Figure 2.

Cbp^+/− mice show impaired EE-enhanced spatial navigation and pattern recognition ability. (A) The two-way ANOVA analysis of path lengths in the water maze task revealed a significant housing effect (F_{(1,31)housing}=4.81, P=0.04), no genotype effect (F_{(1,31)genotype}=0.37, P=0.55), and indicated a possible genotype × housing interaction (F_{(1,31)genotype × housing}=3.53, P=0.07). More precisely, EE improved the performance in WT mice (upper panel, two-way ANOVA, #: significant housing effect), but not in cbp^+/− mice (lower panel, NS: non-significant); n=8–10 mice per group. (B) EE housed wt mice showed more annulus crossings in the first and the second probe trials (upper panels: P1, P=0.06 no significant difference; P2, ^*P=0.03), whereas cbp^+/− mice did not exhibit any housing effect (lower panels: P1, P=0.90; P2, P=0.70). (C) (Upper panels) Schematic representation of the WRM tests used to measure pattern separation. Mice were tested for their pattern separation ability by comparing their performance in two types of tests: low separation tests (LOW) in which the target arm (T, where the platform is located) and the choice arm (C) were contiguous, and high separation tests (HIGH) in which the target and the choice arms were separated by a closed arm. Graph: In the third day of training, the mice were subjected to two symmetrical low and high separation tasks and the average performance was calculated. WT mice housed in an enriched environment (WT-EE) performed well both kind of tests (percentage of correct HIGH: t₍₇₎=2.65, P=0.03; percentage of correct LOW: t₍₇₎:3.42, P=0.01), whereas WT housed in standard cages (WT-SC) were only successful in the high separation tests (percentage of correct HIGH: WT-SC, t₍₉₎=3.00, P=0.02). In contrast, cbp^+/− mutants failed in both the HIGH and the LOW tests. ^*P<0.05 t-tests versus 50 (chance); n=8–10 mice per group.