As expected, all PD rats showed a severe and significant reduction of TH expression in the 6-OHDA injected side compared to the intact side, confirming the accuracy of the DA lesion (PD + L-DOPA 8 mg: t(6) = 45.288 p < 0.001; PD + L-DOPA 6 mg: t(6) = 60.612 p < 0.001; PD + saline t(5) = 30.902 p < 0.001; Figures 6A,B). Here, TH is linked to Parkinson disease.