Figure 3

1-Methyltryptophan blocks chronic temporal lobe epilepsy-induced depressive behaviors, inhibits indoleamine 2,3-dioxygenase expression, and normalizes tryptophan metabolites without reducing IL-1β and IL-6 expression in the hippocampus. (A) Compared with saline treatment, the immobility time was diminished in the forced swim test (**P < 0.01 versus before treatment by paired t-test; **P < 0.01 versus saline treatment by one-way analysis of variance (ANOVA)). (B) Saccharin consumption was improved in TPT after 1-methyltryptophan (1-MT) treatment in chronic epileptic rats (*P < 0.05 versus before treatment by paired t-test; * P < 0.05 versus saline treatment by one-way ANOVA). (C) IL-1β and (D) IL-6 expression were unaffected by 1-MT treatment but (E) indoleamine 2,3-dioxygenase 1 (IDO1) expression was inhibited. (F) Kynurenine (KYN)/tryptophan (TRY) and (G) serotonin (5-HT)/TRY ratios were normalized in the hippocampus of chronic epileptic rats. Statistical significance was determined using paired t-test and one-way ANOVA. The data are presented as means ± SEM, n = 5 to 6; *P < 0.05; **P < 0.01; n.s., not statistically significant (P > 0.05).