都可喜对慢性间断性缺氧大鼠学习记忆能力及脑内单胺类神经递质的影响

目的:探讨都可喜(Duxil,阿米三嗪+萝巴新)对慢性间断性缺氧(EHYP)大鼠学习记忆能力和脑内单胺类神经递质水平的影响。方法:建立EHYP大鼠模型,并给予Duxil(0.03片·350g~(-1)体重,bid)干预。用被动避暗回避反射试验评价大鼠学习记忆能力,潜伏期(STL)越长,学习记忆能力越强;用高效液相色谱电化学检测器法测定大鼠皮层、海马和纹状体内去甲肾上腺素(NE)、多巴胺(DA)和5-羟色胺(5-HT)等单胺类神经递质的含量。结果:与对照组相比,EHYP组大鼠STL明显缩短(P<0.01),各脑区单胺类神经递质水平显著降低(P<0.05)。与EHYP组相比,Duxil组大鼠STL显著延长(P<0.01),皮层NE和DA含量、海马NE,DA和5-HT含量以及纹状体NE,DA和5-HT含量显著升高(P<0.05)。结论:Duxil可改善EHYP大鼠学习记忆能力并提高脑内单胺类神经递质水平。     

高效液相色谱-电化学法测定大鼠不同脑区的单胺类神经递质

目的:建立同时测定大鼠脑组织中单胺类神经递质去甲肾上腺素(NE)、多巴胺(DA)和5-羟色胺(5-HT)的高效液相色谱-电化学检测法(HPLC-ECD).方法:采用Diamonsil C18柱,以Na2HP04-枸橼酸-EDTA-庚烷磺酸钠-甲醇-水(80:40:2:7:32:89)为流动相,流速:1.2 ml/min.大鼠脑组织样品经高氯酸沉淀除去蛋白后,电化学检测脑内NE、DA和5-HT的含量.结果:脑组织中NE、5-HT的线性范围为0.50～10.00 ng,DA的线性范围为0.25～30.00ng.脑组织样品的相对回收率为91.7%～110.2%,日内、日间变异均小于15%.经初步研究,正常雄性SD大鼠不同脑区内NE、DA和5-HT的含量分别为伏隔核(508±203)、(3140±486)、(601±105)ng/g,腹侧被盖区(695±152)、(746±143)、(1049±222)ng/g,下丘脑(2032±351)、(332±236)、(847±218)ng/g,纹状体(790±205)、(5816±805)、(538±112)ng/g.结论:该方法具有准确、灵敏、样品制备简便等优点,可用于大鼠部分脑区内单胺类神经递质的分离测定.     

经前平颗粒对愤怒情绪模型大鼠不同脑区单胺类神经递质的影响及分析

目的通过研究愤怒模型大鼠不同脑区单胺类神经递质的含量变化,探讨愤怒发生的微观机制及中药经前平颗粒的可能干预机制。方法采用社会隔离结合居住入侵方法制备愤怒大鼠模型,分别为正常组、愤怒模型组、经前平颗粒给药组;运用高效液相色谱法检测各组大鼠不同脑区单胺类神经递质的含量。结果与正常对照组相比,愤模组大鼠下丘脑NE含量明显下降(P<0.01),给药后愤药组大鼠额叶皮质NE含量异常变化得以纠正(P<0.05);愤模组额叶皮质、顶区皮质、海马DA含量下降(P<0.01,P<0.01,P<0.01),而下丘脑DA含量则上升(P<0.01),给药后下丘脑DA含量恢复至正常水平(P<0.01)。愤模组大鼠下丘脑5-HT含量降低(P<0.01)。结论大鼠愤怒情绪反应与下丘脑NE含量下降,额叶皮质、顶区皮质、海马DA、下丘脑5-HT含量下降,下丘脑DA含量上升有关;干预药物经前平颗粒可能通过纠正上述指标异常变化而发挥药理作用。综上所述,本研究为进一步研究愤怒情绪发病机制及调肝方药治病机制提供理论基础和方向。     

高效液相色谱-电化学法测定大鼠不同脑区的单胺类神经递质

目的:建立同时测定大鼠脑组织中单胺类神经递质去甲肾上腺素(NE)、多巴胺(DA)和5-羟色胺(5-HT)的高效液相色谱-电化学检测法(HPLC-ECD).方法:采用Diamonsil C18柱,以Na2HP04-枸橼酸-EDTA-庚烷磺酸钠-甲醇-水(80:40:2:7:32:89)为流动相,流速:1.2 ml/min.大鼠脑组织样品经高氯酸沉淀除去蛋白后,电化学检测脑内NE、DA和5-HT的含量.结果:脑组织中NE、5-HT的线性范围为0.50～10.00 ng,DA的线性范围为0.25～30.00ng.脑组织样品的相对回收率为91.7%～110.2%,日内、日间变异均小于15%.经初步研究,正常雄性SD大鼠不同脑区内NE、DA和5-HT的含量分别为伏隔核(508±203)、(3140±486)、(601±105)ng/g,腹侧被盖区(695±152)、(746±143)、(1049±222)ng/g,下丘脑(2032±351)、(332±236)、(847±218)ng/g,纹状体(790±205)、(5816±805)、(538±112)ng/g.结论:该方法具有准确、灵敏、样品制备简便等优点,可用于大鼠部分脑区内单胺类神经递质的分离测定.     

茶色素对吗啡成瘾小鼠脑内去甲肾上腺素、多巴胺、5-羟色胺和β-内啡肽的影响

目的:探索茶色素对吗啡依赖小鼠脑内去甲肾上腺素(NE)、多巴胺(DA)、5-羟色胺(5-HT)和β-内啡肽(β-EP)的影响。方法:建立吗啡依赖模型,采用催促戒断治疗实验测定小鼠跳跃反应次数。运用高效液相法测定下丘脑,脑干和大脑皮质内NE、DA、5-HT含量,采用放射免疫法测定大脑皮质内β-EP含量。结果:茶色素12.5,25,50,100 mg.kg-1组均显著降低吗啡依赖小鼠的跳跃次数。降低吗啡依赖小鼠下丘脑中NE和DA的含量。降低吗啡依赖小鼠大脑皮质内β-EP含量。但对下丘脑,脑干和大脑皮质内的5-HT含量没有明显影响。结论:茶色素能降低吗啡依赖小鼠的跳跃次数,其机制可能与茶色素降低吗啡依赖小鼠下丘脑中NE和DA及大脑皮质β-EP含量相关。     

复方瑞康欣对吗啡依赖大鼠戒断症状和单胺类神经递质的影响

目的:观察复方瑞康欣对吗啡依赖大鼠戒断症状、脑干和脊髓单胺类神经递质的影响。方法:SD大鼠按剂量递增法皮下注射(sc)吗啡建立大鼠吗啡依赖模型。用复方瑞康欣灌胃(ig)5 d后经纳洛酮催瘾,观察戒断症状、脑干和脊髓NA,DA,5-HT和5-HIAA含量的变化。结果:复方瑞康欣能降低纳洛酮催促产生的戒断症状的评分值(P<0.01),能抑制吗啡依赖大鼠戒断后的体重丢失(P<0.05);降低脑干DA,NA,5-HT及5-HIAA的浓度(P<0.05),而对脊髓单胺类神经递质水平几乎无影响(P>0.05)。结论:复方瑞康欣对吗啡依赖大鼠具有一定治疗作用,能缓解纳洛酮催促产生的戒断症状。     

七十味珍珠丸对脑损伤大鼠脑内单胺类神经递质的影响

目的 :通过对脑损伤大鼠脑内单胺类神经递质含量的测定 ,研究七十味珍珠丸 (RNSP)治疗脑血管疾病的作用机理。方法 :RNSP ig给药后 ,制成脑损伤病理模型 ,采用荧光分光光度法检测脑内 5 -羟色胺 (5 -HT)、去甲肾上腺素 (NA)、多巴胺(DA)含量。结果 :RNSP具有显著降低脑损伤所致大鼠脑内 5 -HT、NA含量升高的作用 (P<0 .0 5、P<0 .0 1) ,对 DA含量的抑制 ,也有一定的作用趋势 (P>0 .0 5 )。结论 :RNSP治疗脑血管疾病的作用机理 ,可能与它具有调节脑内单胺类神经递质的作用有关     

立体定向毁损内囊前肢对大鼠脑内递质的影响

目的探讨内囊前肢毁损后AMP模型大鼠脑内单胺类递质含量的变化,为难治性精神病病因的研究和外科治疗提供参考.方法经腹腔注射苯丙胺(AMP)制作精神病动物模型,应用立体定向技术电极毁损大鼠内囊前肢,采用荧光分光光度法和放射免疫法测定大鼠前额叶、间脑和脑干多巴胺(DA)、5-羟色胺(5-HT)和去甲肾上腺素(NE)的含量.结果内囊前肢毁损组前额叶DA和NE低于假毁损组(P＜0.01),5-HT均高于假毁损组(P＜0.01);毁损组间脑DA、NE均低于假毁损组(P＜0.01),5-HT高于假毁损组(P＜0.01);脑干 DA低于假毁损组(P＜0.01),5-HT高于假毁损组(P＜0.01).结论 AMP模型大鼠前额叶DA含量增高、5-HT和NE含量下降,间脑DA、NE含量增高、5-HT含量下降,脑干DA含量增高,5-HT含量下降.立体定向毁损内囊前肢改变了脑内单胺类递质的水平.     

孕酮对大鼠吗啡位置偏爱效应及中枢单胺递质水平的影响

目的观察孕酮对于吗啡所致奖赏效应及脑内单胺类神经递质水平的影响。方法采用大鼠条件性位置偏爱(CPP)模型,高效液相色谱-电化学法测定大鼠伏隔核及腹侧被盖区内去甲肾上腺素(NE)、多巴胺(DA)和5羟色胺(5HT)的含量。结果吗啡(5mg·kg-1)可诱导大鼠产生稳定的CPP效应;孕酮(5、20mg·kg-1)本身不产生CPP效应,但能抑制吗啡的CPP效应。与对照组比较,吗啡CPP形成时,伏隔核内NE和DA的水平明显升高(P<0.01)。与吗啡组比较,合用5mg·kg-1或20mg·kg-1孕酮均可使伏隔核内DA水平下降(P<0.01,P<0.05);合用20mg·kg-1孕酮还可使伏隔核内的NE水平下降(P<0.01)。结论孕酮可有效抑制吗啡的CPP效应,其机制可能与降低伏隔核内DA及NE的水平有关。     

抗抑郁候选化合物GL-21对大鼠脑皮质中神经递质含量影响的研究

目的:研究抗抑郁候选化合物GL-21对大鼠脑皮质中神经递质去甲肾上腺素(NE)及5-羟色胺(5-HT)含量的影响。方法:采用微透析法取样和高效液相色谱法测定大鼠脑皮质中NE及5-HT的含量。结果:分别给大鼠GL-21 2,4和8 mg/kg后,可大幅增加大鼠脑皮质中神经递质NE及5-HT的含量(P<0.05 or P<0.01),且呈一定的剂量关系。结论:抗抑郁候选化合物GL-21可增加大脑皮质单胺类递质NE及5-HT含量。     

急性吗啡依赖大鼠脑内G_(i2)蛋白的表达

目的研究急性吗啡成瘾后大鼠腹侧背盖区(Ventral tegmental area,VTA)、伏隔核(Nucleus accumbens,NAc)、前额皮质(Prefrontal cortex,PC)、海马(Hippocampus)及去甲肾上腺能神经中枢蓝斑(Locus coeruleus,LC)五个脑区Gi2蛋白的改变,探讨急性吗啡成瘾的可能机制。方法18只SD大鼠随机分为三组,每组6只,分别是急性吗啡成瘾组、急性吗啡戒断组、空白对照组。吗啡成瘾组和戒断组腹腔注射吗啡,直到吗啡成瘾模型建立。戒断组腹腔注射纳络酮5mg/kg,作用30min后断头处死各组大鼠。取出脑组织,进行冰冻切片。用免疫组化技术检测NAc、PC、LC、VTA和Hippocampus五个脑区相对Gi2蛋白水平。结果急性吗啡成瘾组和急性戒断组与空白对照组相比,NAc区Gi2蛋白水平有明显降低(P<0.01),其它脑区则未发现明显的改变。结论急性吗啡成瘾可引起大鼠脑内Gi2蛋白水平发生改变,NAc区Gi2蛋白水平有明显降低,其它脑区则未发现明显的改变。Gi2蛋白水平的改变可能是吗啡耐受和依赖潜在的分子机制。     

褪黑素对吗啡戒断大鼠脑内cAMP和cGMP含量的影响

目的 :观察褪黑素 (MT)对吗啡戒断大鼠不同脑区cAMP和cGMP含量的影响。方法 :以剂量递增法连续皮下注射吗啡建立吗啡依赖模型 ,采用放射免疫学方法测定脑内cAMP和cGMP的含量。结果 :(1)MT对大鼠吗啡戒断症状具有明显的抑制作用 ;(2 )与对照组比较 ,吗啡依赖大鼠的纹状体、间脑、中脑、脑桥和海马内cAMP含量显著增高 (P <0 0 5 ,P <0 0 1) ,cGMP含量显著下降 (P <0 0 5 ,P <0 0 1)。与吗啡依赖组比较 ,催促戒断大鼠海马和纹状体内cAMP的含量显著升高 (P <0 0 5 ) ,而cGMP含量显著下降 (P <0 0 5 ,P <0 0 1) ,其他部位则无明显变化 ;(3)褪黑素急性治疗可使吗啡戒断大鼠纹状体、间脑、中脑、脑桥和海马内cAMP含量明显下降 (P <0 0 5 ,P <0 0 1) ,cGMP含量明显增高 (P <0 0 5 ,P <0 0 1)。结论 :MT可显著抑制大鼠吗啡戒断反应 ,并与调节中枢cAMP和cGMP含量有关。     

Potentiation of hexobarbital and amphetamine effects in male and female rats physically dependent on morphine

Morphine dependence (following s.c. implantation of 207 mg morphine in pellet form) increases hexobarbital sleeping time in both male and female rats; this is accompanied by an apparent increase in brain sensitivity to hexobarbital. Only male morphine-dependent rats manifested a decrease in in vitro hepatic metabolism of hexobarbital as well as a significantly faster rate of decline of hexobarbital from the brain. In vivo uptake of hexobarbital into the brain revealed no difference between male and female morphine-dependent and sham-implanted animals. The suggested mechanism for the observed changes in male rats is a combination of inhibition of hepatic metabolism and an additive effect of morphine and hexobarbital. In female rats only an additive effect is manifested. In male rats morphine dependence also increases amphetamine-stimulated locomotor activity (open-field), increases amphetamine brain levels, and decreases in vitro metabolism of aniline. Morphine-dependent female rats manifested increases in brain levels of amphetamine but no other changes were observed. The in vivo decline of amphetamine from the brain of either male or female morphine-dependent rats was not significantly different from their respective controls. The suggested mechanism for the changes in male morphine-dependent rats is an increase in the brain uptake of amphetamine.     

Brain lesions modifying the abstinence signs in morphine-dependent rats.

Abstinence signs, mastication (teeth chattering), myoclonic twitch and repetitive shaking movements (wet shakes) were precipitated by naloxone and were recorded electromyographically from the suprahyoideal muscle in morphine-dependent rats anaesthetized with urethane. Transverse brain lesions were made bilaterally with an iridectomy knife in urethane anaesthetized morphine-dependent rats. Lesions at the level of the anterior commissure did not inhibit the myoclonic twitch and mastication but markedly potentiated wet shakes. Lesions which separated the connection between the corpus striatum and the thalamus completely abolished mastication, but the twitching activity and wet shakes were not affected. Mid-thalamus lesions did not inhibit wet shakes and mastication, but the myoclonic twitch activity was markedly reduced. Lesions at the mid-collicular level abolished all of the three activities observed. The results suggest that different precipitated withdrawal signs may originate from different brain areas.     

Anatomically dissociable effects of dopamine D1 receptor agonists on reward and relief of withdrawal in morphine-dependent rats

Rationale  Chronic opiate administration induces neuroadaptations within the nucleus accumbens (NAc) and ventral tegmental area (VTA) that can contribute to dependence. We have shown that morphine dependence shifts the behavioral consequences of D1 dopamine (DA) receptor signaling: systemic administration of a D1 receptor agonist is rewarding and blocks naloxone-precipitated withdrawal signs in morphine-dependent rats, but has minimal effects in nondependent rats. These data suggest that D1 receptors acquire the ability to regulate reward and withdrawal in morphine-dependent rats. The brain regions involved in these effects are not known. Objective  Studies were designed to test the hypothesis that the nucleus accumbens shell (NASh) and the ventral tegmental area (VTA) are important sites for mediating the behavioral effects of D1 receptor activation in morphine-dependent rats. Materials and methods  The effects of microinjecting the D1 receptor agonist SKF 82958 into the NASh or the VTA on place conditioning and somatic withdrawal signs were studied in morphine-dependent and nondependent rats. Results  Intra-NASh microinjection of SKF 82958 (1 μg/side) established conditioned place preferences in morphine-dependent but not nondependent rats, but had no effect on naloxone-induced place aversions or somatic withdrawal signs. Intra-VTA microinjection of SKF 82958 (2 μg) did not establish place preferences under any conditions, but blocked naloxone-induced place aversions without effects on somatic withdrawal signs. Conclusions  There is an anatomical dissociation between D1 receptor-mediated reward and relief of withdrawal in morphine-dependent rats. When combined, the individual effects of D1 receptor activation in the NASh and VTA on the affective signs of precipitated morphine withdrawal resemble those seen with systemic administration.     

Stress-induced anxiety and endogenous anxiogenic substances

Anxiety observed in animals subjected to stress was stated in relation to anxiety level and biological backgrounds of animals, changes in neurotransmitters and causal stressors. 1. Anxiety is thought to be a negative emotion caused by many kinds of stress such as restraint stress, SART (specific alternation of rhythm in temperature) stress (a repeated cold stress caused by environmental temperature), social stress, etc. 2. Emotional behavior in those stressed animals were attenuated by anxiolytics like diazepam, a benzodiazepine receptor agonist and buspirone, a serotonin (5-HT) 1A agonist. 3. Stressed rats had changed brain levels of a variety of neurotransmitters such as corticotropin-releasing factor (CRF), noradrenaline, 5-HT, dopamine, acetylcholine, histamine, cholecystokinin, etc. The percentage of time spent on the open arms of an elevated plus-maze apparatus decreased in those stressed animals. Abnormal elevated plus-maze behaviors were attenuated by diazepam, buspiron and a CRF antagonist. 4. Anxiety level differs according to the coping strategy of the recipients. Rats of different strain, sex, aging and/or family display different behaviors in elevated plus-maze. 5. Stress-induced anxiety-related behaviors were observed when levels of some neurotransmitters became unbalanced. Thus modulators of unbalanced brain substances are thought to have anxiolytic properties.     

不同频率电刺激VTA对吗啡成瘾大鼠ACbSh的放电活动的影响

目的:观察电刺激大鼠腹侧被盖区(VTA)对吗啡成瘾大鼠伏隔核壳部(ACbSh)神经元的影响,为应用脑深部电刺激技术治疗阿片类药物成瘾提供实验依据。方法:采用单管玻璃微电极细胞外记录法,观察不同频率电刺激VTA对吗啡成瘾大鼠ACbSh神经元放电的影响。结果:低频(50Hz)电刺激VTA,吗啡组ACbSh神经元主要表现为无反应(47.83%);高频(135Hz)电刺激VTA,吗啡组多数ACbSh神经元表现为抑制性作用(50.00%)。结论:高频电刺激VTA有可能作为新方法用于治疗阿片类药物成瘾。     

Brain and spinal cord 5-HT2 receptors of morphine-tolerant-dependent and -abstinent rats

The effects of morphine tolerance-dependence and abstinence on 5-HT2 receptors in brain and spinal cord of the rat were determined. Tolerance to and physical dependence on morphine was induced in male Sprague-Dawley rats by implanting six morphine pellets (each containing 75 mg of morphine free base) during a seven day period. Two groups of rats were used for binding studies. In one group the pellets were left intact and in the other they were removed. The rats were killed and spinal cords and brains were excised and dissected into six regions (amygdala, hippocampus, hypothalamus, striatum, midbrain and pons + medulla). 5-HT2 receptors were characterized by using [3H]spiperone as the ligand and unlabelled ketanserin to determine the non-specific binding. In morphine and placebo abstinent rats the binding of [3H]spiperone to 5-HT2 receptors in brain regions and spinal cord did not differ. The Bmax values of [3H]spiperone to bind to membranes prepared from non-abstinent morphine-dependent rats were increased in amygdala (78.0%), midbrain (65.0%) and pons + medulla (92.0%). The Kd values were unaffected. It is concluded that in morphine-tolerant-dependent rats 5-HT2 receptors are up-regulated in amygdala, midbrain and pons + medulla, but in morphine-abstinent rats they are unaffected.     

Neurochemical changes associated with chronic administration of typical antipsychotics and its relationship with tardive dyskinesia

The therapeutic success of atypical antipsychotics has focused the attention on the role of receptor systems other than dopaminergic system in the pathophysiology of neuroleptic-associated extrapyramidal side effects such as tardive dyskinesia. In the present study we planned to study time-dependent changes in extracellular levels of norepinephrine, dopamine and serotonin in cortical and subcortical (including striatum) regions of brain and tried to correlate them with hyperkinetic motor activities (vacuous chewing movements [VCMs], tongue protrusions and facial jerking) in rats treated chronically with typical neuroleptics (haloperidol and chlorpromazine). Chronic administration of haloperidol (1 mg/kg) and chlorpromazine (5 mg/kg) resulted in a time-dependent increase in orofacial hyperkinetic movements. There were also significant changes in the extracellular levels of different neurotransmitters in different brain regions (cortical and subcortical regions) as measured by high-performance liquid chromatography/electrochemical detection (HPLC/ED). Both haloperidol and chlorpromazine produced time-dependent decreases in the levels of these neurotransmitters.