title: Robust and fragile aspects of cortical blood flow in relation to the underlying angioarchitecture.
abstract: We review the organizational principles of the cortical vasculature and the underlying patterns of blood flow under normal conditions and in response to occlusion of single vessels. The cortex is sourced by a two-dimensional network of pial arterioles that feeds a three-dimensional network of subsurface microvessels in close proximity to neurons and glia. Blood flow within the surface and subsurface networks is largely insensitive to occlusion of a single vessel within either network. However, the penetrating arterioles that connect the pial network to the subsurface network are bottlenecks to flow; occlusion of even a single penetrating arteriole results in the death of a 500 μm diameter cylinder of cortical tissue despite the potential for collateral flow through microvessels. This pattern of flow is consistent with that calculated from a full reconstruction of the angioarchitecture. Conceptually, collateral flow is insufficient to compensate for the occlusion of a penetrating arteriole because penetrating venules act as shunts of blood that flows through collaterals. Future directions that stem from the analysis of the angioarchitecture concern cellular-level issues, in particular the regulation of blood flow within the subsurface microvascular network, and system-level issues, in particular the role of penetrating arteriole occlusions in human cognitive impairment.
authors.affiliation: Department of Neurosciences, Medical University of South Carolina, Charleston, SC.
authors.forename: Andy Y
authors.initials: AY
authors.lastname: Shih
authors.affiliation: Department of Physics, University of California at San Diego, La Jolla, CA.
authors.forename: Charlotta
authors.initials: C
authors.lastname: Rühlmann
authors.affiliation: Department of Neurobiology, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Pablo
authors.initials: P
authors.lastname: Blinder
authors.affiliation: Department of Neurosciences, University of California School of Medicine, La Jolla, CA.
authors.forename: Anna
authors.initials: A
authors.lastname: Devor
authors.affiliation: Department of Engineering Science and Mechanics, Pennsylvania State University, University Park, PA.
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Drew
authors.affiliation: Department of Pharmacology, University of California School of Medicine, La Jolla, CA.
authors.forename: Beth
authors.initials: B
authors.lastname: Friedman
authors.affiliation: Department of Physics, University of California at San Diego, La Jolla, CA.
authors.forename: Per M
authors.initials: PM
authors.lastname: Knutsen
authors.affiliation: Department of Neurology, Cedars-Sinai Hospital, Los Angeles, CA.
authors.forename: Patrick D
authors.initials: PD
authors.lastname: Lyden
authors.affiliation: Department of Physics, University of California at San Diego, La Jolla, CA.
authors.forename: Celine
authors.initials: C
authors.lastname: Mateo
authors.affiliation: Department of Physics, University of California at San Diego, La Jolla, CA.
authors.forename: Lisa
authors.initials: L
authors.lastname: Mellander
authors.affiliation: Department of Biomedical Engineering, Cornell University, Ithaca, NY.
authors.forename: Nozomi
authors.initials: N
authors.lastname: Nishimura
authors.affiliation: Department of Biomedical Engineering, Cornell University, Ithaca, NY.
authors.forename: Chris B
authors.initials: CB
authors.lastname: Schaffer
authors.affiliation: Department of Physics, University of California at San Diego, La Jolla, CA.
authors.forename: Philbert S
authors.initials: PS
authors.lastname: Tsai
authors.affiliation: Department of Physics, University of California at San Diego, La Jolla, CA.|Section of Neurobiology, University of California, La Jolla, CA.
authors.forename: David
authors.initials: D
authors.lastname: Kleinfeld
mesh_terms: D000818:Animals; D001160:Arterioles / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D002540:Cerebral Cortex / Q000098:blood supply* / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D002560:Cerebrovascular Circulation; D006801:Humans; D008833:Microcirculation; D009457:Neuroglia / Q000378:metabolism / Q000473:pathology; D009474:Neurons / Q000378:metabolism / Q000473:pathology
keywords: imaging; microvessels; penetrating vessels; pial vessels; rodent