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Psychiatry Research: Neuroi
The role of the striatal dopamine transporter in cognitive aging
Nina Erixon-Lindrotha, Lars Fardea, Tarja-Brita Robins Wahlinb, Judit Sovagoa,
Christer Halldina, Lars B7ckmanc,d,*
aDepartment of Psychiatry, Department of Clinical Neuroscience, Karolinska Hospital, Box 6401, S-113 82, Stockholm, Sweden
bResearch and Development Center in Elderly Care, Karolinska Institute, S-113 82, Stockholm, Sweden
cAging Research Center, Division of Geriatric Epidemiology, Neurotec, Karolinska Institute, Stockholm, Sweden
dMax Planck Institute for Human Development, Berlin, Germany
Received 22 April 2004; received in revised form 30 August 2004; accepted 1 September 2004
Abstract
We examined the relationship of age-related losses of striatal dopamine transporter (DAT) density to age-related deficits in
episodic memory and executive functioning in a group of subjects (n=12) ranging from 34 to 81 years of age. The radioligand
[11C]h-CIT-FE was used to determine DAT binding in caudate and putamen. Results showed clear age-related losses of striatal
DAT binding from early to late adulthood, and a marked deterioration in episodic memory (word and figure recall, face
recognition) and executive functioning (visual working memory, verbal fluency) with advancing age. Most importantly, the age-
related cognitive deficits were mediated by reductions in DAT binding, whereas DAT binding added systematic cognitive
variance after controlling for age. Further, interindividual differences in DAT binding were related to performance in a test of
crystallized intelligence (the Information subtest from the Wechsler Adult Intelligence Scale-Revised) that showed no reliable
age variation. These results suggest that DAT binding is a powerful mediator of age-related cognitive changes as well as of
cognitive functioning in general. The findings were discussed relative to the view that the frontostriatal network is critically
involved in multiple cognitive functions.
D 2004 Elsevier Irelan