Using Sepia melanin as a PD model to describe the binding characteristics of neuromelanin - A critical review.

Parkinson's disease is characterised pathologically by a relatively selective death of dopaminergic neurons in the substantia nigra of the brain. The vulnerability of these neurons appears to be linked to the pigment neuromelanin. However, as yet there is limited understanding behind the mechanisms of this disease process. Complications arise due to the difficulty in obtaining appreciable quantities of neuromelanin. Furthermore, an appropriate model for studying neuromelanin has not been identified. To date there has been many studies looking at the binding and chemical characteristics of neuromelanin. However, a range of different synthetic and organic melanins have been used as models and leading to many varied conclusions being drawn. Therefore, the aim of this review is to present Sepia melanin as the most appropriate study model for the binding characteristics of neuromelanin. Considerations included chemical structure, surface characteristics and structural features of both synthetic and organic melanins.