Glial Responses to Degenerating Cerebellar Cortico-nuclear Pathways in the Cat

Eager, Robert P.; Eager, Patricia R.

doi:10.1126/science.153.3735.553

Cited by 31 publications

(3 citation statements)

References 11 publications

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Section: Resume: Etudes Ultrastructurales De Cellules Formant Des Fibmentioning

confidence: 99%

“…1 Acceptance of microglia as a distinct cell population was hindered by difficulties encountered in identifying them by means of electron microscopy. [2][3][4] The combination of silver staining and close correlation with light microscopy subsequently yielded a definitive identification of the microglial cell group. 5 " 8 Microglial cells were characterized as small oval cells with a variable number of branching processes and scant cytoplasm which usually contained dense bodies.5-7,9,10 Four different forms of microglia have been identified: (1) resting or ramified, (2) reactive, (3) amoeboid which is recognized as a transient cell form during development and (4) round cell which is restricted to the early postnatal period.…”

mentioning

confidence: 99%

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Ultrastructural Studies of the Cells Forming Amyloid Fibers in Classical Plaques

Wisniewski

Węgiel²,

Wang

et al. 1989

Can. J. Neurol. Sci.

216

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ABSTRACT:Three-dimensional reconstruction and ultrastructural studies of classical plaques from the cortex of patients with Alzheimer's disease showed that microglial cells of the plaques are the amyloid-forming cells. The amyloid star of the single plaque represents the product of five or six microglial cells covering about 80% of the amyloid star surface. The amyloid fibers appear to be formed within altered cisterns of the endoplasmic reticulum. Distended cisterns form channels filled with amyloid fibers. Numerous vesicles derived from the Golgi apparatus appear to be attached to or fused with the amyloid-filled channels. Reconstruction of the amyloid star and the microglia cell pole that forms the amyloid star reveals three different zones of distribution of cytoplasmic organelles and amyloid deposits. The peripheral zone comprises channels filled with loosely packed amyloid fibers arranged in a parallel manner. The transient zone consists of a mixture of fusing amyloid channels and products of disintegration of cytoplasmic pockets, dense bodies and fragments of cellular membranes. The core of the amyloid star is composed of condensed, densely packed amyloid fibers that are free of cellular debris. Formation of the three zones supports the idea that the microglia/macrophages are not phagocytes but instead are the cells manufacturing the amyloid fibers.

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Section: Resume: Etudes Ultrastructurales De Cellules Formant Des Fibmentioning

confidence: 99%

mentioning

confidence: 99%

Ultrastructural Studies of the Cells Forming Amyloid Fibers in Classical Plaques

Wisniewski

Węgiel²,

Wang

et al. 1989

Can. J. Neurol. Sci.

216

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“…Perhaps the most remarkable of all these features involved the Golgi system (Figs. 6,8). This was hyperplastic and extended considerable distances from the paranuclear area.…”

Section: Normal Human Fetal Fibroblasts (Hff5)mentioning

confidence: 99%

The Ultrastructure of Human and Murine Astrocytes and of Human Fibroblasts in Culture

Macintyre¹,

Pontén²,

Vatter³

1972

Acta Pathologica Microbiologica Scandinavica Section A Patholog

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A study was undertaken to seek fine structural differences between normal and maglinant astrocytes and normal fibroblasts in cell culture. A series of human adult normal astrocytes and malignant astrocytes (including RSV-transformed cells) whose cultural characteristics had previously been reported formed the basis of the study. Also included were matched normal human fetal fibroblasts and astrocytes (from the same fetus) and methylcholanthrene-induced murine malignant astrocytes. Pellets of cells scraped from their culture vessel and sectioned as well as in situ preparations were examined. T h e fibroblasts were the only cells whose external microfibrils were collagenare-sensitive and considered to be tropocollagen. Both the benign and the malignant astrocytes had intracytoplasmic microfibril bands (gliofibrils) and some had external collagenare-resistant microfibrils. Malignant astrocytes had a much more developed membrane system (used in its widest sense) than normal astrocytes, had many free ribosomes and some had morphologically abnormal mitochondria. Virus was seen only in the niurine malignant astrocytes, was abundant and of the murine leukemia virus group. Areas interpreted as representing fusion in progress were seen at the surface of some RSV-transfomed giant tumor astrocytes. The fine structure of one cell type from an IgC-producing culture from human glioblastoma corresponded with that reported for immunocytes.The cytology and growth kinetics of human astrocytes in cell culture have been described (Ponte'n & Macintyre 1968). This series was obtained by culturing routinely all neurosurgical specimens taken over a prolonged period. These biopsies included tissues of tumor and non-tumor origin from brain. Variants transformed by Rous sarcoma virus (RSV) were derived from these cells (Ponte'n & Macintyre 1968, Macintyrp et. al. 1969. The aim of the present study has been to examine the fine structure of these same cultures, in order Received 9.ix.71

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The external glial limiting membrane in Macaca: Ultrastructure of a laminated glioepithelium

Bondareff

McLone

1973

Am. J. Anat.

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The external glial limiting membrane in Macaca is a multilaminar epithelium-like mantle formed by the perikarya and interdigitating cell processes of astrocytes. It is separated from the overlying subarachnoid space by a typical basement membrane. Tonofilaments, about 100 in diameter, course through the cytoplasm of the processes in sheaths which run in different planes in successive layers of the mantle, forming a course brushwork. Beneath the surface plasma membrane of the superficial astrocytes is a filamentous layer, 500-700 A thick, which is composed of microfilaments, about 50 A in diameter. These microfilaments were continuous with the inner aspect of the plasma membrane. The tonoflaments appeared to terminate in the microfilamentous network. The similarity of these microfilaments to the cytocholasin B-sensitive microfilaments of epithelial cells suggested contractile properties and their participation in the motility of glial cells at the border of the brain and subarachnoid space.In mammalian central nervous tissue, astrocytes are recognized mainly by the relative abundance of intracytoplasmic particulate glycogen and the presence of numerous, variously distributed glial filaments (Peters et al., '70). The latter, about 130 A in diameter, are similar to the tonofilaments characteristic of epithelial cells and often are gathered up into sheaths, which course through the cytoplasm. They are especially prominent in the attenuated cytoplasmic processes of astrocytes.The function of these glial filaments in astrocytes is essentially unknown, yet they increase in number in several degenerative neuronal diseases (Terry and Weiss, '63; Eager and Eager, '66; Luse, '68) and in so-called "glial scars" formed in brain tissue in response to tissue injury (Schultz and Pease, '59; Luse, '68). They are found normally in the astroglial cells forming the external glial membrane (Nominu HistoZogica, '70), which separates the molecular layer of the cerebral cortex from the overlying pia-arachnoid tissues.In vertebrates, generally, the external glial limiting membrane is composed of variably distributed cell bodies and cytoplasmic processes of astrocytes (Held, '09; AM. J. ANAT., 136: 277-296.Penfield, '32; Bohme, '66). In animals subjected to perinatal asphyxia, then permitted to come to term normally, an atrophic cortical sclerosis (ulegyria) results with an associated hypertrophy of cortical astrocytes (Meyers, '69) and presumably an hypertrophy of the external limiting membrane astrocytes.We report here the results of an electron microscopic study of the external glial limiting membrane in normal rhesus monkeys and those subjected to perinatal asphyxia. The submicroscopic distributions of tonofilaments and microfilaments, which previously have been unknown in mammalian astrocytes, are described. The relationships of these two types of filaments to the plasma membrane and its associated basement membrane suggests similar relationships, well known in typical epithelial cells. MATERIALS AND METHODSThis study concern...

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Glial Responses to Degenerating Cerebellar Cortico-nuclear Pathways in the Cat

Abstract: Astrocytic changes in regions of long-term, cerebellar corticonuclear degeneration are characterized by large increases in cytoplasmic volume, as well as by formation of vacuoles and fibrils. Lipids are demonstrable in the vacuoles with oil red-O staining.

Cited by 31 publications

References 11 publications

Ultrastructural Studies of the Cells Forming Amyloid Fibers in Classical Plaques

Ultrastructural Studies of the Cells Forming Amyloid Fibers in Classical Plaques

The Ultrastructure of Human and Murine Astrocytes and of Human Fibroblasts in Culture

The external glial limiting membrane in Macaca: Ultrastructure of a laminated glioepithelium

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