title: Cerebral hemodynamic response to acute hyperoxia in awake mice.
abstract: Cerebral hemodynamic response to acute hyperoxia was investigated in awake mice. Using laser-Doppler flowmetry (LDF), baseline cerebral blood flow (CBF) and the cerebrovascular responses to whisker stimulation were measured in awake mice during normoxia and hyperoxia. Using two-photon laser scanning microscopy (TPLSM), the changes in cortical microvasculature were measured during normoxia and hyperoxia. During hyperoxia (PaO2=482.3±19.7mmHg), baseline CBF was 6.8% lower than normoxia (PaO2=97.3±6.0mmHg). The degree of increase in CBF evoked by whisker stimulation was greater during hyperoxia (18.1±5.0%) than normoxia (13.1±3.5%) (P<0.05). TPLSM imaging of the somatosensory cortex showed vasconstriction in arterioles and capillaries during hyperoxia. Since the effective diffusivity for oxygen in the capillary bed might decrease by hyperoxia due to a decrease in capillary blood volume according to Hyder׳s model, an increase in the cerebral metabolic rate of oxygen utilization by neural activation during hyperoxia might need a greater increase in CBF as compared with normoxia. The hemodynamic response to neural activation could be modified by acute hyperoxia due to modification of the relation between changes in CBF and oxygen consumption by neural activation.
authors: Department of Biophysics Program, Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, Japan; Department of Neurological Surgery, Chiba University Graduate School of Medicine, Chiba, Japan.
authors: Yosuke
authors: Y
authors: Tajima
authors: Department of Biophysics Program, Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, Japan.
authors: Hiroyuki
authors: H
authors: Takuwa
authors: Division of Thermo-Biosystem Relations, United Graduate School of Agricultural Science, Iwate University, Morioka, Japan.
authors: Asuka
authors: A
authors: Nishino
authors: Division of Thermo-Biosystem Relations, United Graduate School of Agricultural Science, Iwate University, Morioka, Japan.
authors: Tetsuya
authors: T
authors: Matsuura
authors: Department of Biophysics Program, Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, Japan.
authors: Hiroshi
authors: H
authors: Kawaguchi
authors: Department of Biophysics Program, Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, Japan.
authors: Yoko
authors: Y
authors: Ikoma
authors: Department of Biophysics Program, Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, Japan.
authors: Junko
authors: J
authors: Taniguchi
authors: Department of Biophysics Program, Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, Japan.
authors: Chie
authors: C
authors: Seki
authors: Department of Biophysics Program, Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, Japan; Center for Frontier Science and Engineering, University of Electro-Communications, Tokyo, Japan.
authors: Kazuto
authors: K
authors: Masamoto
authors: Department of Biophysics Program, Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, Japan.
authors: Iwao
authors: I
authors: Kanno
authors: Department of Neurological Surgery, Chiba University Graduate School of Medicine, Chiba, Japan.
authors: Naokatsu
authors: N
authors: Saeki
authors: Department of Biophysics Program, Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, Japan. Electronic address: hito@nirs.go.jp.
authors: Hiroshi
authors: H
authors: Ito
mesh_terms: D000208:Acute Disease; D000818:Animals; D001160:Arterioles / Q000503:physiopathology; D001784:Blood Gas Analysis; D001810:Blood Volume / Q000502:physiology; D002196:Capillaries / Q000503:physiopathology; D002560:Cerebrovascular Circulation / Q000502:physiology*; D018496:Hyperoxia / Q000503:physiopathology*; D017078:Laser-Doppler Flowmetry; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D010101:Oxygen Consumption / Q000502:physiology; D010812:Physical Stimulation; D013003:Somatosensory Cortex / Q000098:blood supply* / Q000503:physiopathology*; D055698:Touch Perception / Q000502:physiology*; D014661:Vasoconstriction / Q000502:physiology; D014738:Vibrissae / Q000502:physiology; D014851:Wakefulness / Q000502:physiology*
keywords: Acute hyperoxia; Cerebral blood flow; Mouse; Neural activation; Two-photon laser scanning microscopy