Fig. 2: Alcohol drinking behavior of control and Per2 knockout mice.

a A representative image of PER2 immunofluorescence staining in dorsal striatal tissue of control and Per2 knockout mice. PER2: red, Gpr88-Cre-GFP: green. n = 3/genotype, scale bar = 50 µm. b A representative image of BMAL1 immunofluorescence staining in dorsal striatal tissue of control, and Per2 knockout mice. BMAL1: red, Gpr88-Cre-GFP: green. n = 3/genotype, scale bar = 50 µm. c Daily alcohol consumption (left) and average alcohol consumption (right) of control and Per2 knockout male mice. Two-way repeated measure ANOVA (RM-ANOVA), significant genotype effect, F (1, 14) = 8.332, p = 0.0120. Unpaired two-tailed t-test, *p < 0.05. d Daily alcohol consumption (left) and average alcohol consumption (right) of control and Per2 knockout female mice. RM-ANOVA, no significant effect, F (1, 17) = 0.014, p = 0.9072. Unpaired two-tailed t-test, NS. e Daily alcohol preference (left) and average alcohol preference (right) of control and Per2 knockout male mice. RM-ANOVA, significant genotype effect, F (1, 14) = 6.552, p = 0.0227. Unpaired two-tailed t-test, *p < 0.05. f Daily alcohol preference (left) and average alcohol preference (right) of control and Per2 knockout female mice. RM-ANOVA, no significant effect, F (1, 17) = 0.01779, p = 0.8955. Unpaired two-tailed t-test, NS. g Daily fluid intake (left) and average fluid intake (right) of control and Per2 knockout male mice. RM-ANOVA, no significant effect, F (1, 14) = 0.142, p = 0.7116. Unpaired two-tailed t-test, NS. h Daily fluid intake (left) and average fluid intake (right) of control and Per2 knockout female mice. RM-ANOVA, significant genotype effect, F (1, 17) = 5.665, p = 0.0293. Unpaired two-tailed t-test, *p < 0.05. NS = no significant differences. CTR: control, HET: Per2 heterozygote, SKO: Per2 knockout. c–h The values express mean ± S.E.M. a, b n = 3/genotype. c, e, g, CTR n = 8, SKO n = 8. d, f, h CTR n = 9, SKO n = 10.