Format

Send to

Choose Destination
See comment in PubMed Commons below
J Comp Neurol. 1997 Mar 31;380(1):95-104.

Intact sciatic myelinated primary afferent terminals collaterally sprout in the adult rat dorsal horn following section of a neighbouring peripheral nerve.

Author information

  • 1Department of Anatomy and Developmental Biology, University College London, United Kingdom.

Abstract

Peripheral nerve section induces sprouting of the central terminals of axotomized myelinated primary afferents outside their normal dorsoventral termination zones in lamina I, III, and IV of the dorsal horn into lamina II, an area that normally only receives unmyelinated C-fiber input. This axotomy-induced regenerative sprouting is confined to the somatotopic boundaries of the injured nerve in the spinal cord. We examined whether intact myelinated sciatic afferents are able to sprout novel terminals into neighbouring areas of the dorsal horn in the adult rat following axotomy of two test nerves, either the posterior cutaneous nerve of the thigh or the saphenous nerve. These peripheral nerves have somatotopically organized terminal areas in the dorsal horn that overlap in some areas and are contiguous in others, with that of the sciatic central terminal field. Two weeks after cutting either the posterior cutaneous or the saphenous nerve, intact sciatic myelinated fibers labelled with the B fragment of cholera toxin conjugated to horseradish peroxidase (B-HRP) sprouted into an area of lamina II normally only innervated by the adjacent injured test nerve. This collateral sprouting was strictly limited, however, to those particular areas of the dorsal horn where the A-fiber terminal field of the control sciatic and the C-fiber terminal field of the injured test nerve overlapped in the dorsoventral plane. No mediolateral sprouting was seen into those areas of neuropil solely innervated by the test nerve. We conclude that intact myelinated primary afferents do have the capacity to collaterally sprout, but that any resultant somatotopic reorganization of central projections is limited to the dorsoventral plane. These changes may contribute to sensory hypersensitivity at the edges of denervated skin.

PMID:
9073085
[PubMed - indexed for MEDLINE]

LinkOut - more resources

Full Text Sources

Other Literature Sources

PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Wiley
    Loading ...
    Write to the Help Desk