Vérant Pascale, Serduc Raphaël, Van Der Sanden Boudewijn, Rémy Chantal, Vial Jean-Claude
CNRS, UMR5588, Laboratoire de Spectrométrie Physique, Grenoble, France.
J Cereb Blood Flow Metab. 2007 May;27(5):1072-81. doi: 10.1038/sj.jcbfm.9600415. Epub 2006 Oct 25.
Knowledge of the blood volume per unit volume of brain tissue is important for understanding brain function in health and disease. We describe a direct method using two-photon laser scanning microscopy to obtain in vivo the local capillary blood volume in the cortex of anesthetized mouse. We infused fluorescent dyes in the circulating blood and imaged the blood vessels, including the capillaries, to a depth of 600 microm below the dura at the brain surface. Capillary cortical blood volume (CCBV) was calculated without any form recognition and segmentation, by normalizing the total fluorescence measured at each depth and integrating the collected intensities all over the stack. Theoretical justifications are presented and numerical simulations were performed to validate this method which was weakly sensitive to background noise. Then, CCBV had been estimated on seven healthy mice between 2%+/-0.3% and 2.4%+/-0.4%. We showed that this measure of CCBV is reproductible and that this method is highly sensitive to the explored zones in the cortex (vessel density and size). This method, which dispenses with form recognition, is rapid and would allow to study in vivo temporal and highly resolute spatial variations of CCBV under different conditions or stimulations.
了解单位体积脑组织的血容量对于理解健康和疾病状态下的脑功能至关重要。我们描述了一种使用双光子激光扫描显微镜的直接方法，用于在活体状态下获取麻醉小鼠皮质中的局部毛细血管血容量。我们将荧光染料注入循环血液中，并对包括毛细血管在内的血管进行成像，成像深度可达脑表面硬脑膜下方600微米。通过对每个深度处测量的总荧光进行归一化，并对整个堆栈收集的强度进行积分，在无需任何形式识别和分割的情况下计算毛细血管皮质血容量（CCBV）。给出了理论依据并进行了数值模拟，以验证该方法对背景噪声敏感度较低。然后，在7只健康小鼠上估计出CCBV在2%±0.3%至2.4%±0.4%之间。我们表明，这种CCBV测量方法具有可重复性，并且该方法对皮质中的探索区域（血管密度和大小）高度敏感。这种无需形式识别的方法快速，并且能够在不同条件或刺激下研究CCBV的活体时间和高分辨率空间变化。
