The behavioral test battery used in the present study showed that a history of alcohol drinking (4-months) was associated with deficits in 3xTg-AD mice as compared to saccharin exposed and WT controls. As discussed above, 3xTg-AD mice, and other mouse models of AD, develop age-dependent pathologies in these behavioral domains irrespective of alcohol exposure (Webster et al., 2014). However, at the age range tested (7–8 months) saccharin exposed 3xTg-AD mice in the present study did not show major behavioral abnormalities as compared to wild-type controls with the only notable deficit appearing in spatial learning in Morris Water Maze (e.g., acquisition). By contrast, a history of nondependent alcohol drinking produced behavioral deficits in spatial memory as tested in the Morris Water Maze (probe trial), sensorimotor gating (PPI of the startle response), and emotional processing as indexed by enhanced cued fear response.
