可乐定脱毒治疗对吗啡依赖大鼠吗啡条件性位置偏爱效应和镇痛作用的影响

目的:研究给予吗啡依赖大鼠可乐定治疗对吗啡奖赏效应和镇痛作用的影响。方法:采用剂量递增法(5-40mg·kg-1,每天3次,30d)建立吗啡依赖大鼠模型,在自然戒断后7d内给予可乐定(0.1mg·kg-1,每天3次)进行治疗;停用可乐定后训练大鼠吗啡(1mg·kg-1)条件性位置偏爱(CPP),观察CPP的形成速度和维持情况;期间利用热痛甩尾法,观察吗啡(5mg·kg-1)的镇痛作用。结果:CPP训练4d后,经可乐定治疗的大鼠形成了吗啡CPP,而未经可乐定治疗的大鼠没有形成CPP;经过8d训练后,经可乐定治疗及未治疗的大鼠均形成了明显的吗啡CPP;在训练停止后14d,经可乐定治疗大鼠的CPP已消退,而未经可乐定治疗的大鼠CPP没有消退。在镇痛实验中,可乐定治疗及未治疗大鼠应用吗啡前后的甩尾时间组间比较差异不显著。结论:可乐定治疗能改变吗啡依赖大鼠的吗啡奖赏效应,但不影响大鼠对吗啡镇痛作用的耐受。     

归元片对吗啡条件性位置偏爱的影响

目的:探讨不同剂量的戒毒中药归元片对吗啡诱导的条件性位置偏爱(conditionedplacepreference ,CPP)的影响及其自身是否引起CPP。方法:(1)♂Wistar大鼠sc吗啡(5mg·kg-1)训练7d ,干预组于每次给吗啡前15min注射不同剂量的归元片(12 . 5 - 37 .5mg·kg-1,sc) ,观察其对吗啡CPP效应的干预作用;(2 )♂Wistar大鼠sc归元片(2 5mg·kg-1及5 0mg·kg-1)训练7d ,d8测定大鼠对伴药侧的偏爱效应。结果:(1) 5mg·kg-1吗啡可以诱导大鼠对伴药侧产生显著的CPP ;而两个剂量的归元片均不能使大鼠形成CPP ;(2 ) 2. 5mg·kg-1和37 .5mg·kg-1的归元片可剂量依赖性地降低吗啡诱导的CPP的形成。结论:一定剂量的归元片可拮抗大鼠对吗啡偏爱效应的获得,且自身不引起CPP ,提示该药有治疗阿片类药物精神依赖性的潜力。     

咖啡因对大鼠吗啡条件性位置偏爱获得和重现的影响

目的:本文以大鼠条件性位置偏爱(CPP)为模型,探讨咖啡因对阿片类物质奖赏效应的影响。方法:30只大鼠分为四组:吗啡组、吗啡+咖啡因组、咖啡因组和生理盐水对照组。前三组大鼠隔日分别皮下注射(sc)吗啡(5mg·kg-1)、吗啡+咖啡因(5mg·kg-1+5mg·kg-1)、咖啡因(5mg·kg-1)和生理盐水进行CPP训练。生理盐水组大鼠一直给予等体积的生理盐水。CPP建立后,比较CPP效应强度。待各组大鼠CPP消退后,均sc咖啡因(5mg.kg-1)观察CPP重现情况。结果:吗啡组、吗啡+咖啡因组、咖啡因组大鼠均形成了CPP。吗啡+咖啡因组大鼠CPP强度最高,但与吗啡组、咖啡因组比较差异无显著性。单次sc咖啡因可使咖啡因+吗啡组CPP重现,但没有使吗啡组和咖啡因组大鼠CPP重现。结论:咖啡因与吗啡的奖赏作用可能具有相加或协同作用;单剂量咖啡因给药可使吗啡和咖啡因的混合物形成的CPP重现;实验结果提示阿片类物质中掺杂咖啡因不但是成瘾形成的危险因素,也可能是诱导复吸的危险因素。     

吗啡依赖大鼠海马长时程增强改变及归元片的干预效应

目的:在体观察吗啡条件性位置偏爱(conditioned place preference,CPP)大鼠海马齿状回(dentate gyrus,DG)长时程增强(long-term potentiation,LTP)的变化,评价归元片自身有无依赖性以及对吗啡CPP和LTP的干预效应。方法:(1)连续给予吗啡(5mg·kg-1)7d,使大鼠产生明显的吗啡CPP,观察吗啡CPP的自然消退;(2)归元片(25mg·kg-1及50mg·kg-1)训练7d,d8测定大鼠对伴药箱的偏爱效应;(3)在归元片干预实验中,干预组在每次给予吗啡前15min分别给予不同剂量归元片(25、37.5mg·kg-1),观察归元片对吗啡CPP形成的影响。在以上模型的基础上,应用在体脑立体定位胞外记录技术测量海马齿状回LTP的变化。结果:(1)5mg·kg-1吗啡诱导大鼠对伴药侧产生显著性CPP;(2)归元片不能诱导大鼠形成CPP,同时也不影响DG-LTP;(3)吗啡CPP大鼠在高频刺激(high frequency stimulation,HFS)后,各时间点所记录的群体峰电位(population spikes,PS)相对幅值较对照组显著增高;(4)归元片25和37.5mg·kg-1均可拮抗吗啡CPP的获得,并能抑制吗啡对PS相对幅值的影响;(5)吗啡CPP在停用吗啡后12d消退,此时海马PS相对幅值与对照组比较无差异。结论:吗啡可诱导CPP,海马LTP在CPP形成时增强,在CPP消退后恢复正常,提示LTP参与药物成瘾过程。归元片自身不能诱导CPP,但可抑制吗啡CPP的获得与LTP的增强。     

左旋四氢巴马汀对吗啡条件性位置偏爱的影响

目的探讨不同剂量的左旋四氢巴马汀(lTetrahydropalmatine,lTHP)对吗啡诱导的条件性位置偏爱(CPP)的影响以及自身能否产生CPP效应。方法本实验采用倾向性实验程序,①对♂SD大鼠sc吗啡(5.00mg·kg-1)或生理盐水(NS)训练8d,d9测定大鼠对伴药侧的偏爱效应或测试前40minipNS或不同剂量的lTHP(1.25～5.00mg·kg-1),观察这些预处理对该效应的影响;②测量不同剂量的lTHP(1.25～5.00mg·kg-1)慢性用药(每天1次,ip)对CPP效应消退的影响;③测试ipNS或lTHP(1.25～5.00mg·kg-1)能否诱导大鼠对伴药侧产生偏爱(方法同吗啡)。结果5.00mg·kg-1吗啡诱导大鼠对伴药盒产生明显的CPP;测试前ip2.50mg·kg-1或5.00mg·kg-1的lTHP明显降低吗啡诱导的CPP效应的表达(P<0.05),其慢性给药明显加速吗啡CPP效应的消退;3个剂量的lTHP均不能诱导大鼠形成CPP。结论lTHP能抑制吗啡的奖赏效应,可在吗啡成瘾的治疗中发挥一定的作用。     

吗啡依赖和复吸时大鼠脑内神经甾体水平的变化

目的探讨吗啡精神依赖和复吸对大鼠脑内神经甾体水平的影响。方法采用条件性位置偏爱(CPP)实验,吗啡诱导大鼠CPP形成,足底电击应激诱发CPP重建,高效液相色谱-质谱法测定大鼠额叶皮质、海马及血浆中孕烯醇酮(PREG)及其硫酸酯(PREGS)、别孕烯醇酮(AP)、脱氢表雄酮(DHEA)及其硫酸酯(DHEAS)的含量。结果5 mg.kg-1吗啡训练10 d诱导大鼠产生了稳定的CPP,间歇足底电击有效诱发CPP的重建。与对照组比较,吗啡CPP形成时,大鼠额叶皮质内DHEA、PREG水平升高(P<0.05),海马内DHEA水平降低(P<0.05);与吗啡消退组比较,足底电击诱发CPP重现时,大鼠额叶皮质内PREG水平降低(P<0.01),而海马内PREG水平升高(P<0.05)。结论大鼠额叶皮质和海马内神经甾体水平的变化可能与吗啡依赖和复吸有关。     

大鼠相关脑区p—CREB和c—Fos在吗啡点燃条件性位置偏爱条件下的变化

目的：研究磷酸化cAMP反应元件结合蛋白（phospho—cAMP response element binding protein,p-CREB）和c-Fos在吗啡点燃条件性位置偏爱激活大鼠海马、杏仁核表达的变化。方法：以剂量递增连续皮下（s．c．）注射吗啡6d建立吗啡诱导大鼠条件位置性偏爱（conditionedplacepreference,CPP）模型,第7天用生理盐水替代吗啡训练大鼠10d,使CPP消退,单次s．c．吗啡（4mg／kg）激发已消退的CPP。采用免疫组化技术测定吗啡激发CPP重现时大鼠海马、杏仁核p-CREB和c—Fos的变化。结果：吗啡可使大鼠产生CPP效应,吗啡4mg／kg可使已消失的CPP效应激活;吗啡诱发CPP激活时大鼠海马、杏仁核p-CREB和c—Fos的表达增加。结论：海马、杏仁核p-CREB和c—Fos蛋白的表达参与了吗啡点燃CPP重现。     

下边缘皮质中神经元周围基质网络(PNNs)的降解联合消退训练能够抑制吗啡奖赏记忆的复燃

目的:利用硫酸软骨素酶(ChABC)降解下边缘皮质神经元周围基质网络(PNNs)之后,观察对于吗啡奖赏记忆复燃的影响。方法:采用条件性位置偏爱(CPP)模型,用核团微注射方法。结果:(1)与PBS对照组相比,消退训练前在下边缘皮质微注射ChABC将PNNs降解之后联合消退训练能够抑制消退后低剂量吗啡引起的CPP复燃;(2)与对照组相比,吗啡CPP训练前下边缘皮质微注射ChABC,对于吗啡CPP的获得没有影响。结论:本研究发现下边缘皮质神经元周围基质网络(PNNs)/硫酸软骨素蛋白聚糖(CSPGs)降解之后,可以抑制消退后低剂量药物引起的觅药行为的复现。这种作用可能是通过PNNs/CSPGs降解能够增强吗啡奖赏消退记忆来发挥作用的。     

奥丹西隆对小鼠吗啡条件性位置偏爱效应的影响

目的 :探讨 5 -HT3 型受体特异性拮抗剂奥丹西隆对吗啡诱导的条件性位置偏爱 (CPP)效应的影响。方法 :建立小鼠吗啡CPP模型 ,观察奥丹西隆对CPP的影响。结果 :吗啡 (5mg·kg-1,sc)可诱导小鼠对伴药箱产生显著的CPP ;测试前 30min注射奥丹西隆 (0 0 1- 1mg·kg-1,sc)不影响小鼠已形成的对吗啡的位置偏爱 ;而训练阶段于每次注射吗啡同时注射奥丹西隆 (0 0 1- 0 1mg·kg-1,ip)可拮抗小鼠对吗啡的CPP效应 ,但较大剂量奥丹西隆 (1mg·kg-1,ip)则不影响其效应 ,而且此剂量单独给药亦表现出自身的CPP潜力。结论 :一定剂量的奥丹西隆可拮抗小鼠对吗啡的偏爱效应的获得 ,但不影响其表达 ,提示该类药物有治疗阿片类依赖的潜力。     

褪黑素对吗啡依赖大鼠复吸行为的抑制作用

目的 :研究褪黑素对吗啡依赖大鼠复吸行为的抑制作用。方法 :以剂量递增法连续皮下注射 (sc)吗啡 6d建立吗啡诱导的大鼠条件性位置偏爱 (CPP)模型 ,d7用生理盐水替代吗啡训练大鼠 10d ,以使形成的CPP逐渐消退。单次sc 4mg·kg- 1 吗啡以唤起消退的CPP的恢复。部分大鼠在注射吗啡前 30min分别腹腔注射 (ip)褪黑素 2 0、4 0和 80mg·kg- 1 进行治疗。结果 :与吗啡依赖组相比 ,在sc 4mg·kg- 1 吗啡引燃刺激前 30min应用褪黑素 4 0和 80mg·kg- 1 急性治疗 ,可以使大鼠在伴药箱的停留时间明显缩短 ,(P <0 0 5、P <0 0 1) ;而褪黑素 2 0mg·kg- 1 急性治疗亦使大鼠在伴药箱的停留时间缩短 ,但无统计学意义 ,P >0 0 5。结论 :褪黑素在一定程度上可以抑制吗啡引燃的吗啡依赖大鼠的复吸行为     

下边缘皮质中神经元周围基质网络（PNNs）的降解联合消退训练能够抑制吗啡奖赏记忆的复燃

目的：利用硫酸软骨素酶（ChABC）降解下边缘皮质神经元周围基质网络（PNNs）之后,观察对于吗啡奖赏记忆复燃的影响。方法：采用条件性位置偏爱（CPP）模型,用核团微注射方法。结果：（1）与PBS对照组相比,消退训练前在下边缘皮质微注射ChABC将PNNs降解之后联合消退训练能够抑制消退后低剂量吗啡引起的CPP复燃;（2）与对照组相比,吗啡CPP训练前下边缘皮质微注射ChABC,对于吗啡CPP的获得没有影响。结论：本研究发现下边缘皮质神经元周围基质网络（PNNs）/硫酸软骨素蛋白聚糖（CSPGs）降解之后,可以抑制消退后低剂量药物引起的觅药行为的复现。这种作用可能是通过PNNs/CSPGs降解能够增强吗啡奖赏消退记忆来发挥作用的。     

丹参、黄芪小复方对吗啡依赖小鼠复吸行为的抑制作用

目的:研究丹参、黄芪小复方抑制吗啡依赖小鼠复吸行为的药理作用。方法:利用条件性位置偏爱(conditioned place preference,CPP)的方法,建立吗啡精神依赖小鼠复吸模型,给予丹参、黄芪小复方,研究其对吗啡依赖小鼠复吸行为的作用。结果:与吗啡对照组比较,在sc小剂量(3mg·kg-1)吗啡引燃刺激前30min应用丹参、黄芪小复方60、120mg·kg-1急性治疗,可以使小鼠在伴药箱停留时间显著缩短(P<0.05);而丹参、黄芪小复方30mg·kg-1急性治疗使小鼠在伴药箱停留时间有一定程度缩短,但无统计学意义(P>0.05)。结论:丹参、黄芪小复方在一定程度上可以抑制吗啡引燃的吗啡依赖小鼠的复吸行为。     

侧脑室注射隐丹参酮单体对吗啡诱导的小鼠条件性位置偏爱效应形成和一氧化氮含量的影响

目的:探讨隐丹参酮单体对吗啡诱导的小鼠条件性位置偏爱(CPP)效应形成的影响及成瘾过程中一氧化氮(NO)递质水平改变与小鼠精神依赖的相关联系。方法:利用CPP实验方法,建立吗啡精神依赖模型。侧脑室注射(icv)隐丹参酮单体,观察其对吗啡诱导的CPP效应形成的影响。实验结束后用NO试剂盒测定小鼠全脑NO含量。结果:生理盐水组与吗啡组比较有显著的统计学意义(P<0.001);与吗啡组比较,隐丹参酮低、中、高剂量组(20ug.kg-1,40ug.kg-1,80ug.kg-1,icv)均能降低吗啡诱导的CPP得分,其中,中剂量组有明显的统计学意义(P<0.01),低剂量组和高剂量组有统计学意义(P<0.05),3个给药剂量组与生理盐水组比较均无统计学意义;生理盐水组与吗啡组小鼠全脑NO含量比较有明显的统计学意义(P<0.01)。隐丹参酮低、中、高剂量组均能提高小鼠全脑NO含量,其中,中剂量组和高剂量组与吗啡组比较有明显的统计学意义(P<0.01),与生理盐水组比较无统计学意义,低剂量组与生理盐水组和吗啡组比较均有统计学意义(P<0.05)。结论:隐丹参酮能抑制吗啡诱导的小鼠CPP效应形成,可能与抑制CPP效应形成过程中小鼠全脑NO递质含量的降低有关。     

Blockade of cue- and drug-induced reinstatement of morphine-induced conditioned place preference with intermittent sucrose intake

Sucrose intake has been suggested to alter the expression of morphine-induced conditioned place preference (CPP). To date, the potential effects of sucrose intake on the extinction and drug-induced reinstatement of CPP have not been determined. In the present study, sucrose solution (15%) was given prior to, during, and following the acquisition of morphine-induced CPP. Place preference was subsequently assessed during expression, extinction, and morphine-induced reinstatement. The results showed that the sucrose solution given prior to place conditioning training transiently suppressed the expression of morphine CPP. Sucrose solution given during place conditioning training had no effects on the expression, extinction, and reinstatement of CPP. When the sucrose solution was given following the acquisition of morphine CPP, the extinction of morphine CPP was accelerated, and morphine-induced reinstatement was profoundly inhibited. The above results demonstrated that sucrose intake could differentially affect the expression, extinction, and reinstatement of morphine-induced CPP, depending on the interference schedules. Our findings suggest that offering non-drug rewards could be a valuable approach to maintain abstinence and preventing relapse in drug addicts.     

Cross-reinstatement by cocaine and amphetamine of morphine-induced place preference in mice

The cross-reinstatement by psychostimulants of a conditioned place preference (CPP) induced by morphine was evaluated in mice. In Experiment 1, we examined the effects of a single dose of cocaine and amphetamine on a previously extinguished morphine CPP. After acquisition of CPP induced by morphine (40 mg/kg), animals underwent daily extinction sessions of 15 min duration until the CPP was extinguished. Subsequently, animals received a non-contingent injection of cocaine (25 mg/kg) or amphetamine (4 mg/kg), which produced the reinstatement of the extinguished morphine-induced CPP. In Experiment 2, we evaluated the reinstating effects of several priming doses of cocaine (Experiment 2A) or amphetamine (Experiment 2B). As in the first experiment, after conditioning with morphine (40 mg/kg), mice underwent daily 15 min extinction sessions. When the preference was no longer evident, we tested the effects of cocaine (0, 6.25, 12.5, 25 and 50 mg/kg) and amphetamine (0, 0.5, 1, 2 and 4 mg/kg) on the reinstatement of CPP. Doses from 12.5 mg/kg of cocaine upward and doses from 1 mg/kg of amphetamine upward effectively reinstated CPP. Our results demonstrate cross-reinstatement with psychostimulants and opiates, suggesting that in abstinent individuals, drug exposure can produce craving for the previously abused drug and relapse.     

The effect of a systemically active ORL-1 agonist, Ro 64-6198, on the acquisition, expression, extinction, and reinstatement of morphine conditioned place preference

ORL-1 agonists have been proposed as potential therapeutics for substance abuse based on their propensity to counter the effects of mu opioid agonists in several systems, and to inhibit mesolimbic dopamine release, while mostly being devoid of aversive properties. In support of this, ORL-1 agonists have been shown to block the acquisition of morphine conditioned place preference (CPP). We investigated the effect of Ro 64-6198, a systemically active ORL-1 agonist, on the acquisition, expression, extinction, and reinstatement of morphine (20 mg/kg, s.c.) CPP in C57BL6/J mice. Similar to effects obtained with nociceptin/orphanin FQ, Ro 64-6198 (1 mg/kg, i.p.) blocked the acquisition of morphine CPP when given 15 min prior to each drug and vehicle conditioning session. This effect was not due to state dependent learning, since when tested again in the presence of Ro 64-6198 or vehicle no CPP was observed. Administration of Ro 64-6198 (0.3 or 1 mg/kg, i.p.) on the test day alone, in a separate group of animals, failed to block the expression of morphine CPP. Another group of mice was conditioned to morphine to develop CPP, and then exposed to the CPP chambers in the absence of drug once a day for 30 min to extinguish the CPP. Ro 64-6198 (1 mg/kg, i.p.) given 15 min prior to each session during extinction did not affect the rate of extinction. Finally, another group was conditioned to morphine, their CPP extinguished and subsequently reinstated by a priming injection of morphine (20 mg/kg, s.c.). Ro 64-6198 (1 mg/kg, i.p.), given 15 min prior to the priming injection, blocked reinstatement of morphine CPP. These results suggest that Ro 64-6198's effects may be limited to attenuation of the acute rewarding effects of morphine.     

Role of GABAA receptors in dorsal raphe nucleus in stress-induced reinstatement of morphine-conditioned place preference in rats

Rationale

The serotonin (5-hydroxytryptamine, 5-HT) system plays an important role in stress-related psychiatric disorders and substance abuse. Our data indicate that stress inhibits the dorsal raphe nucleus (DRN)-5-HT system via stimulation of GABA synaptic activity by the stress neurohormone corticotropin-releasing factor and, more recently, that morphine history sensitizes DRN-5-HT neurons to GABAergic inhibitory effects of stress.

Objectives

We tested the hypothesis that DRN GABA_A receptors contribute to stress-induced reinstatement of morphine-conditioned place preference (CPP).

Methods

First, we tested if activation of GABA_A receptors in the DRN would reinstate morphine CPP. Second, we tested if blockade of GABA_A receptors in the DRN would attenuate swim stress-induced reinstatement of morphine CPP. CPP was induced by morphine (5 mg/kg) in a 4-day conditioning phase followed by a conditioning test. Upon acquiring conditioning criteria, subjects underwent 4 days of extinction training followed by an extinction test. Upon acquiring extinction criteria, animals underwent a reinstatement test. For the first experiment, the GABA_A receptor agonist muscimol (50 ng) or vehicle was injected into the DRN prior to the reinstatement test. For the second experiment, the GABA_A receptor antagonist bicuculline (75 ng) or vehicle was injected into the DRN prior to a forced swim stress, and then, animals were tested for reinstatement of CPP.

Results

Intraraphe injection of muscimol reinstated morphine CPP, while intraraphe injection of bicuculline attenuated swim stress-induced reinstatement.

Conclusions

These data provide evidence that GABA_A receptor-mediated inhibition of the serotonergic DRN contributes to stress-induced reinstatement of morphine CPP.     

电损毁伏核核部或壳部对大鼠吗啡奖赏效应及其性功能的影响

目的:研究直流电损毁伏核(nucleus accumbens NAc)核部及壳部对大鼠吗啡奖赏效应及其性功能的影响。方法:建成♂大鼠吗啡条件性位置偏爱(5mg.kg-1,ip)后,用直流电损毁或假损毁其NAc核部或壳部。损毁术后7d及10d时再次测试大鼠位置偏爱的表达。12d时给予大鼠小剂量吗啡(2.5mg.kg-1,ip)后,再次进行测试。之后,让大鼠进行一轮交配,记录性功能相关指标。结果:假损毁组大鼠在各时间点测试时,均可稳定表达已形成的吗啡条件性位置偏爱,而核部及壳部损毁组大鼠在术后7d及10d测试时未表达对吗啡伴药侧的偏爱,但12d给予小剂量吗啡后,壳部损毁组动物再次表达出对伴药侧的偏爱,而核部损毁组则仍未表达任何偏爱;各组大鼠的性功能未受影响。结论:NAc核部损毁能抑制大鼠吗啡CPP的重建,而壳部损毁则不能,且该损毁手术对大鼠的性功能无影响。