• We are sorry, but NCBI web applications do not support your browser and may not function properly. More information
Logo of jcellbiolHomeThe Rockefeller University PressEditorsContactInstructions for AuthorsThis issue
J Cell Biol. Jan 1, 1967; 32(1): 113–119.
PMCID: PMC2107085

MICROTUBULES AND FILAMENTS IN THE AXONS AND ASTROCYTES OF EARLY POSTNATAL RAT OPTIC NERVES

Abstract

Changes in the population of microtubules and filaments within the cytoplasm of maturing axons and astrocytes have been studied during the early postnatal development of rat optic nerves. At birth, all of the axons are unmyelinated; most have a diameter of 0.2–0.3 µ and contain 4–10 microtubules. Neurofilaments do not occur with any frequency until about 5 days postnatal when they appear as individual groups, each containing 4–12. Subsequently, the neurofilaments of each group disperse so that they become more evenly distributed in mature axons. Developing astrocytes show similar but rather more dramatic changes. Most astrocytic processes contain only microtubules at birth, but during maturation filaments begin to appear in increasing numbers while microtubules become less common. This process continues until, in the mature fibrous astrocytes, filaments pack the cytoplasm and microtubules are rare. These observations suggest that the filaments within axons and astrocytes may be formed by the breakdown of microtubules.

Full Text

The Full Text of this article is available as a PDF (757K).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.
  • AUBER J. [Method of growth of myofbrils during nymphosis in Calliphora erythrocephala (Mg.)]. C R Hebd Seances Acad Sci. 1962 Jun 4;254:4074–4075. [PubMed]
  • BYERS B, PORTER KR. ORIENTED MICROTUBULES IN ELONGATING CELLS OF THE DEVELOPING LENS RUDIMENT AFTER INDUCTION. Proc Natl Acad Sci U S A. 1964 Oct;52:1091–1099. [PMC free article] [PubMed]
  • PALAY SL. Synapses in the central nervous system. J Biophys Biochem Cytol. 1956 Jul 25;2(4 Suppl):193–202. [PMC free article] [PubMed]
  • SABATINI DD, BENSCH K, BARRNETT RJ. Cytochemistry and electron microscopy. The preservation of cellular ultrastructure and enzymatic activity by aldehyde fixation. J Cell Biol. 1963 Apr;17:19–58. [PMC free article] [PubMed]
  • Tilney LG, Porter KR. Studies on microtubules in Heliozoa. I. The fine structure of Actinosphaerium nucleofilum (Barrett), with particular reference to the axial rod structure. Protoplasma. 1965;60(4):317–344. [PubMed]

Articles from The Journal of Cell Biology are provided here courtesy of The Rockefeller University Press

Formats:

Related citations in PubMed

See reviews...See all...

Cited by other articles in PMC

See all...

Links

  • PubMed
    PubMed
    PubMed citations for these articles