Fig. 2. Xenon and sevoflurane in combination attenuate cell death  in vitro .Pure neuronal cells were preconditioned with 12.5% xenon and 0.67% sevoflurane alone and in combination for 2 h and then 24 h after they were provoked by 75 min of oxygen–glucose deprivation (OGD). Subsequently, cells were stained with annexin V (for apoptosis) and propidium iodide (for necrosis) for flow cytometry analysis. Different cell populations with various gas exposure in the absence (  A ) or presence (  B ) of wortmannin (WM). Mean ± SEM (n = 6). **  P < 0.01  versus OGD.