The cortex exhibited an increase of presenilin 1 and 2 mRNAs within 1–8 days after local ischemia with recirculation (Pennypacker et al., 1999), whereas, the hippocampus exhibited upregulation of presenilin 1 and 2 mRNAs within 4–8 days after ischemia (Pennypacker et al., 1999). This evidence concerns the gene PSEN1 and ischemia.