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. 2007 Aug 31;104(37):14789–14794. doi: 10.1073/pnas.0706945104

Fig. 3.

Fig. 3.

Analgesic responses to morphine in the hot-plate and tail-flick tests. (A and B) Nociceptive thresholds were tested by measuring latencies of analgesic responses in the hot-plate test (A) and in the tail-flick test (B). (C) Analgesic responses to morphine were examined in the hot-plate test every 15 min after s.c. injection of 10 mg/kg morphine [*, P = 0.022, n = 10 (WT) and 11 (KO)]. %MPE, percentage of maximal possible effect. (D and E) Dose–responses of analgesic effects of morphine in the hot-plate test (D) and the tail-flick test (E). Analgesic responses were examined 30 min after s.c. injection of the indicated doses of morphine (*, P = 0.015, n = 6–9). (F) Development of morphine analgesic tolerance was examined once a day 30 min after administration of 10 mg/kg morphine [*, P = 0.015, n = 7 (WT) and 6 (KO)].