In the Morris water maze performed under simplified conditions when compared to WT mice (smaller pool and shorter trials - see Materials and Methods), the APMAP-KO/AD mice were less proficient than their control AD mice, with significantly longer swim paths on day 4 of the training (Fig. 2a), as well as showing a significantly lower target quadrant preference in the probe trial (Fig. 2b). This evidence concerns the gene APMAP and Alzheimer disease.