IMAGING BRAIN BLOOD VESSELS DURING CORTICAL ACTIVITY

皮质活动期间脑血管成像

• 批准号: 2267173
• 负责人: THOMAS A WOOLSEY
• 金额: $ 21.22万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-09-21 至 2000-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2267173
• 关键词: arterioles; brain circulation; capillary; cardiovascular pharmacology; cerebral cortex; cerebrovascular imaging /visualization; cytochrome oxidase; direct cortical response; enzyme activity; glutamates; laboratory rat; microcirculation; neural transmission; neuroanatomy; neuropharmacology; neuropil; sectioning; ultrasound blood flow measurement; vascular smooth muscle nervous control; vasoconstriction; vasodilation; veins; video recording system

Local cerebral blood flow (LCBF) changes with stimulation of whiskers on the rat's face. Responses are related to individual functional columns of neurons of which the barrels in layer IV are a part. Vascular modules that correspond to cortical barrels have been demonstrated. The general hypothesis we will test is that vascular modules are anatomically coincident with and functionally linked to columns in the cerebral cortex. In particular, focal increases in neural activity stimulates capillaries from which signals propagate upstream through electrically coupled endothelium to relax arteriolar smooth muscle and to change LCBF depending on the activity of the neuropil. The experiments are designed to examine this hypothesis directly. We will: l) Characterize the local vascular responses to controlled stimulation of single whiskers or single whisker rows during in vivo videomicroscopy through closed cranial windows in rats by multiple quantitative dynamic parameters. This tests the hypothesis that stimulation of a single whisker increases flow in a single cerebral arteriole. 2) Define directly the vascular module by microperfusion of single terminal arterioles the vascular units of rat barrel cortex. This tests the hypothesis that a single cerebral arteriole supplies a single cortical barrel. And 3) Demonstrate neuron to vessel signalling mechanisms and propagation in cortical slices. This tests the hypotheses that active neural elements in layer IV barrels stimulate capillaries that then transmit signals through electrical coupling to arterioles for control of LCBF. We propose that conjoint neural and vascular modules: (a) provide an optimal mechanism for precise control of LCBF, (b) occur more generally in the brain, and (c) share common features of local microcirculation control with other capillary beds. Understanding this mechanism in the cerebral cortex will improve our appreciation of functional studies (PET, MRI) in normal individuals that depend on changes in LCBF and of microvascular occlusions in stroke.

局部脑血流（LCBF）随着刺激的刺激而变化 老鼠的脸。响应与单个功能列有关 其第四层中的桶中的神经元是一部分。血管模块 已经证明了与皮质桶相对应的。 我们将检验的一般假设是血管模块是 在解剖学上与并在功能上链接到该列中的列 大脑皮层。特别是，神经活动的局灶性增加 刺激毛细血管，从中信号传播到上游 电耦合内皮，放松小动脉平滑肌，然后 根据神经肽的活性更改LCBF。实验是 旨在直接检查该假设。 我们将：l）表征对受控的局部血管反应 体内刺激单晶须或单晶须行 通过多个大鼠闭合颅窗的视频显微镜检查 定量动态参数。这检验了以下假设 单个晶须的刺激会增加单个大脑中的流动 动脉。 2）通过微灌注直接定义血管模块 单末端动脉大鼠桶皮层的血管单位。这 测试单个大脑小动物提供单一的假设 皮质桶。 3）演示神经元对血管信号传导机制 和皮质切片中的传播。这检验了活跃的假设 第四层中的神经元素刺激毛细血管，然后 通过电耦合传输信号到小动脉以控制 LCBF。 我们提出了联合神经和血管模块：（a）提供 精确控制LCBF的最佳机制，（b）更普遍地发生在 大脑和（c）共享局部微循环控制的共同特征 与其他毛细管床。 了解大脑中的这种机制 皮层将改善我们对功能研究的欣赏（PET，MRI） 依赖LCBF和微血管变化的正常个体 中风中的闭合。