Morphine pre-exposure facilitates reinstatement but attenuates retention of morphine-induced place preference  

作　　者：Dongmei Wang Xigeng Zheng Yonghui Li Xiaoyan Yang Nan Sui 

机构地区：[1]Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, China

出　　处：《Neural Regeneration Research》2010年第12期942-947,共6页中国神经再生研究（英文版）

基　　金：the National Key Basic Research Pro-gram of China, No. 2009CB522002;the National Natural Science Foundation of China, No. 30770719;Chinese Academy of Sciences Grants, No. KSCX1-YW-R-68

摘　　要：BACKGROUND： Drug-associated conditioned stimuli are a key factor to induce morphine relapse. To date, limited evidence is available regarding the impact of drug history on propensity or vulnerability to relapse after long-term abstinence. OBJECTIVE： To determine the effect of morphine pre-exposure on acquisition, maintenance and reinstatement of morphine-induced conditioned place preference （CPP） in rats. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment was performed at the Laboratory of Behavior Pharmacology, Institute of Psychology, the Chinese Academy of Sciences, from March to September, 2006. MATERIALS： Morphine hydrochloride was purchased from Qinghai Pharmaceutical, China; CPP software was designed and developed by Taiji Software Company, Beijing, China. METHODS： A total of 64 Sprague Dawley rats were randomly assigned to eight groups （n = 8）. Four morphine pretreatment regimens were used （subcutaneous injections, twice daily for 5 consecutive days and a total of 10 times）： （1） ＂intensive＂ （morphine injections with doses escalating from 10 to 60 mg/kg; （2） ＂moderate＂ （one morphine injection at 5 mg/kg dose and one saline injection at 1 mL/kg daily for 5 days）; and （3） ＂single＂ （nine saline injections at 1 mL/kg followed by one morphine injection at 5 mg/kg; （4） control （ten saline injections at 1 mL/kg）. At 5 days after morphine pretreatment, animals were divided into two subgroups that underwent morphine conditioned or saline conditioned training. The test for acquisition of CPP was performed 24 hours after CPP training. The retention of morphine CPP was measured by repeated tests performed weekly for 1 month after the initial test of place preference. After extinction by pairing each chamber with saline, the reinstatement of place preference by low doses of morphine （0.05, 0.15, 0.45 mg/kg） was tested. MAIN OUTCOME MEASURES： Acquisition, maintenance, and recovery response of CPP behavior. RESULTS： The acquisitionBACKGROUND： Drug-associated conditioned stimuli are a key factor to induce morphine relapse. To date, limited evidence is available regarding the impact of drug history on propensity or vulnerability to relapse after long-term abstinence. OBJECTIVE： To determine the effect of morphine pre-exposure on acquisition, maintenance and reinstatement of morphine-induced conditioned place preference （CPP） in rats. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment was performed at the Laboratory of Behavior Pharmacology, Institute of Psychology, the Chinese Academy of Sciences, from March to September, 2006. MATERIALS： Morphine hydrochloride was purchased from Qinghai Pharmaceutical, China; CPP software was designed and developed by Taiji Software Company, Beijing, China. METHODS： A total of 64 Sprague Dawley rats were randomly assigned to eight groups （n = 8）. Four morphine pretreatment regimens were used （subcutaneous injections, twice daily for 5 consecutive days and a total of 10 times）： （1） ＂intensive＂ （morphine injections with doses escalating from 10 to 60 mg/kg; （2） ＂moderate＂ （one morphine injection at 5 mg/kg dose and one saline injection at 1 mL/kg daily for 5 days）; and （3） ＂single＂ （nine saline injections at 1 mL/kg followed by one morphine injection at 5 mg/kg; （4） control （ten saline injections at 1 mL/kg）. At 5 days after morphine pretreatment, animals were divided into two subgroups that underwent morphine conditioned or saline conditioned training. The test for acquisition of CPP was performed 24 hours after CPP training. The retention of morphine CPP was measured by repeated tests performed weekly for 1 month after the initial test of place preference. After extinction by pairing each chamber with saline, the reinstatement of place preference by low doses of morphine （0.05, 0.15, 0.45 mg/kg） was tested. MAIN OUTCOME MEASURES： Acquisition, maintenance, and recovery response of CPP behavior. RESULTS： The acquisition

关 键 词：conditioned place preference MORPHINE REINSTATEMENT drug history ADDICTION RELAPSE NEUROPHARMACOLOGY neural regeneration 

分 类 号：S858.31[农业科学—临床兽医学] TQ460.72[农业科学—兽医学]