Drug enhancement of memory consolidation: historical perspective and neurobiological implications.
BACKGROUND
Studies of drug enhancement of cognition began with Lashley's (Psychobiology 1:141-170, 1917) report that strychnine administered before daily training trials enhanced rats' maze learning. Many subsequent studies confirmed that finding and found that stimulant drugs also enhance the learning of a wide range of tasks.


CONCLUSIONS
A central problem in interpreting such findings is that of distinguishing the drug effects on brain processes underlying memory formation from many other possible effects of the drugs on the behavior used to assess learning. The subsequent finding that comparable learning enhancement can be obtained by posttraining drug administration provided compelling evidence that drugs can enhance memory by acting on memory consolidation processes. Such evidence stimulated the investigation of endogenous regulation of memory consolidation by arousal-released adrenal stress hormones.


CONCLUSIONS
Considerable evidence now indicates that such hormones regulate memory consolidation via activation of the basolateral amygdala and subsequent influences on many efferent brain regions involved in processing recent experiences. The implications of these findings for the development of cognitive enhancing drugs are discussed.
McGaugh
James L
JL
Center for the Neurobiology of Learning and Memory, University of California, Irvine, CA 92697-3800, USA. JLMCGAUG@UCI.EDU
Roozendaal
Benno
B
D000818:Animals; D018684:Glycine Agents / Q000494:pharmacology; D049673:History, 20th Century; D006801:Humans; D007858:Learning / Q000187:drug effects; D008568:Memory / Q000187:drug effects*; D009424:Nervous System Physiological Phenomena / Q000187:drug effects*; D011619:Psychotropic Drugs / Q000266:history* / Q000494:pharmacology*; D013331:Strychnine / Q000494:pharmacology
D018684:Glycine Agents; D011619:Psychotropic Drugs; D013331:Strychnine