Date of download: 6/24/2016 Copyright © ASME. All rights reserved. From: Oxygen Transport in Brain Tissue J Biomech Eng. 2009;131(7): doi: / Time-relationships of the neural activity induced changes among the cerebral blood flow (light gray), tissue pO2 (dark gray), and estimated oxygen supply (black) (data modified from Masamoto ). The CBF and tissue pO2 were simultaneously recorded with laser Doppler flowmetry (LDF) and polarographic microelectrode, respectively, in anesthetized rat somatosensory cortex, while the sensory stimulation (black bar) was induced for 2 s. Note that the estimated supply of oxygen was expected to lag behind the increase in demand due to a lag in the CBF onset (light gray box) and the diffusion time for oxygen (dark gray box). Figure Legend:

Date of download: 6/24/2016 Copyright © ASME. All rights reserved. From: Oxygen Transport in Brain Tissue J Biomech Eng. 2009;131(7): doi: / The dynamic comparisons of relative changes in tissue pO2 induced by tissue oxygen supply (black) and oxygen demand (dark gray) (data modified from Masamoto, ). Based on the actual measurement of tissue pO2 with polarographic microelectrodes under the normal CBF condition (light gray) and suppressed CBF condition (dark gray), the tissue oxygen supply induced by normal CBF (gray) was estimated. The 10-s stimulation induced 14 mmHg increase in tissue pO2 by the increase in supply and 5 mm Hg decrease in tissue pO2 by the increase in demand, while the CBF and CMRO2 increase 48% and 10% from the baseline, respectively. Note that the 2.5 times larger increase in oxygen supply was maintained relative to the pO2 change induced by evoked CMRO2. Figure Legend:

Date of download: 6/24/2016 Copyright © ASME. All rights reserved. From: Oxygen Transport in Brain Tissue J Biomech Eng. 2009;131(7): doi: / Microvascular structure in rat somatosensory cortex (X-Y projection image). The image was obtained with in vivo two-photon microscopy. The blood plasma was fluorescently labeled with Qdot 605. Figure Legend:

Date of download: 6/24/2016 Copyright © ASME. All rights reserved. From: Oxygen Transport in Brain Tissue J Biomech Eng. 2009;131(7): doi: / Estimated pO2 distribution based on the geometry of one cerebral arteriole (black circle) and randomly-distributed capillaries (black bar). The images were represented for the spatial distribution of tissue pO2 at different layers (depths of 50 μm, 150 μm, and 500 μm). The gray scale indicates tissue pO2 level. Figure Legend: