Quantifying the Brain Metabolism Underlying Task-Based BOLD Imaging

项目总结/摘要 最近的证据表明，代谢功能障碍是精神疾病的一个重要的跨诊断风险因素。 功能性磁共振成像（fMRI）测量与大脑代谢变化相关的血液动力学变化， 弥合精神疾病生物标志物与人类经验和行为之间的关键差距;然而， 作为血液动力学反应基础的代谢过程仍然知之甚少。才能 了解精神疾病的脑代谢功能障碍，我们首先需要了解脑代谢过程中， 健康的认知功能一个特别的争议点是，BOLD对感觉信号的反应， 认知活动与葡萄糖消耗的大幅增加相一致，与O2增加无关 新陈代谢.这个过程称为有氧糖酵解。它的功能仍有争议。我们已经开发出一种 从神经生理学的证据，澄清如何有氧糖酵解提供了一个假设， 神经元通讯的适应功能。拟议的研究将有助于基础科学， 推进测量和解释基于任务的大脑代谢动力学所需的方法和理论。我们 联合收割机结合功能PET成像（fPET）和双校准fMRI的技术创新， 测量局部葡萄糖和O2代谢的绝对速率和基于任务的相对变化。要求1 评价了混合PET/fMRI方法在扫描过程中和扫描过程中的可靠性，以及与既往PET的对比。 衍生估计。目的2测试一个新的假设的作用有氧糖酵解发挥信息 传输我们假设有氧糖酵解补充了交流不可预测的能量 感觉信号，即，预测误差为了验证这一点，我们将使用一个简单的行为任务，操纵 听觉和视觉刺激的可预测性，与感官流之间的注意力操纵交叉。 目标1代表了我们测量大脑代谢动力学能力的一个关键进步，就像之前的研究一样。 仅限于执行独立的PET会话。目标2在更广泛的理论中测试了一个关键的预测， 框架，这有可能显着重新构建现有的功能磁共振成像研究的解释， 在明确的信息和代谢中重新语境化血液动力学反应和“大脑激活”， 届

Project Summary/Abstract Recent evidence suggests that metabolic dysfunction is a crucial transdiagnostic risk factor for mental illness. Functional MRI (fMRI) measures hemodynamic changes related to metabolic shifts in the brain and could bridge a critical gap between biomarkers for mental illness and human experience and behavior; however, metabolic processes underlying the hemodynamic response have remained poorly understood. Before we can understand brain metabolic dysfunction in mental illness, we first need to understand brain metabolism during healthy cognitive function. A particular point of controversy is that the BOLD response to sensory signals and cognitive activity coincides with a substantial increase in glucose consumption, decoupled from increases in O2 metabolism. This process is called aerobic glycolysis. and its function remains disputed. We have developed a hypothesis from converging lines of neurophysiological evidence that clarifies how aerobic glycolysis serves an adaptive function in neuronal communication. The proposed research will contribute to basic science by advancing the methods and theory needed to measure and interpret task-based brain metabolic dynamics. We combine technical innovations in functional PET imaging (fPET) and dual-calibrated fMRI, to simultaneously measure absolute rates and task-based relative changes in regional glucose and O2 metabolism. Aim 1 evaluates the reliability of hybrid PET/fMRI method, within and across scan sessions, and against prior PET- derived estimates. Aim 2 tests a novel hypothesis about the role aerobic glycolysis plays in information transmission. We hypothesize that aerobic glycolysis supplements energy for communicating unpredictable sensory signals, i.e., prediction error. To test this, we will use a simple behavioral task, manipulating the predictability of auditory and visual stimuli, crossed with an attention manipulation between sensory streams. Aim 1 represents a critical advance in our ability to measure brain metabolic dynamics, as prior research has been limited to performing independent PET sessions. Aim 2 tests a key prediction in a broader theoretical framework, which has the potential to significantly reframe interpretations of existing fMRI research, recontextualizing the hemodynamic response and “brain activation” in explicit informational and metabolic terms.