Expression of fos-related antigen-2 in rat hippocampus after middle cerebral arterial occlusion.

AP-1 transcription factors have been shown to be induced in the brain after ischemic injury. However, their roles in neuronal survival or death have yet to be defined. Here, we report the discovery of elevated nuclear levels of fos-related antigen-2 (FRA-2) in the nuclei of hippocampal neurons seven days after middle cerebral artery occlusion (MCAO). Expression of FRA-2 and AP-1 DNA binding activity is elevated in hippocampi ipsilateral as well as contralateral to MCAO. Using Fluoro-Jade staining as a marker of neurodegeneration, FRA-2 was not found to be expressed in degenerating neurons. Thus, FRA-2 is expressed in neurons that survive ischemic insult suggesting a role for this transcription factor in neuronal adaptation to the post-injury state.