Induction of NGFI-A mRNA following middle cerebral artery occlusion in rats: in situ hybridization study.

Middle cerebral artery (MCA) occlusion in halothane-anesthetized rats induced the zinc finger gene, NGFI-A, in brain. In situ hybridization studies showed that NGFI-A was induced throughout all of the cortex following MCA occlusion. By 24 h after MCA occlusion there was little expression of NGFI-A mRNA in the core of the MCA infarct, but the mRNA was still induced in all of cortex outside the infarct. MCA occlusion also induced this gene in subcortical structures: ipsilateral medial striatum; most of thalamus including medial and lateral geniculate nuclei; substantia nigra; and hippocampus at 4 h of MCA occlusion which generally disappeared by 24 h of MCA occlusion. Most of these structures, except for the striatum, are not supplied by the MCA. These data show that changes in brain gene expression can occur in many regions remote from an infarction.