Figure 1: Inversion of neurovascular coupling in cortical brain slices from SAH model animals. (a) (Upper) Infrared-differential interference contrast images from brain slices of control, sham-operated, and SAH model rats before/after electrical field stimulation (EFS). Parenchymal arterioles were preconstricted with U46619 (100 nM). Dashed lines in red display the intraluminal diameter of parenchymal arterioles. Overlapping pseudocolor-mapped Ca2+ levels in astrocyte endfeet were obtained by simultaneous imaging using the fluorescent Ca2+ indicator fluo-4 and two-photon microscopy. Scale bar: 10 μm. (Lower) Simultaneous recordings of EFS-induced changes in diameter and estimated endfoot Ca2+ concentrations obtained from brain slices depicted in upper images. (b)–(d) Summary data of EFS-evoked changes in arteriolar diameter and astrocytic endfoot Ca2+ obtained from control (), sham-operated (), and SAH model () animals. Diameter changes were expressed as percentage of the diameter in the same point before EFS as 100%. ** by one-way ANOVA followed by host hoc comparison of means using the Tukey test (modified from Koide et al. ).