Spatial and temporal cerebral vasodynamic response with Farid Atry
Regional blood supply in the brain is tightly correlated with the level of local neuronal activity. This is vital for the proper function and health of the brain. While cerebral vascular networks distribute blood flow across the cerebrum the details of their dynamics during neuronal activity are not fully understood. We have developed an all-optical platform that utilizes optogenetics and high speed optical coherence tomography to further our understandings of different aspects of vascular response to local neurostimulation. This platform enables us to monitor blood flow, blood velocity, and diameter in the vessels of interest while directly modulating neural activity of the cerebral cortex in transgenic lab animals with desired spatial and temporal patterns. Our observations demonstrated a biphasic vascular response which consists of a transient early peak followed by a late prolonged increase in the blood flow. The maximum blood flow increase in a vessel happened when activity was at the center of its feeding territory. However, stimulus far from a vessel can reduced its blood flow and velocity while causing dilation in the same vessel. We also measured the spatial extent of the correlation between neural activity and the response of pial vessels. At the end, we demonstrated the ability of this system to actively control the vascular blood flow in the brain through dynamic adjustments to photostimulation.