Axotomy along with hypoxia enhances the neuronal NADPH-d/NOS expression in lower brain stem motor neurons of adult rats

Hung Ming Chang, June Horng Lue, Chen Yuan Wen, Jeng Yung Shieh

Research output: Contribution to journalArticle

19 Citations (Scopus)

Abstract

This study was aimed to determine whether axotomy coupled with hypoxia would exert a more profound effect on injury-induced neuronal nitric oxide synthase (NOS) expression. In this connection, the vagus and the hypoglossal nerves of adult rats were transected unilaterally in the same animal, and half of the operated animals were subjected to hypoxia treatment. Both the neuronal NOS immunohistochemistry and the nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) histochemistry were used to assess the neuronal NOS expression. The present results have shown that the number of NADPH-d/NOS-positive [NADPH-d/NOS(1)] neurons in the hypoglossal nucleus (HN) peaked at 14 days after axotomy, while that in dorsal motor nucleus of vagus (DMN) and nucleus ambiguus (NA) was progressively increased up to 60 days. The up-regulation of NADPH-d/NOS in HN and DMN was more pronounced in hypoxic than in normoxic animals, a feature that was not evident in the NA. Quantitative analysis showed that the number of surviving motoneurons in normoxic animals was significantly higher than those subjected to hypoxia at 14 days postaxotomy in HN and at all postaxotomy time points in DMN. The difference may be attributed to their different functional components. Since O2 deprivation leads to poor cellular function, the stronger expression of NADPH-d/NOS and the more drastic neuronal loss following nerve transection in the hypoxic animals compared with the controls suggest that hypoxia plays an important role in peripheral neuropathies in which NO is implicated.

Original languageEnglish
Pages (from-to)116-126
Number of pages11
JournalExperimental Neurology
Volume171
Issue number1
DOIs
Publication statusPublished - 2001
Externally publishedYes

    Fingerprint

Keywords

  • Brain stem motor nuclei
  • Histochemistry
  • Hypoxia
  • Immunohistochemistry
  • Nitric oxide
  • Peripheral nerve injury

ASJC Scopus subject areas

  • Neuroscience(all)
  • Neurology

Cite this