Oxycodone-dependent mice were treated with saline or (2R,6R)-HNK (10 or 30 mg/kg, sc), and the number of (A) paw tremor, (B) rearing, (C) grooming, (D) jumps, (E) hind limb scratching, and (F) writhing events were measured during naloxone-induced withdrawal (n = 16 per group). Data were analyzed via one-way ANOVA followed by Bonferroni post hoc tests. ***P < 0.001. Data are expressed as means (±SEM).