Age-related slowing in cognitive processing speed is associated with myelin integrity in a very healthy elderly sample
Age-related slowing in cognitive processing speed is associated with myelin integrity in a very healthy elderly sample
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DOI：
10.1080/13803395.2011.595397
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发表时间：
2011-01-01
影响因子：
2.2
通讯作者：
Bartzokis, George
中科院分区：
文献类型：
--
作者：
Lu, Po H.;Lee, Grace J.;Bartzokis, George
认知处理速度（CPS）的测量性能随着年龄的增长而减慢，但与这种认知现象相关的生物学基础仍然不完全清楚。我们评估了这样一个假设，即在一个非常健康的老年人群中，年龄相关的CPS减慢与髓鞘形成晚期区域的髓鞘分解有关。从152名健康老年人的前额叶白色物质和胼胝体的胼胝体中获得了髓鞘完整性的体内磁共振成像（MRI）生物标志物。这些区域在大脑发育后期形成髓鞘，并且由于正常衰老的影响，更容易受到破坏。为了评估区域特异性，我们还评估了胼胝体压部作为比较区域，其在发育早期髓鞘化，主要包含参与视觉处理的轴突。髓鞘完整性的测量与高度脆弱的髓鞘形成晚期区域的CPS显著相关，但在压部不相关。这些结果对与大脑衰老相关的认知变化的神经生物学具有启示意义。
Performance on measures of cognitive processing speed (CPS) slows with age, but the biological basis associated with this cognitive phenomenon remains incompletely understood. We assessed the hypothesis that the age-related slowing in CPS is associated with myelin breakdown in late-myelinating regions in a very healthy elderly population. An in vivo magnetic resonance imaging (MRI) biomarker of myelin integrity was obtained from the prefrontal lobe white matter and the genu of the corpus callosum for 152 healthy elderly adults. These regions myelinate later in brain development and are more vulnerable to breakdown due to the effects of normal aging. To evaluate regional specificity, we also assessed the splenium of the corpus callosum as a comparison region, which myelinates early in development and primarily contains axons involved in visual processing. The measure of myelin integrity was significantly correlated with CPS in highly vulnerable late-myelinating regions but not in the splenium. These results have implications for the neurobiology of the cognitive changes associated with brain aging.