Figure 4.

Improved hippocampal-dependent learning and memory in Crabp1 KO mice. (a) Animal movement for 5 minutes, recorded in the open field test (n = 14 per group; P = 0.401). (b) The scheme shows the 3-day procedure of a novel object recognition task (n = 12 per group) (top). Data show visit times (left; familiar object, P = 0.421; novel object, P = 0.007) and discrimination index (right; P = 0.026) during the test session. (c) The acquisition stage shows an improved learning curve in the Crabp1 KO mice compared with the WT mice (left; day 2, P = 0.014; day 3, P = 0.021). The duration spent in each zone in the probe test (right; P = 0.012) shows better memory performance for Crabp1 KO mice than for WT mice (Crabp1 KO, n = 12; WT, n = 10). Results are presented as mean ± standard error of the mean. *P < 0.05, **P < 0.01 compared with the WT group. NE, northeast; NW, northwest; SE, southeast; SW, southwest, the target zone.