New melanic pigments in the human brain that accumulate in aging and block environmental toxic metals

• DOI: 10.1073/pnas.0808768105
• Publication Date: 2008-11-07T02:25:48Z
• Authors: Luigi Zecca; Chiara Bellei; Patrizia Costi; Alberto Albertini; Enrico Monzani; Luigi Casella; Mario Gallorini; Luigi Bergamaschi; Alberto Moscatelli; Nicholas J. Turro; Melvin Eisner; Pier Raimondo Crippa; Shosuke Ito; Kazumasa Wakamatsu; William D. Bush; Weslyn C. Ward; John D. Simon; Fabio A. Zucca
• Keywords: Neuromelanin; Organelle; Human brain

Neuronal pigments of melanic type were identified in the putamen, cortex, cerebellum, and other major regions human brain. These consist granules 30 nm size, contained organelles together with lipid droplets, they accumulate aging, reaching concentrations as high 1.5–2.6 μg/mg tissue brain regions. pigments, which we term neuromelanins, contain melanic, lipid, peptide components. The component is aromatic structure, contains a stable free radical, synthesized from precursor molecule cysteinyl-3,4-dihydroxyphenylalanine. This contrasts neuromelanin substantia nigra, where cysteinyl-dopamine. neuronal have some structural similarities to melanin found skin. precursors components neuromelanins are polyunsaturated lipids present surrounding organelles. synthesis various an important protective process because generated through removal reactive/toxic quinones that would otherwise cause neurotoxicity. Furthermore, resulting serves additional role its ability chelate metals, including environmentally toxic metals such mercury lead.