“…Neuromelanin appears to result from the autoxidation of dopamine, in a process that generates reactive oxygen species (ROS) [100] The presence of high amounts of iron in PD SN [101], which contribute to the production of free radicals via the FentonͲHaber Weiss reaction, has also been pointed out as a cause for selective degeneration of these neurons. In this reaction, hydrogen peroxide (H 2 O 2 ) generated during normal metabolism, during electron transport in mitochondria, or by pathogenic mechanisms, can be subsequently converted to the extremely toxic hydroxyl radical ( .…”