Cerebral blood flow and BOLD responses to a memory encoding task: A comparison between healthy young and elderly adults
Cerebral blood flow and BOLD responses to a memory encoding task: A comparison between healthy young and elderly adults
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DOI：
10.1016/j.neuroimage.2007.05.024
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发表时间：
2007-08-15
期刊：
影响因子：
5.7
通讯作者：
Liu, Thomas T.
中科院分区：
文献类型：
--
作者：
Restom, Khaled;Bangen, Katherine J.;Liu, Thomas T.
内侧颞叶的功能磁共振成像(FMRI)研究主要利用血液氧合水平依赖(BOLD)对神经活动的反应。然而，将BOLD信号解释为内侧颞叶功能的衡量标准可能会很复杂，因为脑血管系统的变化既可能发生在正常衰老中，也可能发生在与年龄相关的疾病中，如阿尔茨海默病。功能性脑血流(CBF)反应的定量测量是对大胆测量的有益补充，并已被证明有助于解释功能磁共振研究。尽管有这些潜在的优势，ASL在认知任务和高危人群的fMRI研究中的应用一直受到限制。在这项研究中，我们展示了应用ASL功能磁共振成像来测量健康年轻人(平均25岁)和老年人(平均74岁)对自然场景编码的CBF和大胆反应。老年人内侧颞叶CBF增加的百分比明显较高，而在基线和任务条件下以及在单独的静息状态扫描期间，老年组的CBF水平明显较低。老年人的大胆反应幅度和CBF的绝对变化值也略高，但年龄组间差异不显著。CBF和BOLD反应的百分比与大脑氧代谢代谢率(CMRO2)对记忆编码的反应随年龄增加是一致的。(C)2007 Elsevier Inc.保留所有权利。
Functional magnetic resonance imaging (fMRI) studies of the medial temporal lobe have primarily made use of the blood oxygenation level dependent (BOLD) response to neural activity. The interpretation of the BOLD signal as a measure of medial temporal lobe function can be complicated, however, by changes in the cerebrovascular system that can occur with both normal aging and age-related diseases, such as Alzheimer's disease. Quantitative measures of the functional cerebral blood flow (CBF) response offer a useful complement to BOLD measures and have been shown to aid in the interpretation of fMRI studies. Despite these potential advantages, the application of ASL to fMRI studies of cognitive tasks and at-risk populations has been limited. In this study, we demonstrate the application of ASL fMRI to obtain measures of the CBF and BOLD responses to the encoding of natural scenes in healthy young (mean 25 years) and elderly (mean 74 years) adults. The percent CBF increase in the medial temporal lobe was significantly higher in the older adults, whereas the CBF levels during baseline and task conditions and during a separate resting-state scan were significantly lower in the older group. The older adults also showed slightly higher values for the BOLD response amplitude and the absolute change in CBF, but the age group differences were not significant. The percent CBF and BOLD responses are consistent with an age-related increase in the cerebral metabolic rate of oxygen metabolism (CMRO2) response to memory encoding. (c) 2007 Elsevier Inc. All rights reserved.