title: Age-related decline in dopamine transporters: analysis of striatal subregions, nonlinear effects, and hemispheric asymmetries.
abstract: Neuroimaging studies have documented an age-related decline in striatal dopamine transporters (DATs) as a marker of dopaminergic neurodegeneration. The authors further elucidated the effects on this neural system in healthy aging, in contrast to Parkinson disease (PD). The effects of age on striatal DAT availability were examined in a large, healthy subject sample (N=126) with [123I]2beta-carbomethoxy-3beta-(4-iodophenyl)tropane ([123I]beta-CIT) and single photon emission computed tomography (SPECT). Striatal DAT availability (V3") showed a significant inverse correlation with age, declining in a nearly linear manner by 46% over the age range 18 to 88 years, or 6.6% per decade. Rates of decline were comparable for caudate (48%) and putamen (45%), with only minimal increase in left-right asymmetry with age. Hemispheric asymmetries were unrelated to the handedness of subjects. These results demonstrate that aging is associated with a relatively symmetric loss of DATs in the caudate and putamen in both hemispheres. These findings have implications not only for healthy aging but also for neurodegenerative disorders such as PD.
authors.affiliation: Department of Psychiatry, Yale University School of Medicine, New Haven, CT 06510, USA. christopher.vandyck@yale.edu
authors.forename: Christopher H
authors.initials: CH
authors.lastname: van Dyck
authors.forename: John P
authors.initials: JP
authors.lastname: Seibyl
authors.forename: Robert T
authors.initials: RT
authors.lastname: Malison
authors.forename: Marc
authors.initials: M
authors.lastname: Laruelle
authors.forename: Sami S
authors.initials: SS
authors.lastname: Zoghbi
authors.forename: Ronald M
authors.initials: RM
authors.lastname: Baldwin
authors.forename: Robert B
authors.initials: RB
authors.lastname: Innis
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000378:metabolism*; D001921:Brain / Q000378:metabolism; D003042:Cocaine / Q000031:analogs & derivatives; D004292:Dominance, Cerebral; D004298:Dopamine / Q000378:metabolism*; D050483:Dopamine Plasma Membrane Transport Proteins; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes; D008297:Male; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins / Q000378:metabolism*; D008875:Middle Aged; D017072:Neostriatum / Q000000981:diagnostic imaging / Q000378:metabolism*; D009419:Nerve Tissue Proteins; D019275:Radiopharmaceuticals; D012016:Reference Values; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods
chemical_list: D050483:Dopamine Plasma Membrane Transport Proteins; D007457:Iodine Radioisotopes; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; D019275:Radiopharmaceuticals; C493214:SLC6A3 protein, human; C069723:2beta-carbomethoxy-3beta-(4-iodophenyl)tropane; D003042:Cocaine; D004298:Dopamine