Fig. 3.

A, Mean ± SEM corrected integrated path length (CIPL; see Materials and Methods) over 4 d (six trials per day) of training in the spatial version of the Morris swim task. The old rats took significantly longer paths to find the platform compared with the young rats on days 2, 3, and 4 of training.B, Mean ± SEM CIPL for six training trials on the visual discrimination version of the Morris swim task. There were no statistically significant differences between age groups.C, Mean ± SEM average distance to the target quadrant and target crossings during the spatial probe trial, in which the platform was removed from the pool. The old rats exhibited longer average distances to the target and fewer target crossings than did the young rats, suggesting poorer spatial performance accuracy in the old animals.