Intrinsic versus extrinsic factors in determining the regeneration of the central processes of rat dorsal root ganglion neurons: The influence of a peripheral nerve graft
The relative contribution of intrinsic growth capacity versus extrinsic growth‐promoting factors in determining the capacity of transected dorsal root axons to regenerate long distances was studied. L4 dorsal root axons regenerating into 4‐cm peripheral nerve grafts on transected dorsal roots were c...
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Published in | Journal of comparative neurology (1911) Vol. 370; no. 1; pp. 97 - 104 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
New York
John Wiley & Sons, Inc
17.06.1996
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Subjects | |
Online Access | Get full text |
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Summary: | The relative contribution of intrinsic growth capacity versus extrinsic growth‐promoting factors in determining the capacity of transected dorsal root axons to regenerate long distances was studied. L4 dorsal root axons regenerating into 4‐cm peripheral nerve grafts on transected dorsal roots were counted. Few dorsal root myelinated axons regenerated to the distal end of the grafts by 10 weeks unless the sciatic nerve was also crushed. Regeneration of unmyelinated axons was also increased by peripheral lesions.
Crush or transection of the dorsal roots without grafting did not alter GAP‐43 mRNA expression in L4 dorsal root ganglion (DRG) cells. Grafting a peripheral nerve onto the cut end of an L4 dorsal root doubled the number of DRG cells expressing high levels of GAP‐43 mRNA after a delay of several weeks. Peripheral nerve crush at the time of nerve grafting resulted in a very rapid rise in GAP‐43 mRNA expression, which then declined to a steady level, twice that of controls, by 7 weeks.
Thus, the rapid increase in the number of DRG neurons expressing high levels of GAP‐43 mRNA after peripheral but not central axotomy correlates with the regeneration of central axons through nerve grafts. Because GAP‐43 mRNA is slowly upregulated in a subpopulation of sensory neurons in response to exposure of their central axons to a peripheral nerve environment, environments favourable for axonal growth may act by increasing the intrinsic growth response of neurons. Lack of intrinsic growth capacity may contribute to the failure of dorsal root axons to regenerate into the spinal cord. © 1996 Wiley‐Liss, Inc. |
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Bibliography: | ark:/67375/WNG-BQPMGVMN-J istex:A24A4CEB9A4BF5BD8C2E19DFD7BDA1A657D947E5 Bristol-Meyers Squibb Unrestricted Pain Research ArticleID:CNE9 Royal Society ISRT MRC ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 ObjectType-Article-1 ObjectType-Feature-2 |
ISSN: | 0021-9967 1096-9861 |
DOI: | 10.1002/(SICI)1096-9861(19960617)370:1<97::AID-CNE9>3.0.CO;2-G |