Fig. 2.

Baseline ${\mathrm{CMRO}}_2$ measurements. (a–d) Tissue ${\mathrm{PO}}_2$ maps (color coded) around penetrating arterioles overlaid on the corresponding FITC images of microvasculature in different animals (rats I to IV). Insets show MIPs of FITC-labeled microvasculature. Arterioles in insets are colored red. The white rectangle in each insert outlines the position of the corresponding panel with the ${\mathrm{PO}}_2$ data. Yellow lines outline regions of interest with ${\mathrm{PO}}_2$ data included in the fitting procedure. Imaging depths below brain surface are $100\mu \mathrm{m}$ (rat I), $150\mu \mathrm{m}$ (rat II), $124\mu \mathrm{m}$ (rat III), and $160\mu \mathrm{m}$ (rat IV). Scale bars, $100\mu \mathrm{m}$. (e–h) Tissue ${\mathrm{PO}}_2$ from the corresponding upper panels as a function of the radial distance from the penetrating arteriole with ${\mathrm{PO}}_2$ fit indicated by solid line.