title: Dopamine Receptor Genes Modulate Associative Memory in Old Age.
abstract: Previous research shows that associative memory declines more than item memory in aging. Although the underlying mechanisms of this selective impairment remain poorly understood, animal and human data suggest that dopaminergic modulation may be particularly relevant for associative binding. We investigated the influence of dopamine (DA) receptor genes on item and associative memory in a population-based sample of older adults (n = 525, aged 60 years), assessed with a face-scene item associative memory task. The effects of single-nucleotide polymorphisms of DA D1 (DRD1; rs4532), D2 (DRD2/ANKK1/Taq1A; rs1800497), and D3 (DRD3/Ser9Gly; rs6280) receptor genes were examined and combined into a single genetic score. Individuals carrying more beneficial alleles, presumably associated with higher DA receptor efficacy (DRD1 C allele; DRD2 A2 allele; DRD3 T allele), performed better on associative memory than persons with less beneficial genotypes. There were no effects of these genes on item memory or other cognitive measures, such as working memory, executive functioning, fluency, and perceptual speed, indicating a selective association between DA genes and associative memory. By contrast, genetic risk for Alzheimer disease (AD) was associated with worse item and associative memory, indicating adverse effects of APOE ε4 and a genetic risk score for AD (PICALM, BIN1, CLU) on episodic memory in general. Taken together, our results suggest that DA may be particularly important for associative memory, whereas AD-related genetic variations may influence overall episodic memory in older adults without dementia.
authors.affiliation: Karolinska Institutet, Solna, Sweden.|Stockholm University.
authors.forename: Goran
authors.initials: G
authors.lastname: Papenberg
authors.affiliation: Karolinska Institutet, Solna, Sweden.|Stockholm University.|Max Planck Institute for Human Development, Berlin, Germany.
authors.forename: Nina
authors.initials: N
authors.lastname: Becker
authors.affiliation: Karolinska Institutet, Solna, Sweden.|Stockholm University.
authors.forename: Beata
authors.initials: B
authors.lastname: Ferencz
authors.affiliation: University of Missouri.
authors.forename: Moshe
authors.initials: M
authors.lastname: Naveh-Benjamin
authors.affiliation: Karolinska Institutet, Solna, Sweden.|Stockholm University.
authors.forename: Erika J
authors.initials: EJ
authors.lastname: Laukka
authors.affiliation: Karolinska Institutet, Solna, Sweden.|Stockholm University.
authors.forename: Lars
authors.initials: L
authors.lastname: Bäckman
authors.affiliation: Karolinska Institutet, Solna, Sweden.|Stockholm University.|Max Planck Institute for Human Development, Berlin, Germany.
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Brehmer
mesh_terms: D000375:Aging / Q000235:genetics* / Q000523:psychology*; D000544:Alzheimer Disease / Q000235:genetics / Q000523:psychology; D001057:Apolipoproteins E / Q000235:genetics; D001244:Association; D015331:Cohort Studies; D005260:Female; D060005:Genotyping Techniques; D006801:Humans; D008297:Male; D008568:Memory; D008875:Middle Aged; D009483:Neuropsychological Tests; D020641:Polymorphism, Single Nucleotide; D011954:Receptors, Dopamine / Q000235:genetics*
chemical_list: D001057:Apolipoproteins E; D011954:Receptors, Dopamine