scholarly journals THE RESPONSE OF VENTRAL HORN NEURONS TO AXONAL TRANSECTION

1972 ◽  
Vol 53 (1) ◽  
pp. 24-37 ◽  
Author(s):  
Donald L. Price ◽  
Keith R. Porter
Keyword(s):  
Endoplasmic Reticulum ◽  
Electron Microscope ◽  
Morphological Changes ◽  
Ventral Horn ◽  
Granular Endoplasmic Reticulum ◽  
Neuronal Nucleus ◽  
Axoplasmic Flow ◽  
Cytoplasmic Matrix ◽  
Show Evidence ◽  
Axonal Transection

The morphological changes induced in the frog ventral horn neurons by axonal transection have been studied with the electron microscope. During the first 2 wk after axotomy the neuronal nucleus becomes more translucent and the nucleolus becomes enlarged and less compact. The cisternae of the granular endoplasmic reticulum vesiculate and ribosomes dissociate from membranes. Free ribosomes and polysomes are dispersed in the cytoplasmic matrix. Neurofilaments and neurotubules are increased in number. These structures appear to be important in the regeneration of the axon. It is proposed that neurotubules, neurofilaments, and axoplasmic matrix are synthesized by the free polyribosomes in the chromatolytic neuron. By the fourth postoperative week, the neurons show evidence of recovery. The cytoplasm is filled with profiles of granular endoplasmic reticulum and many intercisternal polysomes. The substances being manufactured by the newly formed granular endoplasmic reticulum are not clearly defined, but probably include elements essential to electrical and chemical conduction of impulses. The significance of these observations in respect to recent studies of axoplasmic flow is discussed.

An Electron Microscopic Study of the Human Gastric Epithelia with Special Reference to the Cardinal Morphological Changes of the Chief Cells Induced by Insulin Stimulus

1972 ◽  
Vol 30 ◽  
pp. 344-345
Author(s):  
Hiroshi Saito ◽  
Goro Asano ◽  
Kaoru Aihara ◽  
Katsunari Fukushi ◽  
Minoru Yoshida ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Morphological Changes ◽  
Regular Insulin ◽  
Endoscopic Biopsy ◽  
Granular Endoplasmic Reticulum ◽  
Ultrastructural Changes ◽  
Electron Microscopic ◽  
Chief Cells ◽  
Microscopic Studies ◽  
The One

This short communication is dealt with the ultrastructural changes of the chief cells in insulin stimulus in chronic gastritic condition. The bio gastro-endoscopic biopsy was obtained and pepsin activity of the gastric juice was measured in respective cases. Regular insulin of 0.15U/kg was administrated intra-muscularly and in pre-administration of insulin, 10 minutes, 20 minutes and 30 minutes after administration, biopsied specimens were subjected for electron microscopic studies.In the pre-treated chief cells, extensive development of the cysternal structures of the granular endoplasmic reticulum in basal aspect of the cytoplasm and spherical or oval shaped, light homogeneous zymogen granules in supranuclear region and especially apical aspect of the cytoplasm were featured. Moreover, other type of the chief cells as the one characterized by their fragmented and saccular dilated granular endoplasmic reticulum in basal aspect of the cytoplasm, also exist.

Fine structure of the vitteline cells in the cestode Proteocephalus longicollis (proteocephalidea)

1978 ◽  
Vol 36 (2) ◽  
pp. 442-443
Author(s):  
Z. Swiderski ◽  
R. D. Eklu-natey ◽  
L. Subilia ◽  
H. Huggel
Keyword(s):  
Endoplasmic Reticulum ◽  
Lipid Droplets ◽  
Secretory Activity ◽  
Granular Endoplasmic Reticulum ◽  
Secretory Cells ◽  
Cytoplasmic Matrix ◽  
Shell Protein ◽  
Vitelline Cells ◽  
Shell Globule ◽  
Spherical Nuclei

The mature vitelline cells of Proteocephalus longicollis (Zeder, 1800) are ovoid or spherical and measure about 30μm in diameter. They represent the holocrine type of secretory cells.The spherical nuclei, about 10μm in diameter, are localized in the central part of the cell. They contain more or less prominent nucleoli enclosed in the moderately electrondense nucleoplasm (Fig. 1).The cytoplasm (Fig. 2, 3, 4) is packed with numerous shell globules of heterogenous type, large lipid droplets, and a few glycogen islands composed mainly of α-glycogen rosettes.The remaining granular cytoplasmic matrix (Fig. 3, 4) contains: (a) numerous polysomes, (b) cysternae of granular endoplasmic reticulum, (c) several mitochondria, and (d) extended Golgi regions, composed of vesicles of different sizes and density.The extensive development of granular endoplasmic reticulum (GER) and Golgi complexes indicates high secretory activity of these cells. Both Golgi and GER are evidently engaged in shell globule formation and are considered therefore to function as the shell-protein producing units

Differentiation of Neurosensory Cells in Hydra

1969 ◽  
Vol 5 (3) ◽  
pp. 699-726
Author(s):  
LOWELL E. DAVIS
Keyword(s):  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Electron Microscope ◽  
Basal Body ◽  
Neurosecretory Cells ◽  
Nerve Cells ◽  
Granular Endoplasmic Reticulum ◽  
Structural Variations ◽  
Intercellular Bridges ◽  
Undifferentiated Cells

The differentiation of neurosensory cells in Hydra has been studied at the level of the electron microscope. These cells arise from interstitial cells (undifferentiated cells) and not from pre-existing nerve cells. Furthermore, there is no evidence to suggest that neurosensory cells represent a stage in the development of other nerve cells, i.e. ganglionic and neurosecretory cells. Major cytoplasmic changes in fine structure during differentiation include development of a cilium and associated structures (basal body, basal plate, rootlets), development of microtubules and at least two neurites, increase in Golgi lamellae and formation of dense droplets typical of neurosecretory droplets, structural variations in mitochondria and a decrease in the number of ribosomes. Granular endoplasmic reticulum is characteristically poorly developed in all stages of differentiation, including the mature neurosensory cell. Nuclear and nucleolar changes also occur during differentiation but these are less dramatic than the cytoplasmic events. The possibility of neurosensory cells being bi- or multiciliated and the presence of intercellular bridges between these cells are considered. The function of neurosensory cells is discussed briefly in relation to the function of the cilium and neurosecretory droplets.

scholarly journals LIVER PARENCHYMAL CELL INJURY

1963 ◽  
Vol 19 (1) ◽  
pp. 139-157 ◽  
Author(s):  
Edward S. Reynolds
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Carbon Tetrachloride ◽  
Cell Injury ◽  
Chemical Interaction ◽  
Parenchymal Cell ◽  
Granular Endoplasmic Reticulum ◽  
Liver Parenchymal Cell ◽  
Cytoplasmic Matrix ◽  
Liver Parenchymal

The structure of the endoplasmic reticulum, plasma membrane, mitochondria, and Golgi apparatus of the liver parenchymal cell is strikingly altered within 1 hour following the administration of a single oral dose of carbon tetrachloride to rats. Progressive loss of glucose-6-phosphatase activity accompanies dispersal of the ergastoplasm. Electron microscopy reveals that these changes are associated with vacuolization of the cisternae of the granular endoplasmic reticulum, degranulation of its membranes, and the appearance of increased number of free ribosomes in the adjacent cytoplasmic matrix. Concomitantly, calcium enters the liver parenchymal cell and is sequestered by mitochondria. First increased at 30 minutes, calcium content is maximal at 1 hour and returns to normal at 2 hours. Although succinic and glutamic dehydrogenase activity patterns within the liver lobule are unaffected, liver cell mitochondria enlarge and some appear to fuse or assume cup-like configurations. Microvilli lining the space of Disse become irregularly indistinct and increasingly pleomorphic by 30 minutes when the plasma membrane becomes increasingly permeable to calcium. Golgi vesicles swell and discharge their granules during the period of poisoning studied. Although all the changes observed may be the result of direct interaction of carbon tetrachloride with the membranes of the cytoplasmic constituents of the liver parenchymal cell, the possibility that the irreversible changes observed in the granular endoplasmic reticulum may be due to the chemical interaction between the poison and this system is discussed.

scholarly journals INTRANUCLEAR AND CYTOPLASMIC ANNULATE LAMELLAE IN TUNICATE OOCYTES

1965 ◽  
Vol 24 (3) ◽  
pp. 471-487 ◽  
Author(s):  
R. G. Kessel
Keyword(s):  
Endoplasmic Reticulum ◽  
Electron Microscope ◽  
Nuclear Envelope ◽  
Outer Layer ◽  
Growth And Development ◽  
Granular Endoplasmic Reticulum ◽  
Fusion Process ◽  
Morphological Evidence ◽  
Annulate Lamellae ◽  
Stages Of Growth

Electron microscope studies were made on various tunicate oocytes at different stages of growth and development. Both the inner and outer lamellae of the perforated nuclear envelope demonstrate considerable blebbing activity. The blebs of the inner lamella detach into the nucleoplasm where they undergo a special type of fusion process resulting in the formation of numerous, usually single, differentiated annulate lamellae of various lengths. The blebbing of the outer layer of the nuclear envelope contributes to the vesicular and granular endoplasmic reticulum characteristically present in the ooplasm and perhaps to the differentiation of cytoplasmic annulate lamellae as well. Cytoplasmic stacks of annulate lamellae frequently have ribosomes associated with them. In addition, granular accumulations are sometimes observed around or between the annuli. The morphological evidence suggests that, at least in many cases, the annuli in the annulate lamellae are patent.

A Study of Granule Formation in the Bat Parafollicular Cell

1969 ◽  
Vol 5 (2) ◽  
pp. 531-559
Author(s):  
E. A. NUNEZ ◽  
R. P. GOULD ◽  
S. J. HOLT
Keyword(s):  
Endoplasmic Reticulum ◽  
Golgi Complex ◽  
Secretory Granules ◽  
Granular Endoplasmic Reticulum ◽  
Secretory Product ◽  
Central Mass ◽  
Granule Formation ◽  
Cytoplasmic Matrix ◽  
Parafollicular Cell ◽  
Parafollicular Cells

The fine structure of the bat thyroid parafollicular cell has been examined at monthly intervals throughout the hibernating period. During November and December parafollicular cells appear either partly or totally degranulated and intact dense secretory granules are relatively sparse. The degranulated cells exhibit an inconspicuous Golgi complex and relatively few lysosome-type bodies. Few degranulated parafollicular cells are present in thyroid glands from bats collected in January. When found they are characterized by the presence of whorls of cytoplasmic agranular membranes which enclose a central mass of cellular debris. January bat thyroids are characterized by the presence of three different types of parafollicular cell. One type contains no secretory granules. The cytoplasmic matrix of this type is rich in granular endoplasmic reticulum and free ribosomes and its small Golgi complex consists of several slightly dilated saccules. In close proximity to the Golgi complex are numerous small to medium-sized vesicles which often appear to merge with Golgi elements. Such vesicles are considered to represent the vehicle by which secretory product is transferred from the endoplasmic reticulum to the Golgi complex. The second type of parafollicular cell differs from the first in containing large numbers of intact dense secretory granules. It is also characterized by an extensive Golgi complex which appears to be forming new secretory granules, and by a less extensive granular endoplasmic reticulum. The third type of parafollicular cell shows a structure intermediate between the first two. The cytoplasm of all three types of January parafollicular cells contains many structures belonging to the lysosomal-vacuolar system, including autophagic vacuoles, vacuolated dense bodies and multivesicular bodies. By February and March only parafollicular cells of type 2 are observed. They contain few lysosome-like structures. It is concluded that during mid-hibernation (January), parafollicular cells undergo a series of intracellular changes during which new dense secretory granules are produced. Accompanying granule formation is an augmentation of lysosome-like structures which probably serve as a means of digesting debris from previous secretory cycles.

scholarly journals THE EFFECTS OF ENUCLEATION ON THE CYTOPLASMIC MEMBRANES OF AMOEBA PROTEUS

1968 ◽  
Vol 37 (2) ◽  
pp. 300-315 ◽  
Author(s):  
Charles J. Flickinger
Keyword(s):  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Electron Microscope ◽  
Golgi Apparatus ◽  
Amoeba Proteus ◽  
Granular Endoplasmic Reticulum ◽  
Whole Cells ◽  
Golgi Bodies ◽  
Cytoplasmic Membranes ◽  
In Cells

The dependence of cytoplasmic membranes upon the nucleus was studied by examining enucleated amebae with the electron microscope at intervals up to 1 wk after enucleation. Amebae were cut into two approximately equal parts, and the fine structure of the enucleated portions was compared with that of the nucleated parts and starved whole cells which had been maintained under the same conditions. Golgi bodies were diminished in size 1 day after enucleation and were not detected in cells enucleated for more than 2 days. The endoplasmic reticulum of enucleated cells appeared to increase in amount and underwent changes in its morphology. The sparsely scattered short tubules of granular endoplasmic reticulum present in unmanipulated amebae from stock cultures were replaced in 1–3-day enucleates by long narrow cisternae. In 3–7-day enucleates, similar cisternae of granular endoplasmic reticulum encircled areas of cytoplasm partially or completely. It was estimated that in most cases hundreds of these areas encircled by two rough membranes were formed per enucleated cell. The number of ribosomes studding the surface of the endoplasmic reticulum decreased progressively with time after enucleation. In contrast, the membranes of nucleated parts and starved whole cells did not undergo these changes. The possible identification of membrane-encircled areas as cytolysomes and their mode of formation are considered. Implications of the observations regarding nuclear regulation of the form of the Golgi apparatus and the endoplasmic reticulum are discussed.

Copper Localization in Cirrhotic Rat Liver by Scanning Electron Microscopy

1969 ◽  
Vol 27 ◽  
pp. 38-39 ◽  
Author(s):  
J. C. Russ ◽  
E. McNatt
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Electron Microscope ◽  
Copper Acetate ◽  
Lead Citrate ◽  
Dense Bodies ◽  
Transmission Electron ◽  
Electron Mode ◽  
Scanning Electron

In order to study the retention of copper in cirrhotic liver, rats were made cirrhotic by carbon tetrachloride inhalation twice weekly for three months and fed 0.2% copper acetate ad libidum in drinking water for one month. The liver tissue was fixed in osmium, sectioned approximately 2000 Å thick, and stained with lead citrate. The section was examined in a scanning electron microscope (JEOLCO JSM-2) in the transmission electron mode.Figure 1 shows a typical area that includes a red blood cell in a sinusoid, a disse, and a portion of the cytoplasm of a hepatocyte which contains several mitochondria, peribiliary dense bodies, glycogen granules, and endoplasmic reticulum.

Ultrastructural comparison of prolactin adenomas of pituitary in men and women

1988 ◽  
Vol 46 ◽  
pp. 346-347
Author(s):  
R.C. Caughey ◽  
U.P. Kalyan-Raman
Keyword(s):  
Endoplasmic Reticulum ◽  
Electron Microscope ◽  
Phosphate Buffer ◽  
Pituitary Adenomas ◽  
Osmium Tetroxide ◽  
Secretory Granules ◽  
Uranyl Acetate ◽  
En Bloc ◽  
Men And Women ◽  
Transmission Electron

Prolactin producing pituitary adenomas are ultrastructurally characterized by secretory granules varying in size (150-300nm), abundance of endoplasmic reticulum, and misplaced exocytosis. They are also subclassified as sparsely or densely granulated according to the amount of granules present. The hormone levels in men and women vary, being higher in men; so also the symptoms vary between both sexes. In order to understand this variation, we studied 21 prolactin producing pituitary adenomas by transmission electron microscope. This was out of a total of 80 pituitary adenomas. There were 6 men and 15 women in this group of 21 prolactinomas.All of the pituitary adenomas were fixed in 2.5% glutaraldehyde, rinsed in Millonig's phosphate buffer, and post fixed with 1% osmium tetroxide. They were then en bloc stained with 0.5% uranyl acetate, rinsed with Walpole's non-phosphate buffer, dehydrated with graded series of ethanols and embedded with Epon 812 epoxy resin.

Membrane-associated microtubular areays induced in proximal myelinated processes of dorsal root ganglia by large doses of vitamin B6

1986 ◽  
Vol 44 ◽  
pp. 368-369
Author(s):  
V.J. Montpetit ◽  
S. Dancea ◽  
L. Tryphonas ◽  
D.F. Clapin
Keyword(s):  
Animal Model ◽  
Endoplasmic Reticulum ◽  
Dorsal Root Ganglia ◽  
Rough Endoplasmic Reticulum ◽  
Dorsal Root ◽  
Vitamin B6 ◽  
Morphological Changes ◽  
Model System ◽  
Sensory Nerves ◽  
Peripheral Sensory

Very large doses of pyridoxine (vitamin B6) are neurotoxic in humans, selectively affecting the peripheral sensory nerves. We have undertaken a study of the morphological and biochemical aspects of pyridoxine neurotoxicity in an animal model system. Early morphological changes in dorsal root ganglia (DRG) associated with pyridoxine megadoses include proliferation of neurofilaments, ribosomes, rough endoplasmic reticulum, and Golgi complexes. We present in this report evidence of the formation of unique aggregates of microtubules and membranes in the proximal processes of DRG which are induced by high levels of pyridoxine.

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