PDF(Pubmed)
Abstract：
Sensory stimulation evokes a local, vasodilation-mediated blood flow increase to the activated brain region, which is referred to as functional hyperemia. Spontaneous vasomotion is a change in arteriolar diameter that occurs without sensory stimulation, at low frequency (∼0.1 Hz). These vessel diameter changes are a driving force for perivascular soluble waste clearance, the failure of which has been implicated in neurodegenerative disease. Stimulus-evoked vascular reactivity is known to propagate along penetrating arterioles to pial arterioles, but it is unclear whether spontaneous vasomotion propagates similarly. We therefore imaged both stimulus-evoked and spontaneous changes in pial arteriole diameter in awake, head-fixed mice with 2-photon microscopy. By cross-correlating different regions of interest (ROIs) along the length of imaged arterioles, we assessed vasomotion propagation. We found that both during rest and during visual stimulation, one-third of the arterioles showed significant propagation (i.e., a wave), with a median (interquartile range) wave speed of 405 (323) µm/s at rest and 345 (177) µm/s during stimulation. In a second group of mice, with GCaMP expression in their vascular smooth muscle cells, we also found spontaneous propagation of calcium signaling along pial arterioles. In summary, we demonstrate that spontaneous vasomotion propagates along pial arterioles like stimulus-evoked vascular reactivity.
摘要：
感觉刺激唤起了当地人，血管舒张介导的血流增加到激活的大脑区域，这被称为功能性充血。自发性血管舒缩是在没有感觉刺激的情况下发生的小动脉直径的变化，在低频下(~0.1Hz)。这些血管直径变化是血管周围可溶性废物清除的驱动力，其失败与神经退行性疾病有关。已知刺激诱发的血管反应性沿穿透小动脉传播到小动脉，但尚不清楚自发性血管舒缩是否有类似的传播。因此，我们在清醒时对刺激诱发的和自发的小动脉直径变化进行了成像，头部固定的小鼠与双光子显微镜。通过沿着成像小动脉的长度交叉关联不同的感兴趣区域(ROI)，我们评估了血管舒缩的传播。我们发现在休息和视觉刺激期间，三分之一的小动脉显示出显着的传播(即，awave),静态时的中值（四分位数范围）波速为405（323）µm/s，刺激期间为345（177）µm/s。在第二组小鼠中，在他们的血管平滑肌细胞中表达GCaMP，我们还发现钙信号沿软脑膜小动脉自发传播。总之,我们证明了自发性血管舒缩沿着小动脉传播，类似于刺激诱发的血管反应性。
