scholarly journals Secretion and electrogenesis of the supporting cell in the olfactory epithelium

1974 ◽  
Vol 242 (2) ◽  
pp. 353-370 ◽  
Author(s):  
Masaomi Okano ◽  
Sadayuki F. Takagi
Author(s):  
Bert Ph. M. Menco ◽  
Ido F. Menco ◽  
Frans L.T. Verdonk

Previously we presented an extensive study of the distributions of intramembranous particles of structures in apical surfaces of nasal olfactory and respiratory epithelia of the Sprague-Dawley rat. For the same structures these distributions were compared in samples which were i) chemically fixed and cryo-protected with glycerol before cryo-fixation, after excision, and ii)ultra-rapidly frozen by means of the slam-freezing method. Since a three-dimensional presentation markedly improves visualization of structural features micrographs were presented as stereopairs. Two exposures were made by tiling the sample stage of the electron microscope 6° in either direction with an eucentric goniometer. The negatives (Agfa Pan 25 Professional) were reversed with Kodak Technical Pan Film 2415 developed in D76 1:1. The prints were made from these reversed negatives. As an example tight-junctional features of an olfactory supporting cell in a region where this cell conjoined with two other cells are presented (Fig. 1).


1974 ◽  
Vol 83 (2) ◽  
pp. 192-201 ◽  
Author(s):  
Daniel H. Matulionis

Olfactory epithelium from three groups of C57B1/6J and SWR/J mice exposed once or twice daily to 10% cigarette smoke for six or nine days was examined at the ultrastructural level. Olfactory epithelium of SWR/J experimental mice was not affected by cigarette smoke. However, prominent alterations were noted in this epithelium of C57B1/6J smoke treated mice. These alterations included a reduction in size and (possibly) number of olfactory vesicles which sometimes failed to protrude above the epithelial surface and greatly reduced numbers of olfactory vesicle sensory cilia. In the supporting cell population an abnormal electron-lucent cell type was noted among the usually darker types. Both cell types were frequently found protruding abnormally above the epithelial surface. Microvilli of supporting cells were markedly reduced in number. The present study revealed that the olfactory epithelia in all mice of the same strain are not affected equally by acute smoke exposures. In affected animals the degree of morphological alteration suggests that normal olfaction might have been impaired. Strain differences in reaction to smoke insult indicate that susceptibility is genetically determined.


1965 ◽  
Vol 48 (4) ◽  
pp. 559-569 ◽  
Author(s):  
Sadayuki F. Takagi ◽  
Toshi Yajima

Electrical activity and histological changes were studied in the degenerating olfactory epithelium of the bullfrog after the olfactory nerve had been sectioned. After nerve section, the electrical responses to odors disappeared in the olfactory epithelium in 8 days in the summer, in 11 days in the early autumn, and in 16 days in the early winter. In the degenerating olfactory epithelium a striking decrease in the number of olfactory cells was found, but not of supporting cells. The ratio of the number of olfactory cells to that of supporting cells was found to decrease from 5 or 6 to below 2 after the nerve section. At a ratio below 2, the electrical responses to odor disappeared. The histological changes in the bullfrog are compared with those in the mouse and rabbit. The localization of the olfactory pigment and the electrical activity of the supporting cell are discussed. It was concluded that all three types of responses to odors originate from the activity of the olfactory cell.


1985 ◽  
Vol 78 (1) ◽  
pp. 283-310 ◽  
Author(s):  
B.P. Menco ◽  
A.I. Farbman

Rat foetuses from intra-uterine days E13 through E22 (day before parturition) and adults were used for a qualitative electron-microscopic investigation of the development of ciliated/microvillous surfaces of the olfactory epithelium. In the E13 and most of the E14 embryos the epithelial surface is not yet characteristically olfactory. Apical cell profiles show primary cilia. These can arise at the epithelial surface or below. From E14 onwards the epithelial surface acquires olfactory characteristics. Dendritic endings of the olfactory receptor cells can be found amidst microvillous profiles of supporting cells. Either cell type may bear primary cilia. From E16 onwards the receptor cells sprout multiple olfactory cilia, but cells with primary cilia are found throughout pre-natal development. These primary cilia are, at least for a while, retained during the formation of the secondary cilia. Primary cilia always have distinct necklaces at their base. Otherwise, especially with respect to their tips, their morphology can vary. Originally they have expanded tips (up to E14); later on such wide tips are no longer encountered (E16 and E17). Primary cilia of receptor cells never have wide tips. Appreciable numbers of endings with tapering olfactory cilia are discerned around E18 and especially E19. Throughout pre-natal development posterior/superior parts of the septal olfactory epithelium are more precocious than anterior/inferior parts, in particular in the region of transition with the respiratory epithelium. This advance in development includes total densities of dendritic endings of olfactory receptor cells, densities of multiciliated endings alone and lengths of supporting cell microvilli. This difference is discussed with respect to the topography of the olfactory epithelial surface in adult animals. In addition to the systematic topographic variation, a number of more local, apparently not-systematically distributed, topographic variations present during development are described. Most of these also occur in adult animals and they include heterogeneity in length of supporting cell microvilli and the presence of patches of supporting cells with rounded apical protuberances, of patches displaying dendrites with polyaxonemes rather than individual cilia and of scattered atypical cells (neither typical olfactory receptor nor olfactory supporting cells). At their surfaces such atypical cells can resemble inner-ear hair cells. Relative to olfactory receptor and supporting cells there are only very few atypical cells.(ABSTRACT TRUNCATED AT 400 WORDS)


Author(s):  
Mary Beth Downs ◽  
Wilson Ribot ◽  
Joseph W. Farchaus

Many bacteria possess surface layers (S-layers) that consist of a two-dimensional protein lattice external to the cell envelope. These S-layer arrays are usually composed of a single species of protein or glycoprotein and are not covalently linked to the underlying cell wall. When removed from the cell, S-layer proteins often reassemble into a lattice identical to that found on the cell, even without supporting cell wall fragments. S-layers exist at the interface between the cell and its environment and probably serve as molecular sieves that exclude destructive macromolecules while allowing passage of small nutrients and secreted proteins. Some S-layers are refractory to ingestion by macrophages and, generally, bacteria are more virulent when S-layers are present.When grown in rich medium under aerobic conditions, B. anthracis strain Delta Sterne-1 secretes large amounts of a proteinaceous extractable antigen 1 (EA1) into the growth medium. Immunocytochemistry with rabbit polyclonal anti-EAl antibody made against the secreted protein and gold-conjugated goat anti-rabbit IgG showed that EAI was localized at the cell surface (fig 1), which suggests its role as an S-layer protein.


2015 ◽  
Vol 76 (S 01) ◽  
Author(s):  
Chester Griffiths ◽  
Garni Barkhoudarian ◽  
Aaron Cutler ◽  
Huy Duong ◽  
Bjorn Lobo ◽  
...  

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