Fig. 4. The effects of desflurane on learning, memory, and pain sensitivity. ( A ) A significant effect on task acquisition was found at the 1% dose, and acquisition was further inhibited at the 2% dose. ( B ) Desflurane was a potent inhibitor of 24-h retention performance. A significant reduction in memory retention latency occurred with the 0.5% target dose (0.44% measured), and higher doses increased this amnesic effect. ( C ) An analgesic effect only became evident at the 2% dose. The other details are as in figure 1 . * P < 0.05, ** P < 0.01, *** P < 0.001 compared with air controls.