title: Dynamic diameter response of intraparenchymal penetrating arteries during cortical spreading depression and elimination of vasoreactivity to hypercapnia in anesthetized mice.
abstract: Cortical spreading depression (CSD) induces marked hyperemia with a transient decrease of regional cerebral blood flow (rCBF), followed by sustained oligemia. To further understand the microcirculatory mechanisms associated with CSD, we examined the temporal changes of diameter of intraparenchymal penetrating arteries during CSD. In urethane-anesthetized mice, the diameter of single penetrating arteries at three depths was measured using two-photon microscopy during passage of repeated CSD, with continuous recordings of direct current potential and rCBF. The first CSD elicited marked constriction superimposed on the upstrokes of profound dilation throughout each depth of the penetrating artery, and the vasoreaction temporally corresponded to the change of rCBF. Second or later CSD elicited marked dilation with little or no constriction phase throughout each depth, and the vasodilation also temporally corresponded to the increase of rCBF. Furthermore, the peak dilation showed good negative correlations with basal diameter and increase of rCBF. Vasodilation induced by 5% CO2inhalation was significantly suppressed after CSD passage at any depth as well as hyperperfusion. These results may indicate that CSD-induced rCBF changes mainly reflect the diametric changes of the intraparenchymal arteries, despite the elimination of responsiveness to hypercapnia.
authors.affiliation: 1 Department of Neurology, School of Medicine, Keio University, Tokyo, Japan.
authors.forename: Miyuki
authors.initials: M
authors.lastname: Unekawa
authors.affiliation: 1 Department of Neurology, School of Medicine, Keio University, Tokyo, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Tomita
authors.affiliation: 2 Brain Science Inspired Life Support Research Center, University of Electro-Communications, Chofu, Japan.|3 Molecular Imaging Center, National Institute of Radiological Sciences, Chiba, Japan.
authors.forename: Kazuto
authors.initials: K
authors.lastname: Masamoto
authors.affiliation: 1 Department of Neurology, School of Medicine, Keio University, Tokyo, Japan.
authors.forename: Haruki
authors.initials: H
authors.lastname: Toriumi
authors.affiliation: 1 Department of Neurology, School of Medicine, Keio University, Tokyo, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Osada
authors.affiliation: 3 Molecular Imaging Center, National Institute of Radiological Sciences, Chiba, Japan.
authors.forename: Iwao
authors.initials: I
authors.lastname: Kanno
authors.affiliation: 1 Department of Neurology, School of Medicine, Keio University, Tokyo, Japan.
authors.forename: Norihiro
authors.initials: N
authors.lastname: Suzuki
mesh_terms: D000818:Animals; D001158:Arteries / Q000033:anatomy & histology / Q000502:physiology / Q000503:physiopathology*; D002560:Cerebrovascular Circulation; D013181:Cortical Spreading Depression; D006935:Hypercapnia / Q000503:physiopathology*; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D008833:Microcirculation; D014664:Vasodilation
keywords: Cortical spreading depression; hypercapnia; microcirculation; penetrating artery; two-photon microscopy