TH and Parkinson disease: The immunoreactivity of TH-positive fibers in the striatum (Figure 1 and Figure S1 with lower magnification-200x) of the control, MPTP-PD, TUDCA, Syndopa, and TUDCA + Syndopa groups were 94.6, 18.5, 72.2, 56.1, and 79.5%, respectively, and the differences were significant (P < 0.001).