Disruption and restoration of dorsal horn sensory map after peripheral nerve crush and regeneration

Tomosada Sugimoto, Akihiro Yoshida, Katsumi Nishijima, Hiroyuki Ichikawa

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

Formalin injection into the hindpaw of rats produces many neurons with c-fos protein-like immunoreactivity (fos-neurons) in the medial 3 4 of the ipsilateral dorsal horn laminae I and II at the junction of 4th and 5th lumbar segments (the sciatic territory). The tibial nerve transection 2 or 3 days earlier resulted in almost complete elimination of stimulation-induced fos-neurons in the tibial territory (medial 1 2 of the sciatic territory). When the animals had been conditioned by crushing the tibial nerve 2 weeks before stimulation (11 or 12 days before transection), the number of fos-neurons significantly increased compared to simple transection alone. The increase (2.5-fold) was greatest in the tibial territory. Therefore, the dorsal horn neurons in the deafferented tibial territory exhibited hypersensitivity to intact peroneal primary input, and the somatotopy map was disrupted. When the nerve had been crushed 3 weeks (18 or 19 days earlier than transection) rather than 2 weeks before stimulation, however, the number and distribution of fos-neurons were not different from those without conditioning (transection alone). Regenerated tibial nerve fibers were capable of transganglionic transport of WGA-HRP from the hindpaw receptive field to the tibial territory of the dorsal horn by 3 weeks but not by 2 weeks following the nerve crush. When transection was omitted, noxious signal transmitted through the tibial nerve fibers regenerated by 3 weeks after crush was capable of inducing c-fos in the tibial territory. The injury-induced hypersensitivity of dorsal horn neurons and resulting disruption of somatotopy map were reversed by re-establishment of peripheral tissue-nerve interaction.

Original languageEnglish
Pages (from-to)49-54
Number of pages6
JournalPain
Volume63
Issue number1
DOIs
Publication statusPublished - Oct 1995

Keywords

  • Dorsal horn
  • Peripheral nerve injury
  • Peroneal nerve
  • Somatotopy
  • Tibial nerve
  • c-Fos

ASJC Scopus subject areas

  • Neurology
  • Clinical Neurology
  • Anesthesiology and Pain Medicine

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