INDUCTION OF ORNITHINE DECARBOXYLASE MESSENGER-RNA IN TRANSIENT FOCALCEREBRAL-ISCHEMIA IN THE RAT

We used in situ hybridization to localize the long-term changes in orn ithine decarboxylase (ODC) expression after a 90 min occlusion of the middle cerebral artery (MCAO) in the rat. The ODC mRNA was induced in the ipsilateral dentate gyrus (DG) and throughout the ischemic cortex at 12 h and still at 3 days after reperfusion. The induction was block ed by an N-methyl-D-aspartate (NMDA) receptor antagonist suggesting th at ODC induction is NMDA receptor-mediated. The long-lasting up-regula tion detected in regions where no cellular damage usually occurs, favo rs the hypothesis that ODC expression does not contribute to neuronal death after stroke. (C) 1997 Elsevier Science Ireland Ltd.