title: Vasodynamics of pial and penetrating arterioles in relation to arteriolo-arteriolar anastomosis after focal stroke.
abstract: Changes in blood perfusion in highly interconnected pial arterioles provide important insights about the vascular response to ischemia within brain. The functional role of arteriolo-arteriolar anastomosis (AAA) in regulating blood perfusion through penetrating arterioles is yet to be discovered. We apply a label-free optical microangiography (OMAG) technique to evaluate the changes in vessel lumen diameter and red blood cell velocity among a large number of pial and penetrating arterioles within AAA abundant region overlaying the penumbra in the parietal cortex after a middle cerebral artery occlusion (MCAO). In comparison with two-photon microscopy, the OMAG technique makes it possible to image a large number of vessels in a short period of time without administering exogenous contrast agents during a time-constrained MCAO experiment. We compare vasodynamics in penetrating arterioles at various locations. The results show that the MCA connected penetrating arterioles close to a strong AAA dilate, while those belonging to a region away from AAAs constrict in various degrees. These results suggest AAAs play a major role in supporting the active dilation of the penetrating arterioles, thus compensating a significant amount of blood to the ischemic region, whereas the poor blood perfusion occurs at the regions away from AAA connections, leading to ischemia.
authors.affiliation: University of Washington , Department of Bioengineering, 3720 NE 15th Avenue, Seattle, Washington 98195, United States ; University of Washington , Department of Electrical Engineering, 185 Stevens Way, Seattle, Washington 98195, United States.
authors.forename: Utku
authors.initials: U
authors.lastname: Baran
authors.affiliation: University of Washington , Department of Bioengineering, 3720 NE 15th Avenue, Seattle, Washington 98195, United States.
authors.forename: Yuandong
authors.initials: Y
authors.lastname: Li
authors.affiliation: University of Washington , Department of Bioengineering, 3720 NE 15th Avenue, Seattle, Washington 98195, United States.
authors.forename: Ruikang K
authors.initials: RK
authors.lastname: Wang
keywords: arteriolo-arteriolar anastomosis; middle cerebral artery occlusion; optical coherence tomography; optical microangiography; stroke