Dopamine D1 receptors and age differences in brain activation during working memory
Dopamine D1 receptors and age differences in brain activation during working memory
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DOI：
10.1016/j.neurobiolaging.2009.10.018
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发表时间：
2011-10-01
影响因子：
4.2
通讯作者：
Nyberg, Lars
中科院分区：
文献类型：
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作者：
Backman, Lars;Karlsson, Sari;Nyberg, Lars
在一项功能性磁共振成像研究中，20名年轻人和20名健康的老年人在两个负荷水平下执行空间工作记忆任务时被扫描。在一个单独的场合，相同的受试者进行PET测量使用放射性配体[C-11] SCH 23390，以确定多巴胺D-1受体结合电位（BP）在尾状核和背外侧前额叶皮层（DLPFC）。功能磁共振成像研究显示，年轻人的额叶和顶叶区域的大脑活动有显著的负荷调节（高负荷>低负荷），而老年人则没有。PET测量结果显示尾状核和DLPFC中D-1 BP的显著年龄相关性降低。尾状核和DLPFC D-1结合的统计控制消除了与年龄相关的左额叶皮层负荷依赖性BOLD信号的减少，并大大减弱了右额叶和左顶叶皮层的减少。这些研究结果表明，与年龄相关的多巴胺能神经传递的改变可能有助于在老年工作记忆性能的任务相关的大脑区域招募不足。(C)2009 Elsevier Inc. All rights reserved.
In an fMRI study, 20 younger and 20 healthy older adults were scanned while performing a spatial working-memory task under two levels of load. On a separate occasion, the same subjects underwent PET measurements using the radioligand [C-11] SCH23390 to determine dopamine D-1 receptor binding potential (BP) in caudate nucleus and dorsolateral prefrontal cortex (DLPFC). The fMRI study revealed a significant load modulation of brain activity (higher load > lower load) in frontal and parietal regions for younger, but not older, adults. The PET measurements showed marked age-related reductions of D-1 BP in caudate and DLPFC. Statistical control of caudate and DLPFC D-1 binding eliminated the age-related reduction in load-dependent BOLD signal in left frontal cortex, and attenuated greatly the reduction in right frontal and left parietal cortex. These findings suggest that age-related alterations in dopaminergic neurotransmission may contribute to underrecruitment of task-relevant brain regions during working-memory performance in old age. (C) 2009 Elsevier Inc. All rights reserved.