Multiwavelength optical intrinsic signal imaging of cortical spreading depression
Multiwavelength optical intrinsic signal imaging of cortical spreading depression
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DOI：
10.1152/jn.00729.2001
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发表时间：
2002-11-01
影响因子：
2.5
通讯作者：
Toga, AW
中科院分区：
文献类型：
--
作者：
Ba, AM;Guiou, M;Toga, AW
皮层扩散性抑制(cortical spreading depression，CSD)是研究偏头痛、脑梗塞等疾病的一种重要病理模型.在本研究中，我们利用光学成像的高时间和空间分辨率来表征CSD引起的灌注依赖性和非灌注依赖性变化，并研究CSD期间反射率变化的病因。在本实验中，我们在强调灌注相关变化的波长（610和550 nm）下表征了对CSD的光学响应，并将这些结果与850 nm和血液体积数据进行了比较。使用血管内荧光染料Texas Red右旋糖酐记录CSD期间的血容量变化。我们观察到850和550 nm处的三相光信号，其特征是反射率以大约3-5 mm/min的速率增大、减小、然后增大（图1）。610 nm处的信号具有相似的初始相位，但相位2反应稍微复杂一些，实质反射率减小，但血管反射率增大。在第三阶段，反射率值降低。血容量信号相对于光学固有信号延迟，并在时间上对应于阶段2和3。这是第一次研究，以表征光学成像的内在信号响应CSD，在体内，在多个波长。本文提供的数据表明，光散射的变化先于灌注反应，血容量增加（第2阶段）伴随着脱氧血红蛋白的减少，血容量减少（第3阶段）伴随着脱氧血红蛋白的增加。先前的研究表明，扩散性抑郁症的少血症是代谢需求减少的结果。这项研究表明，在血少期间，氧输送的减少比氧需求的减少更大。
Cortical spreading depression (CSD) is an important disease model for migraine and cerebral ischemia. In this study, we exploit the high temporal and spatial resolution of optical imaging to characterize perfusion-dependent and -independent changes in response to CSD and to investigate the etiology of reflectance changes during CSD. In this experiment, we characterized the optical response to CSD at wavelengths that emphasize perfusion-related changes (610 and 550 nm), and we compared these results with 850 nm and blood volume data. Blood volume changes during CSD were recorded using an intravascular fluorescent dye, Texas Red dextran. We observed triphasic optical signals at 850 and 550 nm characterized by spreading waves of increased, decreased, then increased reflectance (Fig. 1) which expanded at a rate of approximately 3-5 mm/min. The signal at 610 nm had a similar initial phase, but the phase 2 response was slightly more complex, with a parenchymal decrease in reflectance but a vascular increase in reflectance. Reflectance values decreased in phase three. Blood volume signals were delayed relative to the optical intrinsic signals and corresponded temporally to phases 2 and 3. This is the first study to characterize optical imaging of intrinsic signal responses to CSD, in vivo, at multiple wavelengths. The data presented here suggest that changes in light scattering precede perfusion responses, the blood volume increase (phase 2) is accompanied by a reduction in deoxyhemoglobin, and the blood volume decrease (phase 3) is accompanied by an increase in deoxyhemoglobin. Previous studies have suggested the oligemia of spreading depression was a result of decreased metabolic demand. This study suggests that during the oligemic period there is a greater reduction in oxygen delivery than in demand.