Increased dopamine turnover in the striatum in female Fam19a1 KO mice. A–G) Monoamines and their metabolites [NE (A), dopamine (B, DA), 3,4-dihydroxyphenylacetic acid (C, DOPAC), 3-methoxytyramine (D, 3-MT), homovanillic acid (E, HVA), 5-hydroxytryptamine (F, 5-HT; serotonin), and 5-HIAA (G)] concentrations in the striatum were measured by HPLC with electrochemical detection. H, I) Dopamine turnover rate (the ratio of the dopamine metabolites to dopamine. J) Serotonin turnover rate (the ratio of serotonin metabolite 5-HIAA to 5-HT). WT, n = 8; KO, n = 9. Data are expressed as means ± sem. Two-tailed Student’s t tests were used for comparing data of WT vs. KO mice. *P < 0.05, ***P < 0.001.