Probable mechanoreceptor structures of osphradia in marine Caenogastropoda

2020 ◽  
Vol 30 (1) ◽  
pp. 33-39
Author(s):  
N. N. Kamardin
Keyword(s):  
Electron Microscopy ◽  
Apical Surface ◽  
Supporting Cells ◽  
Receptor Cells ◽  
Single Receptor

TEM and SEM electron microscopy have been used to study osphradia in 6 species of marine Caenogastropoda. The ultrastructural features of mechanoreceptor cells that perform the Littorina osmoreception function in osphradium organs are presented. Mechanoreception is based on a possible change in the volume of cisterns of microvilli of supporting cells, which can be transmitted by the cilia of nearby mechanoreceptor cells. These cells obviously, have mechanosensory channels on the apical surface. It has been first discovered in predatory molluscs actively searching for food, that single receptor cells with a mobile sensilla consisting of several cilium were joined together. They are located along the groove zone and follow the direction and force of the movement of water along the osphradium petals.

Fine Structure of the Eye of a Nudibranch Mollusc, Hermissenda Crassicornis

1967 ◽  
Vol 2 (3) ◽  
pp. 349-358
Author(s):  
R. M. EAKIN ◽  
JANE A. WESTFALL ◽  
M. J. DENNIS
Keyword(s):  
Electron Microscopy ◽  
Fine Structure ◽  
Optic Nerve ◽  
Light And Electron Microscopy ◽  
The Other ◽  
Sensory Cells ◽  
Nerve Fibres ◽  
Supporting Cells ◽  
Small Bodies ◽  
Receptor Cells

The eye of a nudibranch, Hermissenda crassicornis, was studied by light and electron microscopy. Three kinds of cells were observed: large sensory cells, each bearing at one end an array of microvilli (rhabdomere) and at the other end an axon which leaves the eye by the optic nerve; large pigmented supporting cells; and small epithelial cells, mostly corneal. There are five sensory cells, and the same number of nerve fibres in the optic nerve. The receptor cells contain an abundance of small vesicles, 600-800 Å in diameter. The lens is a spheroidal mass of osmiophilic, finely granular material. A basal lamina and a capsule of connective tissue enclose the eye. In some animals the eye is ‘infected’ with very small bodies, 4-5 µ in diameter, thought to be symbionts.

scholarly journals The Olfactory Mucosa of the Sheep

1970 ◽  
Vol 23 (2) ◽  
pp. 447 ◽  
Author(s):  
Jean E Kratzing
Keyword(s):  
Electron Microscopy ◽  
Lamina Propria ◽  
Light And Electron Microscopy ◽  
Free Edge ◽  
Cell Types ◽  
Olfactory Nerve ◽  
Olfactory Mucosa ◽  
Basal Cells ◽  
Supporting Cells ◽  
Receptor Cells

The olfactory mucosa of the sheep was studied by light and electron microscopy. The epithelium conforms to the general vertebrate pattern and consists of olfactory receptor cells, supporting, and basal cells. The free edge of the epithelium is made up of long microvilli from the supporting cells and olfactory rods of the receptor cells, each carrying 40-50 cilia. All cell types contain large dark granules which may be the site of olfactory pigment. The basement membrane is not visible in light microscopy and is fine and discontinuous in electron microscopy. Bowman's glands are simple, tubular, mucus-secreting glands in the lamina propria. Their cells contain basal granules resembling those in the epithelial cells. The lamina propria also contains bundles of fine, unmyelinated, olfactory nerve fibres which are the proximal continuations of the receptor cells.

The transcytotic pathway of an apical plasma membrane protein (B10) in hepatocytes is similar to that of IgA and occurs via a tubular pericentriolar compartment

1996 ◽  
Vol 109 (6) ◽  
pp. 1215-1227 ◽  
Author(s):  
I. Hemery ◽  
A.M. Durand-Schneider ◽  
G. Feldmann ◽  
J.P. Vaerman ◽  
M. Maurice
Keyword(s):  
Electron Microscopy ◽  
Plasma Membrane ◽  
Membrane Proteins ◽  
Membrane Protein ◽  
Apical Membrane ◽  
Rat Hepatocytes ◽  
Apical Plasma Membrane ◽  
Apical Surface ◽  
Plasma Membrane Protein ◽  
Microtubule Disruption

In hepatocytes, newly synthesized apical plasma membrane proteins are first delivered to the basolateral surface and are supposed to reach the apical surface by transcytosis. The transcytotic pathway of apical membrane proteins and its relationship with other endosomal pathways has not been demonstrated morphologically. We compared the intracellular route of an apical plasma membrane protein, B10, with that of polymeric IgA (pIgA), which is transcytosed, transferrin (Tf) which is recycled, and asialoorosomucoid (ASOR) which is delivered to lysosomes. Ligands and anti-B10 monoclonal IgG were linked to fluorochromes or with peroxidase. The fate of each ligand was followed by confocal and electron microscopy in polarized primary monolayers of rat hepatocytes. When fluorescent anti-B10 IgG and fluorescent pIgA were simultaneously endocytosed for 15–30 minutes, they both uniformly labelled a juxtanuclear compartment. By 30–60 minutes, they reached the bile canaliculi. Tf and ASOR were also routed to the juxtanuclear area, but their fluorescence patterns were more punctate. Microtubule disruption prevented all ligands from reaching the juxtanuclear area. This area corresponded, at least partially, to the localization of the mannose 6-phosphate receptor, an endosomal marker. By electron microscopy, the juxtanuclear compartment was made up of anastomosing tubules connected to vacuoles, and was organized around the centrioles. B10 and pIgA were mainly found in the tubules, whereas ASOR was segregated inside the vacuolar elements and Tf within thinner, recycling tubules. In conclusion, transcytosis of the apical membrane protein B10 occurs inside tubules similar to those carrying pIgA, and involves passage via the pericentriolar area. In the pericentriolar area, the transcytotic tubules appear to maintain connections with other endosomal elements where sorting between recycled and degraded ligands occurs.

Cis-Diamminedichloroplatinum (II) Ototoxicity in the Guinea Pig

1981 ◽  
Vol 89 (4) ◽  
pp. 638-645 ◽  
Author(s):  
Scott A. Estrem ◽  
Richard W. Babin ◽  
Jai H. Ryu ◽  
Kenneth C. Moore
Keyword(s):  
Electron Microscopy ◽  
Hair Cells ◽  
Supporting Cell ◽  
Cell Ultrastructure ◽  
Outer Hair Cells ◽  
Detectable Change ◽  
Supporting Cells ◽  
Apical Portion ◽  
Ultrastructural Evidence ◽  
Transmission Electron

Cochleas from 12 guinea pigs were evaluated using light, scanning, and transmission electron microscopy after systemic administration of cis-diamminedichloroplatinum (cis-DDP). Administration of cis-DDP resulted in loss of the Preyer reflex and degeneration of outer hair cells (OHC) with increased dose. The OHC degeneration was most pronounced in the basal turns of the cochlea with greatest severity in the inner row. Ultrastructural evidence of OHC degeneration included dilatation of the parietal membranes, softening of the cuticular plate, increased vacuolization and increased numbers of lysosome-like bodies in the apical portion of the cell. Supporting cells appeared more sensitive than OHC. Alteration of supporting cell ultrastructure preceded detectable change in OHC. Injury to the supporting cells was noted with intracellular vesiculation and increased autophagocytosis.

scholarly journals Histoanatomy and surface ultrastructure of the olfactory organ of the freshwater tank goby, Glossogobius giuris (Hamilton, 1822)

2020 ◽  
Vol 28 (3) ◽  
pp. 141-148
Author(s):  
Saroj Kumar Ghosh
Keyword(s):  
Nerve Fibers ◽  
Olfactory Organ ◽  
Basal Cells ◽  
Supporting Cells ◽  
Blood Capillaries ◽  
Surface Ultrastructure ◽  
Receptor Cells ◽  
Mucosal Lining ◽  
Characteristic Features ◽  
Glossogobius Giuris

AbstractCharacteristic features of histology and fine morphology of the olfactory organ in the tank goby, Glossogobius giuris (Perciformes, Gobiidae, Gobiinae), were investigated with light and scanning electron microscopy. The olfactory cavity contained single lamellae that were exposed to the aquatic environment by small anterior and posterior nostrils. Typical olfactory rosettes were not observed. Histologically, each lamella consisted of two layers of epithelium; wrapping the central core that was composed of connective tissue stroma with nerve fibers and blood capillaries. The mucosal lining of lamella was merged with sensory and non-sensory olfactory cells, identified on the basis of structural characters, surface specializations, and staining features. The principal sensory elements were ciliated receptor cells that were characterized by apical dendritic processes expanded from cell soma and microvillous receptor cells equipped with multiple tiny dendrons on the mucosal surface. The bead-like appearance of several labyrinth cells, mucous cells with secreted mucin, scattered lymphatic cells, stratified epithelial cells bearing microfolds, and condensed ciliated supporting cells were observed in the non-sensory epithelia. Undifferentiated basal cells were embedded in the deeper zone of the epithelium above the basement membrane. The cellular organization of the olfactory lining was interpreted with chemoreception of the fish concerned.

Fluorescent markers to study membrane retrieval in antidiuretic hormone-treated toad urinary bladder

1986 ◽  
Vol 251 (2) ◽  
pp. C274-C284 ◽  
Author(s):  
H. W. Harris ◽  
J. B. Wade ◽  
J. S. Handler
Keyword(s):  
Electron Microscopy ◽  
Urinary Bladder ◽  
Horseradish Peroxidase ◽  
Antidiuretic Hormone ◽  
Apical Membrane ◽  
Granular Cell ◽  
Cell Uptake ◽  
Toad Urinary Bladder ◽  
Osmotic Gradient ◽  
Apical Surface

Antidiuretic hormone (ADH) stimulation of toad urinary bladder causes fusion of intracellular vesicles called aggrephores with the apical plasma membrane of granular cells. Aggrephores contain intramembrane particle aggregates whose appearance in the apical membrane is believed to produce a large increase in its water permeability. ADH removal (ADH washout) is thought to cause the retrieval of aggrephores into granular cell cytoplasm. We studied granular cell uptake of dextran and horseradish peroxidase conjugated with fluorescein, rhodamine, or both during ADH washout. Granular cell uptake of fluorescent dextran was dependent on prior exposure to ADH, a linear function of dextran concentration, and increased by a transepithelial osmotic gradient. Immediately after removal of ADH, granular cell fluorescence was finely dispersed and located near the apical surface. Subsequently, it coalesced into larger bodies. This change was most apparent when a single bladder was subjected to two cycles of ADH stimulation and removal using a dextran containing a different fluorophore for each cycle. The ultrastructural correlate for these fluorescent patterns was identified using rhodamine-labeled horseradish peroxidase. Electron microscopy showed that after detachment from the apical membrane, label was initially in tubular-shaped vesicles near the apical surface. Later, these vesicles clustered near multivesicular bodies and transferred their label to these structures. These tubular vesicles closely resemble the morphology of aggrephores visualized by freeze-fracture electron microscopy. We conclude that these fluorescent compounds can be used as markers for the luminal contents of membrane retrieved during ADH washout and allow detailed study of its intracellular processing.

scholarly journals Ulcerative Colitis-Derived Colonoid Culture: A Multi-Mineral-Approach to Improve Barrier Protein Expression

2020 ◽  
Vol 8 ◽  
Author(s):  
Muhammad N. Aslam ◽  
Shannon D. McClintock ◽  
Durga Attili ◽  
Shailja Pandya ◽  
Humza Rehman ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Ulcerative Colitis ◽  
Protein Expression ◽  
Daily Intake ◽  
Adherens Junction ◽  
Ultrastructural Level ◽  
Electrolyte Balance ◽  
Apical Surface ◽  
Cytokeratin 20 ◽  
Proteomic Screen

BackgroundRecent studies demonstrated that Aquamin®, a calcium-, magnesium-rich, multi-mineral natural product, improves barrier structure and function in colonoids obtained from the tissue of healthy subjects. The goal of the present study was to determine if the colonic barrier could be improved in tissue from subjects with ulcerative colitis (UC).MethodsColonoid cultures were established with colon biopsies from 9 individuals with UC. The colonoids were then incubated for a 2-week period under control conditions (in culture medium with a final calcium concentration of 0.25 mM) or in the same medium supplemented with Aquamin® to provide 1.5 – 4.5 mM calcium. Effects on differentiation and barrier protein expression were determined using several approaches: phase-contrast and scanning electron microscopy, quantitative histology and immunohistology, mass spectrometry-based proteome assessment and transmission electron microscopy.ResultsAlthough there were no gross changes in colonoid appearance, there was an increase in lumen diameter and wall thickness on histology and greater expression of cytokeratin 20 (CK20) along with reduced expression of Ki67 by quantitative immunohistology observed with intervention. In parallel, upregulation of several differentiation-related proteins was seen in a proteomic screen with the intervention. Aquamin®-treated colonoids demonstrated a modest up-regulation of tight junctional proteins but stronger induction of adherens junction and desmosomal proteins. Increased desmosomes were seen at the ultrastructural level. Proteomic analysis demonstrated increased expression of several basement membrane proteins and hemidesmosomal components. Proteins expressed at the apical surface (mucins and trefoils) were also increased as were several additional proteins with anti-microbial activity or that modulate inflammation. Finally, several transporter proteins that affect electrolyte balance (and, thereby affect water resorption) were increased. At the same time, growth and cell cycle regulatory proteins (Ki67, nucleophosmin, and stathmin) were significantly down-regulated. Laminin interactions, matrix formation and extracellular matrix organization were the top three up-regulated pathways with the intervention.ConclusionA majority of individuals including patients with UC do not reach the recommended daily intake for calcium and other minerals. To the extent that such deficiencies might contribute to the weakening of the colonic barrier, the findings employing UC tissue-derived colonoids here suggest that adequate mineral intake might improve the colonic barrier.

scholarly journals The cell coat of the sensory and supporting cells of the rainbow trout saccular macula as demonstrated by reaction with ruthenium red and tannic acid.

1990 ◽  
Vol 38 (11) ◽  
pp. 1615-1623 ◽  
Author(s):  
K M Khan ◽  
J S Hatfield ◽  
D G Drescher
Keyword(s):  
Rainbow Trout ◽  
Tannic Acid ◽  
Ruthenium Red ◽  
Sensory Cells ◽  
Surface Coat ◽  
Basal Region ◽  
Apical Surface ◽  
Luminal Surface ◽  
Supporting Cells ◽  
Cell Coat

The surface of most cells is covered by glycoconjugates. The composition and thickness of the surface coat varies among different cell types. The purpose of the present study was to demonstrate the presence of and to characterize the cell coat surrounding the cells in the saccular macula of the rainbow trout. Tissues were fixed in Karnovsky's fixative containing either ruthenium red (0.5, 1, or 2%) or tannic acid (1, 2, or 4%). The apical surface of the sensory and supporting cells reacted with both agents. Varying the concentration of the compounds within a certain range did not significantly affect the degree of tissue staining. Whereas ruthenium red staining was distributed evenly along the luminal surface of the epithelium and along the length of the stereocilia, tannic acid formed electron-dense clumps on the luminal surface of sensory and non-sensory cells and in the basal region of the macular epithelium. The stereocilia of the sensory cells also exhibited tannic acid-positive, electrondense precipitate, particularly near the distal ends of these processes, while uniform staining of the plasma membrane was seen along their lengths. The results of this study suggest that the trout saccular macula is provided with extracellular microenvironments which may be necessary for functional integrity.

scholarly journals BRUSH BORDER DEVELOPMENT IN THE INTESTINAL ABSORPTIVE CELLS OF XENOPUS DURING METAMORPHOSIS

1970 ◽  
Vol 44 (1) ◽  
pp. 151-171 ◽  
Author(s):  
Mary A. Bonneville ◽  
Melvyn Weinstock
Keyword(s):  
Electron Microscopy ◽  
Small Intestine ◽  
Brush Border ◽  
Apical Membrane ◽  
Surface Membrane ◽  
Apical Surface ◽  
Absorptive Cells ◽  
Golgi Region ◽  
Macromolecular Architecture

The differentiation of the brush border which makes up the apical free surface of intestinal absorptive cells has been studied by electron microscopy. Specimens of Xenopus small intestine were fixed at various stages during metamorphosis, the time when a new intestinal epithelium forms. The interpretation of details described herein emphasizes the role of "surface-forming" vesicles. These vesicles are thought to provide membrane both for the initial expansion of the apical surface and for the later elongation of the microvilli. The latter are believed to be "molded" around filamentous cores that appear early in differentiation. The cores are attached to the apical membrane and extend vertically into the supranuclear cytoplasm. This interpretation rests chiefly on (a) the resemblance, both in morphology and in staining properties with colloidal thorium, between the membrane that limits the vesicles and that which limits the microvilli and (b) the distribution and time of appearance of the vesicles with respect to development of the microvilli. According to this view, the specific properties of surface membrane reside in preformed units that arise within the supranuclear cytoplasm. This morphogenetic process probably involves participation of the Golgi region as the site where the complex macromolecular architecture of the cell surface is assembled.

Differentiated lines of cells from rabbit renal medullary thick ascending limbs grown on amnion

1985 ◽  
Vol 249 (1) ◽  
pp. C97-C104 ◽  
Author(s):  
N. Green ◽  
A. Algren ◽  
J. Hoyer ◽  
T. Triche ◽  
M. Burg
Keyword(s):  
Electron Microscopy ◽  
Functional Differentiation ◽  
The Other ◽  
Epithelial Tissue ◽  
Apical Surface ◽  
Tissue Cultures ◽  
Epithelial Monolayers ◽  
Zonula Occludens ◽  
Nephron Segment ◽  
Transepithelial Voltage

Previously we grew differentiated primary epithelial tissue cultures from rabbit renal medullary thick ascending limbs but were unable to subculture them into lines. Now, following the use of amnion as a support during the initial passages, two cell lines have grown from single fragments of medullary thick ascending limbs. Cells have now been in culture past 12 passages over more than 2 yr. On confluence they formed morphologically differentiated epithelial monolayers with polarization of the cells visible on electron microscopy. They had apical zonula occludens and microvilli, lateral cellular interdigitations, and basal membranes flat against the support. “Domes” often were visible when the epithelia formed on dishes, indicative of salt and water transport. Other functional differentiation in some passages of one line or the other included presence of Tamm-Horsfall protein (demonstrated by immunofluorescence) or transepithelial voltage oriented apical surface positive. Both the Tamm-Horsfall protein and the voltage are normally expressed by intact medullary thick ascending limbs and are characteristic of this particular nephron segment.

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