FIGURE 6.

Effects of cyclo[Pro‐Sar‐Phe‐d‐Phe] on (a) ambulation and (b) respiration in C57BL/6J wild‐type, MOPrKO, or KOPrKO mice tested in the CLAMS/Oxymax system. Ambulation and respiration were monitored after i.p. administration of cyclo[Pro‐Sar‐Phe‐d‐Phe] (10 mg·kg⁻¹) or morphine (10 mg·kg⁻¹). Data are presented as % vehicle response ± SEM, ambulation, XAMB (a) or breaths per minute, BPM (b). P < .05, significantly different from vehicle control response; two‐way RM ANOVA with Tukey's multiple comparison post hoc test. Data from 154 animals are shown in this figure