BOLD FMRI RESPONSE IS AN INDIRECT CONSEQUENCE OF CHANGES IN NEURONAL METABOLISM

大胆的 FMRI 反应是神经元代谢变化的间接结果

• 批准号: 7358764
• 负责人: Moriah E Thomason
• 金额: $ 2.49万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-06-01 至 2007-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7358764
• 关键词: BOLD; FMRI; RESPONSE; INDIRECT; CONSEQUENCE

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Many studies seek to draw quantitative inferences about various cognitive functions from measurements of the amplitude and temporal characteristics of the blood-oxygen level dependent (BOLD) response. However, the BOLD contrast is not a direct measure of metabolism but rather results from changes in regional blood flow and attendant alterations in oxygenation.. Thus, increased neuronal firing causes a cascade that culminates in a vasomotor reaction wherein blood flow is upregulated, i.e. metabolic increases cause a local, task-activation-initiated hemodynamic response that is characteristic not only of the neural activity but also the vascular reactivity. Because of this, it would be prudent to remove variations specific to within-subject or within-session hemodynamic response in order to improve specificity of cognitive inferences as well as to improve sensitivity of group measures. Global hypercapnia has been suggested for normalizing neural response between different subjects, different brain regions, and features of the scanning environment (acquisition parameters, field strength, etc. It is expected that BH can be used for normalization, or calibration of BOLD responsiveness, because BH-induced BOLD response is regionally specific and proportional to neural responses measured by BOLD. The present study uses BOLD effect measured in response to a minimally cognitive, hypercapnic challenge, i.e. a breath-holding task, to apply correction to a working memory (WM) cognitive task. The correction was performed within subjects on a voxel by voxel basis in order to reduce variance across subjects, while retaining regional specificity within our global correction. We expect that this form of hemodynamic response correction will provide an important contribution for between-group and longitudinal studies as well as for multi-center studies

该子项目是利用NIH/NCRR资助的中心赠款提供的资源的许多研究子项目之一。子项目和研究者（PI）可能从另一个NIH来源获得主要资金，因此可以在其他CRISP条目中表示。所列机构为中心机构，不一定为研究者机构。许多研究试图通过测量血氧水平依赖（BOLD）反应的幅度和时间特征来定量推断各种认知功能。然而，BOLD对比度不是代谢的直接测量，而是由局部血流的变化和伴随的氧合变化引起的。因此，增加的神经元放电引起级联反应，其在血管反应中达到高潮，其中血流被上调，即代谢增加引起局部的、任务激活启动的血液动力学反应，其不仅是神经活动的特征，而且是血管反应性的特征。因此，为了提高认知推断的特异性以及提高组测量的灵敏度，删除受试者内或疗程内血流动力学反应的特异性变化是谨慎的。已建议使用整体高碳酸血症来使不同受试者、不同脑区和扫描环境特征（采集参数、场强等）之间的神经反应正常化。预计BH可用于BOLD反应的正常化或校准，因为BH诱导的BOLD反应具有区域特异性，并与BOLD测量的神经反应成比例。本研究使用BOLD效应测量响应于最低认知，高碳酸血症的挑战，即屏气任务，适用于校正工作记忆（WM）认知任务。在受试者内逐体素进行校正，以减少受试者之间的方差，同时在我们的全局校正中保留区域特异性。我们期望这种形式的血流动力学反应校正将为组间和纵向研究以及多中心研究提供重要贡献