应激性防御反应与大白鼠脑内c-fos癌基因的表达及痛阈变化的关系

采用足底电击结合噪音制做大鼠应激模型 ,以免疫组织化学 ABC法研究了大鼠脑内 c- fos癌基因蛋白 ( FOS)在慢性应激过程中的表达情况。结果显示 ,正常对照组大鼠脑内无 FOS阳性细胞出现。而应激组大鼠脑内 FOS的表达部位随应激时间的延长而呈下降趋势 ,说明随应激时间的延长大鼠脑内不同核团神经元功能发生不同程度的障碍。大鼠的痛阈在应激后 3,9d无明显变化而在第 1 5天大鼠痛阈明显升高 ,说明长时间的电刺激产生了镇痛。     

Reg-Ⅲβ和C-fosmRNA在尼莫地平抗大鼠背根反射介导的神经病理痛中的作用

目的研究C-fos及Reg-Ⅲβ在大鼠背根反射介导的神经病理痛中的表达变化;并探讨尼莫地平治疗对其的影响。方法建立SD大鼠选择性坐骨神经损伤(SNI)模型,采用Von Frey纤维丝测量不同时间点手术侧后肢的机械痛阈。采用实时荧光定量聚合酶链式反应(RT-qPCR)检测坐骨神经损伤后不同时间内Reg-Ⅲβ及C-fos的mRNA表达,以及不同剂量尼莫地平治疗对这些分子表达的影响。结果与-1 d相比,1、3、5、7、14 d大鼠其SNI术后各时间段脊髓背角组织中的Reg-Ⅲβ及C-fos mRNA表达均普遍上调。腹腔注射尼莫地平对Reg-ⅢβmRNA的表达上调产生明显的时间和剂量依赖性的抑制作用。模型组大鼠的机械痛阈在SNI术后1 d即明显低于基础痛阈,术后5 d降至最低,随后缓慢恢复。尼莫地平治疗后大鼠机械痛阈仍呈下降趋势,但其幅度较模型组显著减小,且术后转归时间显著提前。这些治疗效果随药物浓度提升而明显加大。结论选择性坐骨神经损伤可引起大鼠脊髓背角组织中C-fos及Reg-ⅢβmRNA表达发生时序性变化,尼莫地平能显著减轻神经病理性痛并缩短疼痛转归时间,其机制可能与逆转背根神经节介导的脊髓背角中C-fos及Reg-Ⅲβ的病理性表达有关。     

重症肌无力患者IgG对大鼠脑内NOS不同时间表达的影响

目的观察重症肌无力(myasthenia gravis,MG)患者IgG(AchRab)对大鼠脑内一氧化氮合酶(NOS)表达的影响,探讨NOS在MG中造成中枢神经系统损害的机制.方法将AchRab IgG或健康人的IgG注入大鼠侧脑室,1次/d,连续4次.免疫组化方法观察不同时间点大鼠脑皮质、海马及杏仁核神经元型一氧化氮合酶(nNOS)和诱导型一氧化氮合酶(iNOS)的表达变化.结果侧脑室注射后1周实验组大鼠皮质、海马神经元nNOS表达量明显减少,后2周实验组皮质、海马神经元nNOS表达下降更为明显,同时杏仁核神经元nNOS表达量也减少;实验组及对照组脑内细胞均未见iNOS表达.结论AchRab侧脑室内注射可引起大鼠皮质、海马及杏仁核神经元nNOS表达量减少,且2周内这种减少效应随时间延长而增强,但未能诱导脑内细胞iNOS表达,提示AchRab尚可通过抑制大鼠中枢神经系统nNOS表达,降低脑内正常的一氧化氮浓度,减弱一氧化氮对脑组织的保护作用,增加神经元的易损性.     

单一延长应激对Wistar大鼠海马Calcineurin表达的影响

目的探讨创伤后应激障碍模型-单一延长应激对Wistar大鼠海马钙调神经磷酸酶(Calcineurin,CaN)表达的影响。方法将Wistar大鼠(n=30)随机分为单一延长应激组(n=15)和对照组(Control,n=15)。前者对大鼠实施国际公认的创伤后应激障碍(posttraumatic stress disorder,PTSD)动物模型方法-单一延长应激(Single-Prolonged Stress,SPS)暴露,对照组不给予任何处理。14 d后断脑取海马,通过ELISA、Western blot、免疫组化等方法检测两组大鼠海马CaN的表达改变。结果 ELISA结果显示单一延长应激暴露后大鼠海马组织匀浆CaN水平明显降低(P 0. 05); Western blot检测示单一延长应激组大鼠海马CaN Aα蛋白表达显著低于对照组(P 0. 01);免疫组化表明单一延长应激后CaN Aα蛋白在海马CA_1、CA_3区表达明显减少(P 0. 01),而齿状回区(DG)无明显差异(P 0. 05)。结论单一延长应激可致CaN下调,CaN表达减少可能是PTSD海马损伤的重要分子机制之一。     

慢性应激抑郁模型大鼠强迫游泳后海马中c-fos的表达

目的 研究慢性应激对强迫游泳大鼠海马神经元c-fos表达的影响。方法 采用特异性抗体的免疫组织化学方法,在大鼠慢性应激抑郁模型基础上,观察急性强迫游泳应激后海马神经元c-fos的表达情况。结果 抑郁模型大鼠接受急性强迫游泳应激后,海马CA3区和齿状回(DG)内FOS蛋白的表达在各主要时点均比对照组降低,图像分析提示,上述两区域的FOS阳性神经元对应切面面积比明显降低(P<0.05),平均目标灰度值显著增加(P<0.05)。结论 慢性应激使大鼠在急性强迫游泳应激后海马CA3区和DG内c-fos的表达降低。     

托吡酯对戊四氮点燃慢性癫痫大鼠海马神经细胞黏附分子的影响

目的探讨神经元活化在癫(癎)发生、发展中的作用及托吡酯对其的影响.方法采用戊四氮制备慢性癫(癎)模型,利用托吡酯干扰,选取不同时间点,观察大鼠行为学变化及神经细胞黏附分子在海马回的表达(免疫组织化学染色).结果托吡酯组点燃率在27 d明显低于模型组;模型组及托吡酯组神经细胞黏附分子表达增加,并随时间延长明显;而不同时间点该表达的增加程度,托吡酯组均低于模型组.结论神经细胞黏附分子表达的增加,说明出现了神经元活化及脑可塑性变化,而托吡酯明显地抑制了该表达的增加.     

雌激素致癎作用部位的研究

目的了解雌激素在癫癎大鼠中枢神经系统的作用部位.方法利用海人酸致癎和6-氟二乙酯致癎的两种不同机制的癫癎模型(单纯致癎组),应用免疫组化法检测单纯致癎及给予雌激素后再致癎大鼠海马、大脑皮质、纹状体的FOS表达.结果两种模型单纯致癎组海马、皮质、纹状体FOS表达较正常组显著增高(均P＜0.01).给予雌二醇(E2)后再致癎,海人酸模型中海马、皮质FOS表达较单纯致癎组增加(P＜0.01,P＜0.05);而6-氟二乙酯模型中无变化.结论在两种不同致癎机制的癫癎模型中,雌二醇对鼠脑FOS表达的影响不同.     

杏仁核点燃癫痫鼠模型脑内不同神经结构FOS蛋白的表达

目的 观察杏仁核点燃癫痫鼠模型脑内不同核团FOS蛋白表达顺序及强度以探讨癫痫的传播途径。方法 选择健康Wistar大鼠60只制作杏仁核点燃癫痫模型，分别在点燃后0．5h、1h、2h、4h及24h用免疫组织化学方法观察癫痫大鼠脑内梨状皮质、杏仁核、海马、齿状回、尾壳核、皮质、皮质下结构、小脑Purkinje细胞、小脑齿状核、脑桥网状结构共10个核团FOS蛋白表达情况。结果 杏仁核点燃后0．5h梨状皮质、齿状回、小脑Purkinje细胞开始出现FOS表达，然后表达逐渐增强，杏仁核、海马、小脑齿状核、皮质、皮质下结构、尾状核及脑桥网状核在发作后1～2h开始表达，4h表达明显，癫痫发作24h后大多数核团FOS蛋白表达低于4h但仍高于1h～2h。结论 杏仁核点燃大鼠癫痫发作后可引起脑内FOS蛋白区域性一过性表达。梨状皮质表达最早，是首先被激活的结构之一，而杏仁核、海马、小脑Purkinje细胞、皮质可能为杏仁核点燃模型癫痫传播途径的重要组成部分。     

鞘内注射甘珀酸对大鼠热痛刺激反应的影响

目的:研究甘珀酸对大鼠热痛刺激反应的影响.方法:向实验组大鼠鞘内注射一种缝隙连接的阻断剂甘珀酸;对照组大鼠鞘内注射生理盐水,在注射前和注射后2 h测定热痛刺激大鼠缩足潜伏期(PWTL)的变化,并观察对脊髓背角胶质原纤维酸性蛋白(GFAP)和Fos蛋白表达的影响.结果:实验组阻断后PWTL测定值明显延长,与对照组差异具有统计学意义(P＜0.05);且阻断后Fos阳性神经元与对照组相比数量明显减少,GFAP阳性细胞则未见明显增加或减少.结论:本研究表明大鼠鞘内注射甘珀酸后①痛阈升高;②神经元对伤害性刺激信息的反应程度减弱,而AS的GFAP表达反应并未受影响.这提示,缝隙连接在疼痛的发生和维持中起着重要作用,AS有可能是通过缝隙连接参与对疼痛反应的过程.     

脑缺血大鼠脑皮质中前蛋白转化酶枯草溶菌素9 mRNA的经时表达

氧化的低密度脂蛋白是脑血管病的危险因素,而前蛋白转化酶枯草溶菌素9能升高低密度脂蛋白的水平。因此,课题组设想前蛋白转化酶枯草溶菌素9可能在缺血性脑血管病中发挥作用。实验以阻塞大鼠大脑中动脉100 min后进行再灌注建立短暂性局灶性脑缺血模型,原位杂交染色发现脑缺血大鼠脑皮质内前蛋白转化酶枯草溶菌素9 mRNA表达随再灌注时间延长而增高。说明局灶性短暂脑缺血可上调大鼠缺血脑皮质内前蛋白转化酶枯草溶菌素9 mRNA的表达。 关键词：前蛋白转化酶枯草溶菌素9 mRNA;皮质;脑缺血;大鼠;神经再生     

Denervation study of synapses of organ of corti of old world monkeys

Fine structural characteristics of synapses in the spiral organ of Corti were examined, with reference to differences between inner and outer haircell systems, and to location of neurons of origin of efferent axons. Surgical interruption of crossed olivocochlear bundle, of vestibular nerve, of facial nerve, and excision of superior cervical ganglia were used to determine the pathways of efferent axons. Interruption of the vestibular nerve near the brainstem results in degeneration of all efferent terminals on outer hair cells. Mid-line lesions at, and caudal to, the facial colliculus result in degeneration of about half of these efferent terminals. Efferent synaptic bulbs to the inner hair-cell system are small, of the order of one micron, and form type 2 junctions with afferent dendrites. They tend to have more large dense-core vesicles (about 80 nm) than the large efferent terminals of the outer hair-cell system, and appear to be the terminals of axons in the habenula perforata, which exhibit varicosities laden with large dense core vesicles. The varicosities are unaffected by excision of the superior cervical ganglia. So far as our material can reveal, it appears that the varicosities in the habenula perforata do not survive vestibular root interruption, nor do the efferent processes in the internal spiral bundle or at the base of inner hair cells. Most interestingly, the afferent processes of the inner hair-cell system, as identified for example by their relation to pre-synaptic bodies in the inner hair cells, are subject to a trans-synaptic reaction after severance of the vestibular root. They undergo a dramatic cytological transformation, characterized by increase of volume, engorgement with microtubules, microfilaments, microvesicles of various sizes, and clusters of lysosomes. Thus, both the efferent and afferent terminals of the inner hair-cell system show marked cytological differences from the corresponding terminals of the outer hair cell system.     

Mechanism of action of tubocurarine on nicotinic cholinoreceptors of neurons of the sympathetic ganglia of rats

Tubocurarine (Tc) effect on membrane currents elicited by acetylcholine (ACh) was studied in isolated superior cervical ganglion neurons of rat using patch-clamp method in the whole-cell recording mode. The "use-dependent" block of ACh current by Tc was revealed in the experiments with ACh applications, indicating that Tc blocked the channels opened by ACh. Mean lifetime of Tc-open channel complex, tau, was found to be 9.8 +/- 0.5 s (n = 7) at -50 mV and 20-24 degrees C. tau exponentially increased with membrane hyperpolarization (e-fold change in tau corresponded to the membrane potential shift by 61 mV). Inhibition of the ACh-induced current by Tc (3-30 microM/1) was completely abolished by membrane depolarization to the level of 80-100 mV. Inhibition of ACh-induced current was augmented at increased ACh doses. It is concluded that the open channel block produced by Tc is likely to be the only mechanism for Tc action on nicotinic acetylcholine receptors in superior cervical ganglion neurons of rat.     

The effect of age of onset of PD on risk of dementia

Background Dementia occurs in the majority of patients with Parkinson’s disease (PD). Late onset of PD has been reported to be associated with a higher risk for dementia. However, age at onset (AAO) and age at baseline assessment are often correlated. The aim of this study was to explore whether AAO of PD symptoms is a risk factor for dementia independent of the general effect of age. Methods Two community-based studies of PD in New York (n = 281) and Rogaland county, Norway (n = 227) and two population-based groups of healthy elderly from New York (n = 180) and Odense, Denmark (n = 2414) were followed prospectively for 3–4 years and assessed for dementia according to DSM-IIIR. All PD and control cases underwent neurological examination and were followed with neurological and neuropsychological assessments. We used Cox proportional hazards regression based on three different time scales to explore the effect of AAO of PD on risk of dementia, adjusting for age at baseline and other demographic and clinical variables. Findings In both PD groups and in the pooled analyses, there was a significant effect of age at baseline assessment on the time to develop dementia, but there was no effect of AAO independent of age itself. Consistent with these results, there was no increased relative effect of age on the time to develop dementia in PD cases compared with controls. Interpretation This study shows that it is the general effect of age, rather than AAO that is associated with incident dementia in subjects with PD. Received in revised form: 22 December 2005     

Limits of deinstitutionalization--perspectives of relatives of psychiatric patients

After a hopeful beginning, the social process of the reintegration of those with severe mental illness has come to a standstill. I am led to wonder whether "the community" really wants to live together with people suffering from severe mental illness, and if so, how closely? As long as the medical treatment of mental illness provided by the general practitioners is fundamentally deficient, as they are not able to prescribe the necessary interventions--such as out-patient psychiatric nursing, and service providers in the out-patient sector are content with offering increasingly intensive forms of care for the less seriously ill at the cost of the Social Welfare System--the reintegration of those with serious mental illness remains an illusion--which is mainly to the benefit of providers of residential care in homes and hostels.