Figure 2. Circles depict the percentage of dead hippocampal CA1 neurons in rats as determined 5 days after near-complete forebrain ischemia. Horizontal bars depict group mean values. Isoflurane caused reduced damage after near-complete ischemia when compared with fentanyl-N²O (corrected P < 0.001). Trimethaphan (TMP) abolished the relative protective effect of isoflurane (corrected P < 0.001). In fentanyl-N²O-anesthetized rats, trimethaphan administration did not change the histologic result.