Neuroprotective effects of synthetic TP in the MPTP model of Parkinson's disease. (A) Immunohistochemical staining for TH and (B) stereological analysis of total (NISSL) and TH+-neurons in the SNpc in the acute MPTP model on the 7th day after treatment with TP-319 and TP-500. Bars represent mean±SEM. *p<0.05 compared to saline controls, and #p<0.05 compared to MPTP (n=6 mice per group). (C) Striatal levels of DA measured by HPLC analysis in the acute MPTP model on the 7th day. Bars represent mean±SEM. *p<0.05 compared to saline controls, and #p<0.05 compared to MPTP (n=6 mice per group). (D) Immunohistochemical staining for TH and (E) in the substantia nigra in the subacute MPTP model on the 21st day after treatment with TP-319 and TP-500. Bas represent mean±SEM. *p<0.05 compared to saline controls, and #p<0.05 compared to MPTP (n=6 mice per group). (F) Striatal levels of DA measured by HPLC analysis in the subacute MPTP-model on the 21st day. Bars represent mean±SEM. *p<0.05 compared to saline controls, and #p<0.05 compared to MPTP (n=6 mice per group) (scale bar, 200 μm). DA, dopamine; HPLC, high-performance liquid chromatography; MPTP, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine; SNpc, substantia nigra pars compacta; TH, tyrosine hydroxylase.