Learning Trials for Morris water maze.
Mice learned to find a platform submerged below water level over the course of four days and four trials per day. A) The average daily improvement for each mouse in the time taken to reach the platform (often termed escape latency). A negative value means a shorter time; for example, young WT mice reduced their time-to-platform by more than 10 seconds per day. B) Average swimming speed. Because there were significant differences in swimming speed, data were then reevaluated following normalization. C) Performance normalized for differences in swimming speed and represented by the average daily improvement in the distance travelled to reach the platform for each mouse. For all panels *p<0.05 vs. all other groups.