马桑内酯致癇大鼠大脑皮质、海马NMDA受体亚单位1 mRNA表达的动态变化

NMDA受体与惊厥和癫疒 易感性的形成密切相关.为了探讨癫癇发病的分子机制,采用原位杂交技术,研究了马桑内酯致疒 间大鼠大脑皮质、海马NMDA受体亚单位1(NMDAR1)mRNA 表达的动态变化.结果显示,马桑内酯致癇 大鼠顶叶大脑皮质及海马齿状回NMDAR1 mRNA水平显著高于生理盐水对照组(P<0.01, P<0.05).提示：马桑内酯上调脑组织内NMDAR1亚单位mRNA水平,可能是其致癇及使惊厥易感性增加的分子机制之一.     

马桑内酯致痫大鼠大脑皮层、海马NMDA受体亚单位1(NMDAR1)mRNA表达的变化

目的　探讨癫痫发病的分子机制。方法　采用原位杂交技术 ,研究了马桑内酯致痫大鼠大脑皮层、海马 N-甲基 - D-天门冬氨酸受体亚单位 1(NMDAR1) m RNA表达的变化。结果　马桑内酶致痫大鼠顶叶大脑皮层及海马齿状回 NMDAR1m RNA水平显著高于生理盐水对照组 (P<0 .0 1,P<0 .0 5 )。结论　马桑内酯上调脑组织内NMDAR1m RNA水平 ,此可能是其致痫及惊厥易感性增加的分子机制之一     

马桑内酯致痫大鼠大脑皮质,海马NMDA受体亚单位1mRNA表达的 …

ＮＭＤＡ受体与惊厥和癫痫易感性的形成密切相关。为了探讨癫痫发病的分子机制，采用原位杂交技术，研究了马桑内酯致痫大鼠大脑皮质、海马ＮＭＤＡ受体亚单位１（ＮＭＤＡＲ１）ｍＲＮＡ表达的动态变化。结果显示，马桑内酯致痫大鼠顶叶大脑皮质及海马齿状回ＮＭＤＡＲ１ ｍＲＮＡ水平显著高于生理盐水对照组（Ｐ〈０．０１，Ｐ〈０．０５）。提示：马桑内酯上调脑组织内ＮＭＤＡＲ１亚单位ｍＲＮＡ水平，可能是其致痫及使惊厥易感     

海人酸致癫痫大鼠海马GABAB受体亚单位GBR1a mRNA表达的研究

目的　通过研究海人酸致癫痫大鼠海马 GABAB受体亚单位 GBR1a m RNA表达的变化 ,为进一步探明癫痫发病的受体分子生物学机制奠定基础。方法　在立体定位仪下 ,将海人酸注射至大鼠杏仁核制备癫痫模型。将大鼠随机分为正常组和海马致癫痫组 ,分别于不同时间取材 ,进行脑组织 GABAB受体亚单位 GBR1a m RNA原位杂交检测。结果　正常组海马各区均有极少量的 GABAB受体亚单位 GBR1a m RNA的分布 ;海人酸致癫痫组( 6 h,12 h,2 4h) GABAB受体亚单位 GBR1a m RNA水平显著高于对照组 ( P<0 .0 1)。结论　正常大鼠海马各区存在着少量的 GBR1a m RNA表达 ,海人酸致痫后 6 h,12 h,2 4h,GBR1a m RNA的表达水平上调。     

戊四氮致癎大鼠海马S-100β蛋白变化及其相关性研究

目的　探讨戊四氮致疒间 大鼠脑内海马区S 10 0 β蛋白的变化与癫 疒间 发作持续时间和发作强度之间的关系。方法　应用免疫组化法检测惊厥组、癫疒间 持续状态组和对照组大鼠海马内S 10 0 β蛋白阳性细胞数的变化。结果　惊厥组大鼠海马内S 10 0 β蛋白阳性细胞数于致 疒间 后 12h开始增加 ,2 4h达高峰 ,72h恢复 ,与对照组相比差异有显著性 (P <0 0 1)。癫疒间 持续状态组大鼠海马内S 10 0 β蛋白在 12h、2 4h均有明显增加 ,较惊厥组更为显著。两组相比差异有显著性 (P <0 0 1)。结论　致疒间 大鼠海马内S 10 0 β蛋白阳性细胞数及染色强度与癫疒间 持续时间及发作强度有关 ,提示S 10 0 β蛋白可作为临床上判断癫 疒间 后脑损伤、特别是神经胶质细胞损伤的一种较灵敏而特异的指标。     

马桑内酯致痫大鼠大脑皮层,海马NMDA受体亚单位1（NMDAR1） …

目的 探讨癫痫发病的发子机制。方法 采用原位杂交技术，研究了马桑内酯致痫大鼠大脑皮层、海马Ｎ－甲基－Ｄ－天安门冬氨酸受体亚单位１（ＮＭＤＡＲ１）ｍＲＮＡ表达的变化。结果 马桑内酶致痫大鼠顶叶大脑皮层及海马齿回ＮＭＤＡＲ１ｍＲＮＡＡ水平显著高于生理盐水对照组（Ｐ〈０．０１，Ｐ〈０．０５）。结论 马桑内酯上调脑组织内ＮＭＤＡＲ１ｍＲＮＡ水平，此可能是其致痫及惊痫及惊厥易感性增加的分子机制之一。     

实验性癫痫大鼠发作后海马γ-氨基丁酸B受体亚单位的表达及其激动剂的影响

目的 观察海人酸(KA)诱导的实验性癫疒间(EP)大鼠发作后海马γ-氨基丁酸B受体(GABABR)亚单位mRNA表达及其激动剂巴氯芬的影响.方法 运用原位杂交法检测各实验组大鼠EP发作后及巴氯芬干预后海马区GABABR亚单位GAR1a及GAR2 mRNA表达.结果 KA致疒间早期(6～12 h)2种亚单位mRNA表达水平广泛下降,至1 d仍明显低于对照组(均P<0.05),但齿状回(DG)区mRNA表达开始回升,3 d后表达水平已明显高于对照组(P<0.05),而CA1与CA3区表达仍维持低水平(均P<0.05),但其表达水平渐向对照组水平恢复.巴氯芬干预后亚单位表达明显下降的时间点延迟,且表达水平明显高于非干预的致疒间组(P<0.05～0.01).结论 致疒间鼠2种亚单位表达下降后又上调为颞叶EP的内源性自我保护机制;巴氯芬促进2种亚单位表达,增强GABA抑制作用,有利于控制EP,为筛选针对GABABR亚单位的抗疒间药提供新途径.     

雌孕激素对鼠脑皮层及海马N-甲基-D-天冬氨酸受体亚单位1 mRNA表达的影响

目的　探讨雌、孕激素对中枢神经系统作用的分子机制。方法　采用原位杂交技术 ,研究雌、孕激素对大鼠大脑皮层、海马N 甲基 D 天冬氨酸受体亚单位 1(NMDAR1)mRNA表达的影响。结果　给予雌二醇后大鼠顶叶大脑皮层及海马CA1、CA3 及齿状回NMDAR1mRNA水平显著高于生理盐水对照组 ;给予孕酮后大脑皮层及海马各区NMDAR1mRNA水平与生理盐水对照组比较 ,差异无显著性意义。结论　雌激素上调脑组织内NMDAR1mRNA水平 ,使惊厥易患性增加 ,此可能是雌激素致癫痫作用的分子机制之一。而孕激素的抗癫痫作用与调节NMDAR1mRNA的表达没有明显关系     

氯化锂-匹罗卡品致(疒间)大鼠脑髓鞘转录因子的表达及其意义

目的探讨氯化锂-匹罗卡品致疒间大鼠脑髓鞘转录因子1(MyT1)的表达及其意义.方法给SD大鼠先后腹腔注射氯化锂、匹罗卡品,制成癫疒间动物模型;用免疫荧光组化法检测癫疒间大鼠癫疒间发作后不同时间大脑皮质和海马CA1区MyT1阳性细胞数.结果与对照组相比,癫疒间后1 d组大鼠海马CA1区MyT1阳性细胞数显著减少(P＜0.05),癫疒间后其他各时间组大鼠脑皮质和海马CA1区MyT1阳性细胞数均有明显的增加,其中癫疒间后7 d组MyT1阳性细胞数最多(P＜0.01,P＜0.05).结论氯化锂-匹罗卡品致疒间大鼠早期大脑MyT1表达增加,并有时程性变化.     

雌激素和克罗米酚对致(疒间)大鼠海马γ-氨基丁酸免疫反应细胞和GABAA受体α1亚单位表达的影响

目的了解雌激素和克罗米酚对海人藻酸(KA)致(疒间)大鼠癫(疒间)发作行为学的影响及其影响癫(疒间)活动的部分机制.方法将去势的雌性大鼠添加雌激素(20mg/kg)或添加雌激素和克罗米酚治疗,比较各组大鼠致(疒间)后癫(疒间)发作的行为学变化;并采用间接免疫荧光法检测各组大鼠海马中γ-氨基丁酸(GABA)免疫反应细胞及GABAA受体α1亚单位表达的变化.结果添加雌激素治疗组大鼠癫(疒间)发作的潜伏期和到达4/5级(4级或5级)的时间[分别为(24.63±11.44)min和(41.50±16.22)min]均较去势组[分别为(46.75±14.61)min和(65.13±12.99)min]明显缩短,而同时添加雌激素和克罗米酚治疗组的潜伏期[(43.50±5.75)min]比单纯添加雌激素组明显延长.雌激素组的阳性免疫反应细胞数在大鼠海马的某些区域也较去势组明显减少,克罗米酚组与雌激素组相比则有所增多.结论高水平的雌激素可促进癫(疒间)发作,克罗米酚添加治疗具有一定的抗癫(疒间)作用.这可能与脑内GABA能系统某些功能的改变有关.     

Effect of minocycline on pentylenetetrazol-induced chemical kindled seizures in mice

Inflammation is one of the mechanisms involved in seizure induction. In this study, the effect of minocycline, an anti-inflammatory drug, was investigated on kindling acquisition. Chemical kindling was induced by injection of a subthreshold dose of pentylenetetrazol (PTZ; 37.5 mg/kg) in mice on every other day. Two groups of animals received minocycline (25 mg/kg) at 1 h before or 1 h after PTZ injection. Following the last PTZ injection, the changes in gene expression of TNF-α receptor, γ₂ subunit of GABA_A receptor and NR₂A subunit of NMDA receptor were assessed in the hippocampus and piriform cortex. Injection of minocycline before PTZ increased the latency to stage 4 seizure, and decreased the duration of stages 4 and 5 seizure. It also prevented the increase in the mRNA of NR₂A subunit of NMDA receptor in the hippocampus and removed the PTZ-induced increase in mRNA of γ₂ subunit of GABA_A receptor in piriform cortex of PTZ kindled mice. Minocycline also prevented the increase in TNF-α receptor gene expression in both hippocampus and piriform cortex. Injection of minocycline after PTZ had no significant effect on measured parameters. Therefore, it can be concluded that minocycline may exert an anticonvulsant effect through preventing the increase in GABA_A and NMDA receptor subunits. These effects are accompanied by a reduction in an important inflammation index, TNF-α receptor.     

Differences in ionotropic glutamate receptor subunit expression are not responsible for strain-dependent susceptibility to excitotoxin-induced injury

Systemic administration of kainic acid in C57BL/6 and FVB/N mice induces a comparable level of seizure induction yet results in differential susceptibility to seizure-induced cell death. While kainate administration causes severe hippocampal damage in mice of the FVB/N strain, C57BL/6 mice display no demonstrable cell loss or damage. At present, while the cellular mechanisms underlying strain-dependent differences in susceptibility remain unclear, some of this variation is assumed to have a genetic basis. As glutamate receptors are thought to participate in seizure induction and the subsequent neuronal degeneration that ensues, previous studies have proposed that variation in the precise subunit composition of glutamate receptors may result in differential susceptibility to excitotoxic cell death. Thus, we chose to examine the relationship between the cellular distribution and expression of glutamate receptor subunit proteins and cell loss within the hippocampus in mouse strains resistant and susceptible to kainate-induced excitotoxicity. Using semi-quantitative Western blot techniques and immunohistochemistry with the use of antibodies that recognize subunits of the KA (GluR5,6,7), AMPA (GluR1, GluR2, and GluR4), and NMDA (NMDAR1 and NMDAR2A/2B) receptors, we found no significant strain-dependent differences in the expression or distribution of these glutamate receptor subunits in the intact hippocampus. Following kainate administration, expression changes in ionotropic glutamate receptor subunits paralleled the development of susceptibility to cell death in the FVB/N strain only. Strain differences in hippocampal vulnerability to kainate-induced status epilepticus are not due to glutamate receptor protein expression.     

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。     

Withdrawal from repeated amphetamine administration reduces NMDAR1 expression in the rat substantia nigra, nucleus accumbens and medial prefrontal cortex

Glutamate plays a critical role in neuroadaptations induced by drugs of abuse. This study determined whether expression of the NMDAR1 subunit of the NMDA receptor is altered by repeated amphetamine administration. We quantified NMDAR1 mRNA (using in situ hybridization with 35S-labelled oligonucleotide probes) and immunolabelling (using immunocytochemistry with 35S-labelled secondary antibodies) in rat ventral midbrain, nucleus accumbens and prefrontal cortex after 3 or 14 days of withdrawal from five daily injections of saline or amphetamine sulphate (5 mg/kg/day). No changes in NMDAR1 expression were observed after 3 days of withdrawal, whereas significant decreases were observed in all regions after 14 days. NMDAR1 mRNA levels in midbrain were too low for reliable quantification, but immunolabelling was decreased significantly in intermediate and caudal portions of the substantia nigra. This may indicate a reduction in excitatory drive to substantia nigra dopaminergic neurons. In the nucleus accumbens, there were significant decreases in NMDAR1 mRNA levels (74.8 +/- 7. 7% of control, P < 0.05) and immunolabelling (76.7 +/- 4.4%, P < 0. 05). This may account for previously-reported decreases in the electrophysiological responsiveness of nucleus accumbens neurons to NMDA after chronic amphetamine treatment, and contribute to dysregulation of goal-directed behaviour. In prefrontal cortex, there was a significant decrease in NMDAR1 mRNA levels (76.1 +/- 7. 1%, P < 0.05) and a trend towards decreased immunolabelling (89.5 +/- 7.0%). This may indicate decreased neuronal excitability within prefrontal cortex. A resultant decrease in activity of excitatory prefrontal cortical projections to nucleus accumbens or midbrain could synergize with local decreases in NMDAR1 to further reduce neuronal excitability in these latter regions.     

大鼠失神样癇性发作时GABA_B受体亚单位GBR1a mRNA改变

目的 :探讨GABAB 受体亚单位在失神癫发病机制中的作用。方法 :用原位杂交的方法测定AY 9944大鼠癫模型在失神样性发作时GABAB 受体亚单位GBR1amRNA在鼠脑的表达。结果 :大脑皮质 ,海马CA1、CA3 及丘脑的mRNA表达均见不同程度的升高 ,而以大脑皮质及海马CA3 区尤为显著。结论 :GABAB 受体亚单位GBR1a可能参与失神性癫的发病机制。这种受体亚单位的改变为筛选有效的抗癫药物提供新的途径     

AY-9944大鼠失神样痫性发作模型的GABA_B受体R1亚单位基因表达改变

目的 :探讨 GABAB受体亚单位在失神癫痫发病机制中的作用。方法 :用原位杂交的方法测定 AY- 9944大鼠癫痫模型在失神样痫性发作时 GABAB受体亚单位 GBR1a及 GBR1b pan m RNA在鼠脑的表达。结果 :大脑皮层 ,海马 CA1,CA3及丘脑的 GBR1a m RNA表达均见不同程度的升高 ,而以大脑皮层及海马 CA3区尤为显著。GBR1b pan大脑皮层 ,海马及丘脑的 m RNA表达均见不同程度的升高 ,而以大脑皮层及海马 CA1区域的改变最为显著。结论 :GABAB受体亚单位 GBR1可能参与失神性癫痫的发病机制 .这种受体亚单位的改变为筛选有效的抗癫痫药物提供新的途径。     

Alterations in long-term seizure susceptibility and the complex of PSD-95 with NMDA receptor from animals previously exposed to perinatal hypoxia

PURPOSE: Perinatal hypoxia is an important cause of brain injury in the newborn and has consequences that are potentially devastating and life-long, such as an increased risk of epilepsy in later life. The postsynaptic density (PSD) is a cytoskeletal specialization involved in the anchoring of neurotransmitter receptors and in regulating the response of postsynaptic neurons to synaptic stimulation. The postsynaptic protein PSD-95 binds to the N-methyl-D-aspartate receptor (NMDAR) subunit, and hence activates cascades of NMDAR-mediated events, such as cyclic adenosine monophosphate (cAMP)-responsive element binding protein phosphorylation at serine-133 (pCREB(Serine-133)). Here we studied the effect of perinatal hypoxia on protein interactions involving PSD-95 and the NMDAR, as well as pCREB(Ser-133) expression at an age when the animals show increased seizure susceptibility. METHODS: Rats were assigned randomly to the control rats or the rats exposed to transient global hypoxia at postnatal day 10 (P10). At P45, some rats from both groups were treated with pentylenetetrazol (PTZ) intraperitoneally to test the seizure threshold, and others were studied for neuronal loss, pCREB(Serine-133), PSD-95, and NMDAR expressions in the midbrain, temporal cortex, and hippocampal CA1 subfield by using immunohistochemistry, co-immunoprecipitation, and immunoblotting techniques, respectively. RESULTS: The rats with prior exposure to perinatal hypoxia exhibited increased seizure susceptibility to PTZ, compared with the control rats. Associated with this long-term change in seizure susceptibility, selective neuronal loss was observed in the midbrain region while pCREB(Ser-133) expression was reduced in the midbrain, temporal cortex, and hippocampal CA1 subfield. Perinatal hypoxia led to a decrease in PSD-95 expression in the both midbrain and hippocampal CA1 subfield, with the exception of temporal cortex. Furthermore, the association between PSD-95 and NMDAR subunits (NR1, NR2A, and NR2B) in the hippocampal CA1 was also markedly altered by perinatal hypoxia. CONCLUSIONS: This study demonstrates that the decrease in several protein complexes that are essential components of the postsynaptic apparatus is associated with the observed increase in seizure susceptibility in adult rats with prior exposure to perinatal hypoxia. The results indicate that reductions in PSD-95 expression, PSD-95 binding of NMDAR subunits, and subsequent NMDAR-mediated CREB phosphorylation, particularly in hippocampal CA1, are long-term consequences of perinatal hypoxia and may, at least in part, contribute to perinatal hypoxia-induced reduction in seizure threshold.     

雌激素对癫癎大鼠中枢神经系统Fos蛋白表达的影响及其作用部位的研究

目的 :了解雌激素致作用的部位。方法 :利用红藻氨酸和 6 氟二乙酯致的两种大鼠癫模型 ,应用免疫组化法检测单纯致及给予雌激素后再致大鼠海马 ,大脑皮质 ,纹状体的Fos表达。结果 :两种模型单纯致组海马、皮质、纹状体Fos表达较正常组显著增高 (P <0 0 1)。给予雌二醇 (E2 )后再致 ,红藻氨酸模型中海马 ,皮质Fos表达较单纯致组增加 (P <0 0 1,P <0 0 5 ) ;而 6 氟二乙酯模型中无变化。结论 :E2 促进癫发作的敏感性不是普遍增加全脑神经元兴奋的结果 ,而是与海马有关