中文摘要：

目的观察不同剂量的片剂吗啡作用后,C57小鼠的成瘾行为学变化,为吗啡成瘾的研究提供参考。方法用3月龄雄性C57小鼠分别腹腔注射0、5、10、15、20 mg/kg的吗啡,观察指标为竖尾反应持续的时间以及条件位置偏爱（Conditioned place preference）中的白箱时间差。结果与对照组（0 mg/kg）相比,吗啡10、15和20 mg/kg组小鼠出现竖尾反应的时间有显著差异（P〈0.05）;在条件位置偏爱实验中,与对照组相比,吗啡10、15、20 mg/kg剂量组逆转了小鼠偏爱呆在黑箱的天然倾向,白箱时间差有统计学差异。其中,吗啡10 mg/kg组P=0.049,而15 mg/kg组和20 mg/kg组（P〈0.001）。结论在吗啡剂量为10、15、20 mg/kg时,白箱偏爱明显形成,15 mg/kg是较为敏感而稳定的吗啡成瘾小鼠模型剂量,可作为敏感而又稳定的较低剂量。

英文摘要：

Objective To observe the conditioned place preference （CPP） changes in mice after treated with different doses of morphine, and provide reference for the further study of morphine addiction. Method 3-month-old male C57 mice were injected intraperitoneaUy with 0 mg/kg, 5 mg/kg, 10 mg/kg, 15 mg/kg and 20 mg/kg of morphine, CPP and Straub tail reaction analysis were carried out. Result The Straub tail reaction analysis showed that： compared with control group, mice in morphine 10 mg/kg, 15 mg/ kg, and 20 mg/kg groups demonstrated longer Straub tail reaction time （P〈 0.05）. The CPP analysis also showed that, compared with the control group mice, 15mg/kg and 20mg/kg morphine reversed the natural tendency to black box of mice, which spent more time in the white box （P〈 0.001）. Meanwhile, the time spend in the white box was also statistically longer in the 10 mg/kg morphine group compared with the control group （P=0.049〈0.05）. Conclusion 15 mg/kg morphirte can produce a significant adaptive change in CPP test in mice, which is an ideal dosage to construct morphine addiction model in mice.