Pattern of labelling of poly (A)-associated RNA in the CA3 region of rat hippocampus during training.

Newly synthesized poly (A)-associated mRNA was analysed in the hippocampal CA3 pyramidal nerve cells in rats subjected to training to reverse handedness. The nerve cells of trained animals showed a smaller percentage of poly(A)-associated mRNA than did the active controls. However, a specific fraction of this poly (A) hippocampal RNA with a SE value of around 25 was reproducibly stimulated. This qualitative nerve cell mRNA change is discussed in relation to similar changes in the protein pattern as a function of training.