Researchers at the Tufts University Cummings School of Veterinary Medicine in North Grafton, Mass., exposed female rats to morphine for 10 days during adolescence.

研究人员在位于马萨诸塞州北格拉芙顿的塔夫茨大学康明斯兽医学院里给正在青春期中的母鼠持续注射吗啡十天。