Injury-associated induction of GAP-43 expression displays axon branch specificity in rat dorsal root ganglion neurons.


Journal Article

Peripheral nerve injury results in the increased synthesis and axonal transport of the growth-associated protein GAP-43 in dorsal root ganglion (DRG) neurons, coincident with regenerative growth of the injured peripheral axon branches. To determine whether the injury-associated signalling mechanism which leads to GAP-43 induction also operates through the central branches of DRG axons, we used immunocytochemistry to compare the expression of GAP-43 in adult rat DRG neurons 2 weeks after dorsal root crush lesions (central axotomy) or peripheral nerve crush lesions (peripheral axotomy). In uninjured ganglia, a subpopulation of smaller DRG neurons expresses moderate levels of GAP-43, whereas larger neurons generally do not. At 2 weeks following peripheral axotomy, virtually all axotomized neurons, large and small, express high levels of GAP-43. At 2 weeks following dorsal root lesions, no increase in GAP-43 expression is detected. Thus, the injury-associated up-regulation of GAP-43 expression in DRG neurons is triggered by a mechanism that is responsive to injury of only the peripheral, and not the central, axon branches. These findings support the hypothesis that GAP-43 induction in DRG neurons is caused by disconnection from peripheral target tissue, not by axon injury per se.

Full Text

Duke Authors

Cited Authors

  • Schreyer, DJ; Skene, JH

Published Date

  • July 1993

Published In

Volume / Issue

  • 24 / 7

Start / End Page

  • 959 - 970

PubMed ID

  • 8228973

Pubmed Central ID

  • 8228973

International Standard Serial Number (ISSN)

  • 0022-3034

Digital Object Identifier (DOI)

  • 10.1002/neu.480240709


  • eng

Conference Location

  • United States