Enhanced release of synaptic glutamate underlies the potentiation of oxygen-glucose deprivation-induced neuronal injury after induction of NOS-2

Aniruddha S. Vidwans, Sandra Hewett

Research output: Contribution to journalArticle

13 Scopus citations

Abstract

Reactive nitrogen oxide species (RNOS) may contribute to the progression/enhancement of ischemic injury by augmentation of glutamate release, reduction of glutamate uptake, or a combination of both. Consistent with this, induction of nitric oxide synthase (NOS-2) in murine neocortical cell cultures potentiated neuronal cell death caused by combined oxygen-glucose deprivation in association with a net increase in extracellular glutamate accumulation. However, uptake of glutamate via high affinity, sodium-dependent glutamate transporters was unimpaired by induction of NOS-2 under either aerobic or anaerobic conditions. Further, blocking possible routes of extra-synaptic glutamate release with NPPB [5-nitro-2-(3-phenylpropylamino)-benzoic acid], a volume-sensitive organic anion channel blocker, or TBOA (d,l-threo-β- benzyloxyaspartate), an inhibitor of glutamate transport, exacerbated rather than ameliorated injury. Finally, treatment with riluzole or tetanus toxin attenuated the enhancement in both glutamate accumulation and oxygen-glucose deprivation-induced neuronal injury supporting the idea that increased synaptic release of glutamate underlies, at least in part, the potentiation of neuronal injury by RNOS after NOS-2 induction.

Original languageEnglish (US)
Pages (from-to)91-101
Number of pages11
JournalExperimental Neurology
Volume190
Issue number1
DOIs
StatePublished - Nov 2004
Externally publishedYes

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Keywords

  • Cerebral ischemia
  • Excitotoxicity
  • Hypoxia/hypoglycemia
  • Inducible nitric oxide synthase
  • Mixed cortical cell cultures
  • Neurodegeneration

ASJC Scopus subject areas

  • Neurology
  • Neuroscience(all)

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