THE ROLE OF AGE-DEPENDENT BEHAVIORS IN THE RETENTION OF AN APPROACH-AVOIDANCE RESPONSE IN PREWEANLING RATS

The role of age‐dependent responses in infantile amnesia was examined. Ten‐ and 15‐day old rats were trained in an approach‐mother, avoid‐shock paradigm and tested for retention immediately and after a 1‐day delay. Ten‐day‐old rats were also tested after 6 days. Half of all the pups received a shock reactivation treatment before the delayed retention tests and half did not. In comparison to immediate retention, performance declined after 1 day but was reinstated by reactivation. A similar reactivation effect was found on 10‐day‐old pups tested after 6 days except that a different age‐specific response was substituted for the original behavior. These effects were not found in untrained controls. These data show that learning may be expressed differently when acquisition and retention are measured at different developmental stages, a pattern that may be mistaken for infantile amnesia. Copyright © 1990 John Wiley & Sons, Inc.