Figure 2.

Perinatal fentanyl exposure results in aberrant effects at birth, withdrawal behavior, and impaired sensory function. A, Timeline depicting withdrawal behavior 24 h after weaning and sensory behavior test during adolescence. Exposure resulted in smaller litter size (B) and a higher litter mortality rate (C). D, Mice exposed to fentanyl perinatally exhibited abnormal weight during early development. E, At weaning (PD21), exposed male mice weighed less than controls. F, At adolescence (PD35), exposed male mice weighed more than controls and males weighed more than females at each concentration of fentanyl tested. G, By adulthood (PD55), males weighed more than females, but there were no differences between fentanyl exposure groups. H, Perinatal fentanyl exposure induces spontaneous somatic withdrawal behavior 24 h after cessation, at all concentrations of fentanyl tested. I, Perinatal fentanyl exposure impaired sensory adaptation to continuous application of tactile stimuli (I) but did not influence paw withdrawal threshold (J). Data depict means with 95% confidence intervals. *p < 0.05 compared to vehicle control, †p < 0.05 compared to opposite sex condition.