Memory enhancement: the search for mechanism-based drugs.

Rapid progress has been made in understanding the synaptic changes required for memory encoding. Several companies are now attempting to use information about the induction and consolidation phases of this process to build memory-enhancing drugs. These efforts have produced novel compounds that improve retention scores across a broad range of tests and species. Initial clinical results are encouraging. Issues now arise about appropriate applications of candidate drugs and optimal cellular targets for future development.