Fig. 4

Opioid adaptations in C57BL/6 wild-type and Mpdz ^+/− mice. In panel (a) the results of experiments measuring opioid-induced hyperalgesia using changes in mechanical withdrawal thresholds are displayed. In panel (b) the anangesic effect of cumulitive doses of morphine are shown for wild-type and Mpdz ^+/− mice both before and after 4 days of escalating dose morphine treatment. In panel (c) naloxone-induced jumping behavior for wild-type and Mpdz ^+/− mice is displayed. Finally, in panel (d) data for morphine-induced weight loss are provided. For each trait the mean value is displayed +/− S.E.M., n = 8 mice per strain. ##, **p < 0.01, ###, ****p < 0.001