[Analysis of hippocampal RNA in rats with genetically determined differences in their ability to learn].

Selection for twelve generations, by the speed of elaboration of a food-procuring motor conditioned reflex, produced an increased intensity of the synthesis of n and c fractions of the hippocampal RNA in rapidly learning animals as compared with those slowly learning. Electrophoretic analysis of the two fractions revealed similar series of RNA classes in the initial and the learning animals' groups. With high molecular RNA classes, insertion of the radioactive precursor was higher in the rapidly learning animals than in the slow learning ones. The learning process was attended with an increased insertion of the radioactive precursor in the area of high molecular n-RNA classes and in the area of 18S-4S RNA c-RNA. The percentage of radioactivity inserted in the poly-A RNA, as well as a change due to learning were significantly higher in the rapidly learning animals.