Investigation of the retinal neurovascular networks through modulation of blood oxygen levels in humans

简介：人类视网膜由神经元组成，将视觉信息传递到大脑。需要将氧有效地分布到视网膜的不同层以支持它们的结构和功能完整性。视网膜和脉络膜血管确保适当的氧气分配到神经组织。向组织的氧气输送强烈依赖于动脉氧浓度。在实验上，可以通过改变吸入空气中的氧气或二氧化碳浓度来改变动脉氧水平。目的：为了量化视网膜神经元及其血液供应对血液中正常氧浓度变化的反应性变化。科学方法：将通过闪光视网膜电图a波、b波和振荡电位以及图形诱发视网膜电图无创监测代表主要视网膜神经元活动的生物电反应。将使用专用系统记录视网膜中的全局和局灶性血流以及离散血管和毛细血管床中的血流。这些测量将在氧合动脉血程度改变期间进行。预期意义：这项研究将提供新的见解，正常的视网膜功能的依赖程度上的血液灌注解剖学上不同的视网膜层的氧合。如果我们要了解血管在视网膜疾病中的作用，特别是那些与视网膜缺血相关的疾病，这些知识是必不可少的。

Introduction: The human retina is comprised of neurons that relay visual information to the brain. An effective distribution of oxygen to the different layers of the retina is required to support their structural and functional integrity. The retinal and choroidal vasculatures insure proper oxygen distribution to neural tissue. Oxygen delivery to a tissue is strongly dependent on the arterial oxygen concentration. Experimentally, it is possible to modify the arterial oxygen level by modifying the oxygen or carbon dioxide concentrations in inspired air. Objective: To quantify changes in the responsiveness of retinal neurons and their blood supply to carefully controlled changes in the normal concentration of oxygen in blood. Scientific approach: The bio-electrical responses representing the activity of the principal retinal neurons will be monitored non-invasively through the flash electroretinogram a-wave, b-wave and oscillatory potentials, as well as the pattern evoked electroretinogram. Global and focal blood flow in the retina, and blood flow in discrete vessels and capillary beds will be recorded with dedicated systems. These measurements will be carried out during alterations in the degree of oxygenated arterial blood. Expected significance: This research will provide new insights into the dependence of normal retinal function on the degree of oxygenation in the blood perfusing the anatomically distinct retinal layers. This knowledge is essential if we are to understand the vascular role in retinal diseases, particularly those associated with retinal ischemia.