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. 1988 Aug;159:49–56.

Quantitative relationships between axoplasm and Schwann cell sheath in unmyelinated nerve fibres. An electron microscope study.

E Pannese 1, G Arcidiacono 1, D Frattola 1, L Rigamonti 1, P Procacci 1, M Ledda 1
PMCID: PMC1262008  PMID: 3248972

Abstract

The quantitative relationships between the size of the Schwann cell sheath and that of its related axoplasm were studied by electron microscopy in cross sections of bundles of unmyelinated axons (Remak bundles) of the spinal roots of lizard (Lacerta muralis). It was found that (i) the cross sectional area of the Schwann cell sheath is directly proportional to that of its related axoplasm (correlation coefficient 0.84), and (ii) the ratio between the cross sectional area of the Schwann cell sheath and that of its related axoplasm tends to diminish as the cross sectional area of the latter increases. Thus, under normal conditions, in the bundles of unmyelinated axons of the spinal roots of lizard a quantitative balance exists between the nerve tissue and its associated glial tissue. These results agree with those previously obtained in the myelinated fibres of the same region and in the spinal ganglia of the lizard, gecko, cat and rabbit. Some of the mechanisms probably involved in the control of the quantitative balance between nerve tissue and its associated glial tissue in peripheral nerves are listed.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Abercrombie M., Johnson M. L. Quantitative histology of Wallerian degeneration: I. Nuclear population in rabbit sciatic nerve. J Anat. 1946 Jan;80(Pt 1):37–50. [PMC free article] [PubMed] [Google Scholar]
  2. Aguayo A. J., Bray G. M., Perkins S. C. Axon-Schwann cell relationships in neuropathies of mutant mice. Ann N Y Acad Sci. 1979;317:512–531. [PubMed] [Google Scholar]
  3. Aitken J. T. The effect of peripheral connexions on the maturation of regenerating nerve fibres. J Anat. 1949 Jan;83(Pt 1):32–43. [PMC free article] [PubMed] [Google Scholar]
  4. EVANS D. H. L., VIZOSO A. D. Observations on the mode of growth of motor nerve fibers in rabbits during post-natal development. J Comp Neurol. 1951 Dec;95(3):429–461. doi: 10.1002/cne.900950304. [DOI] [PubMed] [Google Scholar]
  5. EVANS D. H., MURRAY J. G. A study of regeneration in a motor nerve with a unimodal fiber diameter distribution. Anat Rec. 1956 Nov;126(3):311–333. doi: 10.1002/ar.1091260305. [DOI] [PubMed] [Google Scholar]
  6. Pannese E., Bianchi R., Calligaris B., Ventura R., Weibel E. R. Quantitative relationships between nerve and satellite cells in spinal ganglia. An electron microscopical study. I. Mammals. Brain Res. 1972 Nov 13;46:215–234. doi: 10.1016/0006-8993(72)90017-0. [DOI] [PubMed] [Google Scholar]
  7. Pannese E., Rigamonti L., Procacci P., Ledda M., Arcidiacono G., Frattola D. An electron microscope study of quantitative relationships between axon and Schwann cell sheath in myelinated fibres of peripheral nerves. Anat Embryol (Berl) 1987;175(4):423–430. doi: 10.1007/BF00309678. [DOI] [PubMed] [Google Scholar]
  8. Pannese E., Ventura R., Bianchi R. Quantitative relationships between nerve and satellite cells in spinal ganglia: an electron microscopical study. II. Reptiles. J Comp Neurol. 1975 Apr 15;160(4):463–476. doi: 10.1002/cne.901600404. [DOI] [PubMed] [Google Scholar]
  9. REYNOLDS E. S. The use of lead citrate at high pH as an electron-opaque stain in electron microscopy. J Cell Biol. 1963 Apr;17:208–212. doi: 10.1083/jcb.17.1.208. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Salzer J. L., Bunge R. P., Glaser L. Studies of Schwann cell proliferation. III. Evidence for the surface localization of the neurite mitogen. J Cell Biol. 1980 Mar;84(3):767–778. doi: 10.1083/jcb.84.3.767. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Sobue G., Brown M. J., Kim S. U., Pleasure D. Axolemma is a mitogen for human Schwann cells. Ann Neurol. 1984 May;15(5):449–452. doi: 10.1002/ana.410150508. [DOI] [PubMed] [Google Scholar]
  12. Sobue G., Kreider B., Asbury A., Pleasure D. Specific and potent mitogenic effect of axolemmal fraction on Schwann cells from rat sciatic nerves in serum-containing and defined media. Brain Res. 1983 Dec 5;280(2):263–275. doi: 10.1016/0006-8993(83)90056-2. [DOI] [PubMed] [Google Scholar]
  13. Sobue G., Pleasure D. Adhesion of axolemmal fragments to Schwann cells: a signal- and target-specific process closely linked to axolemmal induction of Schwann cell mitosis. J Neurosci. 1985 Feb;5(2):379–387. doi: 10.1523/JNEUROSCI.05-02-00379.1985. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Weinberg H. J., Spencer P. S. The fate of Schwann cells isolated from axonal contact. J Neurocytol. 1978 Oct;7(5):555–569. doi: 10.1007/BF01260889. [DOI] [PubMed] [Google Scholar]
  15. Windebank A. J., Wood P., Bunge R. P., Dyck P. J. Myelination determines the caliber of dorsal root ganglion neurons in culture. J Neurosci. 1985 Jun;5(6):1563–1569. doi: 10.1523/JNEUROSCI.05-06-01563.1985. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Wood P. M., Bunge R. P. Evidence that sensory axons are mitogenic for Schwann cells. Nature. 1975 Aug 21;256(5519):662–664. doi: 10.1038/256662a0. [DOI] [PubMed] [Google Scholar]

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