Influences of a DRD2 polymorphism on updating of long-term memory representations and caudate BOLD activity: magnification in aging.
Hum Brain Mapp
; 36(4): 1325-34, 2015 Apr.
Article
em En
| MEDLINE
| ID: mdl-25486867
ABSTRACT
A number of genetic polymorphisms are related to individual differences in cognitive performance. Striatal dopamine (DA) functions, associated with cognitive performance, are linked to the TaqIA polymorphism of the DRD2/ANKK1 gene. In humans, presence of an A1 allele of the DRD2/ANKK1-TaqIA polymorphism is related to reduced density of striatal DA D2 receptors. The resource-modulation hypothesis assumes that aging-related losses of neurochemical and structural brain resources modulate the extent to which genetic variations affect cognitive functioning. Here, we tested this hypothesis using functional MRI during long-term memory (LTM) updating in younger and older carriers and noncarriers of the A1-allele of the TaqIa polymorphism. We demonstrate that older A1-carriers have worse memory performance, specifically during LTM updating, compared to noncarriers. Moreover, A1-carriers exhibited less blood oxygen level-dependent (BOLD) activation in left caudate nucleus, a region critical to updating. This effect was only seen in older adults, suggesting magnification of genetic effects on functional brain activity in aging. Further, a positive relationship between caudate BOLD activation and updating performance among non-A1 carriers indicated that caudate activation was behaviorally relevant. These results demonstrate a link between the DRD2/ANKK1-TaqIA polymorphism and neurocognitive deficits related to LTM updating, and provide novel evidence that this effect is magnified in aging.
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Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Envelhecimento
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Núcleo Caudado
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Receptores de Dopamina D2
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Polimorfismo de Nucleotídeo Único
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Memória de Longo Prazo
Limite:
Adult
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Aged
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Female
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Humans
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Male
Idioma:
En
Revista:
Hum Brain Mapp
Assunto da revista:
CEREBRO
Ano de publicação:
2015
Tipo de documento:
Article
País de afiliação:
Suécia