Structure-function correlates of cognitive decline in aging
Structure-function correlates of cognitive decline in aging
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DOI：
10.1093/cercor/bhj036
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发表时间：
2006-07-01
期刊：
影响因子：
3.7
通讯作者：
Buckner, Randy L.
中科院分区：
文献类型：
--
作者：
Persson, Jonas;Nyberg, Lars;Buckner, Randy L.
为了探索衰老过程中认知能力下降的神经相关性，我们使用纵向行为数据来识别两组老年人（n = 40），这两组老年人在情景记忆测试中的表现是否在十年内保持稳定或下降方面存在差异。结构和扩散张量成像（DTI）分析揭示了与认知能力下降相关的一组异质差异。手动追踪海马体积显示，记忆力下降的老年人的海马体积显着减少，DTI 测量的胼胝体前部各向异性分数也显着减少。偶发情景编码过程中的功能磁共振成像显示，两组受试者的左前额叶皮层激活均有所增加，而记忆表现下降最严重的老年受试者的右前额叶皮层则额外激活。此外，前胼胝体的平均 DTI 测量值与右前额叶皮层的激活呈负相关。这些结果表明，认知能力下降与衰老大脑的结构和功能差异有关，并表明激活增加要么是由结构破坏引起的，要么是对这种破坏的补偿反应。
To explore neural correlates of cognitive decline in aging, we used longitudinal behavioral data to identify two groups of older adults (n = 40) that differed with regard to whether their performance on tests of episodic memory remained stable or declined over a decade. Analysis of structural and diffusion tensor imaging (DTI) revealed a heterogeneous set of differences associated with cognitive decline. Manual tracing of hippocampal volume showed significant reduction in those older adults with a declining memory performance as did DTI-measured fractional anisotropy in the anterior corpus callosum. Functional magnetic resonance imaging during incidental episodic encoding revealed increased activation in left prefrontal cortex for both groups and additional right prefrontal activation for the elderly subjects with the greatest decline in memory performance. Moreover, mean DTI measures in the anterior corpus callosum correlated negatively with activation in right prefrontal cortex. These results demonstrate that cognitive decline is associated with differences in the structure as well as function of the aging brain, and suggest that increased activation is either caused by structural disruption or is a compensatory response to such disruption.