Department of Integrated Design Engineering, Keio University, Yokohama, Japan.
Molecular Imaging Center, National Institute of Radiological Sciences, Chiba, Japan.
Adv Exp Med Biol. 2013;789:419-425. doi: 10.1007/978-1-4614-7411-1_56.
The present study reports a semiautomatic image analysis method for measuring the spatiotemporal dynamics of the vessel dilation that was fluorescently imaged with either confocal or two-photon microscope. With this method, arterial dilation induced by whisker stimulation was compared between cortical surface and parenchymal tissue in the vibrissae area of somatosensory cortex in awake Tie2-GFP mice in which the vascular endothelium had genetically expressed green fluorescent protein. We observed that a mean arterial diameter during a pre-stimulus baseline state was 39 ± 7, 19 ± 1, 16 ± 4, 17 ± 4, and 14 ± 3 μm at depths of 0, 100, 200, 300, and 400 μm, respectively. The stimulation-evoked dilation induced by mechanical whisker deflection (10 Hz for 5 s) was 3.4 ± 0.8, 1.8 ± 0.8, 1.8 ± 0.9, 1.6 ± 0.9, and 1.5 ± 0.6 μm at each depth, respectively. Consequently, no significant differences were observed for the vessel dilation rate between the cortical surface and parenchymal arteries: 8.8 %, 9.9 %, 10.9 %, 9.2 %, and 10.3 % relative to their baseline diameters, respectively. These preliminary results demonstrate that the present method is useful to further investigate the quantitative relationships between the spatiotemporally varying arterial tone and the associated blood flow changes in the parenchymal microcirculation to reveal the regulatory mechanism of the cerebral blood flow.
本研究报告了一种半自动图像分析方法，用于测量用共聚焦或双光子显微镜荧光成像的血管扩张的时空动力学。使用该方法，在清醒的 Tie2-GFP 小鼠（其血管内皮细胞中遗传表达了绿色荧光蛋白）的体感皮层胡须刺激区域，比较了皮质表面和实质组织中动脉扩张。我们观察到，在刺激前基线状态下，平均动脉直径在 0、100、200、300 和 400μm 的深度处分别为 39±7、19±1、16±4、17±4 和 14±3μm。机械胡须偏折（10Hz 持续 5s）引起的刺激诱发扩张分别为 3.4±0.8、1.8±0.8、1.8±0.9、1.6±0.9 和 1.5±0.6μm。因此，在皮质表面和实质动脉之间，血管扩张率没有显著差异：相对于基线直径，分别为 8.8%、9.9%、10.9%、9.2%和 10.3%。这些初步结果表明，该方法有助于进一步研究时空变化的动脉张力与脑实质微循环中相关血流变化之间的定量关系，从而揭示脑血流的调节机制。
