Figure 5.

Age-dependent memory impairment in Ptprz-deficient mice. A-D, Wild-type (○) and mutant (•) mice were subjected to the Morris water maze task at the age of 8 weeks (young adult mice; n = 16 each) (A, C) or at the age of 20 weeks (adult mice; n = 21 each) (B, D). Escape latencies in the visible-platform task (A, B) and the hidden-platform task (C, D) are shown. The data points represent the mean ± SEM of two trials per day. E-H, The time spent (E, F) and the number of platform crossings (G, H) in each of four quadrants of the pool in the transfer test. Values are expressed as the mean ± SEM. ^*p < 0.05; Student's t test. T, Target; the quadrant where the platform was constantly located in the hidden-platform task; L, the quadrant left of the target; R, the quadrant right of the target; O, the quadrant opposite of the target; □, wild-type mice; ▪, mutant mice.