A. Effects of 70% nitrous oxide plus 1% isoflurane for six hours, and staurosporine on caspase-3 activation. Each band in the Western blot represents an independent experiment. There is no significant difference in amounts of β-actin in the control condition-, staurosporine- or nitrous oxide plus isoflurane-treated H4-APP cells. B. Caspase-3 activation assessed by quantifying ratio of caspase-3 fragment to FL-caspase-3 in the Western blots, normalized to β-actin levels. We have averaged results from three independent experiments. C. Effects of the nitrous oxide plus isoflurane treatment on TUNEL positive cells. D. Effects of the nitrous oxide plus isoflurane treatment on apoptosis. E. Effects of the nitrous oxide plus isoflurane treatment on BACE levels. F. Quantification of the Western blot, normalized to β-actin levels. We have averaged results from three independent experiments. G. Effects of nitrous oxide plus isoflurane treatment on Aβ40 levels. We have averaged results from ten independent experiments. BACE, β-site amyloid precursor protein-cleaving enzyme; APP, amyloid precursor protein; Aβ, β-amyloid protein; TUNEL, terminal deoxynucleotidyl transferase dUTP nick end labeling; FL, full length. * P < 0.05; ** P <0.01.