The neuromelanin of human substantia nigra and its interaction with metals

Neuromelanin (NM) is a peculiar biochemical component of several neurons in the Substantia Nigra (SN), the target area of the degenerative process in Parkinson Disease (PD). SN NM has peculiarities as to its composition and an impressive capacityof chelating metals, iron in particular, but not exclusively. Gaining insights into the structural and functional characteristics of NM should help understanding the reasons of selective vulnerability of nigral neurons in many parkinsonian conditions. From thepresent data a protective role of NM can be postulated until the buffering capability toward heavy metals are exhausted. Toverloading of NM with iron and other metals in neurons may trigger inflammatory and degenerative processes aggravating theunderlying pathological condition.