NEUROLOGICAL STUDIES

神经学研究

• 批准号: 6109361
• 负责人: MARCUS E RAICHLE
• 金额: --
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-07-01 至 1999-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6109361
• 关键词: anemia; behavioral /social science research tag; blood brain barrier; brain circulation; brain mapping; brain metabolism; cerebral cortex; cerebral ischemia /hypoxia; cerebrovascular imaging /visualization; clinical research; functional magnetic resonance imaging; human subject; language; memory; neurophysiology; perception; positron emission tomography; radiopharmacology

The overall objective of this work is to further our understanding of the relationship between changes in brain cellular activity, caused by the functional activity of the brain in neurologically normal humans, and changes in blood flow and metabolism. Everyone agrees that the resting brain metabolizes glucose aerobically as its main source of energy. On the basis it was assumed that changes in the activity of the brain would be accompanied by parallel changes in blood glow, glucose utilization and oxygen consumption. It came as a considerable surprise when work with positron emission tomography (PET), supported previously under this program project [Fox, 1986#18][Fox, 1988#19], revealed parallel changes in glucose utilization and blood flow unaccompanied by changes in oxygen consumption. This important observation has not only catalyzed a re- evaluation of these relationships but also provided the physiological rationale for functional mapping of the human brain with magnetic resonance imaging (MRI). Despite the immense interest in functional mapping of the brain, uncertainty surrounds our understanding of these functionally-induced metabolic and circulatory changes. This project addresses two central questions concerning that understanding. First, do the changes in blood flow exceed those of oxygen consumption simply to maintain adequate tissue oxygen. To answer this question we propose to examine blood flow responses as a function of oxygen availability. Second, if glucose is used but only metabolized to lactate, why don't tissue lactate levels adequately reflect the increased glycolysis? To answer this question we propose to determine whether lactate egress from brain is facilitated in areas of increased functional activity. These experiments will provide valuable new information on the relationship of brain functional activity to brain energy metabolism in neurologically normal humans and a sounder scientific basis for functional brain imaging with PET and fMRI.

这项工作的总体目标是加深我们对 脑细胞活动变化之间的关系 神经系统正常人的大脑功能活动，以及 血流量和新陈代谢的变化。大家都同意休息 大脑以有氧方式代谢葡萄糖作为其主要能量来源。上 假设大脑活动的变化是 伴随着血红、葡萄糖利用率和 氧气消耗量。当与我们一起工作时，这是一个相当大的惊喜 正电子发射断层扫描 (PET)，之前在此支持 计划项目 [Fox, 1986#18][Fox, 1988#19]，揭示了并行变化 葡萄糖利用率和血流量不伴随氧气的变化 消耗。这一重要的观察不仅催化了重新 对这些关系的评估还提供了生理学 用磁力绘制人脑功能图的基本原理 磁共振成像（MRI）。尽管人们对功能性抱有极大兴趣 大脑的映射，不确定性围绕着我们对这些的理解 功能引起的代谢和循环变化。这个项目 解决了与这种理解有关的两个核心问题。首先，做 血流量的变化超过耗氧量的变化只是为了 保持足够的组织氧。为了回答这个问题，我们建议 检查血流反应作为氧气可用性的函数。第二， 如果使用葡萄糖但仅代谢为乳酸，为什么组织不使用葡萄糖 乳酸水平充分反映了糖酵解的增加？为了回答这个问题 我们提出的问题是确定大脑中乳酸的排出是否是 促进功能活动增加的领域。这些实验 将提供有关大脑关系的有价值的新信息 神经功能正常时脑能量代谢的功能活动 人类和功能性脑成像的更健全的科学基础 PET 和功能磁共振成像。