Sepp1 (-/-) mice exhibit impaired acquisition of spatial learning and memory. (A) Average escape latency from 4 trials per day. Sepp1(-/-) mice showed a significantly longer latency on days 3 and 6 (n = 10 mice per genotype, Day 3 *p = 0.04, Day 6 *p = 0.04). (B) Linear regression of escape latencies per trial from days 2 to 3 (Sepp1(-/-) slope = 0.5, Sepp1(+/+) slope = -3.5). (C) Time spent searching the 4 quadrants for the hidden platform during a 60 sec probe trial on day 5 (TQ-target quadrant, OP-opposite, R-right, L-left). Both genotypes selectively searched the target quadrant. (D) Day 10 latencies to locate a visible platform in the opposite quadrant from training. Both genotypes demonstrated similar ability to locate the visible platform.