Dopamine D1 receptors and age differences in brain activation during working memory
2011 (English)In: Neurobiology of Aging, ISSN 0197-4580, E-ISSN 1558-1497, Vol. 32, no 10, 1849-1856 p.Article in journal (Refereed) Published
In an fMRI study, 20 younger and 20 healthy older adults were scanned while performing a spatial working-memory task under two levels of load. On a separate occasion, the same subjects underwent PET measurements using the radioligand [11C] SCH23390 to determine dopamine D1 receptor binding potential (BP) in caudate nucleus and dorsolateral prefrontal cortex (DLPFC). The fMRI study revealed a significant load modulation of brain activity (higher load > lower load) in frontal and parietal regions for younger, but not older, adults. The PET measurements showed marked age-related reductions of D1 BP in caudate and DLPFC. Statistical control of caudate and DLPFC D1 binding eliminated the age-related reduction in load-dependent BOLD signal in left frontal cortex, and attenuated greatly the reduction in right frontal and left parietal cortex. These findings suggest that age-related alterations in dopaminergic neurotransmission may contribute to underrecruitment of task-relevant brain regions during working-memory performance in old age.
Place, publisher, year, edition, pages
Fayetteville, N.Y: Ankho International , 2011. Vol. 32, no 10, 1849-1856 p.
Aging; Dopamine; D1 receptors; fMRI; Load-dependent BOLD response; Multimodal brain imaging; PET; Spatial working memory
IdentifiersURN: urn:nbn:se:su:diva-94949OAI: oai:DiVA.org:su-94949DiVA: diva2:657119