title: Cortical microcirculatory disturbance in the super acute phase of subarachnoid hemorrhage - In vivo analysis using two-photon laser scanning microscopy.
abstract: OBJECTIVE
  Subarachnoid hemorrhage (SAH) causes cerebral ischemia and drastically worsens the clinical status at onset. However, the arterial flow is surprisingly well maintained on the cerebral surface. We investigated cortical microcirculatory changes in the super acute phase of SAH using two-photon laser scanning microscopy (TPLSM).
  
  
  METHODS
  SAH was induced at the skull base in 10 mice using a prone endovascular perforation model. Before SAH, and 1, 2, 5, 10, 20, 30 and 60min after SAH, the cortical microcirculation was observed with TPLSM through a cranial window. Diameters of penetrating and precapillary arterioles were measured and red blood cell (RBC) velocities in precapillary arterioles were analyzed using a line-scan method after administration of Q-dot 655 nanocrystals.
  
  
  RESULTS
  One minute after SAH, RBC velocity and flow in precapillary arterioles drastically decreased to <20% of the pre-SAH values, while penetrating and precapillary arterioles dilated significantly. Subsequently, the arterioles either dilated or constricted inconsistently for 60min with continual decreases in RBC velocity and flow in the arterioles, suggesting neurovascular dysfunction.
  
  
  CONCLUSIONS
  SAH caused sudden worsening of the cortical arteriolar velocity and flow at onset. The neurovascular unit cannot function sufficiently to maintain cortical microcirculatory flow in the super acute phase of SAH.
authors.affiliation: Department of Neurosurgery, Saitama Medical Center, Jichi Medical University, Japan; Department of Biochemistry School of Medicine, Keio University, Japan. Electronic address: m.ishikawa@jichi.ac.jp.
authors.forename: Mami
authors.initials: M
authors.lastname: Ishikawa
authors.affiliation: Department of Biochemistry School of Medicine, Keio University, Japan.
authors.forename: Mayumi
authors.initials: M
authors.lastname: Kajimura
authors.affiliation: Department of Biochemistry School of Medicine, Keio University, Japan; Department of Stem Cell Biology, Research Institute, National Center for Global Health and Medicine, Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Morikawa
authors.affiliation: Graduate School of Science and Technology, Keio University, Japan.
authors.forename: Kosuke
authors.initials: K
authors.lastname: Tsukada
authors.affiliation: Department of Biochemistry School of Medicine, Keio University, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Tsuji
authors.affiliation: Department of Neurosurgery, Saitama Medical Center, Jichi Medical University, Japan.
authors.forename: Gen
authors.initials: G
authors.lastname: Kusaka
authors.affiliation: Department of Neurosurgery, Saitama Medical Center, Jichi Medical University, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Tanaka
authors.affiliation: Department of Biochemistry School of Medicine, Keio University, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Suematsu
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001253:Astrocytes / Q000378:metabolism; D002540:Cerebral Cortex / Q000098:blood supply* / Q000000981:diagnostic imaging / Q000473:pathology; D002560:Cerebrovascular Circulation / Q000502:physiology*; D004195:Disease Models, Animal; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D021621:Imaging, Three-Dimensional; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D008833:Microcirculation; D018613:Microscopy, Confocal; D013345:Subarachnoid Hemorrhage / Q000000981:diagnostic imaging / Q000473:pathology*; D013997:Time Factors
chemical_list: D049452:Green Fluorescent Proteins
keywords: Ischemia; Microcirculation; Neurovascular function; Subarachnoid hemorrhage; Vasodilation