Dispersion of growing axons within the optic nerve of the embryonic monkey

Robert Williams, P. Rakic

Research output: Contribution to journalArticle

53 Citations (Scopus)

Abstract

To determine whether individual optic fibers grow along constant sets of neighboring fibers, a group of 160 axons and 25 axonal growth cones were traced through a set of 500 serial electron micrographs of an optic nerve taken from a 39-day old monkey embryo (Macaca mulatta). In single transverse sections, growth cones contact an average of 7.9 fibers, whereas axons contact 5.3 other fibers. The particular set of fibers in contact with one another changed rapidly, and, on average, growth cones and axons lost half of their original neighbours over a distance of only 8-10 μm. Between the first and last sections of the series, 92% of all initial contacts were lost. Individual axons moved freely between fiber fascicles, and the distance separating initial neighbours increased progressively. Most remarkably, the sets of fibers touched by the tips and the shanks of growth cones had no common neighbours in 17 out of 25 case. These results demonstrate that, in primates, fibers in the optic nerve do not retain a particular set of immediate neighbours during their outgrowth.

Original languageEnglish (US)
Pages (from-to)3906-3910
Number of pages5
JournalProceedings of the National Academy of Sciences of the United States of America
Volume82
Issue number11
DOIs
StatePublished - Jan 1 1985

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Growth Cones
Optic Nerve
Haplorhini
Axons
Macaca mulatta
Primates
Embryonic Structures
Electrons

All Science Journal Classification (ASJC) codes

  • General

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Dispersion of growing axons within the optic nerve of the embryonic monkey. / Williams, Robert; Rakic, P.

In: Proceedings of the National Academy of Sciences of the United States of America, Vol. 82, No. 11, 01.01.1985, p. 3906-3910.

Research output: Contribution to journalArticle

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