Fig. 1. Histologic damage resulting from near-complete forebrain ischemia in rats anesthetized with 1.1% (0.75 MAC) isoflurane–60% nitrous oxide (N2O) versus 0.8% (0.75 MAC) halothane–60% N2O. After 6.5 min ischemia, isoflurane-anesthetized rats had less damage in the hippocampal CA1 (P = 0.02) and neocortex (P = 0.02) than did halothane-anesthetized rats subjected to 6.5 min ischemia. Extension of the ischemic interval to 8.0 min in isoflurane-anesthetized rats resulted in increased CA1 (P = 0.02) and neocortical (P = 0.03) damage relative to the isoflurane 6.5-min group, but damage was equivalent to that observed in the halothane 6.5-min ischemia group. There was no difference in the striatum between groups. Open circles represent values for individual animals. Horizontal bars depict group mean. n = 19 or 20 animals/group.