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| | #REDIRECT [[Paper - The genesis and structure of the membrana tectoria and the crista spiralis of the cochlea (1918)]] |
| {{Ref-Stricht1919}}
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| {| class="wikitable mw-collapsible mw-collapsed"
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| ! Online Editor
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| | [[File:Mark_Hill.jpg|90px|left]] This 1919 historic paper by Van der Stricht describes the developing inner ear. Published in the series [[Book_-_Contributions_to_Embryology|Contributions to Embryology]] (Carnegie Institution of Washington).
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| <br>
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| See also by this author:
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| <br>
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| '''Moder Notes:'''
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| <br>
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| {{Hearing Links}}
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| |}
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| {{Historic Disclaimer}}
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| =The Arrangement And Structure Of Sustentacular Cells And Hair-Cells In The Developing Organ Of Corti=
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| By 0. Van der Stricht,
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| Professor of Histology and Embryology, Universily of Ghent,
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| Lecturer in Anatomy, Johns Hopkins University.
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| With four plates.
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| :'''Links:''' [[Book_-_Contributions_to_Embryology|Carnegie Institution of Washington - Contributions to Embryology]]
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| -----Content to be added----
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| {{Template:Historic Disclaimer}}
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| ==Introduction==
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| The arrangement of the outer sustentacular and hair-cells of the organ of
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| Corti in adult mammals is rather well known. According to the investigations
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| of Held (1902), N. Van der Stricht (1908), and Kolmer (1909), the body of the cell of
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| Deiters is situated below that of its sensory element, so that the two are connected
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| by a chalice-shaped, greatly modified segment, in the concavity of which hes the
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| deep cytoplasmic portion of the supported hair-cell. In the embrj'onic stages,
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| however, the relation between these two elements is entirely different, and it might
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| be well worth while to trace accurately their connections through the whole developmental stage. The same holds good for the inner and outer rods of Corti, the
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| inner supporting cells, and even some of the so-called cells of Hensen.
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| Most investigators who have tried to clarify the arrangement of the sensory
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| and sustentacular elements in embryonic material have made use of and describe | |
| vertical radial sections of the organ of Corti. Although very interesting, and in fact
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| highly necessarj^, such preparations are hable to be deceptive and lead to misinterpretation. Indeed, most authors incorrectly represent the cells of Deiters. Many
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| authors, even Retzius (1884) and Held (1909), who describe the phalanx process of
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| the sustentacular elements as running obliquely from the cell body towards the
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| lamina reticularis, thus crossing two or three hair cells, generally picture it in illustrations of vertical radial sections as an uninterrupted band connecting the nucle-
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| ated portion of the cell with the free surface of the epitheUum. So, also, do most
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| authors of text-books of histology, notwithstancUng the fact that in a radial vertical
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| section this protoplasmic strand shows at least three interruptions.
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| By making use of sections tangential and alwaj^s somewhat obUque to the surface of the organ of Corti, N. Van der Stricht was able to accuratelj' locate the
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| nucleated body of the supporting elements in successive stages of development and
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| to determine the amount of gradual shifting. In this stud}' the same method of
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| research was apphed in order to locate the more superficial portions of these cells
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| between the sense-epitheUum elements, and to ascertain their exact relation to the
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| hair-cells and the mechanical factors that cause the shifting of the sustentacular
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| elements. Moreover, a series of preparations, exhibiting mitochondrial structures
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| in the supporting cells and hair-cells, has rendered it possible to define the nature of
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| coarser structures noted by previous observers.
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| ==Methods==
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| Kittens, dogs, and rabbits, from birth to 12 days old, white rat fetuses, and
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| young white rats about 2 days old, constituted the material used in these investigations. The isolatetl cochlea was fixed by trichloracetic acid (5 per cent in water),
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| by Bouin's or by Zenker's fluid, and subjected for many weeks to the mordant action
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| of some drops of iodine in alcohol (70 per cent). Where necessary, after fixation by
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| Bouin's or by Zenker's fluid, decalcification was completed by 2 per cent nitric acid
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| in 70 per cent alcohol. Before embedding in paraffin the pieces were stained with
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| borax carmine and the sections with iron hematoxylin, Congo red, and light green.
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| The mitochondria in the sustentacular and hair-cells were fixed in the following
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| manner: Mixture of formalin and bichromate of Regaud (1910), according to the
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| modifications indicated by Cowdry (1916), and subsequent staining with acid
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| fuchsin and methjd-green ; treatment by a 1 per cent aqueous solution of osmic acid
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| for about an hour, followed by immersion in trichloracetic acid, or Bouin's or
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| Zenker's fluid; exposure of the cochlea, the bony wall of which had been previously
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| provided with two or three small o[)enings, to vapors from a 2 per cent a([ueous
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| solution of osmic acid for approximately 30 to 60 minutes, and subsequent treatment of the piece by one of the three above-mentioned agents; fixation for an hour
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| in a 1 per cent aqueous solution of osmic acid, followed bj' immersion in a 1 per cent
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| aqueous solution of silver nitrate for 3 hours. By these methods of fixation, and
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| staining with iron hematoxylin and Congo red, the mitochondria can be brought
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| into prominence within one or two turns of the cochlea, occasionally throughout its
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| extent. Osmic vajjors have been recommended as a fixing agent for mitochondrial
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| structures by M. R. Ijcwis and W. H. Lewis (1914). We are able to confirm tins
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| statement, having for many years successfully used these vapors, and a subsequent
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| treatment by another reagent, for the purpose of fixing the chondriomites in the
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| ova of the dog. Henneguy (1895) was able to bring into view chondrioconts in the
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| spermatocytes of Helix by the use of osmic vapors.
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| The description given herein is illustrated by figures representing three different
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| series of sections:
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| (1) Radial, vertical sections of tho organ of Corti. These are cross-sections of the
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| rows of hair and supporting colls, the knife cutting the latter along their length and from
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| the axis toward the outer wall of the cochlea (figs. 14, 15, and 16).
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| (2) Spiral, vertical sections of the organ of Corti, these being longitudinal sections of
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| the parallel spiral rows, the knife cutting the hair and supporting cells along their length,
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| from the more apical to the more liasal part of the sjiiral organ (figs. 19, 20, 22, and 23).
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| (3) Sections tangential and always somewhat oblique to the surface of the organ of
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| Corti, the knife cutting transversely the hair and sustentacular cells of the spiral parallel
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| rows at all levels, from the surface of the epithehum towards the basilar membrane (figs.
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| 2 tf) 13, 17 and 18), so that their arrangement and structure can be traced in cross-sections
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| throughout their lengths (figs. 2 and 3).
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| :'''Links:''' [[Book_-_Contributions_to_Embryology|Carnegie Institution of Washington - Contributions to Embryology]]
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| -----Content to be added----
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| {{Template:Historic Disclaimer}}
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| {{Glossary}}
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| {{Footer}}
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| [[Category:Historic Embryology]] [[Category:Human]]
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