应激损害吗啡奖赏记忆再巩固及其对海马CA1脑区活性调节细胞骨架蛋白（Arc）表达的影响

目的：观察应激是否损害吗啡奖赏记忆再巩固及其对海马活性调节细胞骨架蛋白（Arc）的影响。方法：（1）建立大鼠吗啡条件位置偏爱（conditioned place preference,CPP）模型,给予不同的处理即暴露、应激、暴露后立即应激,观察应激对吗啡奖赏记忆再巩固的作用。（2）建立吗啡CPP模型,暴露6 h后应激,观察应激损害吗啡奖赏记忆再巩固是否存在时间窗。（3）处理测试后的大鼠断头取脑,采用免疫荧光法和Western blot法分析应激对吗啡CPP大鼠海马Arc表达的影响。结果：（1）吗啡奖赏记忆唤起后立即给予应激,其再巩固受到损害（P〈0.05）。（2）应激损害吗啡奖赏记忆再巩固作用存在时间窗（P〈0.05）。（3）暴露后给予应激组大鼠在CPP测试后海马CA1脑区中的Arc表达下降（P〈0.05）。结论：（1）应激可损害吗啡奖赏记忆再巩固,且其作用具有时间窗。（2）应激损害吗啡记忆再巩固可能与其降低海马CA1脑区的Arc表达有关。     

吗啡短期戒断时大鼠伏核TRPV1受体对兴奋性突触后电流调节功能的变化

目的：研究吗啡短期戒断后,TRPV1受体功能变化对大鼠伏核中等大小有棘神经元接受的自发性兴奋性突触后电流的影响。方法：20只sD大鼠随机分配为对照组和吗啡组,每天分别接受10mg·kg-1的盐酸吗啡和生理盐水腹腔注射,连续5d。在自然戒断的d3制作伏核脑片,采用红外可视全细胞膜片钳记录技术,检测对照组和吗啡组大鼠的TRPV1受体功能变化对伏核中等大小有棘神经元接受的自发性兴奋性突触后电流的频率及幅度的影响。结果：（I）脑片灌流足量TRPV1受体激动剂capsaicin（CAP）后,对照组和吗啡组自发性兴奋性突触后电流的频率分别为基线水平的138．9±s5．3（％）和176．3±s8．8（％）,两组差异显著（P〈0．05）;幅度分别为基线水平的的101．9±s2．2（％）和103．9±s2．3（％）,无显著差异（P〉0．05）。（2）吗啡组脑片依次灌流TRPV1受体拮抗剂capsazepine（CPZ）及激动剂CAP后,记录到自发性兴奋性突触后电流的频率分别为基线水平的99．1±s1．8（％）和101．2±s0．9（％）,两组无显著差异（P〉0．05）。结论：大鼠反复吗啡暴露短期戒断时伏核TRPV1受体功能增强。     

慢性吗啡成瘾戒断大鼠海马Schaffer侧支-海马CA1区突触可塑性的改变

目的利用离体脑片细胞外微电极记录技术,研究吗啡慢性成瘾戒断后大鼠海马Schaffer侧支至CA1区辐射层突触可塑性的改变。方法雄性SD大鼠随机分为空白对照组、吗啡戒断组(n=9)。吗啡戒断组大鼠连续7 d sc注射吗啡5 mg·kg-1),建立吗啡依赖模型,空白对照组大鼠sc注射等体积生理盐水。停止给予吗啡戒断14 d后断头取脑,置于冰冷人工脑脊液中制备400μm冠状切片。采用离体脑片细胞外微电极记录技术,经Schaffer侧支刺激神经元,在海马CA1区记录细胞外场兴奋性突触后电位的变化。结果高频刺激后30 min,空白对照组fEPSP斜率标准化后的数值为基础测量值的(152±7)%,而吗啡戒断组fEPSP斜率为(213±18)%,明显高于空白对照组,有统计学意义(P<0.05)。结论慢性吗啡成瘾戒断后海马CA1区LTP增强,导致海马Schaffer侧支至CA1区突触传递功能增强。     

海马 GDNFmRNA的表达参与大鼠吗啡戒断反应

目的：观察吗啡戒断大鼠侧脑室胶质细胞源性神经营养因子（glial cell derived neurotrophic factor，GDNF）反义寡脱氧核苷酸注射后对海马GDNFmRNA表达的影响。方法：SD大鼠侧脑室立体定位，皮下注射吗啡建立吗啡依赖大鼠模型，侧脑室微注射GDNF有义和反义寡脱氧核苷酸，纳洛酮催促戒断，应用原位杂交方法检测海马GDNFmRNA的表达。结果：侧脑室注射GDNF反义寡脱氧核苷酸能显著抑制大鼠吗啡戒断症状评分（n=t,p〈0．05）。吗啡依赖大鼠海马CA2区GDNFmRNA表达较对照组显著增加（n=3，P〈0．05），CA1和CA3区变化不明显；吗啡依赖大鼠纳洛酮（4mg／kg，岫催促戒断后海马CA1、CA2和CA3区GDNFmRNA表达较依赖组有增加趋势，但均没有显著差异心=3，P〉0．05）；吗啡依赖大鼠纳洛酮激发前24h侧脑室注射GDNF反义寡脱氧核苷酸能显著抑制吗啡依赖大鼠依赖和戒断后CA2区GDNFmRNA表达的增加（n=3，p〈0．05），而CA1和CA3区与戒断组大鼠相应区域相比没有差异；吗啡依赖大鼠纳洛酮激发前24h侧脑室注射GDNF有义寡脱氧核苷酸与戒断组大鼠相比海马CA1、CA2和CA3区GDNFmRNA表达均没有显著性差异（n=3，P〉0．05）。结论：在转录水平，海马CA2区GDNF表达的变化在吗啡依赖和戒断中可能起重要作用。     

高脂饮食对大鼠下丘脑前增食欲素原及CRH表达的影响

目的观察高脂饮食摄入对大鼠下丘脑前增食欲素原增食欲素受体1、2及促肾上腺皮质激素释放激素（cRH）表达的影响。方法高脂饮食喂养3周后,观察高脂饮食摄入前后大鼠下丘脑及前增食欲素原、增食欲素受体1、2mRNA表达;观察CRHmRNA表达水平变化。结果高脂饮食摄入后大鼠前增食欲素原mRNA表达降低（P〈0．05）;两组组间增食欲素受体1和受体2mRNA表达,差异均无统计学意义（P〉0．05）。高脂饮食摄入后下丘脑CRH表达无明显增加。结论高脂饮食诱导大鼠过度摄食的机制可能与下丘脑CRH、增食欲素等食欲调节因子表达失调,对摄食行为失控制有关。     

问歇游泳运动对大鼠下丘脑弓状核Fos蛋白表达的影响

目的以大鼠间歇游泳训练为模型，观察其下丘脑弓状核Fos蛋白在6周游泳训练结束后不同时间点的表达及变化规律。方法将30只雄性SD大鼠随机分为对照组（n=5）和运动组（n=25），6周游泳训练结束后用免疫组织化学技术链霉素亲和素一生物素一过氧化物酶技术（SABC）法检测即刻，0．5，1，2，4h5个时间点弓状核Fos蛋白的表达情况，通过图像分析系统和统计学软件进行图像和数据分析。结果与对照组相比，运动组Fos蛋白表达在运动结束后0h明显增加（P〈0．05），0．5h达到峰值（P〈0．05），1h表达下降（P〈0．05），2h再次升高（P〈0．05），4h降至正常对照水平（P〉0．05）。结论运动性应激可以迅速促进下丘脑弓状核Fos蛋白的活化。     

100Hz电针通过激活伏隔核内κ阿片受体抑制可卡因CPP的表达

目的：探讨100Hz电针抑制大鼠可卡因条件位置偏爱（Conditioned Place Preference,CPP）表达的机制。方法：采用可卡因诱导大鼠CPP模型,观察（1）选择性κ阿片受体拮抗剂nor-BNI加100Hz电针对可卡因CPP表达的影响;（2）每次电针前给大鼠双侧伏隔核内注射nor-BNI,能否阻断电针对可卡因CPP的表达;（3）电针处理可卡因CPP大鼠伏核组织中κ阿片受体mRNA表达的变化。结果：（1）10μg／5μl nor—BNI侧脑室给药或0．3μg／1μl nor-BNI伏隔核内微注射预处理给药都能翻转100Hz电针对可卡因CPP的抑制作用;（2）100Hz电针能显著增加可卡因CPP大鼠伏隔核内κ阿片受体mRNA的表达。结论：100Hz电针通过激活伏隔核内κ阿片受体从而抑制可卡因CPP的表达。     

气体信号分子NO对可卡因戒断所致的大鼠成瘾记忆的影响

目的一氧化氮(NO)作为一种内源性气体信号分子,在中枢神经系统发挥广泛的生物学效应。有研究报道NO参与可卡因等药物成瘾的形成过程。近年来的研究发现,可卡因成瘾戒断会导致伏隔核(NAc)区突触表面的AM-PA受体表达上调,而这种上调被认为与可卡因的行为敏化的维持有关。然而,NO是否也在可卡因成瘾的戒断行为中发挥重要作用则尚未见报道。方法采用Western blotting技术结合脑片膜片钳和场电位记录方法,研究NO在可卡因成瘾戒断所致大鼠成瘾记忆中的作用及其机制。结果可卡因戒断导致大鼠NAc区突触部位GluR1和GluR2亚基的蛋白表达出现不成比例的上调,nNOS的表达、NO的含量,以及NSF的亚硝基化水平均有所增加。外源性使用NO供体可增加戒断大鼠NAc区的NSF亚硝基化水平并选择性上调突触部位GluR2的含量,逆转戒断后NAc区的突触可塑性变化。另外,外源性给予NO供体和亚硝酸钠均可通过增加NAc区NSF与GluR2的结合能力来阻断戒断后大鼠的行为敏化。结论可卡因戒断引起的NAc区NSF亚硝基化水平和突触部位GluR2亚基表达增加是大脑出现的一种内源性代偿机制,从而限制机体对可卡因的长时程异常行为反应。     

吗啡依赖大鼠戒断后心血管活动的改变及机理

目的：观察吗啡依赖大鼠戒断反应后心血管活动的改变。方法：用递增法制备吗啡依赖大鼠模型，并用纳洛酮催促戒断，在清醒状态下用ＰＳ－１００型大鼠尾动脉血压记录仪记录平均动脉血压（ｍＡＢＰ）和心率（ＨＲ）。结果：吗啡依赖大鼠在纳洛酮催促戒断后ｍＡＢＰ明显升高，并持续３０ｍｉｎ以上。皮下注射可乐定可阻断吗啡依赖大鼠戒断后ｍＡＢＰ的升高，且呈明显的量效关系。结论：吗啡依赖大鼠戒断时ｍＡＢＰ有明显的上升，可乐定可使吗啡戒断时上升的ｍＡＢＰ下降     

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。     

孕酮对吗啡位置偏爱大鼠相关脑区中亮氨酸脑啡肽水平的影响

目的:观察孕酮对于吗啡所致奖赏效应及相关脑区中亮氨酸脑啡肽水平的影响。方法:将40只SD大鼠随机均分为对照组(环糊精)、吗啡组、孕酮组和孕酮+吗啡组,建立吗啡条件性位置偏爱(CPP)模型,上午各组皮下给予相应药物后放入白室训练45min;下午各组均皮下和腹腔给予等量的环糊精和生理盐水后放入黑室训练。连续训练10d后进行CPP测试并处死大鼠取脑组织采用放射免疫法测定大鼠不同脑区中亮氨酸脑啡肽(L-EK)的含量。结果:与对照组比较,吗啡组发生CPP效应,下丘脑、伏隔核和额叶皮质中的L-EK水平显著降低(P<0.05或P<0.01);与吗啡组比较,孕酮+吗啡组CPP效应受到抑制,上述位置中L-EK水平显著升高(P<0.05或P<0.01),而海马和中脑内L-EK水平未见显著性变化。结论:孕酮可以有效抑制吗啡CPP效应,其机制可能与其逆转吗啡诱导的相关脑区中的L-EK水平的变化有关。     

Role of lateral hypothalamic orexin neurons in reward processing and addiction

Orexins (also known as hypocretins) are recently discovered neuropeptides made exclusively in hypothalamic neurons that have been shown to be important in narcolepsy/cataplexy and arousal. Here, we conducted behavioral, anatomical and neurophysiological studies that show that a subset of these cells, located specifically in lateral hypothalamus (LH), are involved in reward processing and addictive behaviors. We found that Fos expression in LH orexin neurons varied in proportion to preference for morphine, cocaine or food. This relationship obtained both in drug na?ve rats and in animals during protracted morphine withdrawal, when drug preference was elevated but food preference was decreased. Recent studies showed that LH orexin neurons that project to ventral tegmental area (VTA) have greater Fos induction in association with elevated morphine preference during protracted withdrawal than non-VTA-projecting orexin neurons, indicating that the VTA is an important site of action for orexin's role in reward processing. In addition, we found that stimulation of LH orexin neurons, or microinjection of orexin into VTA, reinstated an extinguished morphine preference. Most recently, using a self-administration paradigm we discovered that the Ox1 receptor antagonist SB-334867 (SB) blocks cocaine-seeking induced by discrete or contextual cues, but not by a priming injection of cocaine. Neurophysiological studies revealed that locally applied orexin often augmented responses of VTA dopamine (DA) neurons to activation of the medial prefrontal cortex (mPFC), consistent with the view that orexin facilitates activation of VTA DA neurons by stimulus-reward associations. We also recently showed that orexin in VTA is necessary for learning a morphine place preference. These findings are consistent with results from others showing that orexin facilitates glutamate-mediated responses, and is necessary for glutamate-dependent long-term potentiation, in VTA DA neurons. We surmise from these studies that LH orexin neurons play an important role in reward processing and addiction, and that LH orexin cells are an important input to VTA for behavioral effects associated with reward-paired stimuli.     

100Hz电针对大鼠可卡因CPP重建的影响

目的:探讨100Hz电针对大鼠可卡因条件位置偏爱(Conditioned Place Preference,CPP)重建的影响.方法:采用可卡因诱导大鼠CPP重建模型,观察100 Hz电针对大鼠可卡因CPP重建的作用及选择性κ阿片受体拮抗剂nor-BNI对电针作用的影响.结果:100 Hz电针5次刺激抑制了可卡因(5 mg/kg)引燃CPP重建,nor-BNI(10μg/5μl)翻转了电针对可卡因CPP重建的抑制作用.结论:多次电针可通过κ阿片受体抑制可卡因引燃CPP的重建.     

Assessing learned associations between conditioned cocaine reward and environmental stimuli in the Wistar Kyoto rat

Clinical studies demonstrate that anxiety disorders increase the risk of substance use disorder. However, few studies have directly assessed anxiety as a vulnerability factor in processing of rewarding stimuli. The Wistar-Kyoto (WKY) rat has been proposed as a model of anxiety vulnerability because it exhibits extreme behavioral inhibition in novel and social environments; yet, it displays paradoxical rapid active avoidance learning that is resistant to extinction. The present study was designed to characterize the acquisition and persistence of cocaine conditioned place preference (CPP) in WKY rats. In the first of a series of three experiments, adult male WKY and Sprague Dawley (SD) rats were given six pairings of cocaine (3, 5, 10, 15 mg/kg) or saline on alternating days. SD rats developed cocaine-induced CPP to each of the four doses of cocaine tested. In contrast, WKY rats demonstrated CPP when conditioned with 3, 5, and 10 mg/kg, but displayed no preference to the 15 mg/kg dose. Next, separate groups of rats were subject to an extended CPP paradigm, which included acquisition, extinction and reinstatement phases. Rats were conditioned with cocaine and saline on alternating days using either a 6/6 (as above) or 4/4 conditioning regimen. Both SD and WKY rats acquired a lasting CPP with the 6/6 conditioning regimen. Results from the 4/4 conditioning regimen show that SD, but not WKY, rats acquired CPP. Preference scores for SD rats during the cocaine primed reinstatement test were significantly different from pretest scores indicating reinstatement of CPP in this group. Paradoxically, WKY rats demonstrated a latent sensitization to the conditioned rewarding effects of cocaine during the drug-primed reinstatement test. Taken together, WKY rats appear to be more sensitive to high doses of cocaine and need more experience with the drug to acquire a preference than SD rats.     

The effects of the kappa agonist U-50,488 on cocaine-induced conditioned and unconditioned behaviors and Fos immunoreactivity

The ability of kappa opioid agonists to modulate dopamine-mediated behavior and Fos immunore-activity was assessed in adult rats. It was predicted that kappa agonist treatment would block the unconditioned and conditioned behaviors produced by cocaine (an indirect dopamine agonist). In the initial experiments, cocaine-induced locomotor activity was assessed after either acute or chronic injections of the kappa receptor agonist U-50,488 (5 mg/kg, SC). As expected, U-50,488 decreased cocaine-induced activity, while leaving baseline activity levels unaffected. Interestingly, chronic treatment with U-50,488 did not induce behavioral tolerance. The conditioned effects of cocaine (20 mg/kg, IP) were assessed using the conditioned place preference (CPP) paradigm. As expected, rats showed a preference for the cocaine-paired compartment, an effect blocked by U-50,488 (5 mg/kg, SC). One hour after CPP testing, rats were killed and Fos immunoreactivity was assessed. Rats conditioned with cocaine, but not U-50,488, showed increased Fos activity in the anterior cingulate cortex, piriform cortex, lateral septal area, and olfactory tubercles. When considered together, these results suggest that U-50,488 was effective at blocking the unconditioned and conditioned effects of cocaine, as well as cocaine-induced neuronal activity (as measured by Fos induction).     

姜黄素通过抗应激作用改善脑缺血再灌注大鼠工作记忆

目的：探讨姜黄素预先给药对大鼠全脑缺血再灌注后空间工作记忆改善作用的机制.方法：成年雄性SD大鼠120只,经T迷宫训练后按随机数字表法分成5组：假手术组（SHAM组）、脑缺血再灌注组（IR组）、姜黄素组（CUR组）、皮质酮组（CORT组）和姜黄素＋皮质酮组（CUR＋ CORT组）,每组24只.各组给予相应药物、溶媒注射,1h后全脑缺血10 min后再灌注,于再灌注7d行T迷宫检测工作记忆,于再灌注2h、1、3、7d采血清和脑组织标本,TUNEL法检测海马CA1区神经元凋亡情况,ELISA检测血清皮质酮（CORT）和海马脑源性神经营养因子（BDNF）的表达.结果：与SHAM组比较,IR组CORT水平增加（164±36 vs 92±24,P＜0.05）,海马BDNF含量降低（8.7±2.8 vs 19.4±5.1,P＜0.05）,海马CA1区凋亡神经元数目增加（233±22 vs 21±4,P＜0.01）,T迷宫正确率降低（65％±7％ vs 87％±9％,P＜0.05）;与IR组比较,CUR组CORT水平降低（102±18,P＜0.05）,海马BDNF含量增加（13.3±3.3,P＜0.05）,海马CA1区凋亡神经元数目减少（163±11,P＜0.05）,T迷宫正确率增高（79％±10％,P＜0.05）;与IR组比较,CORT组海马BDNF降低（4.4±1.2,P＜0.05）,海马CA1区凋亡神经元数目增加（332±35,P＜0.05）,T迷宫正确率降低（58％±6％,P＜0.05）;与CORT组比较,CUR＋ CORT组海马BDNF含量增加（10.5±2.3,P＜0.05）,海马CA1区凋亡神经元数目降低（211±27,P＜0.05）,T迷宫正确率增高（71％±12％,P＜0.05）.结论：姜黄素预先给药可通过抑制应激反应改善大鼠全脑缺血再灌注后空间工作记忆.     

吉西他滨聚氰基丙烯酸正丁酯纳米粒对大鼠脑移植胶质瘤的影响研究

目的:考察主动脑靶向制剂1%吐温-80包衣的吉西他滨(GCTB)聚氰基丙烯酸正丁酯纳米粒(GCTB-PBCA-NP)对大鼠脑移植胶质瘤的影响。方法:用C6脑胶质瘤细胞制作大鼠恶性肿瘤模型,14d后,15只雄性SD大鼠随机分成3组,各组分别给予1%吐温-80包衣的GCTB-PBCA-NP(GCTB包衣组)、注射用盐酸GCTB(阳性对照组)和生理盐水(阴性对照组),考察各组大鼠的平均生存时间和脑组织病理形态学。结果:GCTB包衣组、阳性对照组和阴性对照组的平均生存时间分别为(25.50±2.18)、(23.70±2.28)和(21.50±2.00)d(25.50±2.18vs.21.50±2.00,P<0.05;25.50±2.18vs.23.70±2.28,P>0.05),且GCTB包衣组脑组织病理形态学与阴性对照组比较病变恶化程度更轻。结论:1%吐温-80包衣GCTB-PBCA-NP后对大鼠脑移植胶质瘤具有一定的脑靶向及延长生存时间作用。     

The role of beta-endorphin in the acute motor stimulatory and rewarding actions of cocaine in mice

Rationale Opioid receptor antagonists have been shown to attenuate the rewarding and addictive effects of cocaine. Furthermore, cocaine has been shown to cause the release of beta-endorphin, an endogenous opioid peptide. Objective We assessed whether this neuropeptide would play a functional role in cocaine-induced motor stimulation and conditioned place preference (CPP). Materials and methods Mice lacking beta-endorphin and their wild-type littermates were habituated to motor activity chambers for 1 h, then injected with cocaine (0, 15, 30, or 60 mg/kg, intraperitoneally) or morphine (0, 5, or 10 mg/kg, subcutaneously), and motor activity was recorded for 1 h. In the CPP paradigm, mice were tested for baseline place preference on day 1. On days 2 and 3, mice received an alternate-day saline/cocaine (15, 30, or 60 mg/kg) or saline/morphine (10 mg/kg) conditioning session and then tested for postconditioning place preference on day 4. Results Cocaine-induced motor stimulation and CPP were both reduced in mice lacking beta-endorphin. On the other hand, motor stimulation and CPP induced by morphine were not altered in mutant mice. Conclusion The present results demonstrate that the endogenous opioid peptide beta-endorphin plays a modulatory role in the motor stimulatory and rewarding actions of acute cocaine.     

吗啡精神依赖大鼠奖赏环路多巴胺递质含量和D2受体表达的变化

目的：观察吗啡条件性位置偏爱（cPP）大鼠中脑腹侧被盖区-伏核-前额叶皮质（VTA—NAc—PFC）奖赏环路3个脑区多巴胺（DA）递质和多巴胺2受体（D2受体）的同步变化,从神经递质和受体层面探讨该环路中多巴胺能系统的阿片类精神依赖机制。方法：SD大鼠随机分为模型组和生理盐水组,吗啡剂量递增注射建立大鼠吗啡cPP模型;高效液相色谱法测定各脑区DA含量;免疫组化和Westernblot技术检测D2受体的表达。结果：模型组大鼠伴药箱停留时间增加;vTA、NAc、PFC的DA递质升高、D2受体平均吸光度值和平均光密度值均降低,同Ns组比较,差异有统计学意义（均P〈0．05）。结论：奖赏环路3个脑区多巴胺递质的增加和D2受体表达下调的同步改变,与吗啡精神依赖的形成具有一定的相关性。