AGE-RELATED LEARNING AND MEMORY DEFICITS IN ODOR-REWARD ASSOCIATION IN RATS

In these experiments, potential cognitive deficits in aged rats were s tudied using an odor-reward association task. Aged Fischer 344 rats fi rst performed to an odor-reward association task. After five daily ses sions of 60 trials, the aged rats were globally impaired in comparison to the control rats. However, considering individual performance, 40% of the aged population performed as well as the control animals. Thes e aged rats were then tested for retention at various times. They demo nstrated an increased rate of forgetting which was confirmed by a fina l reversal experiment. The other group of aged rats remained severely impaired and unable to make the odor-reward association correctly unti l the inter-trial interval was decreased from 15 to 5 s. When they wer e submitted to a task requiring the learning and retention of 7 new od or pairs, these aged rats again performed poorly. A subsequent reversa l session confirmed the rapid forgetting phenomenon for this aged grou p, even when the odor-reward associations were in fact made.