Figure 2.

Pial and parenchymal arteries do not dilate in response to hypercapnia after SAH. (a) Representative two-photon microscopy images of pial (top) and parenchymal arteries (bottom) of SAH (left) and sham-operated (right) mice before and during 10% CO₂ inhalation. (b) Surface and (c) parenchymal artery diameter during hypercapnia of mice subjected to sham surgery (white symbols) or SAH (gray symbols). Pial and parenchymal vessel dilated normally in response to inhalation of 10% CO₂ in sham-operated mice (white symbols), while no response was observed after SAH (gray symbols). Mean ± SEM; Mann-Whitney Rank Sum test; 16 to 37 arteries (b) and 25 to 34 arteries (c) in n = 6–7 mice per group. ** P < 0.01, *** P < 0.001.