氯化锂-匹罗卡品致痫大鼠海马EphA5及ephrinA3的表达及意义

目的探讨颞叶癫痫发作后海马EphA5及ephrinA3基因的表达变化和轴突出芽的关系。方法建立氯化锂-匹罗卡品颞叶癫痫大鼠模型,利用原位杂交方法检测致痫后12h、24h、7d、15d、30d、60d海马CA3区、CA1区EphA5及ephrinA3 mRNA的表达,快速Golgi染色观察CA1区的轴突出芽。结果致痫后,EphA5 mRNA在CA3区表达下调,ephrinA3 mRNA在CA1区表达下调,均在7d降至最低点,与对照组相比差异有显著意义(P<0.01),此后逐渐回升,但15d时仍低于对照组(P<0.05),在30d和60d与对照组相比差异无统计学意义(P>0.05)。快速Golgi染色显示,对照组大鼠CA1区轴突走行正常,匹罗卡品致大鼠SE后7dCA1区锥体细胞层出现显著增多的轴突染色。结论CA3区的EphA5和CA1区的ephrinA3的表达下调可能与CA1区的轴突出芽、突触重建有关。     

KA癫痫大鼠ALK5对TGF-β1-ALK1-p-Smad1通路的影响

目的研究癫痫大鼠ALK5对ALK1受体的作用,探讨可能的干预癫痫发作的新靶点。方法红藻氨酸(kainic acid,KA)侧脑室注入SD大鼠制备癫痫模型,随机分为KA模型对照组(A组)、ALK5抑制剂(SB431542)腹腔注射3 d组(B组)、ALK5抑制剂腹腔注射7 d组(C组),另设假手术组为空白对照组(NC组),每组各10只。NC组、A组、B组分别于3 d,C组于7 d取海马,检测海马组织中ALK1和其下游分子p-Smad1的mRNA及其蛋白的表达。结果与正常对照组相比,KA模型对照组大鼠海马区ALK1和p-Smad1的mRNA及蛋白表达均升高,差异有统计学意义(P<0.05);与KA模型组相对比,ALK5抑制剂腹腔注射组(B组和C组)ALK1和pSmad1的mRNA及蛋白表达均下降(P<0.05)。结论 ALK5抑制剂腹腔注射后导致KA诱导的SD癫痫大鼠ALK1受体和p-Smad1表达下调。     

红藻氨酸致痫大鼠海马神经元凋亡及其与caspase-3关系的研究

目的　研究大鼠癫痫发作后海马神经元凋亡及其与天冬氨酸特异性半胱氨酸蛋白酶 -3 (cysteinylasparate-specific proteinase,caspase-3 )表达的关系。方法　采用红藻氨酸 (kainic acid,KA)诱导大鼠癫痫模型 ,以原位末端标记 (TUNEL)及透射电镜检测癫痫发作后 6h及 1、3、7d海马神经元凋亡 ;半定量 RT-PCR及免疫组化法检测 caspase-3 m RNA及 caspase-3阳性表达。结果　KA致痫后 1 d,海马 CA1、CA3及 CA4区开始出现凋亡细胞 ,3 d时明显增多 ,7d时最多。 3个时间组相应区域间凋亡神经元数比较差异均有显著性 (P<0 .0 0 1 )。透射电镜观察可见典型的凋亡细胞形态学改变。 RT-PCR结果显示 ,KA致痫后 6h,海马组织 caspase-3 m RNA表达较对照组显著增高 (P <0 .0 5 ) ,1、3、7d caspase-3 m RNA仍持续高水平表达 (P <0 .0 5 )。免疫组化结果显示 ,KA致痫后 1 d,海马 CA1、CA3、CA4区开始出现 caspase-3阳性表达 ,3 d时阳性表达进一步增强 ,7d时表达最强。结论　凋亡参与 KA致痫大鼠癫痫发作后海马神经元迟发性死亡过程 ,caspase-3可能在癫痫后神经元凋亡过程中具重要的作用。     

海马内注射内皮素-1导致大鼠痫性发作和海马硬化的初步研究

目的 观察大鼠海马内注射内皮素(endothelin,ET)-1是否导致大鼠痫性发作和海马硬化.方法 立体定位在成年大鼠海马CA3区内分别注射1 μL ET-1(200 pmol,15只)、海人酸(kainate,KA 5 pmol,15只)或磷酸盐缓冲液(PBS,0.01 mol,8只),观察大鼠行为学、脑电及对侧海马病理学改变.结果 海马注射PBS后大鼠未见痫性发作,脑电图呈10～15 Hz、150-200μV基本节律.注射ET-1或KA 2 h内大鼠出现不同程度的痫性发作和脑电图异常改变(尖波或尖慢波),KA组3-5级发作率高于ET-1组(86.67% vs 16.67%,P<0.05).部分ET-1和KA组大鼠在给药后2～3周可见癫痫样发作行为学改变.与PBS组比较,El-1和KA组给药后48 h对侧海马各区Nissl染色细胞数明显减少,GFAP表达增强(P<0.05);给药后30 d,对侧CA3区和门齿区苔藓纤维出芽评分高于PBS组(P<0.05).结论 海马注射ET-1可以导致大鼠癫痫样行为改变和海马硬化.     

海马μ型阿片受体在红藻氨酸诱导的癫痫敏感性形成中的作用

目的　探讨海马 μ型阿片受体 (MORs)在红藻氨酸 (KA)诱导的癫痫敏感性形成机制中的作用。方法　惊厥剂量KA(10mg/kg)皮下注射诱导大鼠癫痫发作 ,应用微渗透泵技术在大鼠腹侧海马连续注射MOR激动剂PL0 17和拮抗剂 β FNA。 1周后 ,皮下注射阈下剂量KA (5mg/kg)进行癫痫发作敏感性检测。结果　注射阈下剂量KA后 ,PL0 17+KA组 10 0 0 %出现 4级以上发作 ,而 β FNA+KA组只有 2 8 6 %。PL0 17+KA组潜伏期为 (10 1± 3 0 )min ,明显短于KA组和人工脑脊液 +KA组(0 0 1

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红藻氨酸致痫后大鼠海马ERK、P38 MAPK和JNK的活性变化

目的研究红藻氨酸(KA)诱导大鼠癫痫发作后海马组织细胞外调节蛋白激酶(ERK)、p38MAPK和c-jun氨基末端激酶(JNK)的活性(磷酸化状态)的变化情况。方法立体定向大鼠侧脑室内注射KA引起大鼠癫痫发作,采用Western-blot方法观察KA致痫后大鼠海马中活性ERK、p38MAPK和JNK的变化。结果KA诱导大鼠癫痫发作后,海马组织ERK、p38MAPK和JNK的磷酸化水平开始增高,分别于30min、1h和30min后达高峰,呈对照组的4.76倍、2.16倍和3.95倍,两组比较差异具有显著性(P<0.01),之后逐渐下降。结论KA致痫大鼠癫痫发作后,海马组织MAPKs的活性产生变化,其信号通路可能参与癫痫发作后海马组织的病理生理反应过程。     

海人酸致痫大鼠海马IL-1β、TNF-α的表达

目的 立体定向手术建立海人酸(KA)颞叶癫痫大鼠模型,检测海马内IL-1β、TNF-α蛋白及其mRNA的表达.方法 大鼠随机分为空白对照组、生理盐水对照组和模型组.模型组大鼠一侧海马CA3区注射KA (生理盐水组注射生理盐水),观察其行为学特征,HE染色和Nissl染色以及电镜观察其病理学改变,免疫组化法检测大鼠海马内IL-1β、TNF-α蛋白的表达,原位杂交法检测TNF-α mRNA的动态表达.结果 大鼠注射KA后出现湿狗样抖动、头面部肌阵挛、肢体阵挛及全面强直阵挛发作等,病理结果显示海马神经元变性、缺失及胶质细胞增生,模型组IL-1β在致痫后3 、6 h表达水平明显增加并于12 h达高峰,之后逐渐下降,7 d后与对照组相比差异无统计学意义(P＞0.05);TNF-α蛋白与mRNA表达时程基本一致,3 h出现,12 h达高峰,而后逐渐下降,7 d后回归至对照组表达水平,15 、30 d又高于对照组(P＜0.05).结论 (1)大鼠一侧海马注射KA是人类颞叶癫痫理想的动物模型;(2)内源性IL-1β、TNF-α参与了癫痫发病机制.     

IL-1β通过NF-κB促进大鼠内侧颞叶癫痫慢性进展

目的探讨白介素1-beta(IL-1β)在大鼠内侧颞叶癫痫(MTLE)模型病情进展中的作用,并探讨其与核因子-κB(NF-κB)的作用关系。方法利用匹罗卡品诱导SD鼠发作癫痫制成MTLE模型,并于制模成功后0.5h侧脑室注射IL-1β,于慢性期(8w),利用行为学观察、脑电图检测观察模型鼠自发癫痫的情况,利用Nissl染色和Timm染色观察模型鼠海马神经元脱失和苔藓纤维增生情况;利用凝胶迁移电泳(EMSA)和免疫组化(IHC)观察海马内NF-κB和NF-κB p65的表达。结果 IL-1β可以提高匹罗卡品诱导的MTLE模型鼠慢性期自发癫痫的发生率,且加重海马内神经元脱失和苔藓样纤维增生,并且NF-κB表达增加,与对照组和单纯匹罗卡品诱导组比较均有统计学差异(P<0.05)。结论 IL-1β通过NF-κB促进匹罗卡品诱导的MTLE模型鼠癫痫慢性自发发作,是导致MTLE进展的机制之一。     

辛伐他汀抑制海人酸模型大鼠癫痫发作

目的 研究辛伐他汀(Sim)抑制海人酸(KA)诱导的大鼠抽搐发作向颞叶癫痫(TLE)发展的长期影响.方法 将大鼠分为健康对照组、盐水治疗癫痫组、Sim治疗癫痫组.KA诱导癫痫半小时后,Sim灌胃.(1)大鼠抽搐后3d评估了细胞因子(TNF-α、IL-1β、IL-6)的水平变化.(2)在4-6个月观察海马胶质细胞增生、神经元死亡、苔状纤维发芽(MFS)和大鼠癫痫发作情况.结果 Sim降低了TNF-α、IL-1β水平,减轻了胶质细胞增生和神经元死亡,并抑制了海马MFS和癫痫发作.结论 Sim具有抑制KA诱导的大鼠急性抽搐发作向TLE发展的效能.     

Semaphorin-3A与苔藓纤维出芽在毛果芸香碱致痫大鼠中的改变及意义

目的探讨海马Semaphorin-3A(Sema3A)与苔藓纤维出芽(MFS)在癫痫发病机制中的作用。方法通过小剂量多次腹腔注射氯化锂-毛果芸香碱建立癫痫大鼠模型,随机将大鼠分为生理盐水对照组和痫性发作组。痫性发作组分别于药物注射后1、5、7d及3、4周时间点,应用Western blotting法检测大鼠海马Sema3A的表达,同时采用neo-Timm银染观察海马MFS情况。结果生理盐水对照组Sema3A仅有少量表达,痫性发作组1、5d无表达,7d表达明显,3周后亦无表达;痫性发作组1、5d未见MFS,7d可见MFS至齿状回内分子层,3周后明显可见MFS至齿状回分子层。痫性发作组Timm评分与生理盐水对照组比较差异有统计学意义(P<0.05)。结论海马区Sema3A表达变化伴有MFS可能是癫痫发病机制的重要因素之一。     

Altered distribution of excitatory amino acid receptors in temporal lobe epilepsy

In temporal lobe epilepsy, excitatory amino acid receptors in the hippocampus and temporal lobe may contribute to both increased excitability and vulnerability to excitotoxic damage. We used receptor autoradiography to examine the density of N-methyl-D-aspartate (NMDA) and kainic acid (KA) receptors in the hippocampus and parahippocampal gyrus obtained from five patients who had undergone anterior temporal lobectomy for the treatment of intractable seizures and from six control individuals, in which the hippocampus was obtained postmortem. Within the hippocampal formation, loss of [3H]KA and NMDA-sensitive L-[3H]glutamate binding was apparent in the sclerotic regions CA3, hilus, and CA1. In the subiculum and molecular layer of the denate gyrus, binding densities were maintained or even increased in some of the epileptic patients. A two-fold increase in L-[3H]glutamate binding, along with an increase in [3H]KA binding, was observed in the parahippocampal gyrus obtained from the epileptic patients. The results suggest that the vulnerability of the hippocampus in temporal lobe epilepsy may result, at least in part, from the presence of aberrant excitatory circuits in the parahippocampal gyrus.     

G蛋白偶联内向整流钾通道亚基2 mRNA在颞叶癫疒间大鼠海马内的表达

目的探讨G蛋白偶联内向整流钾通道亚基2(GIRK 2)在颞叶癫癎大鼠海马内的表达变化.方法应用腹腔注射海人酸致癎大鼠,采用原位杂交法检测大鼠海马GIRK 2 mRNA的表达.结果 GIRK 2 mRNA在癫癎大鼠海马齿状回表达增加,与正常对照组相比差异有显著性( P<0.01).结论癫癎大鼠海马内GIRK2增高是机体对神经元网络过度兴奋的代偿反应.     

Somatostatin and neuropeptide Y neurons undergo different plasticity in parahippocampal regions in kainic acid-induced epilepsy

Parahippocampal brain areas including the subiculum, presubiculum and parasubiculum, and entorhinal cortex give rise to major input and output neurons of the hippocampus and exert increased excitability in animal models and human temporal lobe epilepsy. Using immunohistochemistry and in situ hybridization for somatostatin and neuropeptide Y, we investigated plastic morphologic and neurochemical changes in parahippocampal neurons in the kainic acid (KA) model of temporal lobe epilepsy. Although constitutively contained in similar subclasses of γ-aminobutyric acid (GABA)-ergic neurons, both neuropeptide systems undergo distinctly different changes in their expression. Somatostatin messenger RNA (mRNA) is rapidly but transiently expressed de novo in pyramidal neurons of the subiculum and entorhinal cortex 24 hours after KA. Surviving somatostatin interneurons display increased mRNA levels at late intervals (3 months) after KA and increased labeling of their terminals in the outer molecular layer of the subiculum; the labeling correlates with the number of spontaneous seizures, suggesting that the seizures may trigger somatostatin expression. In contrast, neuropeptide Y mRNA is consistently expressed in principal neurons of the proximal subiculum and the lateral entorhinal cortex and labeling for the peptide persistently increased in virtually all major excitatory pathways of the hippocampal formation. The pronounced plastic changes differentially involving both neuropeptide systems indicate marked rearrangement of parahippocampal areas, presumably aiming at endogenous seizure protection. Their receptors may be targets for anticonvulsive drug therapy.     

雌激素影响海人酸杏仁核点燃大鼠癫(癎)发作机制的初步探讨

目的:探讨雌激素(E)和姜黄素(C)影响癫发作的机制。方法:用E和C单独及联用连续处理去势雌性大鼠5d,第6天以海人酸(KA)杏仁核点燃法制备癫大鼠模型,观察大鼠癫发作的行为学表现,用免疫组化方法检测海马组织c-Jun蛋白的表达。结果:E加C组(EC KA组)大鼠癫重度发作的严重程度较E组(E KA组)明显减轻(P<0.05)。E KA组海马中c-Jun蛋白表达最多,C组(C KA组)及对照组(KA组)均表达较少且没有任何差异;EC KA组海马的CA1区c-Jun蛋白表达较E KA组明显减少(P<0.05)。结论:C能一定程度上减轻E引起的癫发作加重,它可能通过抑制c-Jun/核转录因子激活蛋白-1(activate-protein1,AP-1)活性,使E作用的AP-1通路受阻,从而减轻了E的促神经元兴奋作用。     

托吡酯对颞叶癫痫大鼠海马神经细胞粘附分子表达的影响

目的观察托吡酯对红藻氨酸(KA)诱导颞叶癫痫大鼠海马突触重建标记物神经细胞粘附分子(NCAM)表达的影响,进一步探讨托吡酯的抗痫作用机制。方法采用免疫组织化学染色观察KA诱导癫痫大鼠及托吡酯给药大鼠海马神经细胞粘附分子表达水平,并对两组NCAM表达进行比较。结果KA组NCAM表达水平各时间点平均NCAM阳性密度OD率均明显高于N S组和KA TPM组(P<0.01)。结论本研究提示托吡酯可能通过抑制突触重建的形成,减少痫性放电,从而控制癫痫发作。     

GAP-43 mRNA and protein expression in the hippocampal and parahippocampal region during the course of epileptogenesis in rats

In order to reveal axonal rewiring in the hippocampal and parahippocampal regions after status epilepticus, we investigated the temporal evolution of growth-associated protein-43 (GAP-43) mRNA and protein expression in two rat models of mesial temporal lobe epilepsy (MTLE). Status epilepticus (SE) was induced by electrical stimulation of the angular bundle or by intraperitoneal kainic acid (KA) injections. Despite increased GAP-43 mRNA expression in dentate granule cells at 24 h after SE, GAP-43 protein expression in the inner molecular layer (IML) of the dentate gyrus decreased progressively after 24 h after SE in both models. Nevertheless robust mossy fiber sprouting (MFS) was evident in the IML of chronic epileptic rats. Remaining GAP-43 protein expression in the IML in chronic epileptic rats did not correlate with the extent of MFS, but with the number of surviving hilar neurons. In the parahippocampal region, GAP-43 mRNA expression was decreased in layer III of the medial entorhinal area (MEAIII) in parallel with extensive neuronal loss in this layer. There was a tendency of GAP-43 mRNA up-regulation in the presubiculum, a region that projects to MEAIII. With regard to this parahippocampal region, however, changes in GAP-43 mRNA expression were not followed by protein changes. The presence of the presynaptic protein GAP-43 in a neurodegenerated MEAIII indicates that fibers still project to this layer. Whether reorganization of fibers has occurred in this region after SE needs to be investigated with tools other than GAP-43.     

海人酸致大鼠海马结构GABA_B受体亚单位表达的研究

目的:探讨海人酸诱导大鼠颞叶癫(EP)发作后2种γ-氨基丁酸(GABA)受体亚单位GABABR亚单位1a(GBR1a)和GABABR亚单位2(GBR2)在EP发生、发展中的作用。方法:运用原位杂交及免疫组化法,检测EP发作后GABABR亚单位mRNA及蛋白在海马的表达。结果:致早期CA1和CA3区2种亚单位mRNA表达持续低下后逐渐增加,DG区则暂时性下降后很快回升;而免疫反应早期却未见明显改变,随后CA1和CA3区表达处于低水平,DG区和颞叶皮质表达下降后很快恢复。结论:致后2种GABAB受体亚单位基因和蛋白表达上调为颞叶EP的内源性自我保护机制。     

Intrahippocampal infusion of botulinum neurotoxin E (BoNT/E) reduces spontaneous recurrent seizures in a mouse model of mesial temporal lobe epilepsy

Mesial temporal lobe epilepsy (MTLE) is one of the most common forms of human epilepsy, and it is often resistant to conventional antiepileptic drug (AED) therapy. Here we tested whether a single intrahippocampal administration of the synaptic blocker botulinum neurotoxin E (BoNT/E) is effective in reducing spontaneous recurrent seizures (SRS) in a mouse model of MTLE. Unilateral intrahippocampal injection of kainic acid (KA) in mice was used as a model of MTLE. Electroencephalography (EEG) recordings of SRS were performed during the chronic phase of epilepsy, before and after administration of either BoNT/E or vehicle. Frequency of SRS was significantly decreased for at least 5 days following BoNT/E, but not vehicle, infusion. Our findings demonstrate that BoNT/E can effectively reduce seizure incidence in a mouse model of MTLE.     

红藻氨酸致颞叶癫痫大鼠海马内Semaphorin3C、Semaphorin3F基因表达的研究

目的研究神经轴索导向分子Sem aphorin3C(Sem a3C),Sem aphorin3F(Sem a3F)mRNA对颞叶癫痫(TLE)大鼠海马神经轴索环路重建的调控作用。方法采用侧脑室内注射红藻氨酸(KA)制作TLE大鼠模型,用N issl染色及原位杂交的方法,分别检测致痫后1d、1w、2w、3w、4w大鼠海马的齿状回(DG),CA1区、CA3区神经细胞丢失程度以及Sem a3C、Sem a3F mRNA的表达。结果KA致痫后1d始出现神经元丢失,至4w神经元丢失明显增多。KA致痫后1w,Sem a3C、Sem a3F mRNA在海马的CA1区、Sem a3F mRNA在海马的CA3区表达明显下降,持续至3w(P<0.01),4w时恢复至正常(P>0.05);Sem a3C、Sem a3F mRNA在DG的表达,Sem a3C在CA3区的表达,实验组与对照组均无明显差别(P>0.05)。结论KA致痫后海马CA1区神经元下调Sem a3C、Sem a3F mRNA的表达,CA3区神经元下调Sem a3F mRNA的表达,可能促进TLE大鼠海马神经轴索环路重建。