe (Pollachius virens). Superficial fast muscle fibres isolated from points 0.35, 0.5 and 0.65 body lengths (BL) from the anterior tip had different contractile properties. Twitch contraction time increased from rostral to caudal myotomes and power output (measured by the work loop technique) decreased. Power versus cycle frequency curves of rostral fibres were shifted to higher frequencies relative to those of caudal fibres. In the fish, phase differences between caudally travelling waves of muscle activation and fish bending suggest a change in muscle function along the body. In vitro experiments indicate that in vivo superficial fast fibres of rostral myotomes are operating under conditions that yield maximum power output. Caudal myotomes are active as they are lengthened in vivo and initially operate under conditions which maximise their stiffness, before entering a positive power-generating phase. A description is presented for the generation of thrust at the tail blade by the superficial, fast, lateral muscle. Power generated rostrally is transmitted to the tail by stiffened muscle placed more caudally. A transition zone between power generation and stiffening travels caudally, and all but the most caudal myotomes generate power at some phase of the tailbeat. Rostral power output, caudal force, bending moment and force at the tail blade are all maximal at essentially the same moment in the tailbeat cycle, as the tail blade crosses the swimming track.

How fish power predation fast-starts

1995 ◽  
Vol 198 (9) ◽  
pp. 1851-1861 ◽  
Author(s):  
I A Johnston ◽  
J L van Leeuwen ◽  
M L F Davies ◽  
T Beddow
Keyword(s):  
Tensile Stress ◽  
Muscle Mass ◽  
Power Output ◽  
Average Power ◽  
Temperature Acclimation ◽  
The Body ◽  
Fast Muscle ◽  
Muscle Fibres ◽  
Fast Start ◽  
Tail Beat

Short-horned sculpin (Myoxocephalus scorpius L.) were acclimated for 6­8 weeks to either 5 °C or 15 °C (12 h dark: 12 h light). Fast-starts elicited by prey capture were filmed from above in silhouette using a high-speed video camera (200 frames s-1). Outlines of the body in successive frames were digitised and changes in strain for the dorsal fast muscle calculated from a knowledge of backbone curvature and the geometrical arrangement of fibres. For 15 °C-acclimated fish at 15 °C, muscle strain amplitude (peak-to-peak) during the first tail-beat was approximately 0.16 at 0.32L, 0.19 at 0.52L and 0.15 at 0.77L, where L is the total length of the fish. Fast muscle fibres were isolated and subjected to the strains calculated for the first tail-beat of the fast-start (abstracted cycle). Preparations were electrically stimulated at various times after the initiation of the fast-start using an in vivo value of duty cycle (27 %). Prior to shortening, muscle fibres at 0.52L and 0.77L were subjected to a pre-stretch of 0.055l0 and 0.085l0 respectively (where l0 is resting muscle length). The net work per cycle was calculated from plots of fibre length and tensile stress. For realistic values of stimulus onset, the average power output per abstracted cycle was similar at different points along the body and was in the range 24­31 W kg-1 wet muscle mass. During shortening, the instantaneous power output reached 175­265 W kg-1 wet muscle mass in middle and caudal myotomes. At the most posterior position examined, the muscle fibres produced significant tensile stresses whilst being stretched, resulting in an initially negative power output. The fibres half-way down the trunk produced their maximum power at around the same time that caudal muscle fibres generated significant tensile stress. Fast muscle fibres at 0.37­0.66L produced 76 % of the total work done during the first tail-beat compared with only 14 % for fibres at 0.67­0.86L, largely reflecting differences in muscle mass. The effect of temperature acclimation on muscle power was determined using the strain fluctuations calculated for 0.52L. For 5 °C-acclimated fish, the average power per cycle (± s.e.m.; W kg-1 wet muscle mass) was 21.8±3.4 at 5 °C, falling to 6.3±1.8 at 15 °C. Following acclimation to 15 °C, average power per cycle increased to 23.8±2.8 W kg-1 wet muscle mass at 15 °C. The results indicate near-perfect compensation of muscle performance with temperature acclimation.

Fast muscle function in the European eel (Anguilla anguillaL.) during aquatic and terrestrial locomotion

2001 ◽  
Vol 204 (13) ◽  
pp. 2231-2238 ◽  
Author(s):  
D. J. Ellerby ◽  
I. L. Y. Spierts ◽  
J. D. Altringham
Keyword(s):  
Muscle Activation ◽  
Muscle Power ◽  
The Body ◽  
Muscle Performance ◽  
Fast Muscle ◽  
Axial Position ◽  
European Eel ◽  
Cycle Frequency ◽  
Axial Location ◽  
Power Outputs

SUMMARYEels are capable of locomotion both in water and on land using undulations of the body axis. Axial undulations are powered by the lateral musculature. Differences in kinematics and the underlying patterns of fast muscle activation are apparent between locomotion in these two environments. The change in isometric fast muscle properties with axial location was less marked than in most other species. Time from stimulus to peak force (Ta) did not change significantly with axial position and was 82±6ms at 0.45BL and 93±3ms at 0.75BL, where BL is total body length. Time from stimulus to 90% relaxation (T90) changed significantly with axial location, increasing from 203±11ms at 0.45BL to 239±9ms at 0.75BL. Fast muscle power outputs were measured using the work loop technique. Maximum power outputs at ±5% strain using optimal stimuli were 17.3±1.3Wkg−1 in muscle from 0.45BL and 16.3±1.5Wkg−1 in muscle from 0.75BL. Power output peaked at a cycle frequency of 2Hz. The stimulus patterns associated with swimming generated greater force and power than those associated with terrestrial crawling. This decrease in muscle performance in eels may occur because on land the eel is constrained to a particular kinematic pattern in order to produce thrust against an underlying substratum.

scholarly journals RECRUITMENT PATTERNS AND CONTRACTILE PROPERTIES OF FAST MUSCLE FIBRES ISOLATED FROM ROSTRAL AND CAUDAL MYOTOMES OF THE SHORT-HORNED SCULPIN

1993 ◽  
Vol 185 (1) ◽  
pp. 251-265 ◽  
Author(s):  
I. A. Johnston ◽  
C. E. Franklin ◽  
T. P. Johnson
Keyword(s):  
Power Output ◽  
High Speed ◽  
Prey Capture ◽  
The Body ◽  
Contractile Properties ◽  
Fast Muscle ◽  
Muscle Fibres ◽  
Length Changes ◽  
Tail Beat ◽  
Positive Work

Muscle action during swimming and the contractile properties of isolated muscle fibres were studied in the short-horned sculpin Myoxocephalus scorpius at 5°C. Semi-steady swimming, startle responses and prey-capture events were filmed with a high-speed video at 200 frames s-1, using fish 22–26 cm in total length (L). Electromyographical (EMG) recordings, synchronised with the video, were made from fast muscle in rostral and caudal myotomes at points 0.40L and 0.80L along the body. Fast muscle fibres were first recruited at tail-beat frequencies of 3.7-4.2 Hz, corresponding to a swimming speed of 1.7 L s-1. Electrical activity in the muscles occurred during 16–38 % of each tail- beat cycle regardless of frequency. Muscle fibres were activated during the lengthening phase of the cycle. In caudal myotomes, the onset of the muscle activity occurred at a phase of 75–105° at 3.7 Hz, decreasing to approximately 50° at frequencies greater than 4.5 Hz (0° phase was defined as the point at which muscle fibres passed through their resting lengths in the stretch phase of the cycle; a full cycle is 360°). Prey capture was a stereotyped behaviour consisting of a preparatory movement, a powerstroke at 7–9 Hz and a glide of variable duration. The delay between the activation of muscle fibres in rostral and caudal myotomes during prey capture and startle responses was approximately 10 ms. Fast muscle fibres isolated from rostral and caudal myotomes were found to have similar isometric contractile properties. Maximum tetanic stress was 220 kN m-2, and half-times for force development and relaxation were approximately 50 ms and 135 ms respectively. Power output was measured by the ‘work loop’ technique in muscle fibres subjected to sinusoidal length changes at the range of frequencies found during swimming. Under optimal conditions of strain and stimulation, muscle fibres from rostral and caudal myotomes produced similar levels of work (3.5 J kg-1) and generated their maximum power output of 25–30 W kg-1 at the tail-beat frequencies used in swimming (4–8 Hz). Progressively delaying the onset of stimulation relative to the start of the strain cycle resulted in an initial modest increase, followed by a decline, in the work per cycle. Maximum positive work and net negative work were done at stimulus phase values of 20–50° and 120–140° respectively. The EMG and swimming studies suggest that fast muscle fibres in both rostral and caudal myotomes do net positive work under most conditions.

scholarly journals Respiratory tract infections in children with allergic asthma on allergen immunotherapy during influenza season

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yuyun Li ◽  
Dongming Wang ◽  
Lili Zhi ◽  
Yunmei Zhu ◽  
Lan Qiao ◽  
...  
Keyword(s):  
Respiratory Tract ◽  
Allergic Asthma ◽  
Respiratory Tract Infections ◽  
Allergen Immunotherapy ◽  
Clinical Symptoms ◽  
Influenza Season ◽  
The Body ◽  
History Of ◽  
Tract Infections ◽  
Stage 1

AbstractTo describle how respiratory tract infections (RTIs) that occurred in children with allergic asthma (AA) on allergen immunotherapy (AIT) during an influenza season. Data including clinical symptoms and treatment history of children (those with AA on AIT and their siblings under 14 years old), who suffered from RTIs during an influenza season (Dec 1st, 2019–Dec 31st, 2019), were collected (by face to face interview and medical records) and analyzed. Children on AIT were divided into 2 groups: stage 1 (dose increasing stage) and stage 2 (dose maintenance stage). Their siblings were enrolled as control. During the study period, 49 children with AA on AIT (33 patients in stage 1 and 16 patients in stage 2) as well as 49 children without AA ( their siblings ) were included. There were no significant differences in occurrences of RTIs among the three groups (p > 0.05). Compared with children in the other two groups, patients with RTIs in stage 2 had less duration of coughing and needed less medicine. Children on AIT with maintenance doses had fewer symptoms and recovered quickly when they were attacked by RTIs, which suggested that AIT with dose maintenance may enhance disease resistance of the body.

scholarly journals Myosin heavy-chain composition in striated muscle after tenotomy

1992 ◽  
Vol 282 (1) ◽  
pp. 237-242 ◽  
Author(s):  
A Jakubiec-Puka ◽  
C Catani ◽  
U Carraro
Keyword(s):  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Striated Muscle ◽  
Slow Muscle ◽  
Fast Muscle ◽  
Muscle Fibres ◽  
Adult Rats ◽  
Tendon Regeneration ◽  
Adult Muscle ◽  
Gastrocnemius Muscles

The myosin heavy-chain (MHC) isoform pattern was studied by biochemical methods in the slow-twitch (soleus) and fast-twitch (gastrocnemius) muscles of adult rats during atrophy after tenotomy and recovery after tendon regeneration. The tenotomized slow muscle atrophied more than the tenotomized fast muscle. During the 12 days after tenotomy the total MHC content decreased by about 85% in the slow muscle, and only by about 35% in the fast muscle. In the slow muscle the ratio of MHC-1 to MHC-2A(2S) remained almost unchanged, showing that similar diminution of both isoforms occurs. In the fast muscle the MHC-2A/MHC-2B ratio decreased, showing the loss of MHC-2A mainly. After tendon regeneration, the slow muscle recovered earlier than the fast muscle. Full recovery of the muscles was not observed until up to 4 months later. The embryonic MHC, which seems to be expressed in denervated adult muscle fibres, was not detected by immunoblotting in the tenotomized muscles during either atrophy or recovery after tendon regeneration. The influence of tenotomy and denervation on expression of the MHC isoforms is compared. The results show that: (a) MHC-1 and MHC-2A(2S) are very sensitive to tenotomy, whereas MHC-2B is much less sensitive; (b) expression of the embryonic MHC in adult muscle seems to be inhibited by the intact neuromuscular junction.

The ultrastructure of the epidermis of the redia and cercaria of Parorchis acanthus, Nicoll. A study by scanning and transmission electron-microscopy

Parasitology ◽  
1971 ◽  
Vol 62 (3) ◽  
pp. 479-488 ◽  
Author(s):  
Gwendolen Rees
Keyword(s):  
Electron Micrographs ◽  
Technical Assistance ◽  
Ventral Surface ◽  
The Body ◽  
Muscle Fibres ◽  
Scanning Electron Micrographs ◽  
Large Area ◽  
Transmission Electron ◽  
Parorchis Acanthus ◽  
Scanning Electron

Scanning electron-micrographs have shown the covering of microvilli on the surface of the redia of Parorchis acanthus. In the contracted state the elongated microvilli with bulbous extremities seen in the surface grooves may be the result of compression. The surface of the epidermis of the cercaria is smooth on a large area of the ventral surface and lattice-like with microvilli, laterally, anteriorly, dorsally and on the tail. The spines on the body can be withdrawn into sheaths by the contraction of muscle fibres inserted into the basement lamina below each spine.I would like to express my sincere gratitude to Dr I. ap Gwynn of this department for preparing the scanning electron-micrographs and the School of Engineering Science, University of North Wales, Bangor for the use of their stereoscan. I should also like to thank Mr M. C. Bibby for technical assistance and Professor E. G. Gray and Dr W. Sinclair for assistance with the transmission electron-micrographs.

scholarly journals VI. —Anaphylaxis and anaphylatoxins

1923 ◽  
Vol 211 (382-390) ◽  
pp. 273-315 ◽  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Guinea Pig ◽  
Anaphylactic Shock ◽  
The Body ◽  
Muscle Fibres ◽  
Direct Stimulation ◽  
Fundamental Conception ◽  
The Central Nervous System ◽  
Stimulation Of

In the study of the phenomena of anaphylaxis there are certain points on which some measure of agreement seems to have been attained. In the case of anaphylaxis to soluble proteins, with which alone we are directly concerned in this paper, the majority of investigators probably accept the view that the condition is due to the formation of an antibody of the precipitin type. Concerning the method, however, by which the presence of this antibody causes the specific sensitiveness, the means by which its interaction with the antibody produces the anaphylactic shock, there is a wide divergence of conception. Two main currents of speculation can be discerned. One view, historically rather the earlier, and first put forward by Besredka (1) attributes the anaphylactic condition to the location of the antibody in the body cells. There is not complete unanimity among adherents of this view as to the nature of the antibody concerned, or as to the class of cells containing it which are primarily affected in the anaphylactic shock. Besredka (2) himself has apparently not accepted the identification of the anaphylactic antibody with a precipitin, but regards it as belonging to a special class (sensibilisine). He also regards the cells of the central nervous system as those primarily involved in the anaphylactic shock in the guinea-pig. Others, including one of us (3), have found no adequate reason for rejecting the strong evidence in favour of the precipitin nature of the anaphylactic antibody, produced by Doerr and Russ (4), Weil (5), and others, and have accepted and confirmed the description of the rapid anaphylactic death in the guinea-pig as due to a direct stimulation of the plain-muscle fibres surrounding the bronchioles, causing valve-like obstruction of the lumen, and leading to asphyxia, with the characteristic fixed distension of the lungs, as first described by Auer and Lewis (6), and almost simultaneously by Biedl and Kraus (7). But the fundamental conception of anaphylaxis as due to cellular location of an antibody, and of the reaction as due to the union of antigen and antibody taking place in the protoplasm, is common to a number of workers who thus differ on details.

Red muscle activation patterns in yellowfin (Thunnus albacares) and skipjack (Katsuwonus pelamis) tunas during steady swimming

1999 ◽  
Vol 202 (16) ◽  
pp. 2127-2138 ◽  
Author(s):  
T. Knower ◽  
R.E. Shadwick ◽  
S.L. Katz ◽  
J.B. Graham ◽  
C.S. Wardle
Keyword(s):  
Muscle Activation ◽  
Fork Length ◽  
Force Transducer ◽  
The Body ◽  
Thunnus Albacares ◽  
Katsuwonus Pelamis ◽  
Activation Patterns ◽  
Muscle Activation Patterns ◽  
Red Muscle ◽  
Swimming Mode

To learn about muscle function in two species of tuna (yellowfin Thunnus albacares and skipjack Katsuwonus pelamis), a series of electromyogram (EMG) electrodes was implanted down the length of the body in the internal red (aerobic) muscle. Additionally, a buckle force transducer was fitted around the deep caudal tendons on the same side of the peduncle as the electrodes. Recordings of muscle activity and caudal tendon forces were made while the fish swam over a range of steady, sustainable cruising speeds in a large water tunnel treadmill. In both species, the onset of red muscle activation proceeds sequentially in a rostro-caudal direction, while the offset (or deactivation) is nearly simultaneous at all sites, so that EMG burst duration decreases towards the tail. Muscle duty cycle at each location remains a constant proportion of the tailbeat period (T), independent of swimming speed, and peak force is registered in the tail tendons just as all ipsilateral muscle deactivates. Mean duty cycles in skipjack are longer than those in yellowfin. In yellowfin red muscle, there is complete segregation of contralateral activity, while in skipjack there is slight overlap. In both species, all internal red muscle on one side is active simultaneously for part of each cycle, lasting 0.18T in yellowfin and 0.11T in skipjack. (Across the distance encompassing the majority of the red muscle mass, 0.35-0.65L, where L is fork length, the duration is 0.25T in both species.) When red muscle activation patterns were compared across a variety of fish species, it became apparent that the EMG patterns grade in a progression that parallels the kinematic spectrum of swimming modes from anguilliform to thunniform. The tuna EMG pattern, underlying the thunniform swimming mode, culminates this progression, exhibiting an activation pattern at the extreme opposite end of the spectrum from the anguilliform mode.

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