Figure 1.

Experimental timeline. Saline and morphine (10 mg/kg and 30 mg/kg) was administered once-daily (S.C.) beginning on gestational day 19. During daily injections, mice were checked for general health, body weight and body temperature were recorded. Withdrawal behaviors were measured between PND 0 and PND 7 once-daily, and performed in the morning by the same experimenter and data was analyzed by a blinded experimenter. All pups remained in the same cage as their mother's until weaning at PND 14, and were provided food and water ad libitum.