White-matter connectivity and the reorganization of brain networks in aging

衰老过程中的白质连接和大脑网络重组

• 批准号: 7696447
• 负责人: Simon W Davis
• 金额: $ 4.12万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-25 至 2011-09-24
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7696447
• 关键词: Accounting; Address; Age; Aging; Anisotropy; Anterior; Behavioral; Behavioral Paradigm; Bilateral; Biological; Brain; Brain region; Cognitive; Cognitive Therapy; Communication; Contralateral; Corpus Callosum; Data; Diffusion Magnetic Resonance Imaging; Elderly; Fiber; Functional Magnetic Resonance Imaging; Goals; Individual; Inferior; Ipsilateral; Left; Link; Literature; Measures; Mediating; Methods; Modeling; Morphology; Pattern; Performance; Population; Process; Relative (related person); Research; Research Proposals; Resources; Role; Semantics; Sensory; Series; Sum; Task Performances; Testing; Visual Fields; age effect; age related; design; healthy aging; imaging modality; interest; neuroimaging; neuromechanism; normal aging; novel; novel strategies; pathological aging; programs; relating to nervous system; research study; trend; visual stimulus; water diffusion; white matter; young adult

DESCRIPTION (provided by applicant): A number of functional magnetic resonance imaging (fMRI) studies have show that older individuals often show increased activation outside of the cortical networks typically associated with successful task performance in young adults. Many of these studies have shown that high-performing older adults show both a bilateral pattern of brain activity not observed in young adults or in their low-performing counterparts, as well as a general trend to shift processing from posterior sensory regions to anterior association regions. The models of these patterns, the Hemispheric Asymmetry Reduction in Older adults (HAROLD), and the Posterior to Anterior Shift in Aging (PASA) posit that increases in contralateral and anterior recruitment (CR and AR, respectively) act as compensatory mechanisms for the increase in resource demands brought about by the biological degradation associated with normal aging. To further the understanding of changes in the reorganization of brain networks in aging we seek to identify the neural correlates of CR and AR. We will first seek to show that older adults benefit from bilateral more than unilateral processing (bilateral field advantage: BFA) in a split-visual field paradigm (Specific Aim 1). We will use diffusion tensor imaging (DTI) to evaluate both the structural morphology of the connection that mediate BFA (Specific Aim 2), as well as the influence of white matter integrity on functional networks of activation supporting BFA (Specific Aim 3). We therefore propose a series of multimodal experiments that rely on lateralized matching tasks designed to manipulate intra- and intrahemispheric communication demands between contralateral and ipsilateral brain regions. We expect activations associated with successful performance in older adults to observe a more frontal and bilateral pattern relative to young adult subjects, and that greater fiber integrity will mediate increases in cognitive performance, supporting compensatory accounts of aging. The proposed research program offers several novel approaches to the study of age-related reorganization of effective brain networks, and will clarify the role of white-matter connectivity in supporting healthy aging. Furthermore, this project seeks to characterize mechanisms that help to offset the detrimental effects of aging, and suggests cognitive therapies in both healthy and pathological aging populations.

描述（由申请人提供）：许多功能性磁共振成像（fMRI）的研究表明，老年人通常在通常与年轻人成功任务表现相关的皮质网络之外显示激活增加。这些研究中的许多研究表明，高表现的老年人既显示出在年轻人或表现不佳的年轻人中未观察到的双侧脑活动模式，也表明了从后感觉区域转移到前相关区域的一般趋势。这些模式的模型，老年人（Harold）的半球不对称降低以及衰老前移位（PASA）的后移位（PASA）位置，该位置增加了对侧和前部招募（CR和AR）作为与正常生物学降解相关的资源需求增加的补偿机制的补偿机制。为了进一步了解衰老中大脑网络重组的变化，我们试图识别CR和AR的神经相关性。我们将首先寻求表明，在分裂视野范式中，老年人比单方面加工（双边野外优势：BFA）受益更多（特定的AIM 1）。我们将使用扩散张量成像（DTI）来评估介导BFA的连接的结构形态（特定的目标2），以及白质完整性对支持BFA功能网络的影响（特定目标3）。因此，我们提出了一系列多模式实验，这些实验依赖于侧向匹配的任务，旨在操纵对侧和同侧大脑区域之间的膜内和膜内通信需求。我们期望与年轻人相对于年轻成年受试者，与老年人的成功表现相关的激活会观察到更额的和双边模式，并且更高的纤维完整性将介导认知表现的提高，从而支持衰老的补偿性说明。拟议的研究计划为有效的大脑网络的年龄相关重组提供了几种新型方法，并将阐明白人连通性在支持健康衰老中的作用。此外，该项目试图表征有助于抵消衰老有害影响的机制，并提出健康和病理衰老人群中的认知疗法。