Figure 2.

General health and neurologic screening in chronic fentanyl‐treated mice. We performed neurological screens and neuromuscular strength test twice to examine the effect of fentanyl treatment on the physiologic characteristics of the mice both during fentanyl administration and withdrawal (A). Body weight (B, E), body temperature (C, F), and grip strength (D, G) are shown. In both periods, high‐dose fentanyl treatment led to weaker forelimb muscle function compared with the other treatment groups. Data are presented as means ± SEM for the indicated numbers of animals. The P values indicate treatment effect in one‐way ANOVA. The asterisk indicates a nominally significant difference for comparisons between treatment groups (P < 0.05)