Exploratory activity and spatial learning in 12-month-old APP695SWE/co+PS1/ΔE9 mice with amyloid plaques

APP(695)SWE/co+PSI/Delta E9 mice with A beta plaques in neocortex and hippocampus were evaluated in tests of exploratory activity and spatial learning. On the initial testing day, 12-month-old APP(695)SWE/co+PSI/Delta E9 mice spent more time than non-transgenic controls in the open arms of the elevated plus-maze. The bigenic group also travelled farther in the central region of the open-field without spending more time there. Only the bigenic group alternated above chance in the T-maze. In the Morris water maze, APP(695)SWE/co+PSI/Delta E9 mice were impaired during acquisition of the hidden platform subtask and the probe trial but not in the visible platform test. These results indicate a selective spatial deficit and disinhibitory tendencies in a mouse model with amyloid pathology. (C) 2005 Elsevier Ireland Ltd. All rights reserved.