scholarly journals The Ultrastructure of the Perineurium in two Insect Species, Carausius Morosus and Periplaneta Americana

1967 ◽  
Vol 2 (1) ◽  
pp. 119-128
Author(s):  
S. H. P. MADDRELL ◽  
J. E. TREHERNE
Keyword(s):  
Connective Tissue ◽  
Periplaneta Americana ◽  
Fluid Transport ◽  
Insect Species ◽  
Carausius Morosus ◽  
Insect Central Nervous System ◽  
Connective Tissue Sheath ◽  
Extracellular Sodium ◽  
Perineurial Cells ◽  
Cellular Layer

The organization of the perineurium in two insect species (Carausius morosus and Periplaneta americana) has been examined with the electron microscope. In both species this cellular layer has been found to possess an extensive system of tortuous channels between the lateral cell walls. These channels are open at the outer margin adjacent to the fibrous connective-tissue sheath, but appear to be closed at the inner margin by regions of septate desmosomes and/or ‘tight’ junctions. There is an increased surface area at the inner margin of the perineurial cells produced by the presence of long inwardly directed flanges. An electron-dense coat has also been identified on the cytoplasmic side of the type II perineurial cell membranes at points of contact with the underlying extracellular system and at the outer surface adjacent to the connective-tissue sheath. This organization of the perineurium is strikingly similar to that observed in a variety of fluid-secreting epithelia and its possible function in fluid transport is discussed in relation to the available evidence on the physiology of the insect central nervous system. It is suggested, contrary to some earlier suppositions, that the perineurium may not be primarily involved in the control of the extracellular sodium level and that this regulation may be effected at a deeper level in the central nervous tissues.

The Connective Tissue Sheath of the Locust Nervous System: A Histochemical Study

1959 ◽  
Vol s3-100 (51) ◽  
pp. 401-412
Author(s):  
DOREEN E. ASHHURST
Keyword(s):  
Nervous System ◽  
Connective Tissue ◽  
Collagen Type ◽  
Histochemical Study ◽  
Locusta Migratoria ◽  
System A ◽  
Large Numbers ◽  
Connective Tissue Sheath ◽  
Cellular Layer ◽  
Sheath Cells

The connective tissue sheath surrounding the nervous system of Locusta migratoria has been studied histochemically. It consists of an outer non-cellular layer, the neural lamella, and an inner layer of cells, the sheath-cells. The neural lamella has been identified as being composed of a collagen-type protein and neutral mucopolysaccharide on the evidence of its histochemical reactions and the identification of hydroxyproline by paper chromatography in a hydrolysate of the neural lamella. The sheath-cells possess large numbers of lipochondria composed of phospholipids and cerebrosides, and small spherical mitochondria. The cytoplasm also contains lipids (some of which may be cerebrosides), glycogen, and RNA.

The Connective-Tissue Sheath of the Nervous System of Locusta migratoria: an Electron Microscope Study

1961 ◽  
Vol s3-102 (60) ◽  
pp. 463-467
Author(s):  
DOREEN E. ASHHURST ◽  
J. A. CHAPMAN
Keyword(s):  
Endoplasmic Reticulum ◽  
Nervous System ◽  
Electron Microscope ◽  
Connective Tissue ◽  
Electron Microscope Study ◽  
Locusta Migratoria ◽  
Inner Surface ◽  
Connective Tissue Sheath ◽  
Cellular Layer ◽  
Sheath Cells

The sheath is composed of an outer non-cellular layer, the neural lamella, and an inner layer of sheath cells. The neural lamella possesses a large number of collagen fibrils arranged in layers with differing orientations. The sheath cells are flattened on the inner surface of the lamella and the cytoplasm contains lipochondria, mitochondria, and small amounts of endoplasmic reticulum.

A Histochemical Study of the Connective-Tissue Sheath of the Nervous System of Periplaneta americana

1961 ◽  
Vol s3-102 (60) ◽  
pp. 455-461
Author(s):  
DOREEN E. ASHHURST
Keyword(s):  
Nervous System ◽  
Connective Tissue ◽  
Periplaneta Americana ◽  
Collagen Type ◽  
Histochemical Study ◽  
Type Protein ◽  
Connective Tissue Sheath ◽  
Sheath Cells

The connective-tissue sheath surrounding the nervous system of Periplaneta americana consists of two layers, the neural lamella and the sheath cells beneath it. The neural lamella is composed of a collagen-type protein and neutral muco-polysaccharide. The sheath cells possess numerous lipochondria and mitochondria; the former consist of phospholipid and some cerebroside. The cytoplasm of the sheath cells contains some RNA, glycogen, and lipid.

Uptake of ferritin into neurosecretory terminals

1971 ◽  
Vol 261 (839) ◽  
pp. 391-394 ◽  
Keyword(s):  
Myzus Persicae ◽  
Periplaneta Americana ◽  
Insect Species ◽  
Corpus Cardiacum ◽  
Release Process ◽  
Calliphora Erythrocephala ◽  
Carausius Morosus ◽  
Sequence Of Events ◽  
Dense Marker

The release of neurosecretory products from terminals in the corpus cardiacum has been described in a few insect species (Scharrer 1963, 1968; Johnson 1966; Bowers & Johnson 1966; Normann 1965; Smith & Smith 1966; Smith 1970). Exocytosis has been suggested as the mechanism of release in Calliphora erythrocephala (Normann 1965, 1969) and in Carausius morosus (Smith & Smith 1966; Smith 1970), whereas fragmentation into ‘synaptoid’ regions has been indicated in Periplaneta americana (Scharrer 1963, 1968) and in Myzus persicae (Johnson 1966; Bowers & Johnson 1966). It is clear that structures representing both these features exist and differences in interpretation may depend on the sequence of events contributing to release. Using an electron-dense marker, an attempt has been made to determine the origin of the small vesicles which occur in neurosecretory axons and to throw some light on the dynamics of the release process.

scholarly journals The Fine Structure of Nerve Cells and Fibers, Neuroglia, and Sheaths of the Ganglion Chain in the Cockroach (Periplaneta americana)

1958 ◽  
Vol 4 (6) ◽  
pp. 731-742 ◽  
Author(s):  
Arthur Hess
Keyword(s):  
Fine Structure ◽  
Connective Tissue ◽  
Periplaneta Americana ◽  
Nerve Fibers ◽  
Nerve Cells ◽  
Cresyl Violet ◽  
Dark Cells ◽  
Electron Microscopes ◽  
Pass Through ◽  
Connective Tissue Sheath

The abdominal nerve cord of Periplaneta americana was studied utilizing light and electron microscopes. In the nerve cells, delicate granules, similar to those probably responsible for cytoplasmic basophilia, are evenly distributed in "dark" cells and clumped in "light" cells. Neuroglial cells are stained metachromatically by cresyl violet. The neuroglial cells have many processes which ramify extensively and are enmeshed to form overlapping layers. These imbricated processes ensheath the nerve cells; the inner layer of the sheath penetrates into the neuron and is responsible for the appearance of the trophospongium of Holmgren. Nerve fibers are embedded within glial cells and surrounded by extensions of the plasma membrane similar to mesaxons. Depending on their size, two or several nerve fibers may share a single glial cell. Nerve fibers near their terminations on other nerve fibers contain particles and numerous, large mitochondria. The ganglion is ensheathed by a thick feltwork of connective tissue and perilemmal cells. The abdominal connective has a thinner connective tissue sheath which is without perilemmal cells. The nerve fibers and sheaths in the connective become thinner as they pass through ganglia.

Determination of fatty acid content in some edible insects of Mexico

2016 ◽  
Vol 2 (1) ◽  
pp. 37-42 ◽  
Author(s):  
J.M. Pino Moreno ◽  
A. Ganguly
Keyword(s):  
Oleic Acid ◽  
Fatty Acid ◽  
Acid Content ◽  
Periplaneta Americana ◽  
Fatty Acid Content ◽  
Capric Acid ◽  
Caproic Acid ◽  
Insect Species ◽  
Edible Insects

In the present paper we have determined the fatty acid content of some edible insects of Mexico. A comparative analysis of the insect species studied in this research showed that caproic acid was present in a minimal proportion which ranged between 0.01 for Periplaneta americana (nymphs) and 0.06 (g/100 g, dry basis) for Euschistus strenuus. The highest proportion of caprilic acid (0.09) was found in Tenebrio molitor (adults). Atta sp. had the highest amount of capric acid (0.26). Polistes sp. was found to be rich in lauric acid (0.77) and for myristic acid it had the highest content (5.64). Dactylopius sp. and E. strenuus were rich in palmitic acid (14.89). Euschistus taxcoensis had the highest quantity of palmitoleic acid (12.06). Llaveia axin exhibited the highest quantity of stearic acid (22.75). Polistes sp. was found to be rich in oleic acid (38.28). The highest quantity of linoleic acid was observed in T. molitor (larvae) (10.89), and in L. axin the highest content of linolenic acid (7.82) was obtained. A comparison between the species under the present investigation revealed that, in general, the insects are poor in caproic, caprilic, capric, lauric, myristic, palmitoleic and linolenic acids, because the quantities were either minimal or could not be detected at all. They had moderate quantities of stearic, palmitic and linoleic acids and had high quantities of oleic acid. Finally it was concluded that although a particular insect species is unable to fulfil the total fatty acid need for a human, if consumed in combination they could definitely be able to supply a good amount of this highly valued nutrient.

scholarly journals A case of Giant Perifollicular Fibroma - a Diagnostic Challenge

2020 ◽  
Vol 12 (1) ◽  
pp. 19-21
Author(s):  
Raghavendra Rao ◽  
Srilatha Parampalli Srinivas ◽  
Varsha M. Shetty
Keyword(s):  
Connective Tissue ◽  
Head And Neck ◽  
Neck Region ◽  
Diagnostic Challenge ◽  
Head And Neck Region ◽  
Internal Malignancy ◽  
Essential Tool ◽  
Proliferative Lesion ◽  
Connective Tissue Sheath

AbstractPerifollicular fibroma (PFF) is a rare proliferative lesion originating from the perifollicular connective tissue sheath. It may be congenital or acquired manifesting as skin colored to pink, asymptomatic papules of 1-5 mm in size. They are commonly distributed in the head and neck region. Multiple PFFs may be associated with internal malignancy or as a part of Birt-Hogg-Dube syndrome. Histopathology serves as an essential tool in clinching the diagnosis. Herein we report a case of giant congenital PFF.

Subcutaneous reaction to silicone in ventriculoperitoneal shunts

1974 ◽  
Vol 41 (3) ◽  
pp. 367-371 ◽  
Author(s):  
Oscar Sugar ◽  
Orville T. Bailey
Keyword(s):  
Cerebrospinal Fluid ◽  
Connective Tissue ◽  
Fibrous Connective Tissue ◽  
Subcutaneous Implantation ◽  
Content Type ◽  
Ventriculoperitoneal Shunts ◽  
Silicone Tubing ◽  
Connective Tissue Sheath ◽  
Fine Print

✓Silicone tubing (Silastic) used for ventriculoperitoneal shunts induces a fibrous connective tissue sheath around the tubing in children and adults. Two children examined 8 and 3 years after subcutaneous implantation showed a complete tube of dense fibrous connective tissue around the silicone tubing. The reaction was entirely quiescent. These tubes of connective tissue were apparently capable of conveying cerebrospinal fluid for some months after the silicone tubing was disconnected from the pump or pulled out of the abdomen.

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