title: Two-photon imaging of cortical surface microvessels reveals a robust redistribution in blood flow after vascular occlusion.
abstract: A highly interconnected network of arterioles overlies mammalian cortex to route blood to the cortical mantle. Here we test if this angioarchitecture can ensure that the supply of blood is redistributed after vascular occlusion. We use rodent parietal cortex as a model system and image the flow of red blood cells in individual microvessels. Changes in flow are quantified in response to photothrombotic occlusions to individual pial arterioles as well as to physical occlusions of the middle cerebral artery (MCA), the primary source of blood to this network. We observe that perfusion is rapidly reestablished at the first branch downstream from a photothrombotic occlusion through a reversal in flow in one vessel. More distal downstream arterioles also show reversals in flow. Further, occlusion of the MCA leads to reversals in flow through approximately half of the downstream but distant arterioles. Thus the cortical arteriolar network supports collateral flow that may mitigate the effects of vessel obstruction, as may occur secondary to neurovascular pathology.
authors.affiliation: Department of Physics, University of California San Diego, La Jolla, California, USA.
authors.forename: Chris B
authors.initials: CB
authors.lastname: Schaffer
authors.forename: Beth
authors.initials: B
authors.lastname: Friedman
authors.forename: Nozomi
authors.initials: N
authors.lastname: Nishimura
authors.forename: Lee F
authors.initials: LF
authors.lastname: Schroeder
authors.forename: Philbert S
authors.initials: PS
authors.lastname: Tsai
authors.forename: Ford F
authors.initials: FF
authors.lastname: Ebner
authors.forename: Patrick D
authors.initials: PD
authors.lastname: Lyden
authors.forename: David
authors.initials: D
authors.lastname: Kleinfeld
mesh_terms: D000818:Animals; D005260:Female; D008297:Male; D018384:Oxidative Stress; D051381:Rats; D017207:Rats, Sprague-Dawley; D014055:Tomography, Emission-Computed; D014652:Vascular Diseases / Q000097:blood* / Q000473:pathology / Q000503:physiopathology*