Contribution of Ultra Low Frequency LFPs to Functional MRI

超低频 LFP 对功能 MRI 的贡献

• 批准号: 8546457
• 负责人: Shella D Keilholz
• 金额: $ 31.54万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-20 至 2017-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8546457
• 关键词: Affect; Anesthetics; Attention; Attention deficit hyperactivity disorder; Behavioral; Brain; Clinical; Coupled; Coupling; Data; Dexmedetomidine; Disease; Electroencephalography; Employee Strikes; Frequencies; Functional Magnetic Resonance Imaging; Goals; Human; Image; Individual; Isoflurane; Lead; Link; Location; Magnetic Resonance Imaging; Maps; Measures; Membrane Potentials; Methods; Network-based; Patients; Pattern; Performance; Physiological; Property; Protocols documentation; Rattus; Reaction Time; Reporting; Resolution; Rest; Rodent; Signal Transduction; Site; Spatial Distribution; Stimulus; Time; Variant; awake; base; blood oxygen level dependent; diagnosis evaluation; improved; insight; relating to nervous system; research study; slow potential; spatiotemporal; tool; vasomotion

DESCRIPTION (provided by applicant): Resting state MRI (rsMRI), based on fluctuations in the blood oxygenation level dependent (BOLD) signal, is increasingly used to map networks of spontaneous activity in the brain. The neural basis of these fluctuations is not well understood, with various studies reporting a link to low frequency power, high frequency power, modulation of spiking, and vasomotion. While the frequency range of the BOLD fluctuations is 0-0.1 Hz, previous studies have examined electrical activity in higher frequency bands (>1 Hz). It is known, however, that infra-slow oscillations (IFSOs; <1 Hz) exist in the brain and they have been linked to fluctuations in attentional control and reaction time in normal subjects and ADHD patients. We hypothesize that the BOLD fluctuations have a direct link to electrical fluctuations in the same frequency band, and that the modulation of higher frequencies by these slower oscillations leads to state-dependent relationships with the BOLD signal. 1. Determine the relationship between infra-slow potential fluctuations and activity in typical LFP bands (1-100 Hz). IFSOs and broadband local field potentials (LFPs) will be recorded from a network of cortical and subcortical sites to determine the spatial distribution of IFSOs and how they affect local activity. Simultaneous IFSO and intracellular recording will examine whether membrane potential changes are tied to low frequency oscillations. Different anesthetic states will modulate neural activity. 2. Characterize the contribution of IFSOs to the BOLD signal on a site-by-site and network basis. No studies have looked at the direct frequency correlates of the low frequency BOLD fluctuations. Preliminary data suggests that patterns of IFSOs can be mapped using MRI. Using a simultaneous recording/imaging protocol developed in our lab, we will obtain LFPs (broadband and infra-slow) and BOLD from sites selected from the network examined in aim 1. Correlation between LFPs and local BOLD signal will be performed to determine the largest contribution to BOLD fluctuations, while coherence between band-limited LFPs and BOLD correlation will be compared to identify the best predictors of BOLD correlation. 3. Examine the spatiotemporal dynamics of IFSOs and determine their link to quasi-periodic BOLD fluctuations. Preliminary data indicates that the time-lagged correlation between BOLD and IFSOs demonstrates a pattern of propagation along the cortex that is highly similar to the spatiotemporal dynamics previously observed with the BOLD signal. This aim will directly examine the link between BOLD and IFSO dynamics using the simultaneously-acquired multi-site data collected for aims 1 and 2. This project will provide unique insight into the network activity that underlies functional connectivity maps created with MRI and, if our hypothesis proves correct, will lead to a new way to map the spatiotemporal patterns of the infra-slow activity that modulates attention throughout the whole brain with resolution unobtainable with electroencephalography.

描述（由申请人提供）：基于血液氧合水平依赖性（BOLD）信号的波动的静止状态MRI（RSMRI）越来越多地用于绘制大脑自发活动的网络。这些波动的神经基础尚不清楚，各种研究报告了与低频功率，高频功率，尖峰调制和血管舒张的联系。虽然粗体波动的频率范围为0-0.1 Hz，但以前的研究检查了高频带（> 1 Hz）的电活动。然而，众所周知，大脑中存在中液 - 液振荡（IFSOS; <1 Hz），并且与正常受试者和ADHD患者的注意力控制和反应时间的波动有关。我们假设大胆的波动与同一频带中的电波动有直接链接，并且通过这些较慢的振荡对较高频率的调节会导致与大胆信号的状态依赖性关系。 1。确定典型的LFP带（1-100 Hz）中的基液潜在波动与活性之间的关系。 IFSO和宽带局部场电位（LFP）将从皮质和皮层下部位的网络记录，以确定IFSOS的空间分布及其如何影响局部活动。同时进行IFSO和细胞内记录将检查膜电位变化是否与低频振荡有关。不同的麻醉状态将调节 神经活动。 2。表征IFSOS对BOLD信号的贡献。没有研究研究低频大胆波动的直接频率相关性。初步数据表明，可以使用MRI映射IFSO的模式。使用在实验室中开发的同时记录/成像协议，我们将获得LFP（宽带和弱词），并从AIM 1中检查的网络中选择的站点进行大胆。LFPS与本地BOLD信号之间的相关性将执行，以确定对大胆波动的最大贡献，而对频段限制LFP和Bold Correlation correl的一致性则是对构成型号的相一致性。 3。检查IFSOS的时空动力学，并确定它们与准周期大胆波动的联系。初步数据表明，BOLD和IFSOS之间的时置相关性展示了沿皮质的传播模式，该模式与先前使用BOLD信号观察到的时空动力学高度相似。 This aim will directly examine the link between BOLD and IFSO dynamics using the simultaneously-acquired multi-site data collected for aims 1 and 2. This project will provide unique insight into the network activity that underlies functional connectivity maps created with MRI and, if our hypothesis proves correct, will lead to a new way to map the spatiotemporal patterns of the infra-slow activity that modulates attention throughout the whole brain with resolution unobtainable with脑电图。