DURHAM, N.C. -- In a finding that may offer clues about Parkinson's disease, a team led by Duke University researchers used a sophisticated laser system to gain evidence that a dark brown pigment that accumulates in people's brains consists of layers of two other pigments commonly found in hair.
Other scientists previously had determined via chemical analysis that the dark pigment, called neuromelanin, is composed of the two pigments: eumelanin, found in black-haired people, and pheomelanin, found in redheads. But how those pigments are arranged structurally remained unknown -- and this structuring may prove to be of critical importance, according to the researchers.
In addition, in 2005 a Duke team that included some of the same scientists involved in the current study reported using the laser system to establish that pheomelanin is chemically disposed to activate oxygen while eumelanin is not. Oxygen activation is suspected to play a role in the neurogenic cascade of events behind Parkinson's disease.
In the new report, investigators from Duke, North Carolina State University and the Institute of Biomedical Technologies in Segrate, Italy, outlined evidence that neuromelanins isolated from human brains have cores of oxygen-activating pheomelanin covered by a protective surface of eumelanin.
"This is the first piece of morphological data about how these pigments are constructed," said study leader John Simon, the George B. Geller Professor of chemistry at Duke.
The team published the findings online during the week of Sept. 25 in the journal Proceedings of the National Academy of Sciences. The research was funded by the U.S. Air Force Office of Scientific Research, through grants to the Duke University Free Electron Laser Laboratory, and by the Italian Fund for Basic Science.
The findings "should stimulate renewed interest in the roles of neuromelanin in the pathogenesis of Parkinson's disease, the secon
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Contact: Monte Basgall
monte.basgall@duke.edu
919-681-8057
Duke University
25-Sep-2006