Evidence for specific phases in the development of human neuromelanin.
Neuromelanin is a dark-coloured pigment which forms in the dopamine neurons of the human midbrain. The age-related development and regulation of neuromelanin within these dopamine neurons has not been previously described. Optical density and area measurements of unstained neuromelanin in ventral substantia nigra neurons from 29 people spanning the ages of 24 weeks to 95 years old, demonstrated three developmental phases. Neuromelanin was not present at birth and initiation of pigmentation began at approximately 3 years of age, followed by a period of increasing pigment granule number and increasing pigment granule colouration until age 20. In middle and later life the colour of the pigment granules continued to darken but was not associated with any substantial growth in pigment volume. The identification of three phases and changes in the rate of neuromelanin production over time suggests the regulation of neuromelanin production and turnover, possibly through enzymatic processes.
Fedorow
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Prince of Wales Medical Research Institute and the University of New South Wales, Barker Street, Randwick, Sydney, NSW 2031, Australia.
Halliday
G M
GM
Rickert
C H
CH
Gerlach
M
M
Riederer
P
P
Double
K L
KL
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000378:metabolism*; D002102:Cadaver; D002648:Child; D002675:Child, Preschool; D019317:Evidence-Based Medicine; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008543:Melanins / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism*; D013378:Substantia Nigra / Q000378:metabolism*; D014018:Tissue Distribution
D008543:Melanins; C014121:neuromelanin