Defective spatial learning and memory in CreER-p35 cKO mice. (A) Latency (s) over 9 testing days in the Morris water maze in p35-flox (open square, control, n =6) and CreER-p35 cKO mice (closed rhombus, p35 cKO, n =7). The slope of the learning curve was significantly lower in CreER-p35 cKO mice when compared with control mice (mixed ANOVA test, p =0.027). (B) The probe test after the hidden platform task. Control mice spent longer in the target quadrant (T) than other quadrants (One-way ANOVA test, p = 0.0054), while CreER-p35 cKO mice did not. (C) Total distance (cm), the number of crosses over the region where the platform was formerly located, and swimming speed (cm/s) of the probe test, and total distance (cm) in CreER-p35 cKO and control mice in the visible platform task. CreER-p35 cKO mice crossed the region fewer times than the control mice, and swam as far and as fast as control mice (unpaired t-test, p = 0.034). (D) No difference was observed in the total distance travelled in the visible platform task between the two genotypes. Error bars represent S.E.M. Unpaired t-test, *p<0.05, **p<0.01.