Catechol-O-Methyltransferase Valine158Methionine Polymorphism Modulates Brain Networks Underlying Working Memory Across Adulthood

Fabio Sambataro, Jeff D. Reed, Vishnu P. Murty, Saumitra Das, Hao Yang Tan, Joseph H. Callicott, Daniel R. Weinberger, Venkata S. Mattay

Research output: Contribution to journalArticle

Abstract

Background: Cognitive abilities decline with age with large individual variability. Genetic variations have been suggested to be an important source for some of this heterogeneity. Among these variations, those related to the dopaminergic system, particularly the valine158methionine polymorphism in catechol-O-methyltransferase (COMTval158met), have been implicated in modulating age-related changes in executive function. Methods: We studied 75 subjects (age 21-90 years) using functional neuroimaging while they performed a low-level working memory (WM) task to explore the effects of aging, of the COMTval158met polymorphism, and their interactions on the physiological patterns of interconnected cortical activity engaged by WM. Results: Our results show that val homozygotes and older subjects showed increased activity in dorsolateral prefrontal cortex (DLPFC) and decreased activity in ventrolateral prefrontal cortex (VLPFC) relative to met homozygotes and younger subjects, respectively. Interestingly, there were also independent effects of the COMTval158met polymorphism and age on the strength of connectivity between brain regions within the left prefrontal-parietal network; val homozygotes and older subjects showed greater connectivity between the DLPFC and other brain regions within the network and met homozygotes showed greater connectivity between the VLPFC and other brain regions within the network. Furthermore, the greater functional connectivity strength of DLPFC in val homozygotes relative to met homozygotes was much more pronounced in older adults. Conclusions: Our findings suggest that the COMTval158met polymorphism modulates both the activity and functional connectivity of brain regions within WM networks and most importantly that this effect is exaggerated with increasing age, contributing to the variability in age-related decline in executive cognition.

Original languageEnglish (US)
Pages (from-to)540-548
Number of pages9
JournalBiological psychiatry
Volume66
Issue number6
DOIs
StatePublished - Sep 15 2009
Externally publishedYes

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Keywords

  • Aging
  • COMT
  • functional magnetic resonance imaging
  • independent component analysis
  • working memory

ASJC Scopus subject areas

  • Biological Psychiatry

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