The search for drugs to alter learning and memory processes in animals and man has its roots in mythology as well as the history of medicine. The use of plant alkaloids to improve memory was a recommendation of Benjamin Rush in his "Diseases of the Mind" (1812, P. 284), and the mysterious contents of lethe, a liquid capable of causing the erasure of earthly memories is found in Egyptian and Greek mythology, as well as described by Dante, remains a...