海洛因诱导位置偏爱大鼠额叶联络皮层脑电样本熵分析

为了探究海洛因诱导位置偏爱大鼠的觅药行为及动机形成与样本熵值之间的关联,在黑、白箱停留、白-黑箱穿梭、黑-白箱穿梭四种不同的大鼠行为状态下,研究对照组与海洛因诱导条件性位置偏爱(CPP)组大鼠的前额联络皮层(FrA)脑电(EEG)数据样本熵值。实验结果表明,与对照组比较,海洛因诱导CPP大鼠在白-黑箱穿梭和黑箱停留状态时,FrA区EEG样本熵值无显著改变;但黑-白箱穿梭和白箱停留状态时,FrA区EEG样本熵值显著变小(P0.01)。由此可见,海洛因诱导CPP大鼠觅药动机形成及其行为与EEG样本熵值改变之间密切相关。     

吗啡成瘾大鼠边缘下区脑电活动的无线遥测及分析

 目的：遥测并分析吗啡成瘾大鼠条件性位置偏爱（conditioned place preference,CPP）模型制备前后边缘下区（infralimbic cortex, IL）脑电活动的实时变化。方法：选用雄性SD大鼠随机分2组（吗啡戒断组和盐水对照组,每组各12只）,进行脑立体定位埋植电极手术,采用吗啡注射结合CPP训练制备吗啡成瘾大鼠CPP模型,对照组注射生理盐水。利用CPP视频系统和脑电无线遥测系统,检测造模前后大鼠CPP行为的变化及IL区脑电活动的改变。结果：分别与造模前和对照组白箱内停留时间比较,戒断组大鼠戒断1~3 d在白箱内停留时间延长（均P<0.01）。与对照组比较,戒断组大鼠戒断3 d在白箱停留时,IL区脑电δ波明显减少,β波（β 2）明显增加（P<0.05或P<0.01）,α波及θ波变化无显著差异（P>0.05）;戒断组大鼠由黑箱向白箱穿梭时,IL区脑电表现为δ波显著增加（P<0.01）,α波（α 1、α 2）及β波（β 1、β 2）显著减少（均P<0.01）,θ波无明显变化（P>0.05）;戒断组大鼠在黑箱停留或由白箱向黑箱穿梭时,IL区脑电各波与对照组比较无显著差异（P>0.05）。结论：吗啡成瘾大鼠穿梭觅药与停留在药物相关环境中引发的IL区脑电活动的改变机制可能不同;IL区神经元功能可能存在双重性。     

GluN2亚基在海洛因诱导CPP模型大鼠PrL区的表达

目的:研究大鼠内侧前额叶皮质(mPFC)边缘前区(PrL)GluN2亚基在海洛因诱导条件位置性偏爱(CPP)及戒断状态的表达。方法:24只SD大鼠随机分为对照组(control)和海洛因诱导组。海洛因诱导组大鼠按实验进程分为两种状态,即海洛因诱导CPP状态(heroin)和海洛因戒断状态(withdrawal)。用小剂量递增法皮下注射海洛因,行大鼠海洛因诱导CPP建模,并自然戒断,免疫荧光染色检测各组大鼠PrL区GluN2亚基NR2A、NR2B、NR2C、NR2D的表达。结果:大鼠经过连续7 d小剂量递增法注射海洛因,形成了稳定的CPP;免疫荧光染色结果显示,大鼠CPP状态PrL区NR2B表达较对照组显著增强(P<0.01),其他亚基无明显变化。海洛因自然戒断7 d后,戒断状态大鼠PrL区NR2A、NR2C表达较对照组和CPP状态皆显著增强(P<0.01)。戒断状态NR2B表达水平显著高于对照组(P<0.01),但与CPP状态无显著差异。结论:大鼠海洛因依赖CPP的形成与PrL区NR2B亚基的活性密切相关,NR2A和NR2C可能参与药物戒断症状的调控。推测PrL区GluN2不同亚基在海洛因成瘾不同阶段作用不同,并可能成为临床海洛因成瘾干预和治疗的重要靶点。     

BDNF和GDNF在海洛因诱导条件性位置偏爱大鼠mPFC的表达

目的:研究大鼠边缘前区(PrL)和下边缘皮层(IL)BDNF和GDNF在海洛因诱导条件性位置偏爱(CPP)及戒断状态的表达变化.方法:SD大鼠随机分为对照组(control)和海洛因诱导组,海洛因诱导组分为海洛因诱导CPP状态(heroin)和戒断状态(withdrawal).小剂量递增法行海洛因诱导CPP建模,并自然...     

SD大鼠海洛因CPP易感性差异的伏隔核壳区D2受体及DAT机制

目的:建立大鼠海洛因成瘾易感性差异的条件性位置偏爱模型,检测海洛因CPP易感性差异大鼠伏隔核壳区(AcbSH)D2受体(dopamine D2 receptor,D2R)及多巴胺转运体(dopamine transportor,DAT)蛋白表达的动态变化,探讨海洛因精神依赖易感性差异可能机制.方法:130只雄性SD大鼠随机抽取30为生理盐水对照组(SC),其余100只大鼠为海洛因处理组进行条件性位置偏爱(CPP)训练,海洛因处理组根据海洛因诱导的CPP强度不同再分为高CPP组(HP)和低CPP组(LP),各占总数的30%,利用免疫组化方法对高、低偏爱组及生理盐水对照组大鼠末次海洛因注射后30分钟、戒断第1、3、7、14天AcbSH D2R和DAT蛋白表达进行检测.结果:①海洛因处理后大鼠AcbSH区D2R和DAT蛋白表达均显著下降,而在戒断后逐渐回升;②海洛因高偏爱组大鼠在所有检测时点AcbSH区D2R下凋比低偏爱组大鼠更为明显;③海洛因高偏爱组大鼠各脑区所有检测时点DAT表达与低偏爱组大鼠均无明显差别.结论:①海洛因慢性处理后,大鼠AcbSH区D2R和DAT均出现适应性下调;②不同个体D2R敏感性或受体水平存在差异,低D2R可能与海洛因成瘾的高易感性与有关;③未发现不同易感性的大鼠DAT蛋白水平存在差异,海洛因成瘾易感性与DAT的表达可能没有直接的相关性.     

海洛因诱导大鼠伏隔核NMDA受体亚基对GABA表达的影响

目的:研究大鼠伏隔核(NAc)在海洛因诱导条件性位置偏爱(CPP)状态及戒断状态下，NMDA受体亚基NR2B和NR2C对GABA表达的调控，探索GABA能神经元上NR2B和NR2C亚基在海洛因诱导中的作用。方法:将SD大鼠随机分为两组，即对照组和海洛因诱导组。海洛因诱导组又分为海洛因诱导CPP状态和海洛因戒断状态。采用海洛因小剂量递增法皮下连续注射7 d,建立海洛因诱导CPP模型，再自然戒断7 d,免疫组织化学染色检测各组大鼠伏隔核GABA和NR2B、NR2C亚基的位置关系。结果:采用小剂量递增法连续注射7 d海洛因，大鼠形成了稳定的海洛因诱导CPP模型。免疫荧光染色结果可见，各组大鼠伏隔核均有GABA、NR2B和NR2C表达，且GABA与NR2B及NR2C受体均有共表达。免疫组织化学结果显示，海洛因成瘾状态大鼠伏隔核GABA表达量明显高于对照组和戒断状态，具显著性差异(P<0.01)。戒断状态大鼠GABA表达量最低。结论:GABA的表达变化受NMDA受体亚基活性的影响；NR2B亚基对GABA的调控作用可能参与了海洛因依赖的复燃。     

大鼠主要水溶性晶体蛋白在老化进程中的时相变化

目的: 研究大鼠老化进程中主要晶体蛋白相对含量的时相变化与晶体老化的关系。方法: 常规饲养不同年龄SD大鼠(出生后1 d、8 d、2周、8周、8个月及1.5年);提取水溶性晶体蛋白,双向电泳(等电聚焦/SDS-聚丙烯酰胺凝胶电泳, IEF/SDS-PAGE)得到大鼠晶体蛋白电泳图形;考马斯亮蓝染色后扫描蛋白图形,分别确认各主要晶体蛋白组分并测定其相对含量百分比组成。 结果:(1)所测各组大鼠18种主要晶体蛋白组分中,7种晶体蛋白相对含量呈渐进性时相改变,但总水溶性晶体蛋白水平未见明显变化。(2)晶体蛋白相对含量时相改变主要有4种形式:升高(βB₄、αB₂、αA₂、βA₁)、降低(β₇、β₈、γ_2,3、γ_5,6)、大致保持稳定(βA₃、βB₅)及无规则性改变。(3)晶体蛋白βB₄ /αA₂比值在大鼠老化进程中呈渐进性升高。结论: 晶体蛋白相对含量的渐进性时相改变反映晶状体老化的程度。     

β1整合素抑制β淀粉样蛋白对记忆长时程增强的作用

背景：抑制小鼠海马脑片整合素活动后,虽然不会影响长时程增强的诱导,但却带来快速的长时程增强衰减,证明整合素对于诱导后长时程增强的维持和稳定起到关键的作用。 目的：通过在体电生理技术阐明整合素的β1亚基在活体大鼠的海马CA1区中β淀粉样蛋白抑制长时程增强的过程中所起到的作用。 方法：将15只SD大鼠等分为对照组、β淀粉样蛋白组和β1整合素拮抗剂组,分别给予生理盐水,β淀粉样蛋白和β1整合素的选择性拮抗剂,记录自给予β淀粉样蛋白前10 min至高频强直刺激后3 h时的兴奋性突触后电位。 结果与结论：给予对照组大鼠高频强刺激后兴奋性突触后电位明显增强,增幅在30%以上。β淀粉样蛋白组大鼠给予高频强刺激后兴奋性突触后电位在3 h中被显著抑制,没有出现明显的变化。而β1整合素拮抗剂组大鼠给予高频强刺激后兴奋性突触后电位又出现明显的增强。推测β1整合素在活体大鼠的海马CA1区中β淀粉样蛋白抑制长时程增强的过程中可能起着重要的介导作用,而其特异性的拮抗剂或抗体可以阻断这种介导作用。     

中枢白细胞介素-1β介导束缚应激性升压反应的中枢机制

目的:研究中枢白细胞介素-1β(IL-1β)在束缚应激诱发的升压反应的中枢机制。方法:利用清醒大鼠心血管遥感监测系统、脑立体定位微量注射系统、神经电生理记录系统来观察中枢IL-1β在束缚应激诱发的升压反应机制中的作用;以及与延髓头端腹外侧区神经元放电变化之间的关系。结果:束缚应激可诱导升压反应,侧脑室注射IL-1ra可衰减束缚应激诱导的升压反应;直接将IL-1β注入侧脑室亦可诱导大鼠血压升高,同时伴有延髓头端腹外侧区神经元细胞外放电频率增加,二者呈明显的相关关系(r=0.98,P<0.05)。结论:中枢IL-1β介导束缚应激诱发的升压反应,其作用机制与延髓头端腹外侧区密切相关。     

电刺激POAH对IL-1β作用下兔VSA温敏神经元放电的影响

目的和方法:为了从细胞水平进一步探讨发热时体温正、负调节中枢的调节机制,本实验采用微电极细胞外记录技术,在26只新西兰兔脑腹中隔区(ventralseptalarea,VSA)记录了温敏神经元单位放电,观察电刺激下丘脑视前区(preopticanteriorhypothalamus,POAH)对致热原IL-1_β作用下兔VSA温敏神经元放电的影响。结果:(1)侧脑室注射的白介素-1_β(IL-1_β)能使VSA热敏神经元放电频率增加,冷敏神经元放电减少,而侧脑室注射等量人工脑脊液(ACSF)对热敏神经元和冷敏神经元的放电均无明显影响。(2)电刺激POAH可反转致热原IL-1_β对VSA热敏神经元和冷敏神经元的上述作用。结论:在致热原作用下的体温调节中,正调节中枢POAH和负调节中枢VSA具有密切的相互作用。     

Naloxone attenuates the conditioned place preference induced by wheel running in rats

Pairings, during which an episode of wheel running is followed by confinement in a distinctive place, produce conditioned place preference (CPP) in rats. This finding indicates that wheel running has a rewarding effect that outlasts the activity itself. In two similar experiments, we tested the hypothesis that this rewarding effect of wheel running is mediated by endogenous opioids. During a paired trial, the rats in the naloxone group were first allowed to wheel run for 2 h, then injected with naloxone (0.5 or 0.1 mg/kg in Experiments 1 and 2, respectively), and 10 min later placed in a distinctive chamber. During an unpaired trial, these rats were confined in an adjoining chamber without wheel running. Naloxone was injected before placement in both chambers, so that if naloxone-induced conditioned place aversion occurred, it would have counteracting effects on performance during the preference test. The rats in the saline group were similarly treated, except that saline was injected instead of naloxone. CPP occurred in the saline group, but not in the naloxone group. Thus, naloxone attenuated the CPP induced by wheel running. This finding supports the hypothesis that the rewarding effect of wheel running is mediated by endogenous opioids.     

A morphine-paired environment alters c-Fos expression in the forebrain of rats displaying conditioned place preference or aversion

The question of whether a common mechanism mediates both aversive and rewarding drug-paired cues is still unclear. In this study, we used a place preference conditioning paradigm to train rats to associate 1 chamber with morphine and the other chamber with saline. On the test day, rats were divided into those displaying conditioned place preferences (CPP) versus conditioned place aversion (CPA). After the test, all rats were killed and c-Fos immunocytochemistry was performed. For the control group, rats were treated with the same procedure except that the injections of morphine or saline had no association with the chambers. Compared with the control group, the CPP and CPA groups showed a significant increase of c-Fos expression in the dorsomedial striatum, central medial nucleus of the thalamus, and the basolateral amygdala. However, we saw no difference between CPP and CPA rats in any brain region examined. These results suggest that a morphine-paired environment can elicit neural activity in brain regions that are involved in emotional learning. Morphine-conditioned place preference and aversion may share a common neural circuitry elicited by a morphine-paired environment.     

Contribution of the suprachiasmatic nucleus to day:night variation in cocaine-seeking behavior

Recent work has shown that time-of-day influences drug-seeking behavior. The present experiments tested the hypothesis that the master circadian pacemaker located in the suprachiasmatic nucleus of the hypothalamus (SCN) is required for generating day:night differences in drug-seeking behavior, specifically the acquisition, extinction, and reinstatement of cocaine-induced conditioned place preference (CPP). Sham and SCN-lesioned (SCNx) rats were trained for cocaine-induced CPP behavior at either ZT4 (Zeitgeber time 4, 4 h after lights-on) or ZT12 (lights-off). After being tested for side preference, rats were allowed to extinguish CPP. This was followed by cocaine-induced reinstatement with 5 mg/kg and 10 mg/kg of cocaine. SCNx animals exhibited no 24-h locomotor activity rhythm. Acquisition of CPP behavior did not vary with time-of-day, but was greater in SCNx animals. Sham rats tested at ZT12 took significantly longer to extinguish CPP behavior compared to ZT4, an effect completely abolished by SCN lesions. Cocaine-induced reinstatement of CPP did not vary with time of day in sham rats. However, SCNx animals tested at ZT4 trended towards greater reinstatement to the low dose of cocaine, and displayed significantly less reinstatement to the higher dose of cocaine than sham rats. Additionally, SCNx rats tested for reinstatement to the lower dose of cocaine displayed greater reinstatement at ZT4 than at ZT12. We conclude that: 1) acquisition of CPP behavior does not vary between the two times of day tested but is influenced tonically by the SCN, 2) extinction of cocaine CPP varies with time-of-day and this variation depends critically on the SCN, and 3) reinstatement of cocaine CPP does not vary between the two times of day tested. However, day:night differences in reinstatement are unmasked in animals lacking an SCN, suggesting the possibility that an extra-SCN oscillator is responsible for generating variation in this cocaine-seeking behavior.     

大鼠脑缺血不同时期躯体感觉诱发电位的研究

脑电信号（EEG）具有较高的时间分辨率、可观测脑内活动的动态变化、完全无损检测等优点,常用于对神经系统疾病的诊断,本研究探讨脑缺血后躯体感觉诱发电位（SEP）变化及大脑皮层的功能恢复。利用线栓法建模成功的25只SD雄性大鼠分为5组,分别为正常对照组和左侧中动脉缺血术后4、24、 48 h和1周4个实验组。采用SEP记录法,在术后不同时间段电刺激大鼠的右前爪正中神经支配区,记录对照组和实验组左侧皮层脑电信号,提取SEP,并对安静状态下的脑电进行频谱分析,定量评价左侧中动脉缺血后初级体感皮层SEP及功率谱变化过程。实验结果显示,术后4 h,SD大鼠左侧大脑皮层测得的SEP潜伏期较正常状态显著增大（（16.0±1.1）ms vs（33.7±1.3）ms,P<0.01）,波幅变小（（197.2±13.0）μV vs（25.1±2.0）μV,P<0.01）,θ波、α波、β波、γ波的能量明显变小。θ波：（139 367.86±178.66）μV^2vs（2.22±0.40）μV²,P <0.01;α波:（5389.33±25.55）μV² vs（0.23±0.01）μV²,P<0.01;β波：（7911±416）μV² vs（0.01±0.01）μV²,p<0.01; γ波：（0.30±0.12）μV² vs（0.00±0.00）μV²,P<0.01。随着术后时间的延长,上述特征与对照组的差距逐渐缩小,但还不能达到正常状态的水平。研究提示,SEP可在一定程度上反映脑缺血大鼠大脑皮层功能的变化。     

Insular cortex and perception of temporal patterns

The effects of Piracetam (100 mg/kg) on passive avoidance learning was investigated in a situation in which rats received multiple conditioning trials. The test was based on the untrained preference of rats for a dark, rather than a brightly lit compartment. After the initial black-white preference was tested, rats were restricted to the black compartment for conditioning. Different groups received different percentages of tone-shock pairings. After the conditioning trials the black-white preference was again tested. The saline-injected rats showed overshadowing of the background stimulus by the tone, in the group that had received 100% tone-shock pairings; and an acquired aversion to the background stimuli in the group that had received 0% tone-shock pairings. In the rats injected with 100 mg/kg Piracetam associative strength was partitioned indiscriminately between the tone and the background stimuli, regardless of the tone-shock pairings that had been received during conditioning.     

人β-NGF基因修饰的骨髓间充质干细胞对帕金森病大鼠行为学的影响

 目的：探讨脑内移植人β-神经生长因子(β-NGF)基因修饰的骨髓间充质干细胞(MSCs)对帕金森病(PD)模型大鼠行为学的影响。方法：将成功制备的PD大鼠模型按随机数字法分为β-NGF基因修饰的MSCs移植组(β-NGF-MSCs组)、MSCs移植组(MSCs组)、DMEM/F12培养液纹状体内注射组(DMEM/F12组)和非移植组(PD模型组)。细胞移植后,动态观察PD模型大鼠行为学变化及脑组织形态学的变化。结果：β-NGF基因修饰的MSCs脑内移植能有效改善PD模型大鼠的行为学表现。细胞移植术后第2周、第4周和第6周,β-NGF-MSCs组在阿朴吗啡诱发下30 min内的平均旋转圈数均明显低于MSCs组和PD模型组(P<0.05)。DMEM/F12组和PD模型组的旋转行为手术前后比较无明显变化(P>0.05)。免疫组织化学染色结果显示,移植细胞在PD模型大鼠脑内均能存活,并能够与宿主组织产生整合,具有良好的组织相容性;宿主的脑组织结构无破坏,无胶质瘢痕形成。PD模型大鼠纹状体内移植β-NGF基因修饰的MSCs后,可持续稳定表达β-NGF,其对PD模型大鼠旋转行为的改善明显优于单纯应用MSCs移植治疗。结论:β-NGF基因修饰的MSCs脑内移植能明显改善PD模型大鼠行为学症状,具有潜在的临床应用价值。     

神经调节蛋白1β联合卡托普利对慢性心力衰竭大鼠心肌细胞凋亡及相关基因表达的影响

目的:探讨神经调节蛋白1β(neuregulin-1,NRG-1β)与卡托普利单用及联合应用对慢性心力衰竭大鼠心肌细胞凋亡及相关基因表达的影响。方法:将青年雄性Sprague-Dawley大鼠随机分为假手术组、心衰组、NRG-1β干预组、卡托普利干预组和联合用药组。采用腹主动脉-腔静脉穿刺造瘘法制备心衰模型。通过血流动力学和血浆BNP水平评价大鼠心功能,TUNEL法检测心肌细胞凋亡指数;Western blot检测各组大鼠左心室心肌p-Akt、Bax和Bcl-2的蛋白水平。结果:与心衰组比较,NRG-1β组、卡托普利组及联合用药组左心室舒张末压、心肌凋亡指数明显降低,±dp/dt_(max)明显升高差异有统计学意义(P0.05);Bax蛋白表达明显降低,p-Akt和Bcl-2蛋白水平明显升高,差异有统计学意义(P0.05)。而与NRG-1β组和卡托普利组相比,联合用药组效果更加显著(P0.05)。结论:神经调节蛋白1β与卡托普利单用及联合应用均可有效改善心功能、抑制心肌细胞凋亡,联合用药的疗效优于单独用药。     

甲壳素神经再生室注入聚乳酸-聚乙醇酸-重组人促红细胞生成素微球促进 缺损周围神经的修复

背景：促红细胞生成素除了具有造血的作用以外, 对神经系统损伤的修复也起着重要作用。 目的：观察聚乳酸-聚乙醇酸-重组人促红细胞生成素微球对大鼠坐骨神经再生的作用。 方法：雌性SD大鼠60只,随机分为3组。制备大鼠双侧坐骨神经缺损模型(1 cm缺损)以及可吸收甲壳素神经再生室。实验组室内注入聚乳酸-聚乙醇酸-重组人促红细胞生成素微球;对照组室内注入聚乳酸-聚乙醇酸微球;空白对照组室内注入等渗生理盐水。 结果与结论：实验组再生神经的传导速度优于对照组及空白对照组,且12周优于6周,差异有显著性意义(P < 0.05)。S-100 免疫组织化学及Loyez氏神经染色法显示：实验组神经纤维数量多于对照组及空白对照组,12周多于6周,差异有显著性意义(P < 0.05)。结果提示聚乳酸-聚乙醇酸-重组人促红细胞生成素微球能够促进实验性坐骨神经缺损的再生和功能的恢复。 关键词：重组人促红细胞生成素;周围神经损伤;神经再生;甲壳素导管;传导速度 doi:10.3969/j.issn.1673-8225.2012.12.006