HYPOTHERMIA-PRODUCED RETROGRADE-AMNESIA IN YOUNG AND ADULT RATS

Although the phenomenon of retrograde amnesia has received extensive investigation in adult animals, relatively little attention has been given to the effects of amnestic agents on retention performance of young animals. In the present experiment, 50-66 and 25-31 day old rats were given 1-trial passive avoidance training followed immediately by hypothermia treatment. Adult and young rats cooled to a temperature at or below 21.degree. C within 8-9 min showed little evidence of retention 24 h later. In contrast, 25-31 day old rats cooled in half the time to the same temperature showed evidence of good retention. The implications of these findings for further studies examining the relationship between age and short-term changes in memory traces were considered.