中文摘要：

吗啡是一种有效的镇痛药,但易使动物产生耐受性和成瘾性。在该实验中,中缅树鼩（Tupai a belangeri chinensis）连续7d,每天接受三次肌肉注射递增剂量（5、10、15、20mg/kg体重）吗啡后对吗啡产生耐受和依赖;吗啡注射完成后,腹腔注射纳洛酮（1.25mg/kg体重）催瘾,可诱导其条件性位置厌恶（conditioned place aversion,CPA）及相应吗啡戒断症状的出现。该结果提示树鼩慢性吗啡依赖模型的建立可用于研究吗啡依赖和耐受的生物学机制,以及减轻戒断症状药物的筛选。

英文摘要：

The clinical use of morphine to reduce pain is limited because of its drug tolerance,dependence and addiction.In the present study,the tree shrews（Tupaia belangeri chinensis） developed morphine tolerance and chronic morphine dependence by morphine injections with increasing doses（5,10,15,20 mg/kg body weight for 7 days）.Meanwhile,the naloxone（1.25 mg/kg body weight）-induced conditioned place aversion（CPA） and the withdrawal symptom were also found.The tree shrew model of chronic morphine dependence can be used to investigate the withdrawal symptoms and to select potential withdrawal symptoms reducing drugs in the future.