Neuronal nitric oxide synthase (nNOS) immunoreactivity in the spinal cord of transgenic mice with G93A mutant SOD1 gene

Shoichi Sasaki, Hitoshi Warita, Koji Abe, Makoto Iwata

Research output: Contribution to journalArticle

12 Citations (Scopus)


Immunohistochemical and quantitative analyses were used to examine the evolution of neuronal nitric oxide synthase (nNOS) with time in spinal motor neurons of transgenic mice with a G93A mutant Cu/Zn superoxide dismutase (SOD1) gene. Specimens from age-matched non-transgenic wild-type mice served as controls. In the controls, the anterior horn including the anterior horn neurons was not immunostained for nNOS. In the transgenic mice, at the age of 24 weeks (early presymptomatic), when no pathological change was observed in the spinal cord, anterior horn neurons were only occasionally immunostained for nNOS (0.3%). At the age of 28 weeks (late presymptomatic), nNOS-positive anterior horn neurons and their neuronal processes were occasionally observed (7.6%), and at the age of 32 weeks (early symptomatic), nNOS-positive anterior horn cells, including degenerated ones showing central chromatolysis, were frequently demonstrated (27.6%) and nNOS-positive cord-like swollen proximal axons were also observed in the anterior horns. nNOS expression in the anterior horn neurons was almost always observed in the somata. At the age of 35 weeks (end stage), neuronal loss of the anterior horn cells was severe, and nNOS-positive anterior horn neurons and cord-like swollen axons in the anterior horns were less prominent compared to those at the age of 32 weeks (33.8%), but many reactive astrocytes were immunostained for nNOS. Thus, nNOS immunoreactivity in the anterior horn neurons is observed as early as the presymptomatic stage and varies with the progression of the disease. The selective localization of positive nNOS immunoreactivity in the anterior horn neurons and degenerated ones in particular, and swollen proximal axons suggests that nNOS immunoreactivity may be involved in the degeneration of anterior horn neurons in this SOD1 transgenic mouse model.

Original languageEnglish
Pages (from-to)421-427
Number of pages7
JournalActa neuropathologica
Issue number5
Publication statusPublished - Dec 1 2002



  • Amyotrophic lateral sclerosis
  • Neuronal nitric oxide synthase
  • SOD1 mutation
  • Spinal cord
  • Transgenic mice

ASJC Scopus subject areas

  • Pathology and Forensic Medicine
  • Clinical Neurology
  • Cellular and Molecular Neuroscience

Cite this