To explore the potential long-term impact of nondependent alcohol drinking on specific AD biomarkers, four groups of age-matched (3 months) 3xTg-AD and WT control mice (combined male [n = 14] and female [n = 6]; N = 20 in total) were given a choice between: (1) alcohol [(25%, w/v) + saccharin (0.1%, w/v) vs water (n = 6)]; or (2) saccharin [(0.1%, w/v) vs water (n = 4)] for 11weeks according to our standard two-bottle choice 24-h home-cage procedure (Methods; Fig. 4A and B). There were no statistically significant differences in total alcohol or saccharin intake between 3xTg-AD and WT mice (male and female data combined). Average total alcohol intake ranged from 13.7 to 17.8g/kg/day with preference ratios (alcohol/total fluid) ranging from 36% to 39% between genotypes (Fig. 4A). This level of alcohol intake is below the threshold for induction of physical dependence (e.g., Ogata, Ogato, Mendelson, & Mello, 1972) and observation of mice in this study detected no signs of dependence or withdrawal.
