Fine structure of nerve fibers and growth cones of isolated sympathetic neurons in culture

Mary Bartlett Bunge

Research output: Contribution to journalArticle

344 Scopus citations

Abstract

The leading tips of elongating nerve fibers are enlarged into ‘growth cones’ which are seen in tissue culture to continually undergo changes in conformation and to foster numerous transitory slender extensions (filopodia) and/or a veillike ruffling sheet. After explantation of 1-day-old rat superior cervical ganglia (as pieces or as individual neurons), nerve fibers and tips were photographed during growth and through the initial stages of aldehyde fixation and then relocated after embedding in plastic. Electron microscopy of serially sectioned tips revealed the following. The moving parts of the cone, the peripheral flange and filopodia, contained a distinctive apparently filamentous feltwork from which all organelles except membranous structures were excluded; microtubules were notably absent from these areas. The cone interior contained varied forms of agranular endoplasmic reticulum, vacuoles, vesicles, coated vesicles, mitochondria, microtubules, and occasional neurofilaments and polysomes. Dense-cored vesicles and lysosomal structures were also present and appeared to be formed locally, at least in part from reticulum. The possible roles of the various forms of agranular membranous components are discussed and it is suggested that structures involved in both the assembly and degradation of membrane are present in the cone. The content of these growing tips resembles that in sensory neuron growth cones studied by others.

Original languageEnglish (US)
Pages (from-to)713-735
Number of pages23
JournalJournal of Cell Biology
Volume56
Issue number3
DOIs
StatePublished - Mar 1 1973

ASJC Scopus subject areas

  • Cell Biology

Fingerprint Dive into the research topics of 'Fine structure of nerve fibers and growth cones of isolated sympathetic neurons in culture'. Together they form a unique fingerprint.

Cite this