The effect of low and high freqency electroacupuncture (EA) on the cocaine cravi ng was evaluated based on conditioned place preference (CPP) paradigm. Drug ind uced CPP in animals has been considered as a model of dr...The effect of low and high freqency electroacupuncture (EA) on the cocaine cravi ng was evaluated based on conditioned place preference (CPP) paradigm. Drug ind uced CPP in animals has been considered as a model of drug craving. In the prese nt experiments, rats were trained with an injection (i.p.) of different doses of cocaine under a "biased" CPP schedule and preference scores (PSs) were recorde d on the test session and used as the indicator of preference. 2 and 100 Hz of E A were given respectively before testing, with treatment of foot shock, needle i nsertion, restriction in the holder and no treatment being as the different kind s of control. The timecourse of the effect of EA on 5 mg/kg cocaine induced CPP was also observed. The results showed: ① The PSs after saline (0.27±0.08,n=12) and 0.5 mg/kg of cocaine (0 .26±0.10, n=12) conditioning had no difference from that of natural preference (0.38±0.12, n=12) (P>0.05), while the PSs of 1 ( 0.65±0.12, n=12), 5 (0.70± 0.09, n=12) and 10 mg/kg (0. 71± 0.09, n=12) of cocaine conditioning were significantly higher than tha t of natural preference (P<0.001), indicating that the 1 mg/kg and hig her doses of cocaine can induce significant place preference, which represents c ocaine craving. ② The PSs of 0.5 mg/kg of cocaine conditioning were similar wit h each other (P>0.05, compared with initial expression of CPP) when tes ting daily for at least 10 consecutive days, indicating that the cocaine craving is maintained for a long time once acquired. ③ 100 Hz EA significantly decreas ed the PSs of cocaine conditioning (P<0.05, compared with control grou p), while the treatment of 2 Hz of EA and all other kinds of control we used did n’t (P>0.05). ④ 100 Hz EA inhibited cocaine induced CPP when tested 10, 24 and 48 hours after stimulation. The results of the present study suggest that EA inhibits the cocaine craving in a frequency specific way and the effect of one treatment of EA maintains at least 48 hours.展开更多
High rate of relapse to drug using behavior after long period of abstinence cha racterizes the behavior of experienced users of heroin and other drugs of abuse, and the relapse remains the primary problem for treatmen...High rate of relapse to drug using behavior after long period of abstinence cha racterizes the behavior of experienced users of heroin and other drugs of abuse, and the relapse remains the primary problem for treatment. In the present study we built a putative animal model that mimic human relapse i.e., the reinstatement o f morph ine induced conditioned place preference (CPP) in rats. In this study, we found electroacupuncture (EA) with low frequency (2 and 2/100 Hz) could inhibit drug priming or footshock induced CPP reinstatement in rats whe n it was given 18 hours before reinstatement, and these effects were found to be naloxone reversible, suggesting a mechanism involving the activation of opioid receptors by endogenous opioid ligands; while EA with high frequency (100 Hz) h ad no effect. Pr evious studies in our lab have amply shown that low frequency (2 Hz) stimulation could increase the release of enkephalin which acts on μ and δ opioid recepto rs up the spinal level, while high frequency (100 Hz) stimulation could increase the release of dynorphin which interacts with κ opioid receptor at spinal leve l. So we concluded the effect of EA with low frequency on relapse involving a me chanism of the activation of opioid receptors by endogenous opioid ligands above the spinal level. And we suggest that EA may be used as a putative measure for the prevention of relapse to drug use in humans.展开更多
条件性位置偏爱（conditioned place preference，CPP）实验是药物精神依赖性研究中常用的一种动物模型。就给药剂量方案而言，在以往的研究资料中，恒定剂量给药与每日递增剂量给药两种方式都曾被普遍应用。设计方案的不同影响了同类...条件性位置偏爱（conditioned place preference，CPP）实验是药物精神依赖性研究中常用的一种动物模型。就给药剂量方案而言，在以往的研究资料中，恒定剂量给药与每日递增剂量给药两种方式都曾被普遍应用。设计方案的不同影响了同类实验结论的一致性比较和交流，同时科学实验的操作标准化程度也不够高。相比较而言，恒定剂量给药的方法简便易行有助于提高实验效率。那么，不同的给药剂量方案是否会对CPP的形成及表达产生影响呢？本研究以吗啡所致大鼠CPP的形成及表达为例，就这一问题进行了实验研究。展开更多
文摘The effect of low and high freqency electroacupuncture (EA) on the cocaine cravi ng was evaluated based on conditioned place preference (CPP) paradigm. Drug ind uced CPP in animals has been considered as a model of drug craving. In the prese nt experiments, rats were trained with an injection (i.p.) of different doses of cocaine under a "biased" CPP schedule and preference scores (PSs) were recorde d on the test session and used as the indicator of preference. 2 and 100 Hz of E A were given respectively before testing, with treatment of foot shock, needle i nsertion, restriction in the holder and no treatment being as the different kind s of control. The timecourse of the effect of EA on 5 mg/kg cocaine induced CPP was also observed. The results showed: ① The PSs after saline (0.27±0.08,n=12) and 0.5 mg/kg of cocaine (0 .26±0.10, n=12) conditioning had no difference from that of natural preference (0.38±0.12, n=12) (P>0.05), while the PSs of 1 ( 0.65±0.12, n=12), 5 (0.70± 0.09, n=12) and 10 mg/kg (0. 71± 0.09, n=12) of cocaine conditioning were significantly higher than tha t of natural preference (P<0.001), indicating that the 1 mg/kg and hig her doses of cocaine can induce significant place preference, which represents c ocaine craving. ② The PSs of 0.5 mg/kg of cocaine conditioning were similar wit h each other (P>0.05, compared with initial expression of CPP) when tes ting daily for at least 10 consecutive days, indicating that the cocaine craving is maintained for a long time once acquired. ③ 100 Hz EA significantly decreas ed the PSs of cocaine conditioning (P<0.05, compared with control grou p), while the treatment of 2 Hz of EA and all other kinds of control we used did n’t (P>0.05). ④ 100 Hz EA inhibited cocaine induced CPP when tested 10, 24 and 48 hours after stimulation. The results of the present study suggest that EA inhibits the cocaine craving in a frequency specific way and the effect of one treatment of EA maintains at least 48 hours.
文摘High rate of relapse to drug using behavior after long period of abstinence cha racterizes the behavior of experienced users of heroin and other drugs of abuse, and the relapse remains the primary problem for treatment. In the present study we built a putative animal model that mimic human relapse i.e., the reinstatement o f morph ine induced conditioned place preference (CPP) in rats. In this study, we found electroacupuncture (EA) with low frequency (2 and 2/100 Hz) could inhibit drug priming or footshock induced CPP reinstatement in rats whe n it was given 18 hours before reinstatement, and these effects were found to be naloxone reversible, suggesting a mechanism involving the activation of opioid receptors by endogenous opioid ligands; while EA with high frequency (100 Hz) h ad no effect. Pr evious studies in our lab have amply shown that low frequency (2 Hz) stimulation could increase the release of enkephalin which acts on μ and δ opioid recepto rs up the spinal level, while high frequency (100 Hz) stimulation could increase the release of dynorphin which interacts with κ opioid receptor at spinal leve l. So we concluded the effect of EA with low frequency on relapse involving a me chanism of the activation of opioid receptors by endogenous opioid ligands above the spinal level. And we suggest that EA may be used as a putative measure for the prevention of relapse to drug use in humans.
文摘条件性位置偏爱（conditioned place preference，CPP）实验是药物精神依赖性研究中常用的一种动物模型。就给药剂量方案而言，在以往的研究资料中，恒定剂量给药与每日递增剂量给药两种方式都曾被普遍应用。设计方案的不同影响了同类实验结论的一致性比较和交流，同时科学实验的操作标准化程度也不够高。相比较而言，恒定剂量给药的方法简便易行有助于提高实验效率。那么，不同的给药剂量方案是否会对CPP的形成及表达产生影响呢？本研究以吗啡所致大鼠CPP的形成及表达为例，就这一问题进行了实验研究。
