178 resultados para CPP


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药物成瘾被认为是药物长期作用于脑而产生的一种慢性复吸性脑疾病,长期反复的药物(如吗啡)滥用会导致一系列严重后果,如药物依赖、药物耐受、强迫性药物寻求等.本实验利用条件化位置偏好(conditioned place preference,CPP)模型来检测大鼠对吗啡依赖和心理渴求等过程;采用双声刺激听觉诱发电位来研究大鼠在慢性吗啡给予、戒断以及再给药过程中海马感觉门控(N40)的动态变化.吗啡组大鼠注射吗啡(10mg/kg,i.p.)12d,经历第一次戒断12d,再次注射吗啡(2.5mg/kg,i.p.)1d,之后经历第二次戒断2d;对照组大鼠注射同体积生理盐水,其余实验条件与吗啡组相同.CPP实验表明,这种药物给予方法促使大鼠对吗啡产生药物依赖和心理渴求.双声刺激诱发电位实验表明,吗啡组大鼠在吗啡给予期间海马感觉门控受到损伤;第一次戒断期的第1~2天海马感觉门控能力减弱,第3天增强,第4~12天逐渐恢复到正常水平;再次给予吗啡后海马感觉门控能力与对照组相比显著降低,并且随后2d的戒断期内海马感觉门控能力也一直保持较低水平,表明再次给药使大鼠海马感觉门控对吗啡更加敏感化.结果提示,长期反复的吗啡给予及再给药干扰了海马的感觉门控能力,吗啡成瘾对大脑可能产生长期影响.

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Learning and memory play an important role in morphine addiction. Status epilepticus (SE) can impair the spatial and emotional learning and memory. However, little is known about the effects of SE on morphine-induced conditioned place preference (CPP). Th

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Learned association between drugs of abuse and context is essential for the formation of drug conditioned place preference (CPP), which is believed to engage many brain regions including hippocampus, and nucleus accumbens (NAc). The underlying mechanisms

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The objective of this study is to conduct a bibliometric analysis of all biological invasions-related publications in the Science Citation Index (SCI) from 1991 to 2007. The indicator citation per publication (CPP) was used to evaluate the impact of articles, journals, and institutions. In the 3323 articles published in 521 journals, 7261 authors from 1905 institutions of 100 countries participated. As the most productive country of biological invasions research, the US will benefit from more collaboration between institutions, countries, and continents. In addition, analysis of keywords was applied to reveal research trends.

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With the widespread exposure of people to nicotine through recreational use of tobacco products, research into nicotine has attracted increasing attention. Tobacco smoking is by far the most important cause of lung cancer. As the world's largest producer and consumer of tobacco products, China bears a large proportion of the global burden of smoking-related disease; therefore, information on nicotine publications should be collected to formulate future research policy. In the present study, we investigated nicotine-related research articles published by Chinese authors that were indexed in the Science Citation Index (SCI) from 1991 to 2007. An indicator "citations per publication" (CPP) was used in the study to evaluate the impact of journals, articles, and institutes. The quantity of publications has increased at a quicker pace than the worldwide trend. Article visibility, measured as the frequency of being cited, also increased during the period. However, the overall quality of articles, based on the impact factor of journals publishing those articles, dropped behind the worldwide average level. There has been an increase in international collaboration, mainly with researchers in the USA. The average CPP of international co-authorship articles was higher than that of single country publications. Besides the USA, nicotine research in China will benefit from more collaboration with Taiwan, England, and Germany. Some 110 of 264 articles were published by a single institute, and the top six institutes were compared from various angles. Seventy-two subject categories were covered, and trends (in terms of both quantity and quality) of nicotine research in China were compared with worldwide trends. In addition, analysis of keywords in both nicotine and lung cancer research fields was applied to indicate research interests. Mutual cooperation among multiple disciplines needs further strengthening.

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The basic idea of the finite element beam propagation method (FE-BPM) is described. It is applied to calculate the fundamental mode of a channel plasmonic polariton (CPP) waveguide to confirm its validity. Both the field distribution and the effective index of the, fundamental mode are given by the method. The convergence speed shows the advantage and stability of this method. Then a plasmonic waveguide with a dielectric strip deposited on a metal substrate is investigated, and the group velocity is negative for the fundamental mode of this kind of waveguide. The numerical result shows that the power flow direction is reverse to that of phase velocity.

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在哺乳动物复杂的神经网络中,突触是信息传递的枢纽,其突触传递效能的持续性变化被称为突触可塑性(synaptic plasticity)。长时程增强(long-term potentiation,LTP)和长时程抑制(long-term depression,LTD)现象是两种经典的突触可塑性形式,被视作学习和记忆可能的物质基础,得到了广泛地关注。其中,海马CA1区谷氨酸能突触处的LTP和LTD目前研究得最为广泛。 α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid(AMPA)受体作为介导兴奋性谷氨酸能突触基础传递的主要受体,是海马CA1区LTP和LTD正常表达的必要条件。近期的研究表明,AMPA受体通过胞吞、胞吐及侧向移动等方式在细胞膜和细胞内进行着持续地循环。因此,通过调节AMPA受体的上、下膜,进而影响突触后膜上AMPA受体的数量,便能对LTP和LTD产生影响。在本研究中,我们利用生物信息学的手段,以AMPA受体为靶点,设计出了旨在特异阻断LTP或LTD的多肽。运用离体脑片全细胞记录方式,在海马CA1区证明了干扰肽Pep-A2能够特异地阻断LTP而不影响LTD,Pep-A3能够特异地阻断LTD而不影响LTP。并初步探究了其关键的作用位点,为进一步理解LTP和LTD具体的分子机理打下了基础。成瘾作为异常的学习记忆过程,势必涉及到突触可塑性的变化。而特异性地阻断LTP和LTD,对药物成瘾效果的影响却鲜有报道(Wang YT,2007)。在另一部分工作中,我们采用穿膜肽Tat-A2和Tat-A3,在吗啡条件化位置偏爱(morphine conditioned place preference,morphine CPP)模型小鼠的测试前进行系统给药,结果发现两种干扰肽均能阻断或损伤其CPP的表达过程。这一现象,提示我们LTP和LTD在条件化位置偏爱的表达过程中都是不可或缺的,同时也为人们更好地理解成瘾过程的机理,及开发专一有效的治疗药物提供了新的思路。

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1997~ 1999年在宁南半干旱偏旱区国家宁南 (海原 )旱农试区设置了旱地糜子与春小麦降水生产潜力及其适度开发试验 ,采用肥力梯度法研究有限降水条件下旱地糜子与春小麦的最大产量与适宜开发度。研究结果表明 ,宁南半干旱偏旱区旱地糜子 3年 (3种降水年型 )平均降水生产潜力为 176 0 .5 kg/ hm2 ,水分利用效率 WU E为0 .6 47kg/ m3 ,潜力适宜开发度为 90 % ,适宜施肥量为氮 90 kg/ hm2、磷 45 kg/ hm2 ;宁南旱地春小麦 3年 (1998~1999年 ,有冬灌 )平均水分生产潜力和 WU E分别为 2 5 5 4.0 kg/ hm2 和 0 .90 3kg/ m3 ,1997年纯旱地降水生产潜力和 WUE分别为 115 8.0 kg/ hm2 和 0 .6 90 kg/ m3 ,潜力适宜开发度为 85 % ,适宜施肥量为氮 6 0 kg/ hm2 、磷 30 kg/hm2 。

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一. 快速扫视系统对瞳孔对光反射系统的调制作用快速扫视系统是研究运动神经控制的一个很好的模型。瞳孔对光反射是由进入视网膜的光亮度的增加而引起的瞳孔的收缩。之前的实验研究表明这两个系统都是开放的系统。但是对快速扫视系统是否对瞳孔对光反射系统有调制作用并没有研究过。本实验研究了注视状态和快速扫视状态下的瞳孔对光反射的潜伏期和瞳孔直径的变化。结果显示在注视状态下的和出现快速扫视时瞳孔对光反射的潜伏期表现出显著不同。外展和内收会引起瞳孔对光反射的潜伏期和瞳孔相对收缩率不同变化。在出现外展运动时,瞳孔对光反射的潜伏期显著下降,而出现内收运动时,瞳孔对光反射的潜伏期表现出显著增加。而瞳孔相对收缩率在出现两种运动时与注视状态下相比也发生不同的变化:外展运动引起瞳孔对光反射的瞳孔相对收缩率的增加,而内收运动引起瞳孔相对收缩率的减少。尽管快速扫视本身会引起瞳孔的收缩,但是引起的瞳孔收缩的变化不等于在出现快速扫视时的瞳孔对光反射的瞳孔直径的变化,这个结果说明在出现快速扫视时的瞳孔对光反射的变化并不是来源于光效应和快速扫视效应的简单叠加。基于快速扫视出现时间的进一步分析说明在瞳孔对光反射周期内不同时间出现两种快速扫视引起的瞳孔对光反射的潜伏期和瞳孔相对收缩率的变化不同。这些结果说明两个系统是有相互作用的,快速扫视系统可以调节瞳孔对光反射系统。关键词:快速扫视 瞳孔对光反射 调制二. 麻醉状态下纳洛酮对吗啡依赖大鼠的岛叶神经元的自发放的影响药物成瘾是药物长期作用于脑而产生的一种慢性复吸性脑疾病。之前有研究表明岛叶参与成瘾的过程。本实验以CPP为检测手段,检测实验大鼠是否产生吗啡依赖(吗啡给药方式为隔天给药,腹腔注射(10mg/kg),共三次。然后采用四合一电极对纳洛酮诱发戒断的麻醉大鼠的岛叶和体感皮层进行细胞外电生理记录。与对照组相比,在记录的神经元中,被激活的神经元的所占比例(71.43%)远远大于对照组。将对照组和实验组的发放显著增加的神经元在给药前后的相对平均发放进行比较,两组神经元发放增加并没有显著差异。采用卡方检验比较了对照组和实验组的发放模式,结果显示两组发放模式存在显著差异。说明岛叶参与的方式可能是有更多数目的神经元参与,而不是通过改变单个神经元的发放参与。这也在神经元水平上为岛叶参与成瘾过程提供了一个证据。

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妊娠期给予阿片类药物常常导致子代出现认知功能障碍,近年来随着人们对毒品问题的关注,妊娠期药物滥用问题也越来越受到人们的关注。由于在人体上进行相关的研究受到很大的限制,许多临床报道都很难得到合理的解释。这些限制包括:很难寻找合适的被研究人群;吸食毒品的时间、剂量、种类等很难确定;被研究人群的经济、文化差异不宜消除。有效的动物模型对于研究妊娠期药物滥用对胚胎中枢神经系统发育及子代认知活动的影响是至关重要的。啮齿类中的大鼠、小鼠等哺乳动物是目前研究胚胎期给予阿片类药物对子代影响比较常用的动物模型,但是啮齿类动物模型很难排除母体在妊娠期和哺乳期由于营养、情绪等因素的变化对胚胎及子代发育产生的影响,鸟类和哺乳类的胚胎发育具有很大的相似性,鸡胚是发育生物学研究中常用的一种实验材料。鸡胚可以在人为控制的、不受母体干扰的条件下发育孵化,这就完全排除了来自母体的干扰,在鸡胚上所获得的药物对胚胎发育及子代各种功能影响的结果,相对而言可以说是药物的直接影响,因此应用鸡胚研究吗啡对胚胎发育的影响在很大程度上弥补了啮齿类动物模型的一些不足。本文利用小鸡一次性回避、食物诱导的条件性位置偏好(CPP)、延缓反应任务等几个经典的模型研究吗啡对胚胎发育及子代认知功能影响,结果表明:胚胎期给予吗啡对小鸡的短时记忆影响不明显,但是对长时记忆产生了明显的影响;小鸡食物诱导的CPP不仅没有受到影响,反而得到了强化;小鸡的工作记忆没有受到影响。

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重复使用吗啡将导致吗啡成瘾,其主要表现如依赖、耐受、敏感化以及吗啡停用后的戒断反应。其核心特征是强迫性吗啡使用:即成瘾者失去了对药物寻觅和摄取的控制。药物成瘾是一个复杂的生物学过程,近年来的研究表明学习记忆参与药物成瘾过程。学习记忆和药物成瘾都受到相似的神经营养因子,递质释放与转运的调控,它们都受到cAMP,CREB等调控因子的调控。研究发现在与成瘾相关的线索,如用药有关的人物、地点或暗示等,都可能恢复觅药和用药行为。当把成瘾相关的线索呈现给戒断中的人时,可以发现这些人表现异常,如心率、呼吸加快,血压升高,并表现明显的渴求行为,前额叶在这种线索导致的渴求行为中起重要作用。以前的研究证实条件化位置偏好(conditioned place preference,CPP)是一个很好的模型来研究环境线索在成瘾中作用,可以用来分析检测成瘾行为。因此,在实验一、二中,采用CPP模型来研究吗啡相关的学习记忆与胆碱系统,以及蛋白质合成的关系;实验三研究了前额叶和海马在吗啡成瘾和戒断过程中谷氨酸(GLU)和γ-氨基丁酸(γ-GABA)含量的变化。 (1):学习和记忆依赖于多种递质的共同作用,不同的递质在不同的学习记忆中的作用也不一样。大量的研究表明胆碱系统在学习记忆中起重要作用,胆碱系统抑制剂可以导致学习记忆障碍。在本实验中,我们研究东莨菪碱(经典的抗胆碱能药物,影响记忆的获取过程)对吗啡以及食物相关的线索的记忆的影响,研究抑制胆碱系统对这两种线索相关的奖赏性学习记忆的影响。采用腹腔注射东莨菪碱,三个不同的剂量(0.5、1、2mg/kg),在给吗啡(40 mg/kg)或者食物之前30分钟给东莨菪碱,连续给药4天。结果显示,除了0.5 mg/kg的东莨菪碱不能抑制食物导致的CPP外,其他剂量的东莨菪碱都明显抑制食物导致CPP。但是东莨菪碱并不能抑制吗啡导致的CPP,而且,2.0 mg/kg东莨菪碱强化了吗啡线索相关的学习记忆。这种结果表明吗啡导致的奖赏性学习和普通的普通记忆存在不同的机制。 (2):记忆的形成需要蛋白质的合成,特别是长时程记忆。在记忆形成的不同阶段,蛋白质的合成对记忆的影响不一样,在学习前后较短的时间内给蛋白质合成抑制剂可以有效的抑制长时程记忆的形成。学习记忆参与吗啡成瘾过程,那么抑制蛋白质的合成是否也能抑制吗啡成瘾相关的学习记忆呢?本实验中,采用环己酰亚胺(蛋白质合成抑制剂,抑制记忆的巩固)来研究抑制蛋白质合成对吗啡线索相关的学习记忆的影响。腹腔给环己酰亚胺,剂量30mg/kg,给药时间为给吗啡前30分钟,同时,后30分钟以及后2小时。实验发现在给吗啡前后30分钟内给环己酰亚胺可以削弱对吗啡相关的线索的记忆,但是不能完全抑制这种记忆的形成,而且在吗啡后两小时给环己酰亚胺基本上对这种记忆没有抑制作用。这种结果表明吗啡相关的联合型学习记忆的形成并不完全依赖于蛋白质的合成,脑内还存在其他的途径来参与这种记忆过程。 (3):GLU和GABA参与许多学习记忆过程,同样它们在吗啡成瘾过程中也起重要的作用。前额叶和海马在记忆中都起到重要的作用,而且它们在成瘾记忆中也扮演重要角色。那么在成瘾及戒断过程中,前额叶和海马中GLU和GABA会有什么变化呢?本实验利用高效液相色谱-紫外分析法分析在吗啡成瘾及戒断过程中前额叶和海马中总GLU和GABA的动态变化。实验发现在吗啡成瘾及戒断过程中,GABA和GLU在前额叶和海马中的总含量都没有显著的变化,尽管在给药和戒断中,这两种递质都下调然后逐渐上升,但是跟对照组比较都不显著。但是比较吗啡组之间的变化,可以看出前额叶GLU在给药及戒断过程中有比较显著的变化。该结果提示在吗啡成瘾和戒断过程中,GLU和GABA的总量并没有发生显著的改变。结合前人的研究我们认为,这两种递质在成瘾和戒断过程中,它们的合成,释放以及在突触间的转运等各个环节都受到影响,从而参与吗啡成瘾。

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中文摘要   Ⅰ 慢性阿片类物质滥用对空间认知功能的影响本章首先对成瘾的神经生物学机制进行综述,然后介绍我的实验研究内容,实验目的是探讨海马在阿片类成瘾中的作用,及阿片类物质滥用对空间认知功能的影响。实验1采用单细胞记录技术,记录自由活动大鼠在慢性吗啡给予后戒断期间海马CA1区神经元发放频率,比较其在吗啡相关环境(阳性环境)及无关环境(阴性环境)中神经元发放频率的变化,且比较神经元发放变化率在各组间的差异。实验2检测了在海洛因戒断初期海洛因依赖者的地图/图标跟随及地图/图标工作记忆的能力。实验3采用Y迷宫行为范式检测在戒断不同时期,慢性吗啡给予对小鼠Y迷宫空间识别能力的影响。实验结果如下:实验1:吗啡戒断后,大鼠海马CA1区部分神经元在阳性环境及阴性环境中的发放率有显著性差异,这些神经元分为两类:Ⅰ类神经元在阳性环境中发放频率高于在阴性环境,Ⅱ类神经元在阳性环境中发放频率低于在阴性环境,其中吗啡组的Ⅱ类神经元发放变化率与盐水组相比存在显著性差异。实验2:海洛因依赖者,尤其女性海洛因依赖者,在地图跟随及地图/图标工作记忆中的成绩明显低于正常被试。实验3:在吗啡戒断第2天、第9天、第19天,小鼠Y迷宫空间识别记忆能力均受到损伤。以上实验结果表明,海马神经元在吗啡相关环境与无关环境中发放频率不同,从而编码了环境刺激与药物经历相关的记忆,在阿片类药物成瘾中起到一定作用;以及阿片类物质滥用损伤了大脑空间认知功能。 Ⅱ 嗅觉系统与吗啡成瘾的相互作用本章首先对嗅觉系统的功能及脑疾病引起嗅觉功能异常进行了综述,然后介绍我的实验研究内容,实验目的是探讨嗅觉系统在吗啡成瘾过程中的作用,及慢性吗啡给予对嗅觉功能的影响。实验1:利用条件化位置偏好模型(CPP),研究气味线索对吗啡依赖及渴求的影响。结果发现,单一嗅觉刺激使小鼠建立条件化位置偏好,形成吗啡依赖。当改变外界环境,动物进入完全新异的环境,依然寻求与吗啡相关的气味线索,说明吗啡相关气味线索能有效诱发小鼠对吗啡的渴求。实验2:研究短期及长期吗啡给予后小鼠嗅觉功能的变化。结果发现, 4天或21天的吗啡给予导致小鼠嗅觉敏感度降低(嗅觉阈值升高),而嗅觉辨别能力没有显著影响。小鼠嗅觉记忆能力受到损伤,随着吗啡给予时间的延长,这种记忆损伤更加明显。我们的实验表明嗅觉系统在吗啡依赖及渴求过程起到非常重要的作用,吗啡成瘾导致部分嗅觉功能的损伤。与药物相关的环境线索是诱发渴求及复吸的原因之一,因此,至少在啮齿类动物模型上,用嗅觉刺激作为药物相关的环境线索来研究渴求及复吸的机制,可能是较好的研究方法。

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The synthesis and characterization of two new polyphenylphenyl compounds is reported. One compound (CPP) acts as a blue light-emitting material, but contains strong electron-accepting groups that form exciplexes with electron-donating arylamines that are widely used as hole-transporting materials. Inserting a layer of the other compound into the organic light-emitting diodes (see figure) suppresses the formation of exciplexes, and gives high-efficiency blue-light emission from the CPP layer.

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The influences of nucleating agent EDBS on crystallization behavior and properties of polypropylene UP) and its copolymer with a small amount (4. 48 %, molar fraction) of ethylene (CPP) were studied. DSC results indicated that the crystallization temperature of iPP and CPP samples with 0.5 % (mass fraction) EDBS obviously increased and the degree of crystallinity of these samples became higher. In addition, adding small amount of EDBS enhanced the crystallization of the low isotacticity and low molecular weight segments of the CPP. PLM results showed that their spherulite size decreased markedly, and as a result, the transmittance and haze of the films were all improved.

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Rewarding experience after drug use is one of the mechanisms of substance abuse. Previous evidence indicated that rewarding experience was closely related to learning processes. Neuroscience studies have already established multiple-mode learning model. Reference memory system and habit memory are associated with hippocampus and dorsa striatum respectively, which are also involved in the rewarding effect of morphine. However, the relationship between spatial/habit learning and morphine reward property is still unclear. After drug use, with sensitization to rewarding effect, spatial learning is also changed. To study the mechanism of increment of spatial learning would provide new perspective about reward learning. Based on the individual difference between spatial learning and reward learning, the experiments studied relationship between the two leaning abilities and tested the function of dorsal hippocampus and dorsal striatum in morphine-induced CPP. The results were summarized below: 1 In a single-rule learning water maze task, subjects better in spatial learning also excelled in rewarding learning. In a multi-rule learning task, morphine administration was more rewarding to subjects of use place strategy. 2 Treatment potentiating the rewarding effect of morphine also increased place-rule learning, with no significant improvement in habit learning. 3 Intracranial injections into CA1 of hippocampus or dorsal striatum of M1 antagonist, Pirenzepine, could block the establishment of morphine CPP after three days morphine treatment. In contrast, the antagonist of D1 receptor SCH23390 had no blocking effect. Both Pirenzepine and SCH23390 blocked the locomotor-stimulating effect of morphine. In summary, spatial learning stimulated the behavioral expression of morphine’s rewarding effect, in which CA1 of hippocampus was critically involved. On the other side, a pretreatment schedule of morphine, while increased the rewarding effect, improved place-rule learning, indicating that spatial learning might be one chain of sensitization to drug rewards effects