Figure 9.

Latency to escape from the Morris water maze during sessions 1 through 3 (spatial learning) and sessions 5 and 6 (cued training) in mice aged 4 (n = 21), 12 (n = 26), and 18 (n = 28) months. TS indicates training session. Young mice outperform older mice on session 1 of spatial learning, and group differences disappear by session 2. A one-way ANOVA examining cued training indicated significant differences on session 5 (F_[2,74] = 4.48, P < 0.05), with the 18-month-old group outperforming the 4-month-old group. This is most likely a result based on the observation that young mice tend to show thigmotaxis, an inclination to circle the pool in search of an external escape rather than an internal one.