High-resolution vasomotion analysis reveals novel venous physiological features and progressive modulation of cerebral vascular networks by stroke

Spontaneous cerebral vasomotion, characterized by ~0.1 Hz rhythmic contractility, is crucial for brain homeostasis. However, our understanding of vasomotion is limited due to a lack of high-precision analytical methods to determine single vasomotion events at basal levels. Here, we developed a novel strategy that integrates a baseline smoothing algorithm, allowing precise measurements of vasodynamics and concomitant Ca2+ dynamics in mouse cerebrovasculature imaged by two-photon microscopy. We identified several previously unrecognized vasomotion properties under different physiological and pathological conditions especially in ischemic stroke which is a frequently occurring and highly harmful brain disease result in brain damage and significant neurological impairments that originates from vessel occlusion. First, venules exhibit motion with a ~0.1-Hz peak in the power spectrum; energy at this frequency is depleted by anesthetics, signifying a novel aspect of venule physiology related to basal neural activity. Second, compared to previous diameter-based estimations, our radius-based measurements reveal nonisotropic vascular movements, enabling a more precise determination of the latency between smooth muscle cell (SMC) Ca2+ activity and vasocontraction. Third, Ca2+ dynamics were larger in venular pericytes than in arteriolar SMCs while unrelated to venule vasomotion. Fourth, we characterized single vasomotion event kinetics at scales of less than 4 seconds. Finally, following pathological vasoconstrictions induced by ischemic stroke, vasoactive arterioles transitioned to an inert state and persisted despite recanalization. In summary, we developed a highly accurate technique for analyzing spontaneous vasomotion, and we suggest a potential strategy to reduce stroke damage by promoting vasomotion recovery. ### Competing Interest Statement The authors have declared no competing interest.