The Effect of Metabolic Inhibitors on the Cockroach Nerve-Muscle Synapse

1974 ◽  
Vol 61 (2) ◽  
pp. 331-343
Author(s):  
D. REES
Keyword(s):  
Synaptic Vesicle ◽  
White Muscle ◽  
Metabolic Inhibition ◽  
Metabolic Inhibitors ◽  
Muscle Fibres ◽  
Axon Terminals ◽  
Red Muscle ◽  
Electrophysiological Studies ◽  
Nerve Muscle

1. The application of metabolic inhibitors to nerve-muscle synapses on ‘white’ and ‘red’ fibres in the retractor unguis muscles of P. americana and B. giganteus resulted in a dramatic increase in the spontaneous miniature potential discharge and was accompanied by a summation of the miniature potentials to form ‘composite’ potentials. 2. Axon terminals associated with ‘white’ muscle fibres responded faster to metabolic inhibitors than those axon terminals associated with ‘red’ muscle fibres. 3. Correlated ultrastructural and electrophysiological studies inferred that a tentative relationship existed between the miniature potential activities and synaptic vesicle distributions of the nerve-muscle synapses during the phases of metabolic inhibition.

scholarly journals Development of swimming movements and musculature of larval herring (Clupea harengus)

1984 ◽  
Vol 110 (1) ◽  
pp. 217-229 ◽  
Author(s):  
R. S. Batty
Keyword(s):  
White Muscle ◽  
Single Layer ◽  
Clupea Harengus ◽  
Muscle Fibre Types ◽  
Muscle Fibres ◽  
Inertial Forces ◽  
Red Muscle ◽  
Resistive Forces ◽  
Swimming Style ◽  
White Muscle Fibre

A kinematic analysis was made of swimming of larval herring Clupea harengus L. Swimming style was found to change with growth and development; the amplitude of swimming movements of early post-yolk-sac larvae increases linearly towards the tail, a style of swimming which relies mainly on resistive forces for propulsion. Later, after the caudal and dorsal fins have developed, the swimming style changes, in response to an increase in Reynold's Number, such that inertial forces are more important. In this type of swimming the amplitude increases more rapidly than linearly towards the tail. The distribution of red and white muscle fibre types was studied in relation to development. On hatching, red muscle fibres were found to be arranged as a single layer on the outside of the myotomes. They develop into the adult distribution, concentrated at the midline of the flank near the skin, only after the gills and circulation become fully functional.

The Function and Metabolism of Certain Insect Muscles in Relation to their Structure

1955 ◽  
Vol s3-96 (34) ◽  
pp. 151-159
Author(s):  
GEORGE A. EDWARDS ◽  
HELMUT RUSKA
Keyword(s):  
Endoplasmic Reticulum ◽  
Oxygen Consumption ◽  
Dehydrogenase Activity ◽  
White Muscle ◽  
Muscle Fibres ◽  
Electron Microscopic ◽  
Leg Muscles ◽  
Red Muscle ◽  
Ultrathin Sections

Electron microscopic observations on ultrathin sections of the red thoracic flightmuscles and white leg muscles of Hydrophilus and Dytiscus are reported. In red muscle-fibres with high values in frequency of contraction, oxygen consumption, and dehydrogenase activity, the single fibrils are completely surrounded by huge mitochondria. Tracheoles penetrate the sarcolemma and supply the mitochondria with oxygen by intracellular branches. In the less active white muscle fibres, mitochondria are found irregularly scattered between the fibrils or along the I band. The intracellular tracheolization is sparse but an endoplasmic reticulum is widely spread between the synfibrillar contractile material. The same muscles of the two insects differ considerably in detail.

Release of Transmitter from Degenerating Locust Motorneurones

1973 ◽  
Vol 59 (1) ◽  
pp. 1-16
Author(s):  
P. N. R. USHERWOOD
Keyword(s):  
Transmitter Release ◽  
Synaptic Vesicles ◽  
Schistocerca Gregaria ◽  
Spatial Arrangement ◽  
Muscle Fibres ◽  
Spontaneous Release ◽  
Axon Terminals ◽  
Synaptic Potentials ◽  
Nerve Muscle

1. When the motorneurones to the femoral part of the retractor unguis muscle of the locust Schistocerca gregaria are severed, the changes in impulse-linked release and spontaneous release of transmitter which take place at the synapses between the motorneurones and the retractor unguis muscle fibres can be related to known changes in the numbers and distribution of synaptic vesicles at these synapses. 2. Impulse-linked transmitter release fails when the synaptic vesicles aggregate to form clumps of vesicles, and at this time the miniature discharge recorded from the muscle fibres become characterized, initially, by bursts of miniature excitatory post-synaptic potentials (min. EPSPs) and, eventually, by ‘giant’ intracellular min. EPSPs up to 15 mV in amplitude. 3. The appearance of ‘giant’ potentials is accompanied by an overall fall in the frequency of the miniature discharge, which continues to decline thereafter until spontaneous transmitter release fails. The miniature discharge ceases at a time when the axon terminals are engulfed by glial tissue or become devoid of synaptic vesicles. 4. The parallel changes in temporal arrangement of min. EPSPs and spatial arrangement of synaptic vesicles seen during degeneration of locust nerve-muscle synapses provide further support for the ‘vesicle hypothesis’.

scholarly journals Histological structure of the musculus longissimus lumborum et thoracis in pigs with the same ryanodine receptor genotype (CC) in relation to carcass indicators

2008 ◽  
Vol 52 (No. 1) ◽  
pp. 12-20
Author(s):  
Z. Eliáš ◽  
S. Hluchý ◽  
J. Mlynek
Keyword(s):  
Muscle Fibre ◽  
White Muscle ◽  
Fibre Diameter ◽  
Muscle Fibres ◽  
Histological Structure ◽  
Meat Weight ◽  
Red Muscle ◽  
Longissimus Lumborum ◽  
Positive Correlations ◽  
White Muscle Fibre

The aim of this study was to investigate the histological structure of the longissimus muscle in pigs in relation to carcass value indicators. A total number of 16 pigs of about 101.28 kg average live weight were used. The animals were raised at a Fattening and Carcass Value Experimental Station (FCVES) of Slovak University of Agriculture in Nitra in equal conditions, receiving a standard diet fortified with vitamin-mineral mixture, and they were slaughtered in an experimental abattoir of FCVES. Samples from the musculus longissimus lumborum et thoracisi (MLLT) for histological evaluation were taken within 30 minutes post mortem, immediately frozen in liquid nitrogen and stored at a temperature of −20°C. In the experimental abattoir of FCVES feeding indicators, and indicators of meat quality and carcass value were examined. Samples were processed histochemically and single types of muscle fibres were differentiated according to reactions on SDH on the basis of Vacek’s (1974) method. Nikon microscopic system, Pixelink digital camera and LUCIA software for image analyses for the morphometric analysis of MLLT structure were used. The highest abundance of white and the lowest abundance of intermediate muscle fibres was obtained in the analyzed musculus longissimus lumborum et thoracisi of pigs. Red muscle fibre abundance was only slightly higher than intermediate muscle fibre abundance. Concerning the average muscle fibre diameter, the highest values in white and the lowest values in red muscle fibres were found. Positive correlations of white muscle fibre abundance with loin meat weight, thigh meat weight, carcass length, ribcase length, hot right half weight, valuable meatiness parts in kilograms, thigh weight, thigh percent in the half-carcass and MLLT area weight were obtained. In the case of all fat content and weight indicators negative correlations were obtained except loin fat weight. Red muscle fibre content showed positive correlations with shoulder fat weight, neck meat weight, neck fat weight, head weight, thigh fat weight, average backfat thickness and MLLT area. Correlation coefficients between white muscle fibre diameter and shoulder meat weight, thigh meat weight, carcass length, ribcase length showed weak positive correlations. An increase in the white muscle fibre diameter corresponds with an increase in loin meat weight, valuable meatiness parts in kg, valuable meatiness parts in percents, thigh weight, thigh percent in the half-carcass weight and MLLT area. Concerning the red muscle fibre diameter weak positive correlations were obtained in relation to neck meat weight, thigh meat weight, thigh weight and moderate positive correlations to shoulder meat weight, loin meat weight, valuable meatiness parts in kilograms and percents, thigh percent in half-carcass and MLLT area.

The influence of temperature on muscle function in the fast swimming scup. I. Shortening velocity and muscle recruitment during swimming

1992 ◽  
Vol 163 (1) ◽  
pp. 259-279 ◽  
Author(s):  
L. C. Rome ◽  
I. H. Choi ◽  
G. Lutz ◽  
A. Sosnicki
Keyword(s):  
Sarcomere Length ◽  
White Muscle ◽  
Beat Frequency ◽  
Muscle Mechanics ◽  
Maximum Speed ◽  
Muscle Fibres ◽  
Muscle Recruitment ◽  
Shortening Velocity ◽  
Red Muscle ◽  
Tail Beat

In this study, electromyography showed that scup can swim to a maximum speed of 80 cm s-1 with their red muscle whereas previous results showed that carp can swim to only 45 cm s-1. Our aim was to evaluate the adaptations that enable scup to swim nearly twice as fast as carp. Although we anticipated that, at their respective maximum speeds, the red muscle of scup would be shortening at twice the velocity (V) of carp muscle, we found that the values of V were the same (2.04 muscle lengths s-1). At any given swimming speed, V was higher in carp than in scup because carp had a larger sarcomere length excursion and higher tail-beat frequency. The smaller sarcomere excursion in scup is primarily associated with using a less undulatory style of swimming (i.e. with a smaller backbone curvature). This less undulatory style of swimming may be an important adaptation that not only reduces V but may also reduce drag. At their respective maximum speeds, however, the 28% lower sarcomere length excursion in scup is balanced by a 26% higher tail-beat frequency, giving an equal V to that of carp. Although the scup in this study were somewhat longer than the carp in the previous one (19.7 vs 13.4 cm), we believe that many of the observed differences are species-related rather than size-related. We also found that scup swam in a kinematically similar fashion at 10 degrees C and 20 degrees C. However, at 10 degrees C, the scup could swim to only 54 cm s-1 before recruiting their white muscle whereas, at 20 degrees C, they could swim to 80 cm s-1. The difference in speed of initial white muscle recruitment, as well as information on muscle mechanics, suggests that the scup compress their recruitment order into a narrow speed range at low temperatures, thereby recruiting more muscle fibres. Quantitative analysis of red muscle electromyograms in this paper supports this hypothesis.

A study of glycogen and lactate in the myotomal muscles and liver of the Coalfish (Gadus virens L.) during sustained swimming

1973 ◽  
Vol 53 (1) ◽  
pp. 17-26 ◽  
Author(s):  
I. A. Johnston ◽  
G. Goldspink
Keyword(s):  
Swimming Speed ◽  
Muscle Glycogen ◽  
White Muscle ◽  
Glycogen Content ◽  
Lactate Concentration ◽  
Division Of Labour ◽  
Muscle Fibres ◽  
Red Muscle ◽  
Biochemical Measurements ◽  
The Mean

The locomotor roles of the myotomal muscles of fish are dependent on swimming speed. The mean maximum sustained swimming speed for coalfish (Gadus virens L.) during a 6-h period in an experimental exercise chamber was determined using a fixedvelocity technique and found to be 4 bodylengths/s. Biochemical measurements were made on the concentration of glycogen and lactate in the red muscle and white muscle at a series of known swimming speeds. Evidence is provided that red muscle alone is used at speeds below 2 bodylengths/s. The fall in concentration of red muscle glycogen was directly proportional to increased swimming speed. At speeds in excess of 2 bodylengths/s a statistically significant increase in lactate concentration occurred in the white muscle fibres. A reduction in glycogen content of the white muscle was also noted at speeds at and above the estimated mean sustained swimming speed. These results are discussed in the light of the current ideas pertaining to the division of labour between myotomal muscles in fish.

The co-ordination of the rhythmical fin movements of dogfish

1969 ◽  
Vol 49 (2) ◽  
pp. 357-378 ◽  
Author(s):  
B. L. Roberts
Keyword(s):  
White Muscle ◽  
Muscle Fibres ◽  
Implanted Electrodes ◽  
Red Muscle ◽  
Two Populations

The muscle fibres of the radial muscles of the unpaired fins of dogfish can be divided into two populations—an outer group of red muscle fibres which are smaller and fewer than the inner white muscle fibres and which differ in structure, number of nuclei and pattern of innervation. Two types of potential were detected in the two muscle systems when recordings were made with implanted electrodes during movements of the fins. The red muscle fibres were associated with small, slow junctional potentials which changed in amplitude when the activity of the system was altered.

Metabolic biochemistry of water- vs. air-breathing fishes: muscle enzymes and ultrastructure

1978 ◽  
Vol 56 (4) ◽  
pp. 736-750 ◽  
Author(s):  
P. W. Hochachka ◽  
M. Guppy ◽  
H. E. Guderley ◽  
K. B. Storey ◽  
W. C. Hulbert
Keyword(s):  
White Muscle ◽  
Large Diameter ◽  
Oxidative Capacity ◽  
The Body ◽  
Muscle Enzymes ◽  
Air Breathing ◽  
Red Muscle ◽  
Phosphofructokinase Activity ◽  
Metabolic Biochemistry ◽  
Myotomal Muscle

To delineate what modifications in muscle metabolic biochemistry correlate with transition to air breathing in fishes, the myotomal muscles of aruana, an obligate water breather, and Arapaima, a related obligate air breather, were compared using electron microscopy and enzyme methods. White muscle in both species maintained a rather similar ultrastructure, characterized by large-diameter fibers, very few mitochondria, and few capillaries. However, aruana white muscle displayed nearly fivefold higher levels of pyruvate kinase, threefold higher levels of muscle-type lactate dehydrogenase, and a fourfold higher ratio of fructose diphosphatase –phosphofructokinase activity; at the same time, enzymes in aerobic metabolism occurred at about one-half the levels in Arapaima. Red muscle was never found in the myotomal mass of aruana, but in Arapaima, red muscle was present and seemed fueled by glycogen, lipid droplets never being observed. From these and other data, it was concluded that in myotomal muscle two processes correlate with the transition to air breathing in Amazon osteoglossids: firstly, an emphasis in oxidative metabolism, and secondly, a retention of red muscle. However, compared with more active water-breathing species, Arapaima sustains an overall dampening of enzyme activities in its myotomal muscle, which because of the large myotome mass explains why its overall metabolic rate is relatively low. By keeping the oxidative capacity of its myotomal muscle low, Arapaima automatically conserves O2 either for a longer time or for other more O2-requiring organs in the body, a perfectly understandable strategy for an air-breathing, diving fish, comparable with that observed in other diving vertebrates. A similar comparison was also made of two erythrinid fishes, one that skimmed the O2-rich surface layers of water and one that obtained three quarters of its O2 from water, one quarter from air. Ultrastructural and enzyme data led to the unexpected conclusion that the surface skimmer sustained a higher oxidative capacity in its myotomal muscles than did the facultative air breather.

The resting membrane potential of white muscle from brown trout (Salmo trutta) exposed to copper in soft, acidic water

2000 ◽  
Vol 203 (14) ◽  
pp. 2229-2236 ◽  
Author(s):  
M.W. Beaumont ◽  
E.W. Taylor ◽  
P.J. Butler
Keyword(s):  
Membrane Potential ◽  
Brown Trout ◽  
Salmo Trutta ◽  
White Muscle ◽  
Low Ph ◽  
Ammonium Ion ◽  
Muscle Membrane ◽  
Resting Membrane Potential ◽  
Muscle Fibres ◽  
Brown Trout Salmo Trutta

Previously, the distribution of ammonia between the intracellular and extracellular compartments has been used to predict a significant depolarisation of the resting membrane potential (E(M)) of white muscle from brown trout (Salmo trutta) exposed to a sub-lethal combination of copper and low pH. However, this prediction is based upon two assumptions (i) a relatively high membrane permeability for the ammonium ion with respect to that for ammonia gas and (ii) that this is unaltered by exposure to copper and low pH. Since there is conflicting evidence in the literature of the validity of these assumptions, in the present study E(M) was directly measured in white muscle fibres of trout exposed to copper and low pH (E(M)=−52.2+/−4.9 mV) and compared with that of unexposed, control animals (E(M)=−86.5+/−2.9 mV) (means +/− s.e.m., N=6). In confirming the predicted depolarisation, these data support the hypothesis of electrophysiological impairment as a factor in the reduction in the swimming performance of trout exposed to these pollutants. In addition, the results of this study support the role of a significant permeability of the muscle membrane to NH(4)(+) in determining the distribution of ammonia in fish.

Electrical and Mechanical Properties of the Red and White Muscles in the Silver Carp

1972 ◽  
Vol 57 (2) ◽  
pp. 551-567
Author(s):  
T. YAMAMOTO
Keyword(s):  
Mechanical Properties ◽  
White Muscle ◽  
Silver Carp ◽  
Membrane Resistance ◽  
Resting Potential ◽  
Resting Membrane Potential ◽  
Mechanical Responses ◽  
Red Muscle ◽  
Red And White Muscles ◽  
Specific Membrane

1. Electrical and mechanical properties of the red muscle (M. levator pinnae pectoralis) and white muscle (M. levator pinnae lateralis abdominis) in the silver carp (Carassius auratus Linné) were investigated by using caffeine and thymol. 2. A complete tetanus could be produced in the red muscle. But in the white muscle no tetanus was produced and there was a gradual decrease in tension during continuous stimulation, even at a frequency of 1 c/s or less. 3. Caffeine (0.5-1 mM) and thymol (0.25-0.5 mM) potentiated the twitch tension in both muscles without an increase in the resting tension; they produced a contracture in both muscles when the concentration was increased further. 4. The falling phase of the active state of contraction was nearly the same in both muscles and was prolonged by caffeine (0.5 mmM) and by thymol (0.25 mM). 5. The resting membrane potential of the red muscle was scarcely affected by caffeine (0.5-5 mM), whereas in the white muscles a depolarization of 10 mV was observed with caffeine of more than 2 mM. The resting potential of both muscles was little changed by o.25 mm thymol. However, at a concentration of more than 0.5mM thymol depolarized the membrane in both muscles to the same extent. 6. In caffeine (2-3 mM) solution the mean specific membrane resistance was reduced from 8.8 kΩ cm2 to 6.0 kΩ cm2 in the red muscle, and from 5.0 kΩ cm2 to 2.7 kΩ cm2 in the white muscle. In thymol (0.5-1 mM) solution it was reduced from 11.2 kΩcm2 to 6.5 kΩ cm2 in the red muscle, and from 5.4kΩ cm2 to 3.1 kΩ) cm2 in the white muscle. The specific membrane capacitance, calculated from the time constant and the membrane resistance, remained more or less the same in both muscles after a treatment with these agents. 7. Electrical properties of the muscles and the effects of caffeine and thymol on mechanical responses suggest that there are no fundamental differences between red and white muscles except for the excitation-contraction coupling. A lack of summation of twitch, a successive decline of twitch, and inability to produce potassium contracture in the white muscle may be due to the fact that the Ca-releasing mechanism is easily inactivated by depolarization of the membrane.

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