Fig. 1.

Effect of infection on dopamine production and tyrosine hydroxylase in dopaminergic cells. Levels of total dopamine (A) and potassium-induced dopamine release (B) from cells infected with increasing numbers of T. gondii parasites were assessed by HPLC-ED (n = 6 independent experiments). A one-way ANOVA was performed (total DA, F_(4,25) = 3.78 p = 0.015; released DA, F_(4,25) = 0.988 p = 0.43). Statistically significant differences are denoted by ^*for p < 0.02 and ^**for p < 0.0001 compared to uninfected cells (Student t-test). Tyrosine hydroxylase (TH) amounts in PC12 cells infected with increasing numbers of induced tachyzoites monitored by qPCR (C) and (n = 3 independent experiments, p > 0.5, ANOVA F_(4,10) = 0.845) Western analysis (D) (n = 3 independent experiments, p > 0.5) with a representative blot are shown. Rat actin served as a control. Western blot analysis of phosphorylation at rat TH ser19 and ser40 (n = 3 independent experiments) that contribute to TH activation shown on a representative blots (E, F). l-DOPA synthetic activity was measured in extracts derived from PC12 cells infected with increasing doses. The graph shows the mean log of the increased l-DOPA measured by HPLC-ED with the SEM (n = 5 independent experiments, p value = 0.03, Student t-test) (G).