癫痫大鼠海马内谷氨酸含量与神经元凋亡的相关性

目的 研究癫痫大鼠大脑海马组织CA3区中谷氨酸(Glu)含量与神经元凋亡的相关性.方法 SD大鼠随机分成两组:海人酸(KA)致痫组大鼠海马杏仁核注射KA 2μg/kg后分为6 h、1 d、3 d、7 d组,每组8只;对照组注射与致痫剂等容量生理盐水.采用高效液相色谱(HPLC)测定大鼠海马组织CA3区中Glu含量变化,流式细胞术及原位末端标记法(TUNEL)测定相应区域神经元凋亡情况,对海马组织CA3区中Glu含量与神经元凋亡数据进行相关性分析.结果 致痫组6 h后海马组织出现神经元凋亡,Glu含最增加,两者在3 d时达到高峰,7 d时出现下降.海马组织CA3区中Glu含量与神经元凋亡组间有统计学相关性.结论 急性期癫痫大鼠海马组织神经元凋亡增多,提示早期使用抑制Glu增加的药物可能会减少脑损害.     

脑源性神经营养因子对戊四氮致癫痫大鼠海马神经肽Y表达的影响

目的 研究侧脑室内注入脑源性神经营养因子(BDNF)对戊四氮(PTZ)致癫痫大鼠海马区神经肽Y(NPY)表达的影响.方法 采用PTZ制备大鼠癫痫模型.立体定向自侧脑室注入BDNF.免疫组化观察NPY在海马CA1 区的表达,放射免疫测定海马,皮层,下丘脑组织NPY匀浆浓度.结果 免疫组化显示点燃模型组阳性反应神经元增多,BDNF干预组阳性反应神经元明显增多.点燃模型组海马组织匀浆NPY的放射免疫测定浓度增高 (P＜0.05);BDNF干预组海马组织匀浆NPY的放射免疫浓度明显高于点燃模型组(P＜0.05).结论 NPY参与了癫痫的发病过程,BDNF可以增加脑组织NPY浓度.     

左乙拉西坦对海人酸致痫大鼠血清NSE和MBP变化的影响

目的:建立海人酸(KA)致痫大鼠模型并观察癫痫大鼠血清神经元特异性烯醇酶(NSE)和髓鞘碱性蛋白(MBP)的变化及左乙拉西坦(LEV)对其水平的影响,以探讨左乙拉西坦在癫痫脑损伤中是否具有保护的作用。方法:清结级Wistar雄性4~5周龄幼鼠72只,随机分为对照组24只,立体定向右侧海马注射生理盐水,KA组24只,注射海人酸,LEV治疗组24只,注射KA造模成功前12h胃管内注入LEV200mg/kg,以后未处死大鼠均每日给药一次。分别于致痫后6h、24h、72h处死,采用ELISA法检测各组大鼠血清NSE和MBP含量。结果:(1)大鼠癫痫行为;对照组无大鼠癫痫发作,其余组均有行为学改变。LEV组幼鼠癫痫发作程度与KA组类似,但潜伏期较KA组延长。(2)血清NSE变化:KA组和LEV组血清NSE于在致痫后6h升高,24h达高峰,与对照组相比有差异(P<0.05),LEV组与KA组的NSE比较无显著差异(P>0.05)。(3)MBP变化:KA组和LEV组血清MBP于致痫后6h升高,72h达高峰,与对照组相比差异有统计学意义(P<0.05),LEV组与KA组的MBP比较无显著差异(P>0.05)。结论:KA致痫大鼠血清NSE、MBP水平显著增高,提示癫痫发作可造成一过性脑损伤,血清NSE、MBP可能作为判断癫痫脑损伤程度的敏感指标,LEV对KA致痫大鼠血清NSE、MBP水平无影响,提示LEV不能减轻亦不加重癫痫发作引起的脑损伤。     

拉莫三嗪对海人酸致癫大鼠血清S100β含量的影响

目的：建立海人酸致痫模型,用ELISA法检测致痫大鼠血清S100β含量的变化及拉莫三嗪对其含量的影响。方法：将72只28d龄的Wistar大鼠随机分为3组,生理盐水组24只,KA组24只,LTG组24只,KA组及LTG组大鼠分别在脑立体定位仪下于海马CA3区注射海人酸建立KA模型。LTG组在建立模型前12h进行LTG灌胃治疗2次,各组模型点燃成功后分别于6h、12h、24h、72h于右心室采血,ELISA法测定血清S100β含量值。结果：与生理盐水组比较KA组及LTG组血清S100β含量明显升高（P〈0.05）,但LTG组与KA组比较血清S100β含量无显著变化（P〉0.05）。结论：提示S100β与癫痫发作存在着密切的关系,LTG可能并不是通过降低致痫大鼠血清S100β含量而发挥抗癫痫作用。     

托吡酯对大鼠海马神经元内Bax和Bcl-2表达的影响

目的:检测慢性癫痫大鼠海马区脑组织内凋亡相关蛋白Bax和Bcl-2的含量变化,研究托吡酯对脑组织神经元保护机制.方法:腹腔注射海人酸(KA)建立慢性癫痫大鼠模型,通过腹腔注射不同剂量TMP对模型治疗4周,采用免疫组织化学方法对海马区脑组织内Bax、Bcl-2含量变化进行检测.结果:①正常组动物海马区脑组织内Bax阳性细...     

海人酸致痫大鼠中多药耐药相关蛋白1和主穹窿蛋白的表达及作用

目的:探讨多药耐药相关蛋白1(MRP1)和主穹窿蛋白(MVP)在难治性癫痫中的耐药机制.方法:用免疫组化法检测海人酸(KA)致痫大鼠海马组织中MRP1和MVP的表达,应用SPSS17.0软件进行统计分析.结果:KA组的MRP1和MVP的表达均比对照组明显增高(P<0.01).KA组的MRP1和MVP的表达相似,随时间段...     

托吡酯对海人酸致痫大鼠海马组织P-糖蛋白和核转录因子表达的影响

目的:探讨p-糖蛋白(P-gp)和核转录因子(NF-κB)与难治性癫痫耐药机制的关系及托吡酯(TPM)对其表达的影响.方法:84只Wistar大鼠随机分成对照组24只;海人酸组(KA组)30只;TPM治疗组30只.应用KA前每天给TPM治疗组大鼠灌胃一次,至第14d灌胃后2h注射KA.分别于注射KA后6h、24h、3d...     

左乙拉西坦对癫痫大鼠认知功能及海马组织中NPY和NCAM-mRNA表达的影响

目的:研究左乙拉西坦对癫痫大鼠海马组织中NPY和NCAM-mRNA的表达及左乙拉西坦对癫痫大鼠认知功能的影响.方法:将96只Wistar大鼠随机分为盐水组(NS)24只、模型组(Li-PILO) 24只、模型组十左乙拉西坦组(Li-PILO+LEV) 24只和左乙拉西坦组(LEV)24只,将Li-PILO+ LEV组和LEV组予以LEV200mg/kg每日一次灌胃,连续4周.应用PCR方法分别在1周、2周和4周动态检测4组大鼠海马组织中NPY和NCAM-mRNA的表达,Morris水迷宫检测大鼠的认知功能.结果:与盐水组相比,造模组大鼠海马组织中NPY和NCAM-mRNA表达水平显著升高(P＜0.05),Li-PILO+LEV组显著低于造模组;水迷宫中造模组大鼠逃避潜伏期延长(P＜0.05),穿越平台数减少(P＜0.05),与造模组相比Li-PILO+ LEV组大鼠逃避潜伏期明显缩短(P＜0.05);大鼠穿越平台次数显著增加(P＜0.05).结论:癫痫发作时大鼠海马组织中NPY和NCAM-mRNA的表达水平明显升高,左乙拉西坦能抑制癫痫大鼠海马组织中NPY和NCAM-mRNA的表达并在治疗癫痫的同时,还会改善癫痫大鼠的认知功能.     

海人酸致痫大鼠血清S100β与IL10的含量及左乙拉西坦对其含量的影响

目的:建立大鼠海人酸致痫模型,检测大鼠血清中S100β和白细胞介素(i-nterleukin,IL)-10的含量,以探讨LEV与神经保护之间的关系。方法:将96只28d龄Wistar大鼠随机分为正常对照组32只、KA组32只、左乙拉西坦(leve-tiracetamLEV)治疗组(LEV组)32只。在立体定位仪的精确定位下向右侧海马CA3区注射海人酸点燃大鼠,并观察癫痫行为分级,治疗组在KA注射前12h给予左乙拉西坦200mg/kg灌胃治疗每日一次,并分别于6h,12h,24h,72h处死各组大鼠,以免疫酶联吸附反应方法检测各组大鼠血清S100β和IL-10的含量。结果:①KA组与LEV组在KA注射后1～2h内出现痫性发作。②KA组与LEV组血清S100β含量与对照组比较,6h无明显变化(P>0.05),12h开始升高(P<0.05),24h达高峰(P<0.01),72h接近正常(P>0.05)。LEV组与KA组比较血清S100β含量在各时间点无显著差异(P>0.05)。③KA组与LEV组血清IL-10含量比较,6h开始升高(P>0.05),12h达高峰(P<0.01),24h开始下降(P<0.05),72h接近正常(P>0.05)。LEV组与KA组比较血清IL-10含量在各时间点无显著差异(P>0.05)。结论:KA致痫大鼠血清中S100β含量显著增高,其升高可能与癫痫所致的脑损伤有关,血清IL-10含量显著增高,提示IL-10与癫痫的病理生理之间存在着密切的关系,LEV对癫痫大鼠血清中S100β和IL-10的含量无影响,提示LEV不会导致脑损伤但亦不能减轻癫痫所致的脑损伤程度。     

左乙拉西坦对青霉素点燃癫痫幼鼠海马钙调素依赖蛋白激酶Ⅱα的影响

目的:比较新型抗癫痫药物左乙拉西坦(LEV)和传统抗癫痫药物苯巴比妥(PB)对青霉素点燃癫痫幼鼠海马CA3区神经元形态及钙调素依赖蛋白激酶Ⅱα(CaMKⅡα)的影响。方法:选出生后20 d健康的SD大鼠(雌雄不限)50只,随机分为青霉素致痫组40只和空白对照组10只,将存活的造模成功大鼠随机分为癫痫对照组(用生理盐水灌胃)、LEV组[300 mg/(kg.d)灌胃]和PB组[30 mg/(kg.d)灌胃]。在用药5周后,HE染色观察海马CA3区神经元形态,免疫组化检测CaMKⅡα的表达。结果:空白对照组大鼠海马CA3区神经元排列密集、规则,而致痫组海马神经元排列紊乱、疏松;癫痫对照组、PB组、LEV组与空白对照组比较CaMKⅡα的表达明显减少,差异有统计学意义。PB组与癫痫对照组比较CaMKⅡα的表达稍减少,但差异无统计学意义。LEV组与PB组比较CaMKⅡα的表达增加,差异有统计学意义。结论:发育期反复惊厥可导致大鼠成年后海马神经细胞损伤,造成海马CA3区CaMKⅡα表达下降,故可推测CaMKⅡα的表达下降可能是反复癫痫发作致认知损害的机制之一;长期使用苯巴比妥可使海马CA3区CaMKⅡα表达下降,而长期使用左乙拉西坦对海马CA3区CaMKⅡα表达的影响较小。     

Neuroprotective effect of NPY on kainate neurotoxicity in the hippocampus

Previous studies showed that neuropeptide Y (NPY) inhibited hippocampal epileptiform activity and that endogenous NPY might have neuroprotective effects. Therefore, in the present study, the effect of NPY microinjected intrahippocampally on the kainate-induced lesion and changes in NPY immunoreactivity (-IR) were investigated in rat hippocampus. Male Wistar rats, chronically cannulated, were unilaterally injected with kainic acid (KA) 2.5 nmol/1 microl, or additionally with NPY (470 pmol/1 microl) 30 min before or 30 min after KA injection, into the CA1 or dentate gyrus (DG) area of the hippocampus. Seven days later, their brains were taken out and analyzed histologically to estimate the lesion extent, and immunohistochemically to assess NPY-IR. It was found that KA induced extensive degeneration of CA pyramidal neurons and NPY-IR interneurons in the injected hippocampus. Simultaneously, NPY immunoreactivity appeared in mossy fibres and some granular cells in the contralateral hippocampus. NPY given 30 min after the KA injection into CA1 region, induced significant diminution of the lesion extent in the CA pyramidal layer (diminution by 61%). No significant effect was found when NPY was given 30 min before KA or when rats were microinjected into the DG area. The obtained results indicate neuroprotective action of NPY in some models of the kainate-induced hippocampal degeneration.     

Neuropeptide Y expression in mouse hippocampus and its role in neuronal excitotoxicity

Aim: To investigate neuropeptide Y (NPY) expression in mouse hippocampus within early stages of kainic acid (KA) treatment and to understand its role in neuronal excitotoxicity. Methods: NPY expression in the hippocampus within early stages of KA intraperitoneal (ip) treatment was detected by immunohistochemistry (IHC) and in situ hybridization (ISH) methods. The role of NPY and Y5, Y2 receptors in excitotoxicity was analyzed by terminal deoxynucleotidyl transferase-mediated UTP nick end-labeling (TUNEL) assay. Results: Using IHC assay, in granule cell layer of the dentate gyrus (DG), NPY positive signals appeared 4 h after KA injection, reached the peak at 8 h and leveled off at 16 and 24 h. In CA3, no positive signal was found within the first 4 h after KA injection, but strong signal appeared at 16 and 24 h. No noticeable signal was detected in CA1 at all time points after KA injection. Using the ISH method, positive signals were detected at 4, 8, and 16 h in CA3, CA1, and hilus. In DG, much stronger ISH signals were detected at 4 h, but leveled off at 8 and 16 h. TUNEL analysis showed that intracerebroventricularly (icv) infusion of NPY and Y5, Y2 receptor agonists within 8 h after KA insult with proper dose could remarkably rescue pyramidal neurons in CA3 and CAI from apoptosis. Conclusion: NPY is an important anti-epileptic agent. The preceding elevated expression of NPY in granule cell layer of DG after KA injection might partially explain its different excitotoxicity-induced apoptotic responses in comparison with the pyramidal neurons from CA3 and CA1 regions. NPY can not only reduce neuronal excitability but also prevent excitotoxicity-induced neuronal apoptosis in a time-and doserelated way by activation of Y5 and Y2 receptors.     

癫痫大鼠血清和脑脊液中S100B水平及其在海马组织的表达

目的探讨S100B与癫痫的关系。方法采用侧脑室注射红藻氨酸建立SD大鼠颞叶癫痫动物模型(癫痫组,40只),在痫性发作后6、12、24、72h和1周,用ELISA方法测定血清和脑脊液中S100B的含量,用免疫组化染色法观察各组大鼠海马组织中S100B蛋白的表达。其结果与正常SD大鼠(对照组,8只)比较。结果血清和脑脊液中S100B含量在癫痫发作后6h逐渐增加,24h达高峰;海马CA3和齿状回区S100B免疫阳性胶质细胞致痫后24、72h显著增高。结论 S100B蛋白在癫痫后的海马组织中大量表达,提示S100B蛋白参与了癫痫早期的病理过程;血清和脑脊液中S100B水平可作为判断癫痫所致脑损伤的早期生化指标。     

盐酸地尔硫卓对癫痫幼鼠海马中多药耐药基因表达的影响

目的探讨盐酸地尔硫卓对癫痫幼鼠海马中多药耐药(MDR)基因表达的影响。方法将75只出生7 d Wistar大鼠随机分为海人酸(KA)1 mg/kg组(A组,39只)和对照组(B组,36只)。将造模成功的A组31只大鼠随机分为A1(10只)、A2(11只)和A3组(10只),B组随机均分为B1、B2和B3组。其中,A2、B2组予拉莫三嗪治疗,A3、B3组予拉莫三嗪及盐酸地尔硫卓联合治疗。用药6周后,将各组大鼠断头取海马,用RT-PCR法测定mdr1a和mdr1b mRNA表达。结果与B1组相比,A1、A2组大鼠海马中mdr1a和mdr1b mRNA表达明显升高(P<0.01),而A3组mdr1a和mdr1b mRNA表达低于A1、A2组(P<0.05);B3组mdr1a和mdr1b mRNA表达与B1、B2组无统计学差异(P>0.05)。结论盐酸地尔硫卓可以抑制癫痫幼鼠海马中MDR基因表达的增加。     

The effect of intrahippocampal injection of group II and III metobotropic glutamate receptor agonists on anxiety; the role of neuropeptide Y.

Earlier studies conducted by our group and by other authors indicated that metabotropic glutamatergic receptor (mGluR) ligands might have anxiolytic activity and that amygdalar neuropeptide Y (NPY) neurons were engaged in that effect. Apart from the amygdala, the hippocampus, another limbic structure, also seems to be engaged in regulation of anxiety. It is rich in mGluRs and contains numerous NPY interneurons. In the present study, we investigated the anxiolytic activity of group II and III mGluR agonists after injection into the hippocampus, and attempted to establish whether hippocampal NPY neurons and receptors were engaged in the observed effects. Male Wistar rats were bilaterally microinjected with the group II mGluR agonist (2S,1'S,2'S)-2-(carboxycyclopropyl)glycine (L-CCG-I), group III mGluR agonist O-Phospho-L-serine (L-SOP), NPY, the Y1 receptor antagonist BIBO 3304, and the Y2 receptor antagonist BIIE 0246 into the CA1 or dentate area (DG). The effect of those compounds on anxiety was tested in the elevated plus-maze. Moreover, the effects of L-CCG-I and L-SOP on the expression of NPYmRNA in the hippocampus were studied using in situ hybridization method. It was found that a significant anxiolytic effect was induced by L-SOP injection into the CA1 region or by L-CCG-I injection into the DG. The former effect was inhibited by BIBO 3304, the latter by BIIE 0246. NPY itself showed antianxiety action after injection into both structures. In the CA1 area, the effect of NPY was prevented by BIBO 3304, whereas in the DG by BIIE 0246. Both the mGluR agonists L-CCG-I and L-SOP induced a potent increase in NPYmRNA expression in the DG region of the hippocampal formation. The obtained results indicate that group II and III mGluR agonists, L-CCG-I and L-SOP, as well as NPY display anxiolytic activity in the hippocampus, but act differently in the CA1 and DG. It was observed that group III mGluRs and Y1 receptors were engaged in the response in the CA1 area, whereas group II mGluRs and Y2 receptors played a pivotal role in the DG region.     

选择性COX-2抑制剂NS398干预后对HIBD新生大鼠海马CA1区存活锥体细胞计数的变化

目的研究新生大鼠缺氧缺血性脑损伤(HIBD)时应用选择性COX-2抑制剂NS398干预后海马CA1区存活锥体细胞计数的变化。方法于制备新生大鼠左脑的HIBD模型前30min,应用腹部注射NS39820mg/kg,同时建立未注射HIBD组及对照组,于HIBD后7d,测试左侧海马CA1区存活锥体细胞数。结果统计学比较,HIBD组CA1区存活锥体细胞计数显著低于对照组;NS398干预组存活锥体细胞数显著高于HIBD组。结论应用选择性COX-2抑制剂NS398可以减少新生鼠HIBD时锥体细胞缺失。     

The effects of excitotoxic hippocampal lesions in rats on risperidone- and olanzapine-induced locomotor suppression.

Previous studies have shown that excitotoxic hippocampal lesions in rats attenuate the ability of different doses of haloperidol, but not of clozapine, to suppress locomotor activity. The purpose of the present study was to determine if kainic acid-induced hippocampal damage reduces the degree of locomotor suppression produced by two relatively newer antipsychotic drugs, risperidone and olanzapine. Young adult male rats received bilateral intracerebroventricular infusions of the excitotoxin, kainic acid (KA), or vehicle and were tested for locomotor responses to drug treatment 30 days later. Infusions of KA produced neuronal loss in the CA3 region of the dorsal hippocampus in every rat. As reported previously, KA lesions reduced the ability of haloperidol (0.35 mg/kg) to completely suppress the locomotor activity elicited by amphetamine (1.5 mg/kg) relative to the effect of haloperidol in non-lesioned controls. Lesioned animals treated with a moderate dose of risperidone (1.4 mg/kg) also exhibited significantly more locomotor activity after amphetamine treatment in comparison to control animals. A trend toward greater activity was also observed in the lesioned group relative to the control group after olanzapine (3.0 mg/kg) injection (p =.09, 2-tailed). The locomotor effects of lower and higher doses of risperidone and olanzapine were not altered by kainic acid lesions. These data suggest that the locomotor-suppressive effects of moderate doses of risperidone and, perhaps, olanzapine involve hippocampal neurons, but that higher doses of each drug can suppress activity in a hippocampal-independent manner.     

The locomotor and exploratory activities in rats after lesion of hippocampal pyramidal cells with kainic acid

The effect of single kainic acid (KA) intracerebroventricular(icv) injection on spontaneous locomotor, exploratory, basal and total activities in rats measured a different times was tested. Whereas at 3 hr after KA icv administration an increase of the total, basal and spontaneous activities of rats were observed, a great decrease of the exploratory activity was noted. KA at 24 hr after its administration depressed all types of rats activities. From 72nd hr after KA icv injection a significant increase in the total, exploratory and spontaneous locomotor activities without changes in the basal activity was observed. The above mentioned changes persisted up to 10-20 days after KA administration. The histological examinations showed evident neuropathologic changes in hippocampal stratum pyramidale. The most evident changes concerned the hippocampal areas CA3/CA4 and CA1. There were observed shrinking, narrowing and fragmentation of pyramidal cells. An intense progressive gliotic reaction was present among the fragmented cells, the layer of pyramidal cells being considerably diminished.     

Effect of Rufinamide on the kainic acid-induced excitotoxic neuronal death in the mouse hippocampus

Rufinamide (RUF) is a structurally unique anti-epileptic drug, used in the treatment of seizure disorders such as Lennox-Gastaut syndrome. In the present study, we investigated whether RUF protected against excitotoxic neuronal damage in the mouse hippocampal CA3 region after intraperitoneal kainic acid (KA) injection. Treatment with 25, 50 and 100 mg/kg RUF significantly decreased the KA-induced neuronal death in the hippocampal CA3 region in a dose-dependent manner. In addition, 100 mg/kg RUF treatment reduced the KA-induced oxidative stress-related increase of MDA level and decrease of total SOD activity in the hippocampus. KA-induced increases of pro-inflammatory cytokines, TNF-α and IL-1β, levels as well as KA-induced microglial activation were also suppressed by RUF treatment. These results indicate that RUF displays a neuroprotective effect against KA-induced excitotoxic neuronal death in the mouse hippocampus through anti-oxidant and anti-inflammatory activities.