Brain function and macromolecules. II. Site of increased labeling of RNA in brains of mice during a short-term training experience.

Abstract

We have previously reported increased incorporation of uridine into nuclear and ribosomal-polysomal (RP) RNA from the brains of mice undergoing 15 minutes of avoidance conditioning.1 Since these results were obtained with whole brains, we were unable to state whether the increases represented a generalized change through- out the brain or a relatively large increase in a smaller area of the brain.In an attempt to answer this question, we have dissected the brains of trained and untrained mice into six areas and have analyzed each area for in- corporation of radioactivity into RNA.The results indicate that the increases represent a localized rather than a general change.We had hoped that the results might also help to clarify which aspect of the training situation (i.e., learning, stress, jumping, attention, etc.) was the cause of the increased labeling.However, the localization found does not enable us to make such a distinction and we must await further studies now in progress using autoradiography that may permit more precise localization.Materials and Methods.-MaleC57B1/6J mice, six to eight weeks old, from the Jackson Laboratories were used as the experimental animals.For each experiment a double labeling method involving two mice was used.1 One of the mice received