Quantitative histochemical studies of the peripheral innervation of cod (Gadus morhua) fast myotomal muscle fibres

1981 ◽  
Vol 143 (1) ◽  
pp. 123-127 ◽  
Author(s):  
J. D. Altringham ◽  
I. A. Johnston
Keyword(s):  
Gadus Morhua ◽  
Muscle Fibres ◽  
Peripheral Innervation ◽  
Myotomal Muscle

EFFICIENCY OF ENERGY CONVERSION DURING SINUSOIDAL MOVEMENT OF WHITE MUSCLE FIBRES FROM THE DOGFISH SCYLIORHINUS CANICULA

1993 ◽  
Vol 183 (1) ◽  
pp. 137-147 ◽  
Author(s):  
N. A. Curtin ◽  
R. C. Woledge
Keyword(s):  
Power Output ◽  
High Efficiency ◽  
Fibre Length ◽  
Dry Mass ◽  
Energy Output ◽  
Maximum Efficiency ◽  
Muscle Fibres ◽  
Work Output ◽  
Sinusoidal Movement ◽  
Myotomal Muscle

Net work output and heat production of white myotomal muscle fibres from the dogfish were measured during complete cycles of sinusoidal movement at 12°C. The peak-to-peak movement was about 9 % of the muscle fibre length; three stimuli at 32 ms intervals were given in each mechanical cycle. The frequency of movement and the timing of the stimulation were varied for each preparation to find the optimal conditions for power output and those optimal for efficiency (the ratio of net work output to total energy output as heat+work). To achieve either maximum power or maximum efficiency, the tetanus must start while the muscle fibres are being stretched, before the beginning of the shortening part of the mechanical cycle. The highest power output, averaged over one cycle, was 0.23+/−0.014 W g-1 dry mass (+/−s.e.m., N=9, 46.9+/−2.8 mW g-1 wet mass) and was produced during movement at 3.5 Hz. The highest efficiency, 0.41+/−0.02 (+/−s.e.m., N=13), occurred during movements at 2.0-2.5 Hz. This value is higher than the efficiency previously measured during isovelocity shortening of these fibres. The implications of the high efficiency for crossbridge models of muscle contraction are discussed.

scholarly journals Activation of Multiply Innervated Fast and Slow Myotomal Muscle Fibres of the Teleost Myoxocephalus Scorpius

1988 ◽  
Vol 140 (1) ◽  
pp. 313-324 ◽  
Author(s):  
J. D. ALTRINGHAM ◽  
I. A. JOHNSTON
Keyword(s):  
Action Potentials ◽  
Spinal Nerve ◽  
Resting Potential ◽  
Muscle Fibres ◽  
Significant Difference ◽  
Slow Muscle Fibres ◽  
Myoxocephalus Scorpius ◽  
Nerve Muscle ◽  
Myotomal Muscle ◽  
Tetanic Tension

A nerve-muscle preparation from the sculpin Myoxocephalus scorpius was used to study the membrane response of fast and slow muscle fibres to stimulation of the spinal nerves. There was no significant difference between resting potential in fast (−81.9mV) and slow fibres (−80.8mV). Fast fibres responded to a suprathreshold stimulus in the spinal nerve with an action potential. Overshoots of up to +32 mV were recorded. Both junction potentials and overshooting action potentials were observed in the slow fibres. The twitch/tetanus characteristics of myotomal muscle were investigated using isolated bundles of ‘live’ fast and slow fibres. Both fibre types responded to a single stimulus with a mechanical twitch. Fused tetani were obtained at around 50Hz in fast fibres and 20 Hz in slow fibres. In the slow fibres, tetanic tension increased with frequency up to around 50Hz. At frequencies giving maximum tetanic tension, the twitch/tetanus ratio was 0.70 for fast fibres and 0.29 for slow ones. These results are discussed with reference to the polyneuronal/multiterminal innervation pattern of the myotomal muscle in teleost fish and its role in locomotion.

scholarly journals Power Output and Force-Velocity Relationship of Live Fibres from White Myotomal Muscle of the Dogfish, Scyliorhinus Canicula

1988 ◽  
Vol 140 (1) ◽  
pp. 187-197 ◽  
Author(s):  
N. A. CURTIN ◽  
R. C. WOLEDGE
Keyword(s):  
Power Output ◽  
Maximum Velocity ◽  
Muscle Fibres ◽  
Fish Length ◽  
Skinned Fibres ◽  
Step Method ◽  
Velocity Relationship ◽  
Velocity Of Shortening ◽  
Force Velocity ◽  
Myotomal Muscle

The relationship between force and velocity of shortening and between power and velocity were examined for myotomal muscle fibre bundles from the dogfish. The maximum velocity of shortening, mean value 4.8 ± 0.2 μms−1 half sarcomere−1 (±S.E.M., N = 13), was determined by the ‘slack step’ method (Edman, 1979) and was found to be independent of fish length. The force-velocity relationship was hyperbolic, except at the high-force end where the observations were below the hyperbola fitted to the rest of the data. The maximum power output was 91 ± 14 W kg−1 wet mass (±S.E.M., N = 7) at a velocity of shortening of 1.3 ± 0.13μms−1 halfsarcomere−1 (±S.E.M., N = 7). This power output is considerably higher than that previously reported for skinned fibres (Bone et al. 1986). Correspondingly the force-velocity relationship is less curved for intact fibres than for skinned fibres. The maximum swimming speed (normalized for fish length) predicted from the observed power output of the muscle fibres decreased with increasing fish size; it ranged from 12.9 to 7.8 fish lengths s−1 for fish 0155–0.645m in length.

Swimming Muscles: Myotomal Muscle Fibres

2004 ◽  
pp. 123-148
Author(s):  
B. G. Kapoor ◽  
Bhavna Khanna
Keyword(s):  
Muscle Fibres ◽  
Myotomal Muscle

Muscle growth and development in Atlantic cod larvae (Gadus morhua L.), related to different somatic growth rates

1999 ◽  
Vol 202 (15) ◽  
pp. 2111-2120 ◽  
Author(s):  
T.F. Galloway ◽  
E. Kjorsvik ◽  
H. Kryvi
Keyword(s):  
Gadus Morhua ◽  
White Muscle ◽  
Atlantic Cod ◽  
Muscle Growth ◽  
Somatic Growth ◽  
Cross Sectional Area ◽  
Muscle Fibres ◽  
Sectional Area ◽  
Cross Sectional ◽  
First Feeding

The present study describes the development of the axial musculature in first-feeding larvae of Atlantic cod (Gadus morhua L.) with different somatic growth rates achieved by using different nutritional conditions. Muscle growth was assessed by determining the number of muscle fibres (hyperplasia) and the growth of existing fibres (hypertrophy). Larvae were fed rotifers containing a high (1. 4; treatment 1) or low (0.2; treatment 2) ratio of docosahexaenoic acid to eicosapentaenoic acid from day 5 after hatching. From day 17, the larvae were fed Artemia nauplii with the same enrichment in both treatments. Treatment 1 gave the highest somatic growth rate and hence the highest dry mass at the end of the experiment, but no difference in larval standard length was found between treatments. In slow-growing larvae, higher priority was thus put into reaching a certain length than into increasing muscle mass. The largest fibres, which were present from hatching, increased in cross-sectional area during larval development, but no differences were found between treatments in the cross-sectional area of individual fibres or the total cross-sectional area of these fibres at the end of the experiment. The first white recruitment fibres were observed at the dorsal and ventral apices of the myotome at approximately the onset of first feeding (larval length 4.5 mm). In larvae 8.5 mm long, the total cross-sectional area of white muscle fibres in the treatment 2 group was 75 % of that in the treatment 1 group. The highest somatic growth rate was associated with an increased contribution of hyperplasia to axial white muscle growth. In the faster-growing larval group, the relative contribution of hyperplasia to the total white muscle cross-sectional area was 50 %, whereas it was 41 % in the slower-growing larval group. The subsequent growth potential may thus be negatively affected by inadequate larval feeding.

The Ultrastructure of the White Striated Myotomal Muscle of the Cod, Gadus morhua

1967 ◽  
Vol 24 (12) ◽  
pp. 2549-2553 ◽  
Author(s):  
C. M. Bishop ◽  
P. H. Odense
Keyword(s):  
Skeletal Muscle ◽  
Sarcoplasmic Reticulum ◽  
Cross Section ◽  
Actin Filaments ◽  
Gadus Morhua ◽  
Striated Muscle ◽  
Fish Muscle ◽  
Transverse Tubular System ◽  
Tubular System ◽  
Myotomal Muscle

The structure of the white skeletal muscle of the cod (Gadus morhua) is described. The peripheral fibrils are ribbon-like and rectangular in cross section with the long axis normal to the sarcolemma. The inner fibrils are mainly polygonal in cross section. Most of the mitochondria and nuclei are peripheral to the fibrils and next to the sarcolemma. The arrangement of the contractile proteins is typical for striated muscle, and the sarcoplasmic reticulum and transverse tubular system are similar to those in other white skeletal fish muscle. A distinct N-band is apparent with indications of branching and reorientation of the actin filaments. Mitochondria are often closely associated with the Z line.

Muscle growth in the Antarctic teleost, Notothenia neglecta (Nybelin)

1991 ◽  
Vol 3 (1) ◽  
pp. 29-33 ◽  
Author(s):  
John C. Battram ◽  
Ian A. Johnston
Keyword(s):  
Muscle Fibre ◽  
Muscle Growth ◽  
Somatic Growth ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Slow Muscle ◽  
Muscle Fibres ◽  
Slow Muscle Fibres ◽  
The Antarctic ◽  
Myotomal Muscle

A histochemical and electron microscopy study was carried out on muscle growth in demersal stages of the Antarctic teleost Notothenia neglecta Nybelin. The total number of myotomal muscle fibres was similar in fish ranging in body mass from 11.9g to 889g. Post-anal myotomes contained around 17,000 slow muscle fibres and 70,000 fast muscle fibres. Myosatellite cells were extremely rare. The diameter of fast fibres varied from <10μm to 130μm in the smallest, and from >40μm to 450μm in the largest fish studied. Slow muscle fibre diameters in the largest fish ranged from >30μm to 260μm. Even the largest diameter slow fibres contained significant numbers of mitochondria, which suggests that the diffusion of oxygen does not limit metabolism. The results confirm that muscle fibre hyperplasia ceases prior to the demersal stages of the life history, and that subsequent muscle growth is entirely via the hypertrophy of existing fibres. Comparative studies suggest that this may be one of the factors contributing to the relatively slow rate of somatic growth in this species.

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