Abstract
Base composition measurements were used as a criterion of RNA changes in goldfish brain. RNA synthesized during the acquisition of new swimming skills was found to have a uridine/cytidine ratio 20-80 per cent higher than that of RNA formed under nonlearning conditions. A variety of behavioral situations were used to demonstrate that these RNA changes were not due to such factors as intense physical exertion, passive responses to stress, or the intense electrical activity of the brain and convulsive behavior produced by KCl injections. The RNA changes were produced by two behavioral situations; (1) during the process of acquiring new swimming skills, and (2) as a result of attempts to master an impossible task. The results suggest that the modified RNA synthesis taking place during the acquisition of new behavioral patterns is probably not specific as to the particular information content being stored, but may be required for the consolidation step of new information storage.