The biochemical basis of memory.

Several lines of research have indicated that the metabolism of both RNA and protein in the brain are important for permanent learning. One problem is to distinguish learning from stimulation per se, and whether it is meaningful to do so. Another problem is the biochemical interpretation of experiments using tracer precursor techniques. Evidence for the involvement of hormones such as ACTH as mediators of the biochemical responses and perhaps as stimulators of learning is discussed.