Localized fMRI of heterogeneous neural responses

异质神经反应的局部功能磁共振成像

• 批准号: 8420473
• 负责人: Cheryl A. Olman
• 金额: $ 21.23万
• 依托单位: UNIVERSITY OF MINNESOTA
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-02-15 至 2015-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8420473
• 关键词: Access to Information; Accounting; Affect; Animal Model; Area; Automobile Driving; Behavior; Biological Markers; Biological Neural Networks; Brain; Characteristics; Code; Complex; Computer Simulation; Coupling; Data; Dependence; Detection; Disease; Equilibrium; Event; Exhibits; Functional Magnetic Resonance Imaging; Funding; Goals; Grant; Human; Image; Imaging Device; Individual; Link; Literature; Masks; Measurement; Measures; Methodology; Minority; Modeling; Neural Inhibition; Neurons; Neurophysiology - biologic function; Neurosciences; Output; Pattern; Perception; Physiological; Play; Population; Protocols documentation; Psychology; Publications; Reporting; Research Personnel; Resolution; Sampling; Schizophrenia; Scientist; Seizures; Series; Shapes; Signal Transduction; Source; Stimulus; Structure; Techniques; Testing; Theft; Time; Visual; Visual Cortex; Work; area striata; base; blood oxygen level dependent; blood oxygenation level dependent response; design; hemodynamics; improved; inhibitory neuron; innovation; interest; neural model; neural patterning; neuroimaging; relating to nervous system; research study; response; tool

DESCRIPTION (provided by applicant): Functional magnetic resonance imaging (fMRI) is undeniably the neuroimaging methodology that has become the workhorse for neuroscience and psychology researchers who want access to localized measurements of physiological changes in the brain that correlate with human behavior. The high value of fMRI measurements is based on the fact that they have been shown, time and again, to exhibit a linear correlation with the local neural population response. There are, however, a recent smattering of articles in the literature indicating a mismatch between the fMRI response and the measured or presumed neural activity. These mismatches appear limited to experiments in which only a small neural population is stimulated; they also seem most likely to occur when the balance between local neural excitation and inhibition is tipped in favor of inhibition. These reports of fMRI responses that fail to correlate with neural responses are puzzling at best, and potentially troublesome for scientists who want to draw quantitative conclusions about neural population activity from fMRI data. Our first series of proposed experiments will characterize the effects of sampling resolution on the interpretability of the fMRI response to small stimuli. Not only do flanking negative responses confound accurate interpretation of the fMRI response to small patches of neural activity, because the boundary regions are large compared to the total neural response, but size-dependent intrinsic inhibition shapes the neural response yet has an unknown representation in the hemodynamic response. The result of the first series of experiments will be a computational model characterizing (1) neuro-hemodynamic coupling at the edges of isolated patches of neural activity, and (2) the contribution of inhibitory neural activity to the fMRI response. Our second series of experiments will characterize fMRI response evoked by neural networks with different balances between excitation and inhibition. All local neural codes contain a balance between input and output; local computations use a balance of excitation and inhibition to shape the input and define output spiking rates. In this series of experiments, we will investigate the implications of our recent study showing that localized fMRI of individual image patches cannot be predicted simply from the responses of the neurons that respond best to those stimuli. Working with a computational model that demonstrates how the entire local neural population response can be used to predict fMRI responses, this second series of experiments will seek to identify signature hemodynamic response characteristics that are present when heterogeneous neural responses mask key information encoded in a sub-population of neurons. Together, these experiments will improve our ability to use high-resolution fMRI to characterize patterned neural activity, improving the utility of fMRI for clinicl applications such as neurosurgical planning and seizure locus detection.

描述（由申请人提供）：不可否认的是，功能磁共振成像（fMRI）是神经影像学方法，该方法已成为希望访问与人类行为相关的大脑生理变化的局部测量的神经科学和心理学研究人员的主力。功能磁共振成像测量值的高价值基于以下事实：它们一次又一次地显示出与局部神经种群反应的线性相关性。但是，文献中最近有一篇文章示意，表明fMRI反应与所测量或推测的神经活动之间存在不匹配。这些不匹配似乎仅限于仅刺激少量神经种群的实验。当局部神经激发与抑制措施之间的平衡以抑制时，它们似乎也很可能发生。这些关于未能与神经反应相关的功能磁共振成像反应的报告充其量令人困惑，对于想要从fMRI数据中得出有关神经人口活动的定量结论的科学家来说，可能会麻烦。 我们提出的第一个实验将表征抽样分辨率对fMRI对小刺激反应的解释性的影响。负面反应不仅会使fMRI对小神经活动斑块的反应进行准确的解释，因为与总神经反应相比，边界区域很大，而且依赖大小的内在抑制作用形成了神经反应，但在该神经反应中却有未知的表示。血液动力学反应。第一系列实验的结果将是一种计算模型，表征（1）在分离的神经活性斑块边缘的神经 - 移动动力耦合，以及（2）抑制性神经活性对fMRI反应的贡献。 我们的第二系列实验将表征由激发和抑制之间具有不同平衡的神经网络引起的fMRI反应。所有局部神经代码都包含输入和输出之间的平衡；本地计算利用激发和抑制平衡来塑造输入并定义输出尖峰率。在这一系列的实验中，我们将研究我们最近的研究的含义，表明无法简单地从对这些刺激的神经元的反应中预测单个图像斑块的局部fMRI。使用计算模型，该模型展示了如何使用整个局部神经种群反应来预测fMRI的反应，第二系列实验将寻求识别当异构神经反应掩盖掩盖在亚下编码的非均质神经反应时存在的签名血液动力学反应特征神经元的种群。 这些实验将共同提高我们使用高分辨率fMRI来表征图案神经活动的能力，从而改善了fMRI在临床应用中的效用，例如神经外科计划和癫痫发作基因座检测。