Genes to remember

It has been known for several decades that the formation of long-term memor y requires gene expression, In recent years, the use of genetic and molecul ar approaches has led to the identification and characterization of genes a nd molecules that pl:ay a fundamental role in the biological mechanisms und erlying learning and memory. From these studies, it appears that molecules and molecular mechanisms essential for the process of memory have been cons erved throughout evolution. The cyclic AMP (cAMP)dependent activation pathw ay and a cAMP-dependent cascade of gene expression have been shown to be es sential for memory formation in Aplysia californica, Drosophila melanogaste r and rodents. Moreover, members of the transcription factor family cAMP re sponse element binding proteins (CREBs) seem to represent key molecules for transforming incoming information into long-term memory. Here, we review t he studies showing that conserved molecules and biological mechanisms are e ngaged in simple and complex forms of memory.