GABA受体基因转染对癫痫大鼠皮层脑电的影响

目的探讨在下丘脑乳头体上核内转染γ-氨基丁酸(GABA)受体基因后对海人藻酸(KA)致痫大鼠皮层脑电产生的影响,从而为难治性癫痫的治疗开辟新的途径。方法在右侧杏仁核内注射KA制备癫痫动物模型作对照,GABA基因转染组则利用仙台病毒(HVJ)-脂质体转染法预先在下丘脑的乳头体上核内转染被脂质体包被的GABA受体基因,48h后在杏仁核内注射KA,两组大鼠分别进行皮层脑电测定。结果KA致痫组大鼠脑电在尖波的背景上出现持续性放电,GABA转基因组大鼠则以散发的尖波、棘波以及阵发性放电为主,出现持续性放电的时间明显缩短。结论下丘脑内转染GABA受体基因后可以抑制癫痫发作的程度。     

GluR2Q在下丘脑乳头体上核内过度表达对于大鼠颞叶癫痫脑电的影响

目的 探讨下丘脑乳头体内兴奋性刺激对于颞叶癫痫脑电变化的影响。方法 利用HVJ－脂质体转染法在下丘脑乳头体内转染兴奋性氨基酸受体亚基GluR2Q，研究其对于海人酸（kainic acid,KA)诱发的癫痫模型脑电变化的影响。结果 GluR1Q基因转染组大鼠癫痫连续性放电的开始时间明显早于KA对照组，且持续时间较KA对照组明显延长。结论 下丘脑内GluR2Q基因转染能提高其兴奋性，并促进癫痫波在海马内的传播。     

下丘脑内基因转染对大鼠癫痫行为的影响

目的探讨下丘脑过度兴奋对于颞叶癫痫行为学变化的影响，从而进一步阐明下丘脑与颢叶癫痫的关系以及谷氨酸受体2亚基Q型(glutamate receptor 2Q，GluR2Q)在癫痫发病中的作用机制。方法20只Wistar大鼠随机分为海人酸(kainic acid or kainite，KA)组(KA对照组)与KA GluR2Q组，分别观察两组大鼠的癫痫行为。结果KA对照组大鼠癫痫发作程度较轻，主要以部分性发作为主且发作次数少，持续时间短，较少出现全面性发作。KA GluR2Q组大鼠癫痫发作程度剧烈，部分性癫痫发作较KA对照组更早、更频繁且由部分性发作转化为全面性发作的比率高于KA对照组。结论通过HVJ-脂质体基因转染技术将GluR2Q基因转染到下丘脑乳头体可以提高其兴奋性，并使该兴奋性冲动通过下丘脑与海马之间的联络纤维传导至海马齿状回及CA3、CA1区，使海马区原有的兴奋性加强，表现为癫痫行为的加重，从而促进了癫痫的发展及传播。     

下丘脑内基因转染对大鼠颞叶癫痫海马病理变化的影响

目的 探讨下丘脑过度兴奋对于颞叶癫痫海马病理变化的影响。方法 利用仙台病毒(HVJ)-脂质体转染法在下丘脑的乳头体内转染兴奋性氨基酸受体亚基GluR2Q，研究其对于海人酸(kainic acid，KA)致痫鼠海马病理变化的影响。结果 GluR2Q能加重KA引起的海马齿状回损伤，但是对CA1及CA3区神经元损伤有一定程度的改善作用。结论 GluR2Q可以使下丘脑兴奋性增强，通过对海马齿状回的抑制解除作用促进癫痫波在海马内的传播。     

耐药性杏仁核点燃癫痫模型海马组织中γ-氨基丁酸受体表达变化

目的 建立多药耐药性癫痫模型,观察海马组织γ-氨基丁酸(GABA)受体表达变化从而探讨其在耐药性杏仁核点燃癫痫形成中的作用.方法 选用Wistar大鼠100只制作慢性杏仁核点燃癫痫模型,模型制作成功(n=52)后用经典抗癫痫药苯妥英钠和苯巴比妥进行筛选,根据大鼠对苯妥英钠和苯巴比妥的反应区别出耐药癫痫大鼠(n=8)及药物敏感大鼠(n=8),然后处死动物留取脑组织标本,用免疫组织化学染色方法观察海马组织内GABAA受体表达变化,用蛋白质印迹法检测GABAA受体含量,观察耐药癫痫大鼠和药物敏感大鼠之间的不同.结果 耐药癫痫性颞叶大鼠海马细胞变性坏死,排列紊乱,结构特征消失;耐药性颞叶癫痫大鼠海马组织内GABAA受体阳性表达细胞的灰度值(141.15±14.72)比药物敏感大鼠增高(92.56 ±5.17;t =3.380,P=0.006);蛋白质印迹方法提示受体条带变淡变窄,蛋白含量明显减少(0.38 ±0.08),与药物敏感大鼠(0.88 ±0.18)比较,差异具有统计学意义(t=5.420,P=0.002);但两组间GABAA受体阳性细胞数百分率比较差异无统计学意义.结论 耐药性颞叶癫痫大鼠海马组织内GABA受体表达明显减少,这可能在耐药性颞叶癫痫的形成过程中发挥部分作用.     

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.     

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。     

神经肽Y对海人酸致痫大鼠中NR1、NR2A受体的影响

目的探讨重组腺相关病毒载体神经肽Y(r AAV2/1-NPY-EGF-P)干预前后海人酸致痫大鼠海马中NR1、NR2A表达的变化。方法将36只雄性Wistar大鼠随机等分为对照组、海人酸致痫大鼠组(KA组)以及神经肽Y(NPY)干预组(NPY组)各12只。KA组和NPY组均在海马CA3区注射海人酸建立为慢性癫痫模型,造模成功后,NPY组向脑室注射10l滴度为5×10~(11)μg·mL~(-1)的r AAV2/1-NPYEGFP进行基因转染,KA组不注射病毒,对照组海马CA3区注射等量的生理盐水。各组动物分别于基因转染后2w、4w,取海马保存于液氮。每组动物选取12只,每个时间点6只大鼠,用免疫组化方法检测各组NR1,NR2A的表达情况。对试验结果采用双盲法进行统计,应用半定量积分的方法,把每个时间点的大鼠CA3区NPY的阳性细胞率和阳性细胞着色强度进行分级记分,最后依据两项之积计算其阳性强度(IHS)。结果 2w及4w时KA组和NPY组NR1、NR2A阳性细胞数量、染色强度和IHS分数均高于对照组,(P<0.05);4w时NPY组阳性细胞比例、染色强度和IHS评分均低于KA组,(P<0.05)。结论 NR1、NR2A受体的低表达可能参与了NPY抑制癫痫发作的发病机制。     

瘦素受体在大鼠脑的免疫组织化学定位研究

观察瘦素受体在SD大鼠脑的组织学定位.采用高度特异的抗瘦素受体血清,用免疫组织化学ABC法观察瘦素受体在大鼠脑的分布.结果表明:在SD大鼠的前脑(包括嗅球)、皮质Ⅳ～Ⅴ层、海马、下丘脑、杏仁核、丘脑等可以观察到瘦素受体免疫反应阳性物质(LR-IR),其中下丘脑弓状核、视上核、视交叉上核、杏仁基底外侧核、孤束核有较强的LR-IR,而下丘脑外侧视前区、杏仁中央核有较弱的LR-IR.提示:瘦素受体广泛存在于大鼠脑,包括下丘脑、杏仁核等与味觉和摄食调节密切相关的核团.     

致痫后雌性大鼠血清及海马雌二醇和孕烯醇酮水平的动态变化

目的 观察致病后雌性大鼠血清及海马雌二醇(E2)和孕烯醇酮(PREG)水平的动态变化,研究海马E2水平与癫痫发作严重程度的关系. 方法 选择动情期雌性大鼠制备海人藻酸(KA)经杏仁核点燃的癫痫模型,观察大鼠癫痫发作的行为学表现.应用放射免疫法和酶联免疫吸附分析分别检测癫痫发作后0、1、2、3、4、5、6、12和24 h的大鼠以及经杏仁核注射生理盐水后相应时间的大鼠血清及海马组织E2和PREG水平.对检测结果进行统计学分析. 结果 杏仁核注入KA后5～10min大鼠均出现痫样发作,3 h达峰值,随后呈下降趋势.致痫后的大鼠血清E2水平无明显变化,但海马E2水平在癫痫发作后1 h开始上升,4 h达峰值,随后呈下降趋势,12 h恢复至对照水平,1～12 h相邻时间点E2水平差异均有统计学意义(P,0.05).此外,随着大鼠的癫痫发作程度的加重,海马E2水平逐渐升高,进行相关性检验后发现.海乌E2水平与癫痫发作严重程度呈正相关(R~2=0.646,P<0.05).致痫前及致痫后24 h内不同时间点各组大鼠海马的PREG水平没有明显变化. 结论 癫痫发作后大鼠海马E2水平的动态变化与癫痫发作程度相关.癫痫发作可以诱导大鼠海马局部E2的合成.     

Activation of a subpopulation of orexin/hypocretin-containing hypothalamic neurons by GABAA receptor-mediated inhibition of the nucleus accumbens shell, but not by exposure to a novel environment

Gamma-amino butyric acid (GABA)A receptor stimulation in the nucleus accumbens shell produces intense hyperphagia in rats and increases Fos expression in the lateral hypothalamus. To explore the involvement of hypothalamic orexin/hypocretin- or melanin concentrating hormone-immunoreactive neurons in this effect, the GABAA agonist, muscimol (0, 50 ng), was infused directly into the nucleus accumbens shell of rats; 90 min later, their brains were collected and subsequently processed for immunohistochemistry. A group exposed to a novel environment was included to evaluate the specificity of Fos expression changes with regard to general arousal. Alternating sections through the hypothalamus were double-stained for orexin/hypocretin-Fos or melanin concentrating hormone-Fos combinations. Intra-accumbens shell muscimol treatment significantly increased the percentage of orexin/hypocretin-containing neurons expressing Fos in the lateral, but not medial, portion of the perifornical/lateral hypothalamic area. Regardless of treatment condition, greater percentages of orexin/hypocretin-containing neurons in the medial portion of the hypothalamus expressed Fos relative to cells located more laterally. None of the manipulations increased Fos expression in melanin concentrating hormone-immunoreactive neurons. Muscimol treatment also markedly increased Fos expression in the arcuate nucleus, which connects reciprocally to the lateral/perifornical hypothalamic area. Thus, orexin/hypocretin-containing neurons in lateral sectors of the hypothalamus, along with cells in the arcuate nucleus, display phasic increases in Fos expression after an orexigenic pharmacological manipulation of the nucleus accumbens shell, but to a lesser degree after the heightened arousal associated with exposure to a novel environment.     

颞叶癫痫大鼠不同时期海马细胞外氨基酸类递质的变化

目的探讨海人酸(Kainic Acid,KA)诱发颞叶癫痫大鼠不同时期海马CA3区细胞外谷氨酸(gluta-mate,GLU)、γ-氨基丁酸(gamma-aminobutyric acid,GABA)、甘氨酸(glycine,GLY)、天冬氨酸(aspartic acid,ASP)、牛磺酸(taurine,TAU)等递质水平的变化。方法 21只SD大鼠随机分为对照组(9只)和KA组(12只)。KA组大鼠海马CA3区注射0.8μgKA,对照组海马CA3区注射同体积生理盐水,于1天(急性期)、7天(静止期)、30天(慢性期)对大鼠海马CA3区行微透析,用高效液相色谱法(high-performance liquid chromatography,HPLC)测定透析液中GLU、GLY、GABA、ASP、TAU含量的变化。结果急性期:与对照组相比,KA组CA3区细胞外GLU(P=0.004)、GLU/GABA(P=0.002)明显增高,GABA(P=0.001)、GLY(P<0.001)明显减少,ASP(P=0.23)、TAU(P=0.28)与对照组相比无明显差异。静止期:KA组GLU(P=0.003)、GLU/GABA(P<0.001)较对照组明显降低,而GABA(P<0.001)、ASP(P<0.001)、TAU(P<0.001)较对照组明显增高,GLY(P=0.49)与对照组相比无明显差异。慢性期:与对照组相比,KA组GLU(P<0.001)、GABA(P=0.013)、ASP(P<0.001)、TAU(P<0.001)、GLU/GABA(P<0.001)明显升高,GLY与对照组相比无明显差异(P=0.86)。结论海马CA3区兴奋性与抑制性氨基酸类递质失衡可能是癫痫发生发展的重要机制之一。     

红藻氨酸致痫大鼠海马S100B、CGRP蛋白表达及病理改变

目的 研究红藻氨酸(KA)致痫大鼠海马S100B、降钙素基因相关肽(CGRP)的表达及病理改变.方法 雄性SD大鼠按照完全随机数字表法分成对照组(8只)和模型组(40只),模型组再根据处死时间分为造模后6 h、12 h、24 h、72 h、1周5个亚组,每组8只.模型组采用KA建立颞叶癫痫动物模型,对照组用等体积生理盐水代替KA注射.模型组造模后6 h、12 h、24 h、72 h、1周,对照组注射后24 h取大鼠海马组织行Nissl染色、Timm染色和免疫组化染色,观察S100B、CGRP蛋白的表达情况以及海马神经元和胶质细胞的病理变化.结果 Nissl染色结果显示,模型组大鼠1周后CA3区出现大量固缩的坏死神经元,胞体萎缩,尼氏体消失.Timm染色结果显示,模型组大鼠1周后CA3区始层出现条带状分布的棕色颗粒,齿状回内分子层亦可见少量棕色颗粒.免疫组化染色结果显示,模型组大鼠海马CGRP蛋白大量表达,72 h时达到高峰,同时伴随大量神经元丧失及胶质细胞增生.结论 KA致痫大鼠出现S100B、CGRP蛋白高表达,尼氏体消失,苔藓纤维发芽等一系列病理学改变,推测S100B、CGRP蛋白参与了癫痫发生.

Abstract：

Objective To investigate the expressions of S100B and calcitonin gene related peptide (CGRP) and the pathologic alterations of the hippocampus in kainic acid (KA)-induced epileptic rats. Methods Male SD rats were randomly divided into control group (n=8) and model group (n=40).Animal models of temporal lobe epilepsy were established by intracerebroventricular injection of KA; the same volume of saline was injected into the rats in the control group. Hippocampal tissues within various phases after seizures (6, 12, 24 and 72 h, and 24 h after the success of model making) were performed Nissl staining, Timm staining and immunohistochemical staining. The expressions of S100B and CGRP were observed, and the pathologic alterations of the hippocampal neurons and glial cells were studied.Results All rat models were successfully induced with epileptic seizures. Nissl staining showed that pyknotic neuronal necrosis appeared in the CA3 area of the hippocampus in the model group with cell body atrophy and disappearance of Nissl bodies 1 week after the injection. Timm staining showed that brown particles showed stripped distribution in the CA3 area of the hippocampus and some brown particles in the molecular layer of fascia dentate. Immunohistochemical staining indicated that significant neurons lost and gliosis appeared after seizures with abundant expressions of S100B and CGRP.Conclusion KA-induced epileptic rats express abundant S100B and CGRP and appear such pathological changes as disappearance of Nissl bodies and mossy fiber sprouting, indicating that both S100B and CGRP participate in the onset of epilepsy.     

Glutamate receptor antagonists and benzodiazepine inhibit the progression of granule cell dispersion in a mouse model of mesial temporal lobe epilepsy

PURPOSE: Unilateral intrahippocampal injection of kainic acid (KA) in adult mice induces the progressive dispersion of dentate granule cells, one of the characteristic pathologic changes of mesial temporal lobe epilepsy. However, little is known about the mechanisms that trigger this dispersion. In this study, the possible involvement of glutamatergic and gamma-aminobutyric acid (GABA)ergic neurotransmissions in the development of granule cell dispersion (GCD) was examined in this model. METHODS: Antagonists of N-methyl-d-aspartate (NMDA) receptor (MK-801) and non-NMDA receptor (GYKI52466), and an agonist of benzodiazepine-GABA(A) receptor (midazolam) were injected before and after KA in various ways, and the morphologic changes of the hippocampus, especially GCD, were examined. RESULTS: MK-801 (5 mg/kg, i.p.) did not reduce GCD when injected 2 h before KA injection but inhibited GCD almost completely for 相似文献   

Effect of central administration of QRFP(26) peptide on energy balance and characterization of a second QRFP receptor in rat

The recently identified neuropeptide QRFP(26) is predominantly expressed in the hypothalamus and was suggested to play a role in the regulation of food intake following the observation of an acute orexigenic effect after central administration in mice. QRFP(26) exerts its effect via GPR103 and a newly identified receptor in mouse. The aim of our study was (a) to investigate the distribution of QRFP(26) and a newly discovered QRFP receptor mRNA in rat and (b) to further characterize the effects of central administration of QRFP(26) on energy balance in rats. QRFP(26) mRNA was detected in the retrochiasmatic nucleus, periventricular nucleus, arcuate nucleus and restricted areas of the lateral nucleus of the hypothalamus. We found an additional receptor with high homology for GPR103 in rat. This receptor increases inositol triphosphate production in transfected cells in presence of QRFP(26) and its mRNA was particularly enriched in ventral and posterior thalamic groups, anterior hypothalamus and medulla. When QRFP(26) (10 microg and 50 microg) was administered centrally before the start of the light phase both doses increased food intake for 2 h after injection without reaching statistical significance. QRFP(26) caused no changes in locomotor activity or energy expenditure. In summary, central QRFP(26) injection causes slight and transient hyperphagia in rats without changing any other energy balance parameters after 24 h. We conclude that QRFP(26) has limited impact on the central regulation of energy balance in rats and that its essential function remains to be clarified.     

Concomitant regulation of running activity and metabolic change by the ventromedial nucleus of the hypothalamus

The aim of this study was to elucidate the involvement of kainate (KA) type glutaminergic, GABAergic and adrenergic receptors in the ventromedial nucleus of the hypothalamus (VMH) in inducing running activity and metabolic adaptations. Injection of either KA or bicuculline methiodide (BM), a GABA_A receptor antagonist, into the VMH of conscious rats resulted in an increase in plasma glucose, norepinephrine, epinephrine and corticosterone, as well as running activity. KA or BM increased plasma glucose and catecholamines even under urethane anesthesia. Co-injection of either α- or β-adrenergic receptor antagonist, i.e. phentolamine or timolol, respectively, with KA into the VMH of conscious rats elicited only a slight increase in plasma glucose and catecholamines, though it successfully induced hyper-running. However, plasma corticosterone was higher in the animals injected with adrenergic blockers, suggesting that an insufficient supply of energy substrates would enhance the activity of the hypothalamo-pituitary-adrenal system. We conclude that: (1) KA type glutaminergic and GABAergic receptors in the VMH are involved in regulating running activity and the sympathetic nervous system; (2) the brain noradrenergic system may mediate the KA action on the sympathetic nervous system.     

Dual roles in feeding for AMPA/kainate receptors: receptor activation or inactivation within distinct hypothalamic regions elicits feeding behavior

We have previously shown that hypothalamic injections of glutamate, or agonists of its ionotropic receptors (iGluRs), elicit intense feeding responses in satiated rats [Brain Res. 613 (1993) 88, Brain Res. 630 (1993) 41]. While attempting to clarify the role of the AMPA and kainate (KA) receptor subtypes in glutamatergic feeding systems, we discovered that lateral hypothalamic (LH) injection of high doses of the competitive AMPA/KA receptor antagonist, NBQX (10 and 30 nmol), elicited a pronounced feeding response. We questioned whether this effect was due to inactivation of AMPA or possibly KA receptors. To determine whether other AMPA/KA antagonists can also elicit feeding, we tested whether injection of CNQX, another AMPA/KA receptor antagonist, also stimulates eating and whether these feeding stimulatory effects were due to antagonists' actions in the LH or in other hypothalamic sites. Here we report that NBQX and CNQX elicit feeding in a dose dependent manner and are most effective when injected into the perifornical hypothalamus (PFH), or into the paraventricular nucleus (PVN) and, to a lesser extent, into the LH of satiated rats. In contrast, AMPA was most effective in stimulating feeding when injected into the LH, confirming previous reports. These data suggest that either activation or inactivation of AMPA/KA receptors in distinct but overlapping hypothalamic sites may be sufficient to induce feeding behavior, indicating a broadened role for glutamate in hypothalamic feeding mechanisms.