Furthermore,the increased SIRT3 levels have been implicated in the improvementof pathologies induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP) or rotenone, both associated with PD.167,168 Elevated expression of SIRT3 serves to counteract the loss of dopaminergicneurons caused by α-synuclein, a protein linked to PD pathology(Figure 7). This evidence concerns the gene SIRT3 and Parkinson disease.