Innervation of the Abdominal Intersegmental Muscles in the Grasshopper

1971 ◽  
Vol 55 (2) ◽  
pp. 305-313
Author(s):  
N. M. TYRER
Keyword(s):  
Electron Microscope ◽  
Individual Variation ◽  
Light Microscope ◽  
Abdominal Segment ◽  
Serial Sections ◽  
Dorsal Muscle ◽  
Melanoplus Differentialis ◽  
Dorsal Nerve

1. The course of the dorsal nerve in the fourth abdominal segment of the grasshopper Melanoplus differentialis is described. 2. Unconventional techniques of making serial sections of the dorsal nerve for examination with the electron microscope are described in detail. The method permits a higher resolution than the light microscope but lower than more conventional electronmicroscope techniques. 3. It has been demonstrated that the median dorsal internal muscles are all innervated from eight axons in the dorsal nerve. 4. Although there is individual variation in the size of these axons there is some indication that they can be divided into four pairs according to their size. 5. Of the remaining 13 axons in the dorsal nerve, two supply the median external dorsal muscle and 11 are concerned with the innervation of the heart.

CYTOPLASMIC BRIDGES AND MUSCLE SYSTEMS IN SOME POLYMYARIAN NEMATODES

1966 ◽  
Vol 44 (2) ◽  
pp. 329-340 ◽  
Author(s):  
K. A. Wright
Keyword(s):  
Electron Microscope ◽  
Muscle Cell ◽  
Light Microscope ◽  
Muscular Activity ◽  
Muscle Cells ◽  
Serial Sections ◽  
Cell Systems ◽  
Hydrostatic Skeleton ◽  
Cytoplasmic Bridges ◽  
Somatic Musculature

The somatic musculature of nine genera of nematodes (Contracaecum, Toxascaris, Toxocara, Porrocaecum, Cyslidicola, Amplicaecum, Physaloptera, Thoracostoma, and Dermatoxys) was examined by means of serial sections and dissections examined with the light microscope, and, in one instance (Thoracostoma), by use of an electron microscope. Interconnections between muscle cells (cytoplasmic bridges) were demonstrated in the musculature of the polymyarian nematodes, but could not be seen in Dermatoxys, the only meromyarian nematode studied. Cytoplasmic bridges occur in greater frequency in the anterior end of the nematodes. Innervation processes of muscle cells frequently branch before they associate with the median chords. In the head end of Toxascaris, Toxocara, and Porrocaecum, muscle cells are doubly innervated, sending innervation processes to sublateral nerve cords as well as to the median hypodermal chords. Cytoplasmic bridges probably are the basis of the electrical pathways by which contraction impulses are spread from cell to cell. The complexly interconnected muscle cell systems demonstrated undoubtedly serve, along with the nematode's hydrostatic skeleton, as the mechanism by which coordinated muscular activity is achieved.

Selective Staining of Acid Mucopolysaccharides By Ruthenium Red

1968 ◽  
Vol 26 ◽  
pp. 38-39
Author(s):  
J. H. Luft
Keyword(s):  
Electron Microscope ◽  
Light Microscopy ◽  
Light Microscope ◽  
Osmium Tetroxide ◽  
Single Cells ◽  
Ruthenium Red ◽  
Collagen Fibers ◽  
Selective Staining ◽  
Pectic Substances ◽  
Solid Tissues

Ruthenium red is one of the few completely inorganic dyes used to stain tissues for light microscopy. This novelty is enhanced by ignorance regarding its staining mechanism. However, its continued usefulness in botany for demonstrating pectic substances attests to selectivity of some sort. Whether understood or not, histochemists continue to be grateful for small favors.Ruthenium red can also be used with the electron microscope. If single cells are exposed to ruthenium red solution, sufficient mass can be bound to produce observable density in the electron microscope. Generally, this effect is not useful with solid tissues because the contrast is wasted on the damaged cells at the block surface, with little dye diffusing more than 25-50 μ into the interior. Although these traces of ruthenium red which penetrate between and around cells are visible in the light microscope, they produce negligible contrast in the electron microscope. However, its presence can be amplified by a reaction with osmium tetroxide, probably catalytically, to be easily visible by EM. Now the density is clearly seen to be extracellular and closely associated with collagen fibers (Fig. 1).

Cell morphology, volume, and surface area determinations from multilevel contouring within HVEM micrographs of serial sections and whole-cell mounts

1987 ◽  
Vol 45 ◽  
pp. 588-589
Author(s):  
M. Marko ◽  
A. Leith ◽  
D. Parsons
Keyword(s):  
Surface Area ◽  
Electron Micrographs ◽  
Cell Morphology ◽  
Individual Variation ◽  
Serial Section ◽  
Stereo Pair ◽  
Complex Structures ◽  
Serial Sections ◽  
Surface Areas ◽  
Computer Based

The use of serial sections and computer-based 3-D reconstruction techniques affords an opportunity not only to visualize the shape and distribution of the structures being studied, but also to determine their volumes and surface areas. Up until now, this has been done using serial ultrathin sections.The serial-section approach differs from the stereo logical methods of Weibel in that it is based on the Information from a set of single, complete cells (or organelles) rather than on a random 2-dimensional sampling of a population of cells. Because of this, it can more easily provide absolute values of volume and surface area, especially for highly-complex structures. It also allows study of individual variation among the cells, and study of structures which occur only infrequently.We have developed a system for 3-D reconstruction of objects from stereo-pair electron micrographs of thick specimens.

scholarly journals ELECTRON MICROSCOPE STUDIES ON THE DICTYOSOMES AND ACROBLASTS IN THE MALE GERM CELLS OF THE CRICKET

1956 ◽  
Vol 2 (4) ◽  
pp. 123-128 ◽  
Author(s):  
H. W. Beams ◽  
T. N. Tahmisian ◽  
R. L. Devine ◽  
Everett Anderson
Keyword(s):  
Electron Microscope ◽  
Golgi Apparatus ◽  
Electron Micrographs ◽  
Germ Cells ◽  
Light Microscope ◽  
Golgi Body ◽  
Duplex Structure ◽  
Male Germ Cells ◽  
Secondary Spermatocyte ◽  
A Chain

The dictyosome (Golgi body) in the secondary spermatocyte of the cricket appears in electron micrographs as a duplex structure composed of (a) a group of parallel double-membraned lamellae and (b) a group of associated vacuoles arranged along the compact lamellae in a chain-like fashion. This arrangement of ultramicroscopic structure for the dictyosomes is strikingly comparable to that described for the Golgi apparatus of vertebrates. Accordingly, the two are considered homologous structures. Associated with the duplex structure of the dictyosomes is a differentiated region composed of small vacuoles. This is thought to represent the pro-acrosome region described in light microscope preparations. In the spermatid the dictyosomes fuse, giving rise to the acroblast. Like the dictyosomes, the acroblasts are made up of double-membraned lamellae and associated vacuoles. In addition, a differentiated acrosome region is present which, in some preparations, may display the acrosome vacuole and granule. Both the dictyosomes and acroblasts are distinct from mitochondria.

Marine fungi from Seychelles. I. Nimbospora effusa and Nimbospora bipolaris sp. no v. from driftwood

1985 ◽  
Vol 63 (3) ◽  
pp. 611-615 ◽  
Author(s):  
Kevin D. Hyde ◽  
E. B. Gareth Jones
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Light Microscope ◽  
Marine Fungi ◽  
Undescribed Species ◽  
Scanning Electron

Collections of filamentous marine fungi in Seychelles included Nimbospora effusa Koch and an undescribed species, Nimbospora bipolaris Hyde & Jones sp. nov. Tha latter differs from N. effusa in the size of the ascospores and in ascospore appendage morphology. Both species are illustrated by light microscope and scanning electron microscope micrographs.

The Ultra-fine Structure of Lipid Globules in the Neurones of Helix aspersa

1958 ◽  
Vol s3-99 (46) ◽  
pp. 279-284
Author(s):  
J.T. Y. CHOU ◽  
G. A. MEEK
Keyword(s):  
Methylene Blue ◽  
Fine Structure ◽  
Electron Microscope ◽  
Electron Micrographs ◽  
Light Microscope ◽  
Helix Aspersa

The three kinds of lipid globules recognizable in the living neurones of Helix aspersa have been examined under the electron microscope. The globules of the kind that can be stained blue with methylene blue during life are seen in electron micrographs as spheres or spheroids, with concentric lamination, after calcium-osmium fixation. After fixation with sucrose-osmium laminated crescentic bodies are seen instead; these appear to be formed by distortion of the ‘blue’ globules. The yellow globules contain electrondense material, and sometimes appear reticular. It is possible that the yellow globules may originate by transformation of some of the ‘blue’ globules. The colourless globules generally appear as crenated objects; this appearance may be a shrinkage artifact. Apart from the mitochondria and the three kinds of lipid globules described, no other object large enough to be identified with the light microscope has been seen in the cytoplasm.

The structure of the Spiracles of the cattle tick, Boophilus microplus

1967 ◽  
Vol 15 (5) ◽  
pp. 941 ◽  
Author(s):  
HE Hinton
Keyword(s):  
Electron Microscope ◽  
Ambient Air ◽  
Adult Tick ◽  
Boophilus Microplus ◽  
Ixodid Ticks ◽  
Cattle Tick ◽  
Serial Sections ◽  
Peripheral Part ◽  
Gas Exchanges ◽  
Spiracular Plate

The structures of the nymphal and adult spiracles of the tick, Boophilus microplus, have been examined by means of serial sections and a stereoscan electron microscope. Contrary to the views of recent writers, the functional openings of the spiracle have been found to be holes or aeropyles in the peripheral part of the spiracular plate of the adult tick. The ostium of previous writers is shown to be the ecdysial tube, which is present only in the spiracles of adult ixodid ticks. After the nymphal-adult ecdysis, the ecdysial tube is closed. There is thus no ostium in this stage, as has been claimed by previous writers who supposed that the chief or only route for gas exchanges between the atrium of the spiracle and the ambient air was through the so-called ostium. The ecdysial process of the spiracles of ticks is shown to be basically similar to the ecdysial process of the spiracles of certain insects such as scarabaeid larvae and the larvae of some Diptera-Cyclorrhapha.

scholarly journals AN ELECTRON MICROSCOPE STUDY OF THE EMBRYOLOGY OF THE INTERCALATED DISC IN THE HEART OF THE RABBIT

1957 ◽  
Vol 3 (2) ◽  
pp. 193-202 ◽  
Author(s):  
Alan R. Muir
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Cardiac Muscle ◽  
Microscope Study ◽  
Light Microscope ◽  
Electron Microscope Study ◽  
Muscle Cells ◽  
Intercalated Disc ◽  
Adult Cell ◽  
Embryonic Muscle

Prenatal and postnatal cardiac muscle from rabbits has been studied by electron microscopy, after osmium fixation and methacrylate embedding. The observations showed that 1. Cell membranes divide the muscle into cellular units from the youngest embryo which was studied (9½ days after coitus) until the adult state. 2. The embryonic muscle cells contain only one nucleus, whereas the adult cell may be multinucleated. 3. At all stages of development, wherever a myofibrillar axis crosses a cellular boundary, the myofilaments are interrupted by an intercalated disc. 4. With age, increase in size and complexity of the discs render them recognisable by the light microscope.

scholarly journals Individual microtubules viewed by immunofluorescence and electron microscopy in the same PtK2 cell

1978 ◽  
Vol 77 (3) ◽  
pp. R27 ◽  
Author(s):  
M Osborn ◽  
RE Webster ◽  
K Weber
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Light Microscope ◽  
Immunofluorescence Microscopy ◽  
Uranyl Acetate ◽  
Tubulin Antibodies ◽  
Ptk2 Cell ◽  
Cytoplasmic Microtubules ◽  
Triton X ◽  
Microtubular Structures

PtK2 cells were grown on gold grids and treated with Triton X-100 in a microtubule stabilizing buffer. The resulting cytoskeletons were fixed with glutaraldehyde and subjected to the indirect immunofluorescence procedure using monospecific tubulin antibodies. Grids were examined first by fluorescence microscopy, and the display of fluorescent cytoplasmic microtubules was recorded. The grids were then stained with uranyl acetate and the display of fibrous structures recorded by electron microscopy. Thus the display of cytoplasmic microtubular structures in the light microscope and the electron microscope can be compared within the same cytoskeleton. The results show a direct correspondence of the fluorescent fibers in the light microscope with uninterrupted fibers of diameter approximately 550 A in the electron microscope. This is the diameter reported for a single microtubule decorated around its circumference by two layers of antibody molecules. Thus under optimal conditions immunofluorescence microscopy can visualize individual microtubules.

SEM OBSERVATIONS ON 'TAWARA-SHIBO' (A SERIES OF SWELLINGS ALONG THE AXIS) STEMS OF CHAMAECYPARIS OBTUSA

IAWA Journal ◽  
2002 ◽  
Vol 23 (1) ◽  
pp. 83-96 ◽  
Author(s):  
Ryogo Nakada ◽  
Kaichiro Kawamura
Keyword(s):  
Growth Rate ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Growth Rates ◽  
Light Microscope ◽  
Chamaecyparis Obtusa ◽  
Stem Form ◽  
Anatomical Features ◽  
Hormonal Secretion ◽  
Scanning Electron

The anatomy of tawara-shibo stems of Chamaecyparis obtusa (Siebold & Zucc.) Endl. was observed using a scanning electron microscope (SEM) and a light microscope. Tawara-shibo is a strange stem form with a series of swellings that appear at regular intervals along the stem axis. Multiseriate rays, trabeculae and related structures, and modified tracheids were frequently observed at swollen portions. These features were less frequent at non-swollen portions.We conclude that abnormal cambial activities, occurring at regular longitudinal intervals, cause the formation and development of these three anatomical features and higher growth rates at swollen portions. As a result of differences in growth rate between swollen and non-swollen portions, the stem form of tawara-shibo develops. It is suggested that formation of the characteristics observed in tawara-shibo stems is genetically controlled by hormonal secretion into or within the cambium.

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