Fig. 1

CD38^−/− mice show impaired hippocampus-dependent learning and memory. a The learning curve during 5 training days of the Morris water maze task showing the latency for the mice to reach the target platform. (CD38^+/+, n = 9; CD38^−/−, n = 13) b Time spent in each quadrant during a 1-min probe test after training sessions on training day 3. T: target, R: right, O: opposite, L: left quadrant. c Time spent in each quadrant during a 1-min probe test after training sessions on training day 5. T: target, R: right, O: opposite, L: left quadrant. d Freezing levels of CD38^+/+ (black) and CD38^−/− (blue) mice before (pre-training) and 24 h after (retrieval) contextual fear conditioning (CD38^+/+, n = 9; CD38^−/−, n = 13). n.s., not significant. All graphs are plotted using means ± SEM