1. German Retrospect

Dr. Gierke, of Breslau, has, in two articles in the “Neurologisches Centralblatt” (Numbers 16 and 17, 1883), given the results of special researches on the neuroglia. He accuses Deiters, Boll, Golgi, and Jastrowitz of making incorrect descriptions, and of mistaking the results of their own reagents and dyes for natural structures. Gierki promises to publish his researches at greater length with illustrations, which are highly necessary in the description of delicate tissues. In the meantime he gives a number of details which could only be fairly reproduced by translating his papers. The neuroglia is the supporting tissue or frame-work of the nervous centres. It forms one-third of the substance of the grey matter, and its cells throw out branching processes which, taking the shape of flattened fibres, form sheaths for the nerve tubes. These never lie against one another, as Boll imagined. The cells of the neuroglia in the spinal cord of the sheep have a diameter of from 0·005 to 0·008 mm., and their processes are sometimes as long as from 0·4 to 0·2 mm. The neuroglia is everywhere, save at a part of the medulla oblongata, where the nerve tubes of the stratum zonale Arnoldi crowd upon one another, and lie directly under the pia mater. In other places, as in the substantia gelatinosa Rolandi, the neuroglia prevails, and there are few nerve elements. In contradiction to those who hold that the perivascular spaces may be owing to retraction of the dead tissues or contraction of vessels, Dr. Gierke maintains that there is not the slightest doubt that the perivascular spaces exist in the living brain. They are of varying calibre, and their strongly developed cellular ramifications are analogous to the sinuses in the lymphatic gland. In some places, as in the central canal of the spinal cord, he has found the large vessels surrounded by perivascular canals, which he has traced into real lymphatics.

Download Full-text

V.–Distribution of the Cells in the Intermedio-Lateral Tract of the Spinal Cord

Transactions of the Royal Society of Edinburgh ◽

10.1017/s0080456800011650 ◽

1906 ◽

Vol 45 (1) ◽

pp. 105-131 ◽

Cited By ~ 15

Author(s):

Alexander Bruce

Keyword(s):

Spinal Cord ◽

Grey Matter ◽

Central Canal ◽

Substantia Gelatinosa ◽

Lateral Margin ◽

Cervical Region ◽

Dorsal Region ◽

Lateral Column ◽

Upper Cervical ◽

Lateral Tract

The term intermedio-lateral tract was introduced in 1859 (Phil. Trans., 1859, p. 445) by Lockhart Clarke to designate a tract or column of nerve cells in the spinal cord, which he had previously described in 1851 (Phil. Trans., 1851, ii. p. 613) as occupying that portion of the lateral margin of the grey matter which is intermediate between the anterior and posterior cornua. According to Clarke's original account, the column in question was very transparent in appearance, and resembled somewhat the substantia gelatinosa of the posterior horn. It was found in the upper part of the lumbar enlargement, extended upwards through the dorsal region, where it distinctly increased in size, to the lower part of the cervical enlargement. Here it disappeared almost entirely. In the upper cervical region it was again seen, and could be traced upwards into the medulla oblongata, where, in the space immediately behind the central canal, it blended with its fellow of the opposite side. In the more complete account of the tract published in 1859 (p. 446), its component cells are described as in part oval, fusiform, pyriform, or triangular, and as being smaller and more uniform in size than those of the anterior cornua. In the mid-dorsal region, where they are least numerous, they are found only near the lateral margin of the grey matter, with the exception of some cells which lie among the white fibres beyond the margin of the grey substance. In the upper dorsal region the tract is larger, and not only projects further outwards into the lateral column of the white fibres, but also tapers inwards across the grey substance, almost to the front of Clarke's column. In the cervical enlargement it gradually disappears, although it seems to contain, in part at least, a few scattered cells resembling those of the intermedio-lateral tract of the dorsal region. In the upper cervical region, as already stated, it is again seen occupying a lateral horn similar to that found in the dorsal region. It is composed of the same kind of cells, and can be followed up into the medulla, where it is said to give origin to some of the fibres of the vagus and the spinal accessory.

Download Full-text

Mechanisms underlying the formation and enlargement of noncommunicating syringomyelia: experimental studies

Neurosurgical FOCUS ◽

10.3171/foc.2000.8.3.2 ◽

2000 ◽

Vol 8 (3) ◽

pp. 1-7 ◽

Cited By ~ 58

Author(s):

Marcus A. Stoodley ◽

Nigel R. Jones ◽

Liqun Yang ◽

Christopher J. Brown

Keyword(s):

Spinal Cord ◽

Experimental Studies ◽

Central Canal ◽

Perivascular Spaces ◽

Arterial Pulse ◽

Csf Flow ◽

Spinal Subarachnoid Space ◽

Brachiocephalic Trunk ◽

Rapid Flow ◽

Arterial Pulsation

The pathogenesis of noncommunicating syringomyelia is unknown, and none of the existing theories adequately explains the production of cysts that occur in association with conditions other than Chiari malformation. The authors' hypothesis is that an arterial pulsation–driven perivascular flow of cerebrospinal fluid (CSF) is responsible for syrinx formation and enlargement. They investigated normal CSF flow patterns in 20 rats and five sheep by using the tracer horseradish peroxidase; the effect of reducing arterial pulse pressure was examined in four sheep by partially ligating the brachiocephalic trunk; CSF flow was examined in 78 rats with the intraparenchymal kaolin model of noncommunicating syringomyelia; and extracanalicular cysts were examined using the excitotoxic model in 38 rats. In the normal animals there was a rapid flow of CSF from the spinal subarachnoid space into the spinal cord perivascular spaces and then into the central canal. This flow ceased when arterial pulsations were diminished. In animals with noncommunicating syringomyelia, there was rapid CSF flow into isolated and enlarged segments of central canal, even when these cysts were causing pressure damage to the surrounding spinal cord. Exitotoxic injury of the spinal cord caused the formation of extracanalicular cysts, and larger cysts were produced when this injury was combined with arachnoiditis, which impaired subarachnoid CSF flow. The results of these experiments support the hypothesis that arterial pulsation–driven perivascular fluid flow is responsible for syrinx formation and enlargement.

Download Full-text

The Development of Pneumostrongylus tenuis in the Central Nervous System of White-tailed Deer

Pathologia veterinaria ◽

10.1177/030098586500200404 ◽

1965 ◽

Vol 2 (4) ◽

pp. 360-379 ◽

Cited By ~ 4

Author(s):

Roy C. Anderson

Keyword(s):

Spinal Cord ◽

White Matter ◽

Medulla Oblongata ◽

Grey Matter ◽

Plasma Cells ◽

Central Canal ◽

Surrounding Tissue ◽

Parasite Relationship ◽

Central Nervous Systems ◽

The Central Nervous System

The central nervous systems of five fawns (Odocoileus virginianus borealis), infected experimentally with Pneumostrongylus tenuis, were studied histologically 10, 20, 25, 30, and 40 days after infection. In the 10–30 day fawns young developing worms were found in dorsal horns of the grey matter of all regions of the spinal cord. A few worms were found in white matter and in the medulla oblongata. In the fawn autopsied 40 days after infection all but one of about 25 worms found were in the subdural space. Worms in the grey matter usually lay in cell-free tunnels surrounded by compressed neural tissue. There was little reaction of, or cellular infiltration in, surrounding tissue. Malacia was absent in all parts of grey matter. The central canal was normal and the brain, other than the medulla oblongata, was not involved. In the white matter, scattered single myelin sheath degeneration as well as degeneration and disappearance of axis cylinders were common. Occasionally there were tiny malacic areas in white matter, especially near worms. Infiltrations of eosinophils, lymphocytes, and plasma cells were commonly observed in and on the dura mater, the epineurium, ganglion capsules, and other tissues of the epidural space. The relative dearth of histopathologic findings helps to explain the rarity and slightness of neurologic signs in infected fawns and is indicative perhaps of a long and well established host-parasite relationship. This is in contrast to the situation in moose (Alces a. americana) where severe traumatic damage to the spinal cord by P. tenuis is associated with ataxia and paralysis.

Download Full-text

A modified peroxidase--antiperoxidase procedure for improved localization of tissue antigens: localization of substance P in rat spinal cord.

Journal of Histochemistry & Cytochemistry ◽

10.1177/28.4.6154730 ◽

1980 ◽

Vol 28 (4) ◽

pp. 297-307 ◽

Cited By ~ 128

Author(s):

L L Vacca ◽

S J Abrahams ◽

N E Naftchi

Keyword(s):

Spinal Cord ◽

Substance P ◽

Afferent Fiber ◽

Central Canal ◽

Ventral Horn ◽

Substantia Gelatinosa ◽

Fiber Bundles ◽

Rat Spinal Cord ◽

Increased Sensitivity ◽

Ph Buffer

A procedure is presented which modifies the Sternberger peroxidase--antiperoxidase (PAP) technique in order to visualize additional amounts of immunodeposits representing the antigen substance (SP) in 5-micrometer paraffin tissue sections of rat spinal cord. For increased sensitivity, the new procedure utilizes a "double bridge" and diaminobenzidine in low pH buffer. The modifications have made possible the visualization of immunoreactive beaded processes and punctate bodies, which were then traced to determine patterns of SP circuitry. Using the modified PAP procedure, the greatest number of immunoreactive processes appeared in the dorsal horn, where some punctate bodies and varicose processes could be seen adjacent to the myelinated afferent fiber bundles that penetrate the substantia gelatinosa as dorsal root collaterals. Additional immunoreactive processes and punctate bodies coursed through the myelinated afferent fiber bundles that penetrate the dorsolateral white matter, and extend into the intermediolateral gray region. Substance P was also identified within immunoreactive processes found in Rexed's laminae V and VI, as well as the central canal region, the dorsal gray commissure, and the ventral gray and white commissures. Since the modifications improved the visualization of SP-containing processes in sparsely populated regions of the spinal cord, especially the ventral horn, they may be useful in demonstrating other antigens that normally occur in small quantities within tissues.

Download Full-text

The Segmental Morphometric Properties of the Horse Cervical Spinal Cord: A Study of Cadaver

The Scientific World JOURNAL ◽

10.1155/2013/734923 ◽

2013 ◽

Vol 2013 ◽

pp. 1-9 ◽

Cited By ~ 1

Author(s):

Sadullah Bahar ◽

Durmus Bolat ◽

Muhammet Lutfi Selcuk

Keyword(s):

Spinal Cord ◽

Cross Section ◽

Grey Matter ◽

Reference Data ◽

Cervical Spinal Cord ◽

Central Canal ◽

Ventral Horn ◽

Morphometric Features ◽

Volume Measurements ◽

Area And Volume

Although the cervical spinal cord (CSC) of the horse has particular importance in diseases of CNS, there is very little information about its segmental morphometry. The objective of the present study was to determine the morphometric features of the CSC segments in the horse and possible relationships among the morphometric features. The segmented CSC from five mature animals was used. Length, weight, diameter, and volume measurements of the segments were performed macroscopically. Lengths and diameters of segments were measured histologically, and area and volume measurements were performed using stereological methods. The length, weight, and volume of the CSC were61.6±3.2 cm,107.2±10.4 g, and95.5±8.3 cm3, respectively. The length of the segments was increased fromC1toC3, while it decreased fromC3toC8. The gross section (GS), white matter (WM), grey matter (GM), dorsal horn (DH), and ventral horn (VH) had the largest cross-section areas atC8. The highest volume was found for the total segment and WM atC4, GM, DH, and VH atC7, and the central canal (CC) atC3. The data obtained not only contribute to the knowledge of the normal anatomy of the CSC but may also provide reference data for veterinary pathologists and clinicians.

Download Full-text