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Structure of the White Matter of the Spinal Cord

  • Santiago Ramón y Cajal
Chapter

Abstract

General Structure of the White Matter.—The constituent substance of the spinal funiculi has been described in the section on central nerve fibers of the General Part of this book; therefore, we shall add here only few details.

Keywords

White Matter Gray Matter Dorsal Horn Motor Nucleus Ventral Horn 
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Footnotes

  1. 1.
    For proof of my assertion, consult all neurology books appeared from 1882 to 1890 (i.e. the works of Schwalbe, Ranvier, Toldt, Lenhossék, Obersteiner, Edinger, Flechsig, etc.), in none of which is there any indication of the collaterals. Nor is Golgi (1886) himself speaking about them in his extensive publication on the nervous centers.Google Scholar
  2. 2.
    [For studies with the reduced silver nitrate method, see Trab Lab Invest Biol Univ Madrid after 1903.]Google Scholar
  3. 3.
    Kölliker (1896, p. 106) wrongly attributes to us the opinion that the arborization of collaterals have myelin. We say precisely the reverse in two passages of the reference he cites (Cajal, 1890c). In our view, the initial trunk and large branches do have myelin sheaths, but these are lacking in the terminal varicose branchlets applied against the cells of the gray matter, a fact that reproduces the well known arrangement of the endings of peripheral fibers.Google Scholar
  4. 4.
    The preferred emergence of reflexo-motor collaterals near a bifurcation was reported later and independently by Lenhossék (1895b, pp. 303-304).Google Scholar
  5. 5.
    Not all reflexo-motor collaterals emit branches for the intermediate nucleus; some (half or more of those observed in the mouse) cross this nucleus without giving any collateral, and finally arborize in the motor nucleus. It seems that Lenhossék has observed only this type of unbranched fibers.Google Scholar
  6. 6.
    We have not confirmed Kölliker’s assertion that part of sensory fibers of the lateral radicular bundle would bifurcate within the substantia gelatinosa, sometimes near its ventral border. If such a bifurcation occurred, thereby generating sensory longitudinal packets independent from the dorsal funiculus, it would confirm Lenhossék’s opinion on the nature of the longitudinal bundles of the dorsal horn. Kölliker, however, hesitates in classifying these axons, not knowing whether such displaced radicular fibers incorporate themselves finally in the dorsal funiculus, or whether they form a portion of the cited longitudinal bundle (Kölliker, 1896, p. 75).Google Scholar

Annotations

  1. a.
    Fig. 103.—c, pia mater.Google Scholar
  2. b.
    Fig. 104.—D, neuroglia with long processes; a, terminal conical enlargements of ependymal cells; c, neuroglial sheet around a capillary vessel.Google Scholar
  3. c.
    Fig. 112.—a, collaterals in the zone of Lissauer; b, collateral of the dorsal funiculus entering the dorsal horn; c, unidentified; d, collateral of dorsal funiculus forming part of the dorsal commissural system; f, g, h, collaterals of the lateral funiculus contributing to the dorsal commissure; /, collateral of the ventral funiculus with branches to both ventral horns; j, central canal; /, clear spaces occupied by motoneurons surrounded by tight plexi of sensory-motor collaterals; m, collateral of the ventral funiculus terminating in the ipsilateral gray matter.Google Scholar
  4. d.
    Fig. 114.—B, head of the dorsal horn; I, lateral horn; J, zone of Lissauer; L, large cells of the marginal zone of Waldeyer.Google Scholar
  5. e.
    Fig. 116.—D, probable sensory-motor collateral traversing the column of Clarke.Google Scholar
  6. f.
    Fig. 119.—G, fasciculus cuneatus.Google Scholar
  7. g.
    Fig. 120.—C, arborization within neuroglial-dendritic partition.Google Scholar
  8. h.
    Both Textura and Histologie read in error bundle of the dorsal funiculus instead of dorsal horn bundle.Google Scholar
  9. i.
    See annotation n in Chapter XIX for discussion on the ipsilateral and/or contralateral termination of the ventral corticospinal tract.Google Scholar
  10. j.
    Both Textura and Histologie read in error O instead of F.Google Scholar
  11. k.
    Cajal changed his mind regarding the distribution of collaterals and terminal arborizations. Textura states that, as a rule, most of the fibers that could be followed to their terminal arborizations distribute in the same nucleus as the axon collaterals. Histologie asserts just the contrary and this is the version in the present text.Google Scholar
  12. l*.
    Histologie reads in error B instead of A.Google Scholar
  13. m.
    Fig. 109.—A, group of lateral collaterals; B, group of medial or dorsoventral collaterals; C, group of oblique or dorsolateral collaterals; a, b, collaterals emerging before and after the parent axon crosses the midline.Google Scholar

Copyright information

© Springer-Verlag Wien 1999

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  • Santiago Ramón y Cajal

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