Figure 5. Five phase-contrast micrographs of Nissl-stained sections from slices taken (A) immediately after brain isolation;(B) after 120 min of postdecapitation recovery;(C) after 60 min of reperfusion recovery, hypercapnia pretreatment group;(D) after 60 min of reperfusion recovery, hyperoxia pretreatment group; and (E) after 60 min of reperfusion recovery, hypoxia pretreatment group. Large ripples in C and E are an artifact of the preparation. Qualitatively, the hypercapnia pretreatment reduced cell swelling and the number of shrunken Nissl-stained neurons. The scale bar (20 micro meter) corresponds to the same length in all micrographs.