匹罗卡品致(癎)大鼠海马γ-氨基丁酸能中间神经元生长抑素和微清蛋白mRNA表达研究

目的 观察匹罗卡品致(癎)大鼠海马γ-氨基丁酸能中间神经元生长抑素(SS)mRNA和微清蛋白(PV)mRNA表达水平变化,拟从基因水平探讨其表达阳性γ-氮基丁酸能中间神经元在颞叶癫(癎)发生发展中的作用.方法 建立匹罗卡品致(癎)大鼠模型,采用原位杂交法检测各观察时间点海马SSmRNA和PVmRNA表达阳性神经元数目.结果 模型组大鼠海马各区γ-氨基丁酸能中间神经元SSmRNA表达水平均于出现癫(癎)持续状态后3d降低最为显著(均P=0.000),随后逐渐升高;至发病后60d,海马CA3区SSmRNA表达水平高于对照组(t=1.021,P=0.005),海马门区(t=3.211,P=0.009)和CA1区(t=1.902,P=0.048)则仍低于对照组.模型组大鼠海马门区γ-氨基丁酸能中间神经元PVmRNA表达水平于出现癫(癎)持续状态后6h开始降低,至发病后60d降低最为显著(均P=0.000);海马CA1区PVmRNA表达水平于发病后3d降低最为显著(均P=0.000),随后逐渐升高但仍低于对照组(江2.216,P=0.048);癫(癎)持续状态早期,海马CA3区PVmRNA表达水平无明显变化,至发病后7d逐渐升高且高于对照组(t=1.021,P=0.005).结论 γ-氨基丁酸能中间神经元SSmRNA和PVmRNA表达水平的下调可能在颞叶癫(癎)的发生中起重要作用,至慢性期γ-氨基丁酸能中间神经元SSmRNA和PVmRNA表达水平的恢复或上调可能与颞叶癫(癎)的发展或修复有关.γ-氨基丁酸能中间神经元数目的 变化,部分是由于其标志物mRNA表达水平的调节所致,并非神经元数目变化的唯一因素.     

γ-氨基丁酸能中间神经元的数量变化与颞叶癫癎关系的实验研究

目的 探讨含微白蛋白（PV）、钙视网膜蛋白（CR）、钙结合蛋白-D28K（CB）的梁静慧-氨基丁酸（GABA）能中间神经元在颞叶癫痫发生、发展中的作用。方法 采用氯化锂-匹罗卡品颞叶癫痢大鼠模型,应用免疫组化法分别于制模后6h、12h、24h、7d、15d及60d动态观察海马神经元PV、CR、CB的表达。结果 与对照组相比,实验组大鼠海马PV阳性神经元的数量在CA,区无明显变化,在CA,区呈进行性下降（P〈0．05～0．01）,7d时达最低值;在齿状回门区,6h即出现明显的下降（P〈0．05）,15d时达最低值（P〈0．01）,30d后开始上升,到60d时与对照组相比差异无显著性。实验组大鼠海马各区、各时点CR阳性神经元的数量较对照组均明显下降（P〈0．05～0．01）;在CA3区和CA1区24h组及在齿状回门区15d组数量达最低。CB阳性神经元的数量在CA3区与对照组无明显变化（P〉0．05）;在CA1区,6h后开始减少（P〈0．05）,7d后达最低值（P〈0．01）,然后稍有回升,但仍明显低于对照组（P〈0．05）;齿状回CB阳性神经元的数量7d时开始较对照组明显增加（P〈0．05）,并逐渐升高,60d时达高峰（P〈0．01）。结论 氯化锂-匹罗卡品颞叶癫痢模型中,海马GABA能神经元在CA1区和CA3区的变化可能诱发了颞叶癫痫的发作;在齿状回的改变可能在颞叶癫痫自发性复发性发作的发生和发展中起重要作用。     

匹罗卡品致(癎)大鼠海马中表达生长抑素的中间神经元数目变化及其轴突出芽

目的 探讨表达生长抑素(SS)的中间神经元在颞叶癫(癎)的发生和自我修复中的作用.方法 建立匹罗卡品致(癎)大鼠模型.免疫组织化学方法检测各时间点海马不同区域SS中间神经元的数目变化及其轴突出芽情况;结合Fluoro-Jade B(FJB)行免疫荧光双标方法特异性检测大鼠癫(癎)持续状态(status epilepticus,SE)后7 d和60 d海马不同区域SS中间神经元及其轴、树突的变性情况.结果 实验组大鼠海马各区Ss阳性神经元数目均在SE后7 d减至最低(门区11.1±3.3,CA1区2.8±0.9,CA1区1.8±0.7,t=13.519、9.644、8.808,均P<0.01),慢性期开始部分恢复,SE后60 d时CA1区SS神经元数目(12.8±1.5)超过对照组(8.8±1.3,t=-4.506,P<0.01),但门区和CA3区SS神经元数目(分别为25.5±4.6和4.8±0.8)仍明显低于正常水平(t=4.691、3.953,P<0.01);sE后30 d大鼠海马回腔隙.分子层(lacunosum-moleculare,lm)和齿状回外分子层出现大量SS染色阳性纤维,60 d时海马CA1区全层均可见大量增多的SS阳性纤维.实验组中SE后7 d的海马CA1区、60 d的CA1、CA1区和门区均可观察到少部分被FJB染色的SS中间神经元胞体及其轴、树突.结论 SS中间神经元的缺失在颞叶癫(癎)的发生中起重要作用,其缺失部分是由于神经元的变性死亡所致;慢性期CA,区SS阳性纤维大量增多,可能在颞叶癫(癎)的发生和自我修复中起重要作用.     

匹罗卡品致(癎)大鼠海马中表达生长抑素的中间神经元数目变化及其轴突出芽

Objective To investigate the roles of somatostatin(SS)positive intemeurons in the development and compensation of temporal lobe epilepsy.Methods Piloearpine-induced epilepsy rat model was established.Immunohistochemistry method was used to detect number changes and axonal sprouting of SS positive intemeurons in different domains of the hippocampus at difierent time points.Degeneration of SS positive interneurons and their neurophils were detected by the double immunofluorescence staining with SS and Fluoro-Jade B(FJB)at 7 and 60 days after status epilepticus (SE).Results In the exoerimental rat group,the number of SS positive neurons decreased in each hippocampal domain,and it reached the lowest at 7 days post-SE(There were 11.1±3.3 in hilus,2.8±0.9 in CA1region and 1.8±0.7 in CA1region,t=13.519,9.644 and 8.808,all P<0.01).In chronic phase,the number of SS neurons gradually recovered,and exceeded the control group in CA1 area at 60 days post-SE(12.8±1.5 vs 8.8±1.3,t=-4.506,P<0.01),however,the number of SS neurons in the hilus(25.5±4.6)and CA1 area(4.8±0.8)remained significantly less than normal levels(t value were 4.691 and 3.953.both P<0.01).Increased SS positive fibers were found in the lacunosum-molecular (1m)layer and outer molecular layer of dentate gyrus after 30 days post-SE,and numerous SS positive fibers were seen threnghout the layers of area CA1 at 60 days post-SE.Double immunofluuorescence revealed that a few SS positive interneurons and fibers were also labeled by FJB in area CA1 at 7 days post-SE and in CA domain/hilus at 60 days post-SE.Conclusions SS intemeurons loss plays an important role in the development of temporal lobe epilepsy.The loss is partially caIlsed by the degeneration and death of neurons;SS positive neurophils increase within area CA1 in chronic phase may play a significant role in the generation and compensation of temporal lobe epilepsy.     

匹罗卡品致(癎)大鼠海马中表达生长抑素的中间神经元数目变化及其轴突出芽

Objective To investigate the roles of somatostatin(SS)positive intemeurons in the development and compensation of temporal lobe epilepsy.Methods Piloearpine-induced epilepsy rat model was established.Immunohistochemistry method was used to detect number changes and axonal sprouting of SS positive intemeurons in different domains of the hippocampus at difierent time points.Degeneration of SS positive interneurons and their neurophils were detected by the double immunofluorescence staining with SS and Fluoro-Jade B(FJB)at 7 and 60 days after status epilepticus (SE).Results In the exoerimental rat group,the number of SS positive neurons decreased in each hippocampal domain,and it reached the lowest at 7 days post-SE(There were 11.1±3.3 in hilus,2.8±0.9 in CA1region and 1.8±0.7 in CA1region,t=13.519,9.644 and 8.808,all P<0.01).In chronic phase,the number of SS neurons gradually recovered,and exceeded the control group in CA1 area at 60 days post-SE(12.8±1.5 vs 8.8±1.3,t=-4.506,P<0.01),however,the number of SS neurons in the hilus(25.5±4.6)and CA1 area(4.8±0.8)remained significantly less than normal levels(t value were 4.691 and 3.953.both P<0.01).Increased SS positive fibers were found in the lacunosum-molecular (1m)layer and outer molecular layer of dentate gyrus after 30 days post-SE,and numerous SS positive fibers were seen threnghout the layers of area CA1 at 60 days post-SE.Double immunofluuorescence revealed that a few SS positive interneurons and fibers were also labeled by FJB in area CA1 at 7 days post-SE and in CA domain/hilus at 60 days post-SE.Conclusions SS intemeurons loss plays an important role in the development of temporal lobe epilepsy.The loss is partially caIlsed by the degeneration and death of neurons;SS positive neurophils increase within area CA1 in chronic phase may play a significant role in the generation and compensation of temporal lobe epilepsy.     

匹罗卡品致(癎)大鼠海马中表达生长抑素的中间神经元数目变化及其轴突出芽

Objective To investigate the roles of somatostatin(SS)positive intemeurons in the development and compensation of temporal lobe epilepsy.Methods Piloearpine-induced epilepsy rat model was established.Immunohistochemistry method was used to detect number changes and axonal sprouting of SS positive intemeurons in different domains of the hippocampus at difierent time points.Degeneration of SS positive interneurons and their neurophils were detected by the double immunofluorescence staining with SS and Fluoro-Jade B(FJB)at 7 and 60 days after status epilepticus (SE).Results In the exoerimental rat group,the number of SS positive neurons decreased in each hippocampal domain,and it reached the lowest at 7 days post-SE(There were 11.1±3.3 in hilus,2.8±0.9 in CA1region and 1.8±0.7 in CA1region,t=13.519,9.644 and 8.808,all P<0.01).In chronic phase,the number of SS neurons gradually recovered,and exceeded the control group in CA1 area at 60 days post-SE(12.8±1.5 vs 8.8±1.3,t=-4.506,P<0.01),however,the number of SS neurons in the hilus(25.5±4.6)and CA1 area(4.8±0.8)remained significantly less than normal levels(t value were 4.691 and 3.953.both P<0.01).Increased SS positive fibers were found in the lacunosum-molecular (1m)layer and outer molecular layer of dentate gyrus after 30 days post-SE,and numerous SS positive fibers were seen threnghout the layers of area CA1 at 60 days post-SE.Double immunofluuorescence revealed that a few SS positive interneurons and fibers were also labeled by FJB in area CA1 at 7 days post-SE and in CA domain/hilus at 60 days post-SE.Conclusions SS intemeurons loss plays an important role in the development of temporal lobe epilepsy.The loss is partially caIlsed by the degeneration and death of neurons;SS positive neurophils increase within area CA1 in chronic phase may play a significant role in the generation and compensation of temporal lobe epilepsy.     

匹罗卡品致(癎)大鼠海马中表达生长抑素的中间神经元数目变化及其轴突出芽

Objective To investigate the roles of somatostatin(SS)positive intemeurons in the development and compensation of temporal lobe epilepsy.Methods Piloearpine-induced epilepsy rat model was established.Immunohistochemistry method was used to detect number changes and axonal sprouting of SS positive intemeurons in different domains of the hippocampus at difierent time points.Degeneration of SS positive interneurons and their neurophils were detected by the double immunofluorescence staining with SS and Fluoro-Jade B(FJB)at 7 and 60 days after status epilepticus (SE).Results In the exoerimental rat group,the number of SS positive neurons decreased in each hippocampal domain,and it reached the lowest at 7 days post-SE(There were 11.1±3.3 in hilus,2.8±0.9 in CA1region and 1.8±0.7 in CA1region,t=13.519,9.644 and 8.808,all P<0.01).In chronic phase,the number of SS neurons gradually recovered,and exceeded the control group in CA1 area at 60 days post-SE(12.8±1.5 vs 8.8±1.3,t=-4.506,P<0.01),however,the number of SS neurons in the hilus(25.5±4.6)and CA1 area(4.8±0.8)remained significantly less than normal levels(t value were 4.691 and 3.953.both P<0.01).Increased SS positive fibers were found in the lacunosum-molecular (1m)layer and outer molecular layer of dentate gyrus after 30 days post-SE,and numerous SS positive fibers were seen threnghout the layers of area CA1 at 60 days post-SE.Double immunofluuorescence revealed that a few SS positive interneurons and fibers were also labeled by FJB in area CA1 at 7 days post-SE and in CA domain/hilus at 60 days post-SE.Conclusions SS intemeurons loss plays an important role in the development of temporal lobe epilepsy.The loss is partially caIlsed by the degeneration and death of neurons;SS positive neurophils increase within area CA1 in chronic phase may play a significant role in the generation and compensation of temporal lobe epilepsy.     

匹罗卡品致(癎)大鼠海马中表达生长抑素的中间神经元数目变化及其轴突出芽

Objective To investigate the roles of somatostatin(SS)positive intemeurons in the development and compensation of temporal lobe epilepsy.Methods Piloearpine-induced epilepsy rat model was established.Immunohistochemistry method was used to detect number changes and axonal sprouting of SS positive intemeurons in different domains of the hippocampus at difierent time points.Degeneration of SS positive interneurons and their neurophils were detected by the double immunofluorescence staining with SS and Fluoro-Jade B(FJB)at 7 and 60 days after status epilepticus (SE).Results In the exoerimental rat group,the number of SS positive neurons decreased in each hippocampal domain,and it reached the lowest at 7 days post-SE(There were 11.1±3.3 in hilus,2.8±0.9 in CA1region and 1.8±0.7 in CA1region,t=13.519,9.644 and 8.808,all P<0.01).In chronic phase,the number of SS neurons gradually recovered,and exceeded the control group in CA1 area at 60 days post-SE(12.8±1.5 vs 8.8±1.3,t=-4.506,P<0.01),however,the number of SS neurons in the hilus(25.5±4.6)and CA1 area(4.8±0.8)remained significantly less than normal levels(t value were 4.691 and 3.953.both P<0.01).Increased SS positive fibers were found in the lacunosum-molecular (1m)layer and outer molecular layer of dentate gyrus after 30 days post-SE,and numerous SS positive fibers were seen threnghout the layers of area CA1 at 60 days post-SE.Double immunofluuorescence revealed that a few SS positive interneurons and fibers were also labeled by FJB in area CA1 at 7 days post-SE and in CA domain/hilus at 60 days post-SE.Conclusions SS intemeurons loss plays an important role in the development of temporal lobe epilepsy.The loss is partially caIlsed by the degeneration and death of neurons;SS positive neurophils increase within area CA1 in chronic phase may play a significant role in the generation and compensation of temporal lobe epilepsy.     

匹罗卡品致(癎)大鼠海马中表达生长抑素的中间神经元数目变化及其轴突出芽

Objective To investigate the roles of somatostatin(SS)positive intemeurons in the development and compensation of temporal lobe epilepsy.Methods Piloearpine-induced epilepsy rat model was established.Immunohistochemistry method was used to detect number changes and axonal sprouting of SS positive intemeurons in different domains of the hippocampus at difierent time points.Degeneration of SS positive interneurons and their neurophils were detected by the double immunofluorescence staining with SS and Fluoro-Jade B(FJB)at 7 and 60 days after status epilepticus (SE).Results In the exoerimental rat group,the number of SS positive neurons decreased in each hippocampal domain,and it reached the lowest at 7 days post-SE(There were 11.1±3.3 in hilus,2.8±0.9 in CA1region and 1.8±0.7 in CA1region,t=13.519,9.644 and 8.808,all P<0.01).In chronic phase,the number of SS neurons gradually recovered,and exceeded the control group in CA1 area at 60 days post-SE(12.8±1.5 vs 8.8±1.3,t=-4.506,P<0.01),however,the number of SS neurons in the hilus(25.5±4.6)and CA1 area(4.8±0.8)remained significantly less than normal levels(t value were 4.691 and 3.953.both P<0.01).Increased SS positive fibers were found in the lacunosum-molecular (1m)layer and outer molecular layer of dentate gyrus after 30 days post-SE,and numerous SS positive fibers were seen threnghout the layers of area CA1 at 60 days post-SE.Double immunofluuorescence revealed that a few SS positive interneurons and fibers were also labeled by FJB in area CA1 at 7 days post-SE and in CA domain/hilus at 60 days post-SE.Conclusions SS intemeurons loss plays an important role in the development of temporal lobe epilepsy.The loss is partially caIlsed by the degeneration and death of neurons;SS positive neurophils increase within area CA1 in chronic phase may play a significant role in the generation and compensation of temporal lobe epilepsy.     

匹罗卡品致(癎)大鼠海马中表达生长抑素的中间神经元数目变化及其轴突出芽

Objective To investigate the roles of somatostatin(SS)positive intemeurons in the development and compensation of temporal lobe epilepsy.Methods Piloearpine-induced epilepsy rat model was established.Immunohistochemistry method was used to detect number changes and axonal sprouting of SS positive intemeurons in different domains of the hippocampus at difierent time points.Degeneration of SS positive interneurons and their neurophils were detected by the double immunofluorescence staining with SS and Fluoro-Jade B(FJB)at 7 and 60 days after status epilepticus (SE).Results In the exoerimental rat group,the number of SS positive neurons decreased in each hippocampal domain,and it reached the lowest at 7 days post-SE(There were 11.1±3.3 in hilus,2.8±0.9 in CA1region and 1.8±0.7 in CA1region,t=13.519,9.644 and 8.808,all P<0.01).In chronic phase,the number of SS neurons gradually recovered,and exceeded the control group in CA1 area at 60 days post-SE(12.8±1.5 vs 8.8±1.3,t=-4.506,P<0.01),however,the number of SS neurons in the hilus(25.5±4.6)and CA1 area(4.8±0.8)remained significantly less than normal levels(t value were 4.691 and 3.953.both P<0.01).Increased SS positive fibers were found in the lacunosum-molecular (1m)layer and outer molecular layer of dentate gyrus after 30 days post-SE,and numerous SS positive fibers were seen threnghout the layers of area CA1 at 60 days post-SE.Double immunofluuorescence revealed that a few SS positive interneurons and fibers were also labeled by FJB in area CA1 at 7 days post-SE and in CA domain/hilus at 60 days post-SE.Conclusions SS intemeurons loss plays an important role in the development of temporal lobe epilepsy.The loss is partially caIlsed by the degeneration and death of neurons;SS positive neurophils increase within area CA1 in chronic phase may play a significant role in the generation and compensation of temporal lobe epilepsy.     

癫痫持续状态大鼠内质网应激预适应对海马神经元保护作用的实验研究

目的 探讨2-脱氧葡萄糖诱导内质网应激预适应对癫痫持续状态大鼠海马神经元的保护作用及其可能机制。方法 采用2-脱氧葡萄糖连续腹腔注射诱导内质网应激,并在此基础上制备氯化锂-匹罗卡品癫痫持续状态大鼠模型。Nissl染色观察癫痫持续状态后海马神经元损伤情况、计数海马CA1和CA3区存活神经元数目;免疫组织化学检测海马CA3区内质网应激标志物葡萄糖调节蛋白78（GRP78）和X盒结合蛋白1（XBP-1）表达变化。结果 与癫痫持续状态组相比,癫痫持续状态后第7天时内质网应激预适应组大鼠海马存活神经元数目增加,以CA1区显著（t=5.353,P=0.000）。癫痫持续状态组大鼠发作后6 h,海马CA3区GRP78和XBP-1表达水平升高且高于对照组（均P=0.000）,于发作第2天达峰值水平（均P=0.000）;内质网应激预适应组大鼠发作前海马CA3区GRP78和XBP-1表达即高于对照组（均P=0.000）,GRP78在发作后24 h和2 d时维持在峰值水平（均P=0.000）,XBP-1在发作后24 h达峰值水平（P=0.000）;内质网应激预适应组大鼠海马CA3区GRP78和XBP-1表达在癫痫持续状态前,以及癫痫持续状态后6、12、24 h均高于癫痫持续状态组（均P=0.000）,至第2和7天时与癫痫持续状态组之间差异无统计学意义（P〉0.05）。结论 经2-脱氧葡萄糖诱导的内质网应激预适应对癫痫持续状态大鼠海马神经元具有保护作用,而XBP-1-GRP78信号转导通路的活化可能是其机制之一。     

红藻氨酸致癫痫持续状态大鼠海马neuropilin-2 mRNA及其蛋白表达的研究

目的研究轴索导向分子NPN-2mRNA及其蛋白对癫痫持续状态(SE)后大鼠海马内神经纤维外向性生长和突触重建中的调控作用。方法采用侧脑室内注射红藻氨酸(KA)制作TLE大鼠模型,用Nissl染色、原位杂交和免疫组织化学的方法,分别检测致SE后1d、1w、2w、3w、4w大鼠海马齿状回(DG)、CA1区、CA3区、门区神经元丢失程度以及NPN-2mRNA及其蛋白的表达。结果 KA致SE后1d开始出现神经元丢失,至4w神经元丢失明显增多。KA致SE后1d,NPN-2mRNA及其蛋白在DG和CA1区表达明显下降,持续至3w(P0.01),4w恢复至正常(P0.05);NPN-2mRNA及其蛋白在门区、CA3区表达实验组与对照组无明显差别(P0.05)。结论 KA致SE后,海马DG及CA1区神经元下调NPN-2mRNA及其蛋白的表达,促进DG及CA1区神经纤维外向性生长和突触的重建。     

凋亡诱导因子在戊四氮致痫大鼠海马组织中的表达

目的研究凋亡诱导因子(AIF)mRNA在戊四氮(PTZ)点燃癫痫持续状态(SE)大鼠海马组织中的表达情况。方法通过腹腔注射戊四氮建立急性点燃大鼠模型,运用逆转录聚合酶链反应技术(RT-PCR)分析AIFmRNA在大鼠癫痫发作后的表达情况。结果癫痫发作后海马组织AIFmRNA的表达水平早期即出现升高(6h组与对照组相比,P<0.05),且持续较长一段时间(48h组与对照组相比,P<0.01)。结论AIF可能参与了戊四氮致痫大鼠海马神经元的凋亡过程。     

慢性癫癎模型海马神经元内钙稳态和钙动力学的长期变化

目的 探讨海马神经元内长期钙离子([Ca2+]i)和动力学变化在癫疴发生机制中的作用.方法 建立氯化锂-匹罗卡品慢性癫癎模型,于致痫后6 h和1、3、7、14、30 d不同时间点应用激光共聚焦显微镜观察离体海马神经元内[Ca2+]i的变化以及谷氨酸负荷后神经元内[Ca2+]i恢复速度的变化.结果 正常对照组大鼠急性分离海马神经元[Ca2+]i为(95.4±22.1)nmol/L,致癎后急剧升高至(867.6±35.2)nmol/L,第7天降低(292.8±18.3)mnol/L,此后持续在此水平,30 d后降至(220.8±17.6)nmol/L,仍高于对照组(t=12.55,P<0.01);正常对照组大鼠92%的海马神经元内[Ca2+]i处于正常范围内(25～150 nmol/L),致癎后6 h,所有神经元[Ca2+]i均有升高,并且85%的神经元高于500 nmol/L,致癎7、14、30 d后分别有75%、60%、52%的神经元[Ca2+]i高于正常值,但高于500 nmol/L者逐渐减少;经接触5 μmol/L谷氨酸人工脑脊液2 min后,对照组神经元可在(9.5±3.4)min内恢复至基线水平,而急性期、潜伏期、慢性期的癫癎神经元均存在明显延迟(t=5.08、4.56、4.21,P<0.01).结论 氯化锂-匹罗卡品致疴后可造成海马神经元内长期的[Ca2+]i和钙动力学改变,该种长期可塑性改变在慢性癫癎模型的诱发和维持中起着重要作用.     

Effects of potassium concentration on firing patterns of low-calcium epileptiform activity in anesthetized rat hippocampus: inducing of persistent spike activity

PURPOSE: It has been shown that a low-calcium high-potassium solution can generate ictal-like epileptiform activity in vitro and in vivo. Moreover, during status epileptiform activity, the concentration of [K+]o increases, and the concentration of [Ca2+]o decreases in brain tissue. Therefore we tested the hypothesis that long-lasting persistent spike activity, similar to one of the patterns of status epilepticus, could be generated by a high-potassium, low-calcium solution in the hippocampus in vivo. METHODS: Artificial cerebrospinal fluid was perfused over the surface of the exposed left dorsal hippocampus of anesthetized rats. A stimulating electrode and a recording probe were placed in the CA1 region. RESULTS: By elevating K+ concentration from 6 to 12 mM in the perfusate solution, the typical firing pattern of low-calcium ictal bursts was transformed into persistent spike activity in the CA1 region with synaptic transmission being suppressed by calcium chelator EGTA. The activity was characterized by double spikes repeated at a frequency approximately 4 Hz that could last for >1 h. The analysis of multiple unit activity showed that both elevating [K+]o and lowering [Ca2+]o decreased the inhibition period after the response of paired-pulse stimulation, indicating a suppression of the after-hyperpolarization (AHP) activity. CONCLUSIONS: These results suggest that persistent status epilepticus-like spike activity can be induced by nonsynaptic mechanisms when synaptic transmission is blocked. The unique double-spike pattern of this activity is presumably caused by higher K+ concentration augmenting the frequency of typical low-calcium nonsynaptic burst activity.     

慢性癫癎大鼠脑组织生长抑素mRNA表达变化及糖皮质激素的作用

为探讨生长抑素在癫（疒间）发病中的作用及糖皮质激素对慢性癫（疒间）大鼠脑组织生长抑素mRNA(SOMmRNA)表达的影响.应用原位杂交组织化学方法研究了3组大鼠海马回、齿状回SOMmRNA表达变化,并用显微图像分析仪进行检测分析.结果表明,慢性癫(疒间)大鼠海马回、齿状回SOMmRNA胞体数量、胞体截面积均明显高于对照组,胞体灰度值均明显低于对照,应用地塞米松(Dex)后上述改变不明显.提示:SOM基因的活化参与了癫(疒间)的发病,Dex的抗(疒间)作用与其抑制SOM基因的活化有关.     

Aktl在颞叶癫痫大鼠海马中的表达变化

目的研究颞叶癫痼模型海马区神经元Aktl表达变化,探讨其在癫痫发生发展中的作用。方法采用氯化锂．匹罗卡品方法制备颞叶癫痴大鼠模型,Westernblotting检测海马区总蛋白、Quantitvone软件行灰度值分析;免疫组织化学染色观察海马各区Aktl蛋白表达变化,计数不同处理组阳性神经元数目。结果Westernblotting检测结果显示,与正常对照组相比,癫痫模型组大鼠于癫痫持续状态发作即刻海马区Aktl蛋白表达升高（t=2．445,P=0．034）,并于第30天时达峰值水平（}=1．214,P=0．002）,发作后24h表达水平迅速降低,并低于正常值范围（t=4．294,P=0．000）,其余各测量时间点表达无明显改变;与氯化锂组相比,癫痼模型组大鼠于癫痫持续状态后1h海马区Aktl蛋白表达开始降低,24h降至最低水平（t：4．134,P=0．000）,至发作48h后开始逐渐升高（t=2．481,P=0．002）,并于发作第7天时升至氯化锂组水平。免疫组织化学染色显示,癫痫持续状态发作后海马CA3区Aktl蛋白表达阳性神经元数目立即增加,12h达高峰（t=16．586,P：0．000）,48h减少并降至正常值水平（t=0．357,P=0．089）,发作后第10天再次增加（t=3．123,P=0．000）,于第30天时阳性神经元数目再次达峰值水平（t=18．339,P=0．000）,第50天开始恢复至正常值水平（t=3．219,P=0．000）;氯化锂组仅海马CA3区Aktl蛋白表达于实验初始（0h）升高并高于正常对照组（P〈0．05）,海马CA1和CA2区Aktl蛋白表达变化组间差异均无统计学意义（P〉O．05）。结论海马及海马CA3区Aktl蛋白表达均呈现癫疝持续状态后升高、降低、再升高的动态过程,提示可能存在神经元保护作用,对抗细胞凋亡、促进细胞存活。     

褪黑素对癫痫大鼠海马GABA、GABAARα5表达的影响

目的 探讨褪黑素(Mel)抗癫痫作用的机制.方法 采用匹罗卡品(PILO)诱导大鼠癫痫持续状态(SE)模型,用免疫组化技术检测大鼠SE后4个时相点即6 h、48 h、72 h和7 d海马γ-氨基丁酸(GABA)和GABAA受体α5(GABAARα5)亚单位表达的动态变化,以及Mel对其变化的影响.结果 PILO组大鼠SE后6h,海马内GABA能神经元和GABAARα5亚单位表达均开始减少,尤其以SE后72 h～7 d改变最为明显,与对照组比较差异有极显著意义(P＜0.01);而Mel组大鼠在SE后72 h～7 d,海马各区的GABA能神经元和GABAARα5亚单位表达均显著高于PILO组大鼠(P＜0.05).结论 Mel可能通过上调GABA和GABAARα5亚单位的表达来发挥抗癫痫作用.