Biophysics Program, Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Chiba 263-8555, Japan.
Brain Res. 2012 Sep 7;1472:107-12. doi: 10.1016/j.brainres.2012.06.049. Epub 2012 Jul 10.
Elucidating the mechanisms underlying the regulation of cerebral blood flow (CBF) is important to understanding the hemodynamic changes measured by positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) signals. The purpose of this study was to explore changes in hemodynamic characteristics during resting and sensory stimulation in awake animals as compared with those in anesthetized animals. Changes in CBF, red blood cell (RBC) velocity and concentration in the somatosensory cortex to whisker stimulation were measured using laser-Doppler flowmetry in awake and anesthetized mice. The increase in the rate of RBC velocity change observed during whisker stimulation was far greater than the increase in the rate of RBC concentration change under the awake condition. During the resting condition, significant differences in baseline CBF, RBC velocity and concentration between awake and anesthesia mice were not observed. Isoflurane-induced anesthesia attenuated the increase in RBC velocity and concentration during stimulation, with the attenuation of the RBC velocity increase being greater than that of RBC concentration. The RBC measurement techniques in awake animals should lead to much better understanding of the hemodynamic system evoked by neural activity.
阐明脑血流 (CBF) 调节的机制对于理解正电子发射断层扫描 (PET) 和功能磁共振成像 (fMRI) 信号所测量的血流动力学变化非常重要。本研究旨在探讨清醒动物与麻醉动物相比，在休息和感觉刺激期间血液动力学特征的变化。使用激光多普勒血流仪测量清醒和麻醉小鼠体感皮层对胡须刺激时的 CBF、红细胞 (RBC) 速度和浓度变化。在胡须刺激期间观察到的 RBC 速度变化率的增加远远大于清醒状态下 RBC 浓度变化率的增加。在休息状态下，未观察到清醒和麻醉小鼠之间的基础 CBF、RBC 速度和浓度存在显著差异。异氟烷诱导的麻醉减弱了刺激期间 RBC 速度和浓度的增加，RBC 速度的增加减弱程度大于 RBC 浓度的增加。清醒动物的 RBC 测量技术应能更好地理解神经活动引起的血液动力学系统。
