TH and in situ carcinoma: The expression of TH was significantly reduced in all regions (6-OHDA vs. CIS: −59.8% hippocampus; −52.7% hypothalamus; −82.1 striatum) except in SN where immunofluorescent staining revealed comparable expression of TH in all groups [52] suggesting that slow, progressive, and partial damage spreading from the striatal terminals did not reach SN in 6-OHDA-treated animals by the end of the experiment.