Interspike interval relationship among flight muscle fibres in Drosophila

1980 ◽  
Vol 87 (1) ◽  
pp. 137-147 ◽  
Author(s):  
J. H. Koenig ◽  
K. Ikeda
Keyword(s):  
Interspike Interval ◽  
Flight Muscle ◽  
Motor Units ◽  
Muscle Fibres ◽  
Interspike Intervals ◽  
Neural Input ◽  
Flight Muscles ◽  
Bilateral Pair ◽  
Left And Right ◽  
Driving Source

Simultaneous intracellular recordings were made from the 10 motor units (12 fibres) comprising the bilateral pair of dorsal longitudinal flight muscles in Drosophila melanogaster while in stationary flight. The neural input which commonly drives these units was characterized by observing the influence which this input has on the interspike intervals of the various units. It was observed that the intervals of these units (both ipsilateral and contralateral), when considered collectively (that is, as a series of successively occurring intervals without regard for which unit represents which interval), fluctuate in a serially correlated manner. These interval fluctuations collectively define a fluctuation of complex waveform. The characteristics of this waveform suggest that two (or more) oscillating inputs are involved in commonly driving these units. In addition, a coupling in frequency and timing was observed between certain pairs of ipsilateral units, as well as between the units of one side relative to those of the other side. This coupling suggests that the neural pathway leading from the oscillating driving source might diverge, first to left and right sides, and then at a more peripheral level into three separate pathways, one leading to units 1 and 2, another to units 3 and 4, and a third to unit 5/6.

scholarly journals Neural interactions controlling timing of flight muscle activity in Drosophila

1980 ◽  
Vol 87 (1) ◽  
pp. 121-136 ◽  
Author(s):  
J. H. Koenig ◽  
K. Ikeda
Keyword(s):  
Interspike Interval ◽  
Longitudinal Muscle ◽  
Flight Muscle ◽  
Motor Units ◽  
The Other ◽  
Muscle Fibres ◽  
Neural Interaction ◽  
Neural Interactions ◽  
A Cell ◽  
The Relationship

Simultaneous intracellular recordings were made from the six ipsilateral dorsal longitudinal muscle fibres of Drosophila in stationary flight. The influence of the firing of one motor unit upon the firing of another was analysed by observing the relationship between the interspike interval of a unit and the relative firing times of the other motor units within that interval. The analysis suggests that the influence is insignificant except when one unit would have fired soon after another. Then, a neural interaction occurs that can cause a unit to fire either earlier or later, depending on its firing relationship with the other units. Thus, the observation that no DLM fibre fires soon after another is the result of both a delaying effect and an effect which causes a cell to fire earlier than it normally would have fired.

scholarly journals Mutations of Drosophila melanogaster that affect muscles

Development ◽  
1977 ◽  
Vol 40 (1) ◽  
pp. 35-63
Author(s):  
I. I. Deak
Keyword(s):  
Drosophila Melanogaster ◽  
Flight Muscle ◽  
Fat Body ◽  
Muscle Fibres ◽  
Muscle Structure ◽  
Site Of Action ◽  
Chromosome Mutations ◽  
Complementation Groups ◽  
Flight Muscles ◽  
Genetic Techniques

Eight X-chromosome mutations (falling into five complementation groups) that affect the development and morphology of the indirect flight muscles of Drosophila melanogaster were investigated using histological, behavioural and genetic techniques. All of these mutations result in Sightlessness, in a marked reduction in the ability of the flies to jump, and in the wings being held in abnormal positions. Mutations in each of the complementation groups have different effects on the morphology of the muscles. Two (flapwing, vertical wing) result in absence of most of the indirect flight muscle fibres, a third (upheld) is required for the gross organization of muscle structure, another (heldup) is involved in the maintenance of muscle structure once formed, and the fifth seems to be necessary for the detailed architecture of the muscle fibre (indented thorax). The analysis of flies genetically mosaic with respect to each mutation by the technique of fate-mapping suggests that three (heldup, upheld and indented thorax) of the genes concerned have their primary site of action in the musculature itself, while the other two(flapwing and vertical wing) may function primarily in the fat-body and tracheae respectively.

The Role of Cyclic AMP in the Octopaminergic Modulation of Flight Muscle in the Locust

1991 ◽  
Vol 161 (1) ◽  
pp. 423-438
Author(s):  
MATTHEW D. WHIM ◽  
PETER D. EVANS
Keyword(s):  
Cyclic Amp ◽  
Flight Muscle ◽  
Schistocerca Gregaria ◽  
Phosphodiesterase Inhibitors ◽  
Motor Units ◽  
Blocking Agent ◽  
Receptor Activation ◽  
Octopamine Receptors ◽  
Flight Muscles

The role of cyclic AMP in the octopaminergic modulation of the dorsal longitudinal flight muscles of the locust Schistocerca gregaria has been investigated. Several techniques have been used to elevate cyclic AMP levels in this tissue by mechanisms that bypass the receptor activation stage. These include the use of phosphodiesterase inhibitors to block the metabolism of cyclic nucleotides, the use of forskolin, the diterpene activator of adenylate cyclase, and the direct application of permeable and phosphodiesterase-resistant analogues of cyclic AMP. All these approaches can be shown to mimic the modulatory effects of octopamine on the flight muscle. Surprisingly, the phosphodiesterase inhibitors used were not able to potentiate the actions of octopamine on this preparation. Octopamine increases cyclic AMP levels in a similar fashion in all five motor units of this muscle, an effect that is selectively blocked by phentolamine, an α-adrenergic blocking agent that blocks octopamine receptors in other preparations. In addition, stimulation of the dorsal unpaired median neurone to the dorsal longitudinal flight muscles (DUMDL) results in a frequency-dependent increase in cyclic AMP levels in the muscle that is also blocked by phentolamine. The data presented suggest that the octopamine-mediated modulation of neurally evoked tension in this muscle is brought about by a mechanism that involves an increase in cyclic AMP levels in the tissue.

The Fibrillar Flight Muscles of Giant Water-Bugs: An Electron-Microscope Study

1967 ◽  
Vol 2 (3) ◽  
pp. 435-444
Author(s):  
DOREEN E. ASHHURST
Keyword(s):  
Electron Microscope ◽  
Sarcoplasmic Reticulum ◽  
Flight Muscle ◽  
Muscle Fibres ◽  
Transverse Tubular System ◽  
Tropical Water ◽  
Tubular System ◽  
Flight Muscles ◽  
And Function ◽  
Water Bugs

The fibrillar flight muscles of several species of tropical water-bugs of the family Belostomatidae have been examined in the electron microscope. The myofibrils are very similar to those of the other fibrillar flight muscles which have been studied. The membrane systems, however, display features which appear to be peculiar to this family. The sarcoplasmic reticulum can be divided into three parts: a series of interconnecting vesicles surrounding the Z-lines, randomly scattered small vesicles around the myofibrils, and flattened cisternae which lie along the transverse tubular system, and form the dyads. These three components of the sarcoplasmic reticulum do not appear to be interconnected. The cisternae of the dyads contain an electrondense substance. The narrow tubules of the transverse tubular system or T-system penetrate deep into the fibre from the cell membrane. They follow a course roughly perpendicular to the myofibrils at the level of the M-lines. The dyads are scattered along their length, and may not be near a myofibril. Another system of very large vesicles is found in the muscle fibres, interspersed among the mitochondria. These vesicles usually appear to be empty; their nature and function are not at present known. Numerous mitochondria are present among the myofibrils. The peculiarities of the water-bug fibrillar flight muscle are discussed in relation to the flight muscles of other insects and the physiological properties of fibrillar flight muscle.

scholarly journals Mechanical Properties of Demembranated Flight Muscle Fibres from a Dragonfly

1991 ◽  
Vol 159 (1) ◽  
pp. 135-147
Author(s):  
M. PECKHAM ◽  
D.C. S. WHITE
Keyword(s):  
Mechanical Properties ◽  
Flight Muscle ◽  
Muscle Length ◽  
Psoas Muscle ◽  
Muscle Fibres ◽  
Active Tension ◽  
Rabbit Psoas ◽  
King's College ◽  
Flight Muscles ◽  
Drury Lane

The mechanical properties of demembranated muscle fibres of synchronous flight muscle from a dragonfly Libellula quadrimaculata, asynchronous flight muscle from the giant waterbug Lethocerus indicus and synchronous psoas muscle from rabbit were compared in relaxed, active and rigor conditions. The properties were compared to the known structure and protein compositions of these muscles. We found that active tension of L. indicus flight muscles was stretch-activated (tension was low and was significantly increased following a rapid stretch of 1 % of muscle length), whereas both dragonfly flight muscle and rabbit psoas muscle were not (active tension was high and did not significantly increase following a rapid stretch of 1%). Three different properties have been suggested to give rise to stretch activation in asynchronous muscles: (1) a matching of the helix periodicities of actin target sites to myosin crossbridge heads, (2) a special form of troponin subunit called troponin-H, and (3) the high resting stiffness of these muscles inducing strain in the thick filaments. Rabbit psoas muscle has none of these properties. Dragonfly flight muscles do not have the helix matching, but they do have a form of troponin-H and a high resting stiffness. It seems most likely that dragonfly flight muscles are not stretch-activated because they do not have the helix matching. Note: Present address: Department of Biophysics, King's College London, 26–29 Drury Lane, London, WC2B 5RL, UK.

Motor Unit Distribution of the Dorsal Longitudinal Flight Muscles in Locusts

1963 ◽  
Vol 40 (1) ◽  
pp. 123-136
Author(s):  
A. C. NEVILLE
Keyword(s):  
Motor Unit ◽  
Motor Units ◽  
Average Diameter ◽  
Fast Response ◽  
Muscle Fibres ◽  
Recurrent Nerve ◽  
Motor Axons ◽  
Flight Muscles ◽  
Large Motor ◽  
Longitudinal Muscles

1. The peripheral pathways of the ‘fast’ motor fibres to the locust dorsal longitudinal flight muscles are described at the single unit level, from electrophysiological and histological studies. This is summarized in a diagram on Pl. 1. 2. Both pterothoracic dorsal longitudinal muscles consist of five anatomically distinct motor units, arranged in layers from dorsal to ventral. Each of the four more ventral units of both muscles receives a motor axon from the segment in front via the recurrent nerve, whereas the uppermost motor unit is innervated in each case from the segment containing the muscle. The motor units are nearly equal both in size and capability for work. 3. Each of the five ‘fast’ motor axons innervates one topographically distinct bundle of muscle fibres. There is no overlap between muscle motor units. 4. Even within a single muscle, motor units are capable of vibrating at independent frequencies. This indicates that the coupling of units which occurs during flight is neither structurally nor functionally rigid. 5. With respect to peripheral features, the motor units within each dorsal longitudinal muscle are designed for fast response which improves the synchronization when the relevant neurons fire simultaneously (large motor axons, 15-25 µ in average diameter with high propagation velocity, 8 m./sec. at flight temperature). 6. It is suggested that a tonic motor output, containing at least three units, which was recorded from mesothoracic nerve IBa, travels to the small lateral dorsal muscles.

scholarly journals Characterization of components of Z-bands in the fibrillar flight muscle of Drosophila melanogaster.

1989 ◽  
Vol 109 (5) ◽  
pp. 2157-2167 ◽  
Author(s):  
J D Saide ◽  
S Chin-Bow ◽  
J Hogan-Sheldon ◽  
L Busquets-Turner ◽  
J O Vigoreaux ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Monoclonal Antibodies ◽  
Flight Muscle ◽  
Cross Reactivity ◽  
Antigenic Determinants ◽  
Immunogold Staining ◽  
Thick Filaments ◽  
The Matrix ◽  
Flight Muscles

Twelve monoclonal antibodies have been raised against proteins in preparations of Z-disks isolated from Drosophila melanogaster flight muscle. The monoclonal antibodies that recognized Z-band components were identified by immunofluorescence microscopy of flight muscle myofibrils. These antibodies have identified three Z-disk antigens on immunoblots of myofibrillar proteins. Monoclonal antibodies alpha:1-4 recognize a 90-100-kD protein which we identify as alpha-actinin on the basis of cross-reactivity with antibodies raised against honeybee and vertebrate alpha-actinins. Monoclonal antibodies P:1-4 bind to the high molecular mass protein, projectin, a component of connecting filaments that link the ends of thick filaments to the Z-band in insect asynchronous flight muscles. The anti-projectin antibodies also stain synchronous muscle, but, surprisingly, the epitopes here are within the A-bands, not between the A- and Z-bands, as in flight muscle. Monoclonal antibodies Z(210):1-4 recognize a 210-kD protein that has not been previously shown to be a Z-band structural component. A fourth antigen, resolved as a doublet (approximately 400/600 kD) on immunoblots of Drosophila fibrillar proteins, is detected by a cross reacting antibody, Z(400):2, raised against a protein in isolated honeybee Z-disks. On Lowicryl sections of asynchronous flight muscle, indirect immunogold staining has localized alpha-actinin and the 210-kD protein throughout the matrix of the Z-band, projectin between the Z- and A-bands, and the 400/600-kD components at the I-band/Z-band junction. Drosophila alpha-actinin, projectin, and the 400/600-kD components share some antigenic determinants with corresponding honeybee proteins, but no honeybee protein interacts with any of the Z(210) antibodies.

Discharge patterns in human motor units during fatiguing arm movements

1998 ◽  
Vol 85 (5) ◽  
pp. 1684-1692 ◽  
Author(s):  
L. Griffin ◽  
S. J. Garland ◽  
T. Ivanova
Keyword(s):  
Voluntary Movement ◽  
Motor Units ◽  
Constant Load ◽  
Short Isis ◽  
Interspike Intervals ◽  
Triceps Brachii ◽  
Movement Initiation ◽  
Human Motor ◽  
Discharge Patterns ◽  
Human Motor Units

The purpose of this study was to determine whether short interspike intervals (ISIs of <20 ms) would occur naturally during voluntary movement and would increase in number with fatigue. Thirty-four triceps brachii motor units from nine subjects were assessed during a fatigue task consisting of fifty extension and fifty flexion elbow movements against a constant-load opposing extension. Nineteen motor units were recorded from the beginning of the fatigue task; the number of short ISIs was 7.1 ± 4.1% of the total number of ISIs in the first one-third of the task (unfatigued state). This value increased to 11.8 ± 5.9% for the last one-third of the task (fatigued state). Fifteen motor units were recruited during the fatigue task and discharged, with 16.4 ± 6.0% of short ISIs in the fatigued state. For all motor units, the number of short ISIs was positively correlated ( r 2 = 0.85) with the recruitment threshold torque. Short ISIs occurred most frequently at movement initiation but also occurred throughout the movement. These results document the presence of short ISIs during voluntary movement and their increase in number during fatigue.

scholarly journals The Hippo pathway controls myofibril assembly and muscle fiber growth by regulating sarcomeric gene expression

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Aynur Kaya-Çopur ◽  
Fabio Marchiano ◽  
Marco Y Hein ◽  
Daniel Alpern ◽  
Julie Russeil ◽  
...  
Keyword(s):  
Gene Expression ◽  
Muscle Fiber ◽  
Flight Muscle ◽  
Hippo Pathway ◽  
Muscle Fibers ◽  
Muscle Growth ◽  
Fiber Growth ◽  
Flight Muscles ◽  
Sarcomeric Gene ◽  
The Hippo Pathway

Skeletal muscles are composed of gigantic cells called muscle fibers, packed with force-producing myofibrils. During development the size of individual muscle fibers must dramatically enlarge to match with skeletal growth. How muscle growth is coordinated with growth of the contractile apparatus is not understood. Here, we use the large Drosophila flight muscles to mechanistically decipher how muscle fiber growth is controlled. We find that regulated activity of core members of the Hippo pathway is required to support flight muscle growth. Interestingly, we identify Dlg5 and Slmap as regulators of the STRIPAK phosphatase, which negatively regulates Hippo to enable post-mitotic muscle growth. Mechanistically, we show that the Hippo pathway controls timing and levels of sarcomeric gene expression during development and thus regulates the key components that physically mediate muscle growth. Since Dlg5, STRIPAK and the Hippo pathway are conserved a similar mechanism may contribute to muscle or cardiomyocyte growth in humans.

Flight muscle and flight activity of melon fly, Bactrocera cucurbitae (Diptera: Tephritidae)

2021 ◽  
Vol 30 (2) ◽  
pp. 179-185
Author(s):  
Farhana Ferdousi ◽  
Shanjida Sultana ◽  
Tangin Akter ◽  
Pinakshi Roy ◽  
Shefali Begum
Keyword(s):  
Longitudinal Muscle ◽  
Flight Muscle ◽  
Flight Activity ◽  
The Other ◽  
Bactrocera Cucurbitae ◽  
Male And Female ◽  
Melon Fly ◽  
Length Width ◽  
Flight Muscles ◽  
The Mean

The flight activity and flight muscle of the melon fly, Bactrocera cucurbitae (Coquillett) (Diptera: Tephritidae) were observed. The Tethered technique was used to observe the flight activity in this study. The flight activity, and wing and flight muscles were compared between male and female melon flies. The results indicate that the female was relatively better and strong flier than the male. The mean duration of the flight activity of the females was 13.90 min/hour and of the males was 7.12 min./hour. The mean length, width, volume of wings of the males were 6.07 mm, 2.67 mm and 10.99 mm³, respectively. On the other hand, the mean length, width and volume of the wings of females were 7.07 mm, 2.87 mm and 15.60 mm³, respectively. In case of wing muscles, the mean volume of dorsal longitudinal muscle (DLM) in male and female was found 5.20 mm³ and 5.67 mm³, respectively. The mean length of flight wing muscle of male and female was 2.22 and 2.23 mm, respectively and the mean breadth of male and female was 1.65 and 1.77 mm, respectively. Dhaka Univ. J. Biol. Sci. 30(2): 179-185, 2021 (July)

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