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. Author manuscript; available in PMC: 2017 Aug 11.
Published in final edited form as: Genes Brain Behav. 2017 Jan 17;16(4):449–461. doi: 10.1111/gbb.12362

Figure 2. Genotype and sex differences in alcohol intake (A) and alcohol preference (B) in male (left) and female (right) nPE mice in a 3-week intermittent access (IA) drinking model.

Figure 2

The mice were exposed to the 2-bottle “alcohol (15%) vs. water” choice regimen every other day for 3 weeks. Data are presented after 4, 8 and 24 hours of alcohol access in session 1 on the first day and in session 10 after 3 weeks of IA. Genotype difference: *p<0.05, **p<0.01 or *** p<0.005 vs. nPE+/+ at the same hour; Session difference: #p<0.05, ##p<0.01 vs. the same genotype at the same hour in session 1; and Sex difference: &p<0.01 vs. the same genotype in the same session by 4-way ANOVA with Newman-Keuls post-hoc tests (n=5 in nPE−/−; n=5–8 in nPE+/+). (A) Alcohol intake: 4-way ANOVA revealed significant effects of genotype [F (1, 114) = 146, p<0.000001], session [F (1, 114) = 44, p<0.00001], sex [F (1, 114) = 13, p<0.0005], and interaction between genotype and sex [F (1, 114) = 6.9, p<0.01]. Post hoc analysis showed that: (1) in Session 1 between genotypes, nPE−/− males had less intake at 24 hours than nPE+/+ males [p<0.01]; nPE−/− females had less intake at 8 and 24 hours than nPE+/+ females [p<0.05 and p<0.001, respectively]; (2) in Session 10 between genotypes, both nPE−/− males and females had less intake at 8 and 24 hours than nPE+/+ ones [p<0.01 for all]; and (3) between the Sessions, nPE+/+ males had more intake at 24 hours in Session 10 than in Session 1 [p<0.05]. Though overall interaction between sex and session was not significant, nPE+/+ females had more intake at 24 hours than nPE+/+ males [p<0.01] in both Sessions 1 and 10. (B) Alcohol preference: 4-way ANOVA revealed significant effects of genotype [F (1, 114) = 70, p<0.000001] and session [F (1, 114) = 63, p<0.000001]. Post hoc analysis showed that: (1) in Session 1 between genotypes, both nPE−/− males and females had less preference at 8 hours than nPE+/+ ones [p<0.05]; (2) in Session 10 between genotypes, nPE−/− females had less preference at 4 hours than nPE+/+ ones [p<0.05]; and (3) between the Sessions, both nPE+/+ males and females had more preference at 4 hours in Session 10 than in Session 1 [p<0.01 and p<0.05, respectively]; and nPE−/− males had more preference at 4 and 24 hours in Session 10 than in Session 1 [p<0.05 for both].