Magnified effects of the COMT gene on white-matter microstructure in very old age.

• Autores: Goran Papenberg, Martin Lövdén, Erika J Laukka, Grégoria Kalpouzos, Lina Keller, Caroline Graff, Ylva Köhncke, Tie-Qiang Li, Laura Fratiglioni, Lars Bäckman
• Localización: Brain Structure and Function, ISSN 1863-2653, ISSN-e 1863-2661, Vol. 220, Nº. 5, 2015, págs. 2927-2938
• Idioma: inglés
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• Resumen

  • Genetic factors may partly account for between-person differences in brain integrity in old age. Evidence from human and animal studies suggests that the dopaminergic system is implicated in the modulation of white-matter integrity. We investigated whether a genetic variation in the Catechol-O-Methyltransferase (COMT) Val158Met polymorphism, which influences dopamine availability in prefrontal cortex, contributes to interindividual differences in white-matter microstructure, as measured with diffusion-tensor imaging. In a sample of older adults from a population-based study (60-87 years; n = 238), we found that the COMT polymorphism affects white-matter microstructure, indexed by fractional anisotropy and mean diffusivity, of several white-matter tracts in the oldest age group (81-87 years), although there were no reliable associations between COMT and white-matter microstructure in the two younger age groups (60-66 and 72-78 years). These findings extend previous observations of magnified genetic effects on cognition in old age to white-matter integrity.;