Resting State Connectivity in White Matter

白质的静息态连接

• 批准号: 9254616
• 负责人: John C Gore
• 金额: $ 48.15万
• 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 2021-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9254616
• 关键词: Anesthesia procedures; Anisotropy; Appearance; Architecture; Area; Atlases; Biological Neural Networks; 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 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（由适用提供）：该提案的目标是进一步调查并评估有关磁共振成像（MRI）信号（MRI）信号的最新新发现，该发现的性质是从人类大脑中获得的，在静止状态下获取，这有可能为量化白质功能性建筑的全新基础。我们最近表明，白质中静止状态信号波动之间的局部素间相关性在空间各向异性上。这些各向异性相关性和随后的分析的测量允许推导新的数学描述符，这是一种量化相邻体素和描述之间的功能同步的功能连通性张量（FCT），可以更长的范围动态连接。 FCT的某些特征非常紧密地类似于大脑区域之间扩散张量成像（DTI）数据的外观，但不使用任何差异梯度，并且基于完全不同的生物物理现象。这一发现表明，白质区暴露了功能性的临时变化，进而提出了一种新的方法来整合功能和结构信息。 FCT的构建和分析允许对通常遵循白质区域的功能途径进行交流图，并有可能揭示神经信息流动的方向。此外，即使白质的任务激活已被证明是弹性，功能张量似乎会随着神经刺激的响应而发生变化。静止状态连接已被广泛用于描述皮层内的功能电路，但迄今为止，白质已完全忽略了，并且当前的意见偏向于能够使用MRI检测白质中的神经元活动。因此，这项研究的目标是在静止的正常大脑中构建功能连通性张量，将它们与潜在的结构特征进行比较，并阐明造成其起源的基本生物物理机制。我们的具体目的是（i）衡量和表征正常受试者中休息状态下的功能连通性张量，评估其可重复性，并确定它们如何依赖于获取和后处理的特定技术方面；我们将定量评估FCT数据是否符合白质区域，这可以通过对从共同注册到同一空间的正常受试者人群创建的FCT和DTI地图酶来实现； （ii）研究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； （iii）通过对NN-Human Primes的高场研究来验证这些相关性的基础和解释，在其中我们将确定相关性是否源于血液动力学变化以及它们与潜在的神经电活动的关系。总体而言，这些将是对我们对白质静止状态MRI信号相关性各向异性的新颖观察的首次全面评估。提议使用FCT来映射大脑功能连通性是令人信服的，并提出了提高我们对大脑复杂神经网络功能组织的理解。