Dopamine D1 receptor associations within and between dopaminergic pathways in younger and elderly adults: links to cognitive performance.
Cereb Cortex
; 21(9): 2023-32, 2011 Sep.
Article
em En
| MEDLINE
| ID: mdl-21258043
ABSTRACT
Age-related dopamine (DA) losses have been extensively demonstrated for the D2 receptor subtype. Comparatively little is known about adult age changes regarding D1 receptors. In this study, we demonstrate marked age-related D1 receptor losses in striatal, limbic, and cortical areas using positron emission tomography and the radioligand [(11)C]SCH23390 in humans. Interregional correlations of binding potential (BP) values were high for areas within DA pathways in younger and elderly adults alike. Furthermore, interregional correlations in D1 BP between DA pathways were uniformly high in younger adults, indicating that D1 receptor densities in striatal, limbic, and cortical areas are not regulated independently, despite dopaminergic innervation from different midbrain areas. For elderly adults, between-pathway correlations of D1 receptor densities were preserved only between mesolimbic and mesocortical areas, whereas striatal BPs were weakly related to those in limbic and neocortical regions. Importantly, weak between-pathway correlations in elderly adults were found only for the slower half of the sample when BP was estimated during a cognitive interference task. These results suggest that D1 receptor densities in different pathways are not regulated independently in younger adults, but segregate in older age, and that this segregation of D1 receptor systems may be related to age-related cognitive slowing.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Desempenho Psicomotor
/
Envelhecimento
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Transdução de Sinais
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Dopamina
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Córtex Cerebral
/
Receptores de Dopamina D1
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Cognição
Tipo de estudo:
Risk_factors_studies
Limite:
Adult
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Aged
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Female
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Humans
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Male
Idioma:
En
Ano de publicação:
2011
Tipo de documento:
Article