PS1 knockin mice with the Japanese I213T mutation: effects on exploratory activity, motor coordination, and spatial learning.

Knockin (KI) mice with a PS1/I213T mutation were compared to wild-type controls on the SHIRPA primary screening battery and for exploratory activity, motor coordination, and spatial learning. By comparison to non-transgenic controls, PS1/I213T KI mice had retarded acquisition of place learning in the Morris water maze without being impaired in the probe trial and in the visible platform subtest. PS1/I213T KI mice were more likely to display whole-body startle to an auditory stimulus and a tighter grip on a horizontal grid. PS1/I213T KI mice also had fewer enclosed arm entries in the elevated plus-maze, but did not differ from controls in open-field, photocell actimeter, and T-maze spontaneous alternation tests. No intergroup difference was seen in three motor coordination tests. The dissociation between hidden and visible platform versions in the water maze is consistent with the hypothesis that elevated Abeta42 concentrations cause cognitive disturbances.