In rats with microsphere embolism-induced cerebral ischemia and memory defects, the activity of cAMP/PKA/CREB was significantly decreased in the hippocampus, as indicated by decreased cAMP content, PKA levels and CREB phosphorylation, while enhancement of the activity of this signaling pathway improved the memory function in rats (16,17). This evidence concerns the gene CREB1 and brain ischemia.