IMAGING BRAIN BLOOD VESSELS DURING CORTICAL ACTIVITY

皮质活动期间脑血管成像

• 批准号: 2735604
• 负责人: THOMAS A WOOLSEY
• 金额: $ 24.18万
• 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/2735604
• 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; vibrissae; 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.

局部脑血流量（LCBF）的变化与胡须刺激， 老鼠的脸。响应与 第四层的桶是神经元的一部分。血管模块， 已经证明了与皮质桶相对应。 我们将检验的一般假设是，血管模块 在解剖学上与柱一致，在功能上与柱相连， 大脑皮层特别是神经活动的局部增加 刺激毛细血管，信号从毛细血管向上游传播， 电偶联内皮以松弛小动脉平滑肌， 根据神经元的活动改变LCBF。了实验 旨在直接检验这一假设。 我们将：l）表征局部血管对受控的 在体内过程中刺激单个晶须或单个晶须行 在大鼠中通过多个闭合的颅窗进行视频显微镜检查 定量动力学参数这验证了一个假设， 刺激一根触须会增加一个大脑中的血流 小动脉2)通过微灌注直接定义血管模块 单个终末小动脉是大鼠桶状皮质的血管单位。这 测试了一个单一的大脑小动脉供应一个单一的假设 皮质桶以及3）展示神经元到血管的信号传导机制 以及在皮层切片中的传播。这验证了一个假设， 第四层桶中的神经元件刺激毛细血管， 通过电耦合将信号传输到小动脉以控制 LCBF。 我们提出，联合神经和血管模块：（a）提供一个 精确控制LCBF的最佳机制，（B）更普遍地出现在 大脑，和（c）共享局部微循环控制的共同特征 与其他毛细血管床。 了解大脑中的这种机制 皮质将提高我们对功能研究（PET，MRI）的认识， 正常人依赖于LCBF和微血管的变化， 中风时的闭塞