Resting State Connectivity in White Matter

白质的静息态连接

• 批准号: 9891105
• 负责人: John C Gore
• 金额: $ 49.94万
• 依托单位: VANDERBILT UNIVERSITY MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-04-30 至 2022-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9891105
• 关键词: 3-Dimensional; Anesthesia procedures; Anisotropy; Appearance; Architecture; Area; Atlases; Biophysical Process; Biophysics; Blood Volume; Brain; Brain Mapping; Brain region; Complex; Contrast Media; Data; Derivation procedure; Descriptor; Diffusion; Diffusion Magnetic Resonance Imaging; Disease; Electrophysiology (science); Evaluation; Exhibits; Goals; Human; Image; MION; Magnetic Resonance Imaging; Mathematics; Measurement; Measures; Methods; Microelectrodes; Monkeys; Nature; Pathway interactions; Population; Primates; Reproducibility; Research; Resolution; Rest; Scanning; Signal Transduction; Stimulus; Structure; Variant; Visual system structure; anatomic imaging; base; blood oxygen level dependent; field study; hemodynamics; neural network; neural stimulation; nonhuman primate; novel; novel strategies; public health relevance; relating to nervous system; response; tractography; white matter

 DESCRIPTION (provided by applicant): The goals of this proposal are to further investigate and evaluate recent new discoveries about the nature of temporal variations in magnetic resonance imaging (MRI) signals from the human brain, acquired in a resting state, which potentially provide a completely new basis for quantifying the functional architecture of white matter. We have recently shown that local inter-voxel correlations between resting state signal fluctuations within white matter are spatially anisotropic. Measurements of these anisotropic correlations and subsequent analyses permit the derivation of a new mathematical descriptor, a functional connectivity tensor (FCT) that quantifies the functional synchronization between neighboring voxels and delineates longer range dynamic connections. Some of the features of FCTs superficially closely resemble the appearance of diffusion tensor imaging (DTI) data across large brain regions but without the use of any diffusion gradients and based on completely different biophysical phenomena. This discovery demonstrates that white matter tracts exhibit functional, temporal variations which in turn suggest a new approach for integrating functional and structural information. The construction and analysis of FCTs permits tractography of functional pathways that often appear to follow white matter tracts, potentially revealing directions of flow of neural information. Furthermore, the functional tensors appear to change in response to neural stimulation, even though task-activation of white matter has proven elusive. Resting state connectivity has been extensively used to delineate functional circuits within the cortex but to date has been completely overlooked in white matter, and current opinions are biased against being able to detect neural activity in white matter using MRI. The objectives of this research therefore are to construct functional connectivity tensors in normal brains at rest, compare these to underlying structural features, and elucidate the underlying biophysical mechanisms that account for their origins. Our specific aims are (i) to measure and characterize functional connectivity tensors in a resting state in normal subjects, assess their reproducibility, and determine how they depend on specific technical aspects of acquisition and post- processing; we will quantitatively assess whether FCT data conform to white matter tracts, which may be achieved by analyses of FCT and DTI atlases created from a population of normal subjects co-registered to the same space; (ii) to investigate the biophysical origins of resting state correlational anisotropy in humans, and how they vary with stimulation; and (iii) to validate the basis and interpretation of these correlations by high field studies of nn-human primates, in which we will determine whether the correlations originate from hemodynamic changes and how they relate to underlying neural electrical activity. Overall, these will be the first comprehensive evaluations of our novel observations of anisotropy of correlations in resting state MRI signals from white matter. The proposed use of FCTs for mapping of brain functional connectivity is compelling and offers to advance our understanding of the functional organization of complex neural networks in the brain.

 描述(申请人提供)：这项建议的目标是进一步调查和评估最近关于人类大脑磁共振成像(MRI)信号在静息状态下获得的时间变化性质的新发现，这可能为量化白质的功能结构提供一个全新的基础。我们最近发现，白质内静息状态信号波动之间的局部体素间相关性在空间上是各向异性的。这些各向异性相关性的测量和随后的分析允许导出新的数学描述符，即函数连接张量(FCT)，该函数连接张量量化相邻体素之间的函数同步并描绘更长范围的动态连接。FCT的一些特征表面上类似于大脑区扩散张量成像(DTI)数据的外观，但没有使用任何扩散梯度，基于完全不同的生物物理现象。这一发现表明，白质束表现出功能和时间上的变化，这反过来又为整合功能和结构信息提供了一种新的方法。FCT的构建和分析允许对经常看起来像是跟随白质束的功能通路进行纤维束成像，潜在地揭示神经信息流动的方向。此外，功能张量似乎随着神经刺激的反应而改变，尽管白质的任务激活已被证明是难以捉摸的。静息状态连接被广泛用于描绘皮质内的功能回路，但到目前为止，在脑白质中完全被忽视，目前的观点对使用MRI检测脑白质中的神经活动是有偏见的。因此，本研究的目的是在静息状态下的正常大脑中构建功能连接张量，将这些张量与潜在的结构特征进行比较，并阐明其起源的潜在生物物理机制。我们的具体目标是：(I)测量和表征正常受试者在静息状态下的功能连接张量，评估它们的重复性，并确定它们如何依赖于采集和后处理的特定技术方面；我们将定量评估FCT数据是否符合白质束，这可以通过分析共同注册到同一空间的正常受试者群体创建的FCT和DTI图谱来实现；(Ii)调查人类静息状态相关各向异性的生物物理起源，以及它们如何随刺激而变化；以及(Iii)通过对神经人类灵长类动物的高场研究来验证这些相关性的基础和解释，在这些研究中，我们将确定这些相关性是否源于血液动力学变化，以及它们如何与潜在的神经电活动相关。总体而言，这将是对我们对来自白质的静息状态MRI信号相关性各向异性的新观察结果的首次全面评估。FCT用于绘制大脑功能连接图的提议是引人注目的，并提供了促进我们对大脑中复杂神经网络的功能组织的理解。