Expression of c-fos and inducible hsp-70 mRNA following a transient episode of focal ischemia that had non-lethal effects on the rat brain.

Expression of c-fos and inducible hsp-70 mRNA was studied with in situ hybridization techniques at different times following an episode of middle cerebral artery (MCA) occlusion not resulting in any apparent lethal effect on the rat brain. hsp-70 and c-fos mRNA were found in the ipsilateral striatum and adjacent cortex. In the striatum, levels of hsp-70 mRNA increased from 1 to 2 and 4 h of reperfusion, whereas levels of c-fos mRNA decreased from 1 to 4 h of reperfusion. These results demonstrate that following non-lethal focal ischemia the brain areas within the MCA territory show high c-fos and hsp-70 mRNA expression response, illustrating the concomitant induction of these mRNAs in cells that survive the ischemic insult.