Moreover, as in Parkinson’s disease nigrostriatal dopamine neurons progressively degrade [1, 107, 108], and some studies suggest that there is some sort of compensation for the extensive loss of these dopaminergic neurons via increased dopamine synthesis [68, 109–113], we investigated tyrosine hydroxylase levels and its manipulation via phosphorylation in a dopamine deficient situation. Here, TH is linked to Parkinson disease.