MICROELECTRODE AND BLOOD FLOW STUDIES IN OPTIC NERVE

描述：这个项目的长期目标是获得洞察力 探讨一氧化氮(NO)在调节血液流向心脏的多种作用 视神经头(ONH)，神经元活动与氧气消耗的耦合， 以及与高碳酸血症血管扩张的相互作用。潜在的破坏性角色 NO和过氧亚硝酸盐也将被研究，使用组织 亚硝酸化作为损伤的标志。单管和双管NO和PO2 微型传感器将用于猫眼测量局部化学物质 浓度及其随不同代谢需求和 血液流动受阻。一种非侵入式光学测量方法 ONH中的血管内PO2将被磷光猝灭 集成到现有的基于显微镜的红外激光系统中 激光多普勒流量计(LDF)。这将允许同时使用NO、PO2和 要测量的相对红细胞流量(血流量)。另一种方法 用体内血红蛋白捕捉法测定基础NO水平 将使用微透析。体内微透析技术也将被 用于测量ONH附近玻璃体体液中的其他基质，并在 视网膜附近的其他部位，与NO在 神经毒性事件。这些研究对于理解ONH是如何 血流是在正常生理条件下调节的，是什么 在以下情况下，情况可以将正常的NO神经保护作用逆转为1 可能会发生损坏。预计这些研究将提供洞察力 进入正常的生理过程和病理状态 与青光眼和神经退行性疾病有关。

DESCRIPTION: The long term objective of this project is to gain insight into the multiple roles of nitric oxide (NO) in regulating blood flow to the optic nerve head (ONH), coupling of neuronal activity with O2 consumption, and interaction with hypercapnic vasodilation. Potentially damaging roles of NO and peroxynitrite will also be investigated, using tissue nitrosylation as a marker of damage. Single and double barrel NO and PO2 microsensors will be used in the cat eye to measure local chemical concentrations and their variations with varying metabolic demand and with impaired blood flow. A noninvasive optical method of measuring intravascular PO2 in the ONH by phosphorescence quenching will be incorporated into the existing microscope-based infrared laser system for laser Doppler flowmetry (LDF). This will allow simultaneous NO, PO2 and relative red blood cell flux (blood flow) to be measured. Another method for quantifying basal NO levels using hemoglobin trapping with in vivo microdialysis will be used. In vivo microdialysis techniques will also be used to measure other substrates in the vitreous humor near the ONH, and at other sites near the retina, that are relevant to the role of NO in neurotoxic events. These studies are important for understanding how ONH blood flow is regulated under normal physiological conditions, and what conditions can reverse the normally neuroprotective role of NO to one where damage can occur. It is expected that these studies will provide insight into both normal physiological processes and pathological conditions relevant to glaucoma and neurodegenerative diseases.