ULTRASTRUCTURAL FEATURES OF CRAYFISH PHASIC AND TONIC MUSCLE FIBERS

1967 ◽  
Vol 45 (5) ◽  
pp. 601-606 ◽  
Author(s):  
S. S. Jahromi ◽  
H. L. Atwood
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Transverse Section ◽  
Muscle Fibers ◽  
Orconectes Virilis ◽  
Neuromuscular Synapses ◽  
Thick Filaments ◽  
Tonic Muscle ◽  
Extensor Muscles

Phasic and tonic muscle fibers from the abdominal extensor muscles of the crayfish, Procambarus clarki and Orconectes virilis, were examined for differences in fine structure with the electron microscope. The myofibrils of the two types of fiber were similar in size as seen in transverse section, unlike those in vertebrate twitch and tonus fibers. The ratio of thin to thick filaments was about 5:1 in tonic fibers and 3:1 in phasic fibers. Neuromuscular synapses in tonic fibers were enclosed by arms of noncontractile sarcoplasm, whereas the synapses seen in phasic fibers lacked this feature.

Attachments of phasic and tonic abdominal extensor muscles in crayfish

1976 ◽  
Vol 54 (8) ◽  
pp. 1256-1269 ◽  
Author(s):  
S. S. Jahromi ◽  
H. L. Atwood
Keyword(s):  
Electron Microscopy ◽  
Fine Structure ◽  
Cross Section ◽  
Unit Area ◽  
Longitudinal Axis ◽  
Contractile Properties ◽  
Muscle Attachment ◽  
Tonic Muscle ◽  
Extensor Muscles ◽  
Extracellular Materials

The fine structure of attachments of phasic and tonic crayfish abdominal extensor muscles to the exoskeleton was studied by means of electron microscopy. Tonic muscles contract more slowly and exert more tension per unit area of cross section than phasic muscles. The muscle attachment regions show differences in structure which are correlated with the different contractile properties. In both muscles, microtubule-filled tendinous cells intervene between the end of the muscle and the exoskeleton; but in phasic muscles the tendinous cells are joined to the muscle by rather long extracellular microfibrils which in general run obliquely to the longitudinal axis of the muscle, whereas in tonic muscle, the tendinous cells and the muscle are joined together more directly by shorter microfibrils running parallel to the muscle's longitudinal axis, and also by desmosome-like structures. In addition, the extracellular materials in tonic muscles appear to be firmly attached to the Z lines of the muscle sarcomeres; such an association was not observed in phasic muscle.

scholarly journals THE FILAMENT LATTICE OF COCKROACH THORACIC MUSCLE

1968 ◽  
Vol 36 (3) ◽  
pp. 433-442 ◽  
Author(s):  
Martin Hagopian ◽  
David Spiro
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Flight Muscle ◽  
Insect Flight ◽  
Thick Filament ◽  
Leucophaea Maderae ◽  
Thick Filaments ◽  
Femoral Muscle ◽  
Flight Muscles ◽  
Characteristic 3

The fine structure of the tergo-coxal muscle of the cockroach, Leucophaea maderae, has been studied with the electron microscope. This muscle differs from some other types of insect flight muscles inasmuch as the ratio of thin to thick filaments is 4 instead of the characteristic 3. The cockroach flight muscle also differs from the cockroach femoral muscle in thin to thick filament ratios and diameters and in lengths of thick filaments. A comparison of these latter three parameters in a number of vertebrate and invertebrate muscles suggests in general that the diameters and lengths of the thick filaments and thin to thick filament ratios are related.

scholarly journals ULTRASTRUCTURE OF BARNACLE GIANT MUSCLE FIBERS

1973 ◽  
Vol 56 (1) ◽  
pp. 74-91 ◽  
Author(s):  
Graham Hoyle ◽  
Patricia A. McNeill ◽  
Allen I. Selverston
Keyword(s):  
Plasma Membrane ◽  
Fine Structure ◽  
Sarcoplasmic Reticulum ◽  
Muscle Fibers ◽  
Surface Plasma ◽  
Thick Filaments ◽  
Large Numbers ◽  
Glycogen Particles ◽  
Physiological Research ◽  
Different Parts

Increasing use of barnacle giant muscle fibers for physiological research has prompted this investigation of their fine structure. The fibers are invaginated by a multibranched system of clefts connecting to the exterior and filled with material similar to that of the basement material of the sarcolemmal complex. Tubules originate from the surface plasma membrane at irregular sites, and also from the clefts They run transversely, spirally, and longitudinally, making many diadic and some triadic contacts with cisternal sacs of the longitudinal sarcoplasmic reticulum. The contacts are not confined to any particular region of the sarcomere. The tubules are wider and their walls are thicker at points of contact with Z material. Some linking of the Z regions occurs across spaces within the fiber which contain large numbers of glycogen particles. A-band lengths are extremely variable, in the range 2.2 µm–20.3 µm (average 5.2 µm) Individual thick filaments have thin (110 Å) hollow regions alternating with thick (340 Å) solid ones. Bridges between thick filaments occur at random points and are not concentrated into an M band The thin:thick filament ratio is variable in different parts of a fiber, from 3:1 to 6:1. Z bands are basically perforated, but the number of perforations may increase during contraction.

Regeneration of Phasic Motor Axons on a Crayfish Tonic Muscle: Neuron Specifies Synapses

1998 ◽  
Vol 80 (2) ◽  
pp. 994-997 ◽  
Author(s):  
Kristin M. Krause ◽  
Joanne Pearce ◽  
C. K. Govind
Keyword(s):  
Motor Neuron ◽  
Motor Neurons ◽  
Muscle Fiber ◽  
Muscle Fibers ◽  
Excitatory Postsynaptic Potentials ◽  
Motor Axons ◽  
Postsynaptic Potentials ◽  
Neuromuscular Synapses ◽  
Tonic Muscle

Krause, Kristin M., Joanne Pearce, and C. K. Govina. Regeneration of phasic motor axons on a crayfish tonic muscle: neuron specifies synapses. J. Neurophysiol. 80: 994–997, 1998. Motor neurons are matched to their target muscles, often forming separate phasic and tonic systems as in the abdomen of crayfish where they are used for rapid escape and slow postural movements, respectively. To assess the role of motor neuron and muscle fiber in forming synapses we attempted a mismatch experiment by allotransplanting a phasic nerve attached to its ganglion to a denervated tonic muscle. Regenerating motor axons sprouted 10–30 branches (typical of phasic motor neurons, as tonic ones sprout far fewer branches) to reinnervate muscle fibers and form synapses that produced large excitatory postsynaptic potentials (typical of phasic motor neurons, as tonic synapses give small potentials). Therefore motor neurons, not muscle fibers, appear to specify one of the major properties of regenerating neuromuscular synapses.

A Study on the Fine Structure of the Lateral Line Organ of the Sea Eel

1973 ◽  
Vol 31 ◽  
pp. 648-649
Author(s):  
K. Hama
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Lateral Line ◽  
Low Frequency ◽  
Sensory Cells ◽  
Apical Surface ◽  
Voltage Electron ◽  
Sensory Epithelia ◽  
Low Frequency Vibration ◽  
Transmission Electron

The lateral line organs of the sea eel consist of canal and pit organs which are different in function. The former is a low frequency vibration detector whereas the latter functions as an ion receptor as well as a mechano receptor.The fine structure of the sensory epithelia of both organs were studied by means of ordinary transmission electron microscope, high voltage electron microscope and of surface scanning electron microscope.The sensory cells of the canal organ are polarized in front-caudal direction and those of the pit organ are polarized in dorso-ventral direction. The sensory epithelia of both organs have thinner surface coats compared to the surrounding ordinary epithelial cells, which have very thick fuzzy coatings on the apical surface.

Fine Structure of Interdental Cells in the Mouse Cochlea

1970 ◽  
Vol 28 ◽  
pp. 140-141
Author(s):  
Roberta M. Bruck
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Young Adult ◽  
Uranyl Acetate ◽  
Ground Substance ◽  
Tectorial Membrane ◽  
Lead Citrate ◽  
Unusual Structure ◽  
Thin Sections ◽  
Collagenous Fibers

An unusual structure in the cochlea is the spiral limbus; this periosteal tissue consists of stellate fibroblasts and collagenous fibers embedded in a translucent ground substance. The collagenous fibers are arranged in vertical columns (the auditory teeth of Haschke). Between the auditory teeth are interdental furrows in which the interdental cells are situated. These epithelial cells supposedly secrete the tectorial membrane.The fine structure of interdental cells in the rat was reported by Iurato (1962). Since the mouse appears to be different, a description of the fine structure of mouse interdental cells' is presented. Young adult C57BL/6J mice were perfused intervascularly with 1% paraformaldehyde/ 1.25% glutaraldehyde in .1M phosphate buffer (pH7.2-7.4). Intact cochlea were decalcified in .1M EDTA by the method of Baird (1967), postosmicated, dehydrated, and embedded in Araldite. Thin sections stained with uranyl acetate and lead citrate were examined in a Phillips EM-200 electron microscope.

Fine structure of the retina of the giant scallop, Placopecten magellanicus

1984 ◽  
Vol 42 ◽  
pp. 312-313
Author(s):  
C.V.L. Powell
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Light Intensity ◽  
Scanning Electron Microscope ◽  
Eye Development ◽  
Preliminary Observation ◽  
Columnar Epithelium ◽  
Placopecten Magellanicus ◽  
Environmental Light ◽  
Scanning Electron

The overall fine structure of the eye in Placopecten is similar to that of other scallops. The optic tentacle consists of an outer columnar epithelium which is modified into a pigmented iris and a cornea (Fig. 1). This capsule encloses the cellular lens, retina, reflecting argentea and the pigmented tapetum. The retina is divided into two parts (Fig. 2). The distal retina functions in the detection of movement and the proximal retina monitors environmental light intensity. The purpose of the present study is to describe the ultrastructure of the retina as a preliminary observation on eye development. This is also the first known presentation of scanning electron microscope studies of the eye of the scallop.

Ultrastructure of primary spermatocyte in fish (Tilapia: Oreochromis niloticus): The synaptonemal complex

1986 ◽  
Vol 44 ◽  
pp. 288-289
Author(s):  
T. Guha ◽  
A. Q. Siddiqui ◽  
P. F. Prentis
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Synaptonemal Complex ◽  
Oreochromis Niloticus ◽  
Short Communication ◽  
Primary Spermatocyte ◽  
Mitotic Division ◽  
Meiotic Cell ◽  
Electron Microscope Level ◽  
Homologous Chromosomes

The Primary Spermatocytes represent a stage in spermatogenesis when the first meiotic cell division occurs. They are derived from Spermatogonium or Stem cell through mitotic division. At the zygotene phase of meiotic prophase the Synaptonemal complex appears in these cells in the space between the paired homologous chromosomes. Spermatogenesis and sperm structure in fish have been studied at the electron microscope level in a few species? However, no work has yet been reported on ultrastructure of tilapia, O. niloticus, spermatozoa and spermatogenetic process. In this short communication we are reporting the Ultrastructure of Primary Spermatocytes in tilapia, O. niloticus, and the fine structure of synaptonemal complexes seen in the spermatocyte nuclei.

Some Aspects of Exelfs Analysis in the Electron Microscope

1980 ◽  
Vol 38 ◽  
pp. 118-119
Author(s):  
D. E. Johnson ◽  
S. Csillag
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Energy Loss ◽  
Analytical Electron Microscopy ◽  
Interference Effects ◽  
Interatomic Distances ◽  
X Ray ◽  
Structure Information ◽  
Microanalytical Technique ◽  
Analytical Electron

Recently, the applications area of analytical electron microscopy has been extended to include the study of Extended Energy Loss Fine Structure (EXELFS). Modulations past an ionization edge in the energy loss spectrum (EXELFS), contain atomic fine structure information similar to Extended X-ray Absorbtion Fine Structure (EXAFS). At low momentum transfer the main contribution to these modulations comes from interference effects between the outgoing excited inner shell electron waves and electron waves backscattered from the surrounding atoms. The ability to obtain atomic fine structure information (such as interatomic distances) combined with the spatial resolution of an electron microscope is unique and makes EXELFS an important microanalytical technique.

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