Fine structure and differentiation of ascidian muscle. II. Morphometrics and differentiation of the caudal muscle cells ofDistaplia occidentalis tadpoles

1974 ◽  
Vol 144 (1) ◽  
pp. 23-69 ◽  
Author(s):  
Michael J. Cavey ◽  
Richard A. Cloney
Keyword(s):  
Fine Structure ◽  
Muscle Cells

scholarly journals THE FINE STRUCTURE OF EMBRYONIC CHICK SKELETAL MUSCLE CELLS DIFFERENTIATED IN VITRO

1967 ◽  
Vol 35 (2) ◽  
pp. 445-453 ◽  
Author(s):  
Y. Shimada ◽  
D. A. Fischman ◽  
A. A. Moscona
Keyword(s):  
Electron Microscopy ◽  
Skeletal Muscle ◽  
Fine Structure ◽  
Muscle Cells ◽  
Skeletal Muscle Cells ◽  
Chick Embryos ◽  
Embryonic Chick ◽  
Developing Muscle

Dissociated myoblasts from 12-day chick embryos were cultured in monolayer, and the differentiation of skeletal muscle cells was studied by electron microscopy. The results have revealed a striking ultrastructural similarity between the in vivo and the in vitro developing muscle, particularly with respect to the myofibrils and sarcoplasmic reticulum. This study demonstrates that all the characteristic organelles of mature skeletal muscle can develop in vitro in the absence of nerves.

scholarly journals FINE STRUCTURE OF SMOOTH MUSCLE CELLS GROWN IN TISSUE CULTURE

1971 ◽  
Vol 49 (1) ◽  
pp. 21-34 ◽  
Author(s):  
Gordon R. Campbell ◽  
Yasuo Uehara ◽  
Gerda Mark ◽  
Geoffrey Burnstock
Keyword(s):  
Electron Microscopy ◽  
Smooth Muscle ◽  
Fine Structure ◽  
Cell Membrane ◽  
Smooth Muscle Cells ◽  
Phase Contrast ◽  
Muscle Cells ◽  
Different Types ◽  
Membrane Infoldings

The fine structure of smooth muscle cells of the embryo chicken gizzard cultured in monolayer was studied by phase-contrast optics and electron microscopy. The smooth muscle cells were irregular in shape, but tended to be elongate. The nucleus usually contained prominent nucleoli and was large in relation to the cell body. When fixed with glutaraldehyde, three different types of filaments were noted in the cytoplasm: thick (150–250 A in diameter) and thin (30–80 A in diameter) myofilaments, many of which were arranged in small bundles throughout the cytoplasm and which were usually associated with dark bodies; and filaments with a diameter of 80–110 A which were randomly orientated and are not regarded as myofilaments. Some of the aggregated ribosomes were helically arranged. Mitochondria, Golgi apparatus, and dilated rough endoplasmic reticulum were prominent. In contrast to in vivo muscle cells, micropinocytotic vesicles along the cell membrane were rare and dense areas were usually confined to cell membrane infoldings. These cells are compared to in vivo embryonic smooth muscle and adult muscle after treatment with estrogen. Monolayers of cultured smooth muscle will be of particular value in relating ultrastructural features to functional observations on the same cells.

Fine structure of the synaptic endings between sympathetic axons and skeletal muscle cells and of the varicosities in the bundles of neurites in tissue culture

1984 ◽  
Vol 85 (1) ◽  
pp. 187-201 ◽  
Author(s):  
Takayoshi Kobayashi ◽  
Yoshiaki Matsumoto ◽  
Hiroshi Tsukagoshi ◽  
Katsuhiko Kayanuma ◽  
Shin'Ichiro Hori
Keyword(s):  
Skeletal Muscle ◽  
Tissue Culture ◽  
Fine Structure ◽  
Muscle Cells ◽  
Skeletal Muscle Cells

Hymenolepis nana: the fine structure of the ‘penetration gland’ and nerve cells within the oncosphere

Parasitology ◽  
1981 ◽  
Vol 82 (3) ◽  
pp. 445-458 ◽  
Author(s):  
I. Fairweather ◽  
L. T. Threadgold
Keyword(s):  
Fine Structure ◽  
Secretory Granules ◽  
Polar Filament ◽  
Secretory Activity ◽  
Muscle Cells ◽  
Neurosecretory Cells ◽  
Nerve Cells ◽  
Epithelial Layer ◽  
Hymenolepis Nana ◽  
Penetration Gland

SUMMARYThe fine structure of the oncosphere of Hymenolepis nana has been investigated by transmission and scanning electron microscopy, together with light microscope observations of JB–4 embedded material. The outer surface of the oncosphere is covered by an epithelial layer, termed the embryonic epithelium. Cell types present within the oncosphere include the penetration gland cell, oncoblast, or hook-forming cells, nerve cells, muscle cells (both somatic and hook), and undifferentiated ‘stem’ cells. The penetration gland is a large, U-shaped structure, situated in the anterior region of the oncosphere, and filled with secretory granules of 2 distinct morphological types. Histochemically, the secretory material yields reactions characteristic of an acid mucopolysaccharide. A proteinaceous-substance and small amounts of glycogen are also present. Up to 4 pairs of ducts from the penetration gland have been observed. They pass through the basal lamina and the epithelial layer to open against the polar filament layer at the anterior end of the oncosphere. Nerve cells are described in a cestode oncosphere for the first time. The cells are paraldehyde-fuchsin-positive and show a high level of secretory activity, as evidenced by the large numbers of dense-cored vesicles produced by the Golgi apparatus in the perikarya; consequently, they are tentatively regarded as possible neurosecretory cells. The vesicles are transported down the axon to be stored in specialized swollen axon terminals, which form definite junctions with the muscle cells.

scholarly journals THE FINE STRUCTURE OF MOTOR ENDPLATE MORPHOGENESIS

1969 ◽  
Vol 42 (1) ◽  
pp. 154-169 ◽  
Author(s):  
A. M. Kelly ◽  
S. I. Zacks
Keyword(s):  
Fine Structure ◽  
Schwann Cells ◽  
Basal Lamina ◽  
Plasma Membranes ◽  
Muscle Cells ◽  
Motor Endplate ◽  
Intercostal Muscle ◽  
Motor Endplates ◽  
Terminal Axon ◽  
Small Muscle

The fine structure of the developing neuromuscular junction of rat intercostal muscle has been studied from 16 days in utero to 10 days postpartum. At 16 days, neuromuscular relations consist of close membrane apposition between clusters of axons and groups of myotubes. Focal electron-opaque membrane specializations more intimately connect axon and myotube membranes to each other. What relation these focal contacts bear to future motor endplates is undetermined. The presence of a group of axons lying within a depression in a myotube wall and local thickening of myotube membranes with some overlying basal lamina indicates primitive motor endplate differentiation. At 18 days, large myotubes surrounded by new generations of small muscle cells occur in groups. Clusters of terminal axon sprouts mutually innervate large myotubes and adjacent small muscle cells within the groups. Nerve is separated from muscle plasma membranes by synaptic gaps partially filled by basal lamina. The plasma membranes of large myotubes, where innervated, simulate postsynaptic membranes. At birth, intercostal muscle is composed of separate myofibers. Soleplate nuclei arise coincident with the peripheral migration of myofiber nuclei. A possible source of soleplate nuclei from lateral fusion of small cells' neighboring areas of innervation is suspected but not proven. Adjacent large and small myofibers are mutually innervated by terminal axon networks contained within single Schwann cells. Primary and secondary synaptic clefts are rudimentary. By 10 days, some differentiating motor endplates simulate endplates of mature muscle. Processes of Schwann cells cover primary synaptic clefts. Axon sprouts lie within the primary clefts and are separated from each other. Specific neural control over individual myofibers may occur after neural processes are segregated in this manner.

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