Figure 4.

Circadian variations in the striatal dopaminergic and serotonergic systems. (A, B, C) DA, DOPAC, and HVA levels increased in the WT but did not change in the MOR KO mice, during the night (WT, n=10; KO, n=12) compared with the day (WT, n=8; KO, n=9). (D, E) The ratio of DOPAC to DA or 3-MT to DA decreased in the WT during the night but did not change in the MOR KO mice compared with the ratios of the day. (F) The ratio of 5-HIAA to 5- HT increased in the WT mice during the night compared with the day but did not change in the MOR KO mice. Data were analyzed by the mixed model ANOVA and are presented as the means plus the SDs. DOPAC, 3,4-Dihydroxyphenylacetic acid; DA, Dopamine; HVA, Homovanillic acid; 3-MT, 3-Methoxytyramine; 5-HIAA, 5-Hydroxyindoleacetic acid; 5-HT, Serotonin. Bars represent the means plus the SDs. * p≤0.05; ** p<0.01. p values have been adjusted for multiple comparisons using the Benjamini-Hochberg-Yekutieli false discovery rate [FDR (p < 0.05)]. Only males were used in the experiment. Detailed analyses are in Table 3.