Beyond supplying ATP and modulating Ca2+ levels, mitochondria are also key producers of ROS at the synaptic site.106 Models with Parkinson’s disease mutations such as Pink1, DJ-1 and SNCA have been connected to increased ROS.108,123 Further, cytosolic DA, which is increased in Parkinson’s disease models, undergoes auto-oxidation, creating further ROS. This evidence concerns the gene SNCA and Parkinson disease.