神经肽Y对海马神经元兴奋性突触活动的影响

目的观察神经肽Y(NPY)对体外培养海马神经元兴奋性突触活动的影响。方法 Wistar大鼠海马神经元体外原代培养,无镁细胞外液处理3h,建立稳定的海马神经元癫痫样放电模型,应用全细胞膜片钳记录技术,观察不同浓度NPY对海马神经元自发兴奋性突触后电流(sEPSCs)的影响。结果 (1)体外培养12d的海马神经元轮廓清晰,折光性良好,彼此间广泛突触联系形成,适于神经元电生理试验。(2)癫痫组神经元sEPSCs发放频率(28.826±1.254HZ)高于对照组(1.296±0.241HZ),差异有统计学意义(P<0.05)。0.1μmol NPY组sEPSCs的频率为0.895±0.146HZ;1μmol NPY组频率为0.461±0.394HZ,与癫痫组(28.826±1.254HZ)相比,均有明显降低,差异有统计学意义(P<0.05)。0.1μmol NPY组的频率降低的程度小于1μmol NPY组神经元,差异有统计学意义(P<0.05)。sEPSCs幅度各组相比无明显差异(P>0.05)。结论 NPY能够抑制癫痫神经元sEPSCs的频率,而不影响幅度,这为NPY基因治疗癫痫提供了电生理学证据。     

神经肽Y与癫痫的研究进展

神经肽Y (NPY)是神经系统中含量最多的肽类之一 ,许多研究发现癫痫发作后海马中NPY大量释放 ,NPYmRNA的表达及NPY免疫反应性增强 ;并有大量证据表明NPY具有抗癫痫作用。了解NPY与癫痫的关系 ,为癫痫的治疗提供新的思路。     

神经肽Y与癫痫相关性的研究进展

现已公认,癫痫的发病主要是由于中枢神经系统兴奋性机制与抑制性机制失衡从而导致兴奋性异常增高所致。主要的兴奋性递质和抑制性递质分别是谷氨酸和γ-氨基丁酸（GABA）。在大脑新皮层和海马，产生内源性GABA的是一种中间神经元。在中枢神经系统中，有相当数量的不同类型的中间神经元是以它们各自所表达的一系列神经肽的不同而被区分，而中间神经元在调节中枢神经兴奋性的过程中，神经肽起着非常关键的作用。     

Mg2+对神经元保护机制的研究-Mg2+对培养的大鼠海马神经元GABAA受体介导电流的影响

目的 研究镁离子（Mg^2 ）对神经元保护的机制。方法 采用全细胞膜片钳技术，研究Mg^2 对培养的大鼠海马神经元GABAA受体介导电流的作用。结果 （1）在钳制电压为－40mV时，GABA可通过GABAA受体介导产生内向电流；（2）当GABA和Mg^2 同时作用时，该电流峰值增高；（3）在Mg^2 存在的情况下，GABA的浓度－效应曲线平行左移。结论 Mg^2 通过正性变构调节机制影响GABAA受体的功能，达到保护神经元的作用。     

癫痫动物模型神经肽Y的测定方法及进展

本文主要概述了神经肽Y与癫痫的关系,癫痫动物模型神经肽Y的检测方法,指出随着科学的发展,检测手段会更加先进,从定位、定性的免疫组化、分子学水平的原位杂交到定性基础上进行定量分析的放射免疫分析及发光免疫分析法,必将使癫痫动物模型及人类神经肽Y的检测定位、定性更加具体,定量更加精确,从而进一步明确癫痫与神经肽Y的关系以及癫痫的发病机制,为我们治疗癫痫、研制抗癫痫药物及药物用量等方面提供新的思路和途径。     

癫痫大鼠海马中神经肽Y表达的动态观察及其作用探讨

目的　探讨癫痫大鼠海马中神经肽 Y( NPY)表达的动态变化及其作用 ,以及外源性 NPY对癫痫的影响。方法　将 SD大鼠随机分为 4组 ,采用匹鲁卡品 ( PILO)癫痫动物模型及外源性 NPY侧脑室注入干预法 ,并以免疫组织化学染色观察 NPY的表达。结果　癫痫模型组 PILO注射后 ,门区、CA3区、CA1 区的 NPY阳性细胞数表达增多 ,1 2 h达高峰 ,以后逐渐下降 ,60 d又达一高峰 ;海马颗粒细胞层有 NPY异位表达 ,3 d时最明显 ;NPY干预组门区 NPY阳性细胞数较其对照组表达少。结论　 ( 1 )癫痫发作后急性期海马 NPY表达增多及颗粒细胞层出现异位表达 ,与癫痫发作有关 ;( 2 )外源性 NPY有抗癫痫作用。     

神经肽Y、脑源性神经生长因子与癫痫

神经肽Ｙ(ＮＰＹ)是神经系统中含量最多的肽类之一 ,脑源性神经生长因子 (ＢＤＮＦ)在中枢神经系统中含量也不少。新近许多研究表明 ,两者与癫痫密切相关。为此 ,我们就近几年来ＮＰＹ和ＢＤＮＦ ,特别是前者与癫痫关系的研究进展作一综述。1　ＮＰＹ与癫痫ＮＰＹ是由Ｔａｔｅｍｏｔｏ[1] 于 1982年从猪脑中提取出来的含有 36个氨基酸的多肽 ,广泛分布于中枢神经系统 ,在大脑皮质、海马、丘脑、下丘脑及脑干等处浓度较高 ,尤以海马内浓度最高。它在神经细胞内合成后 ,被运输至神经末梢 ,作为一种神经递质与去甲肾上腺素、肾上腺素、γ 氨基…     

血清神经元特异性烯醇化酶、神经肽Y及神经节苷脂抗体对小儿难治性 癫痫的鉴别价值

目的探讨血清神经元特异性烯醇化酶(NSE)、神经肽Y(NPY)及神经节苷脂抗体(GM1-A)检测对小儿难治性癫痫(RE)的鉴别价值。方法选取45例RE患儿为RE组,50例可控性癫痫(CE)患儿为CE组。检测两组血清NSE、NPY及GM1-A水平,Logistic回归分析NSE、NPY及GM1-A水平与RE的相关性,ROC曲线评价各指标对RE的鉴别诊断价值。结果 RE组患儿血清NSE、GM1-A水平均显著高于CE组,而RE组血清NPY水平则明显低于CE组(均P0.05)。Logistic分析显示,血清NSE、NPY及GM1-A水平与RE存在密切相关性(均P0.05)。血清NSE、NPY及GM1-A检测对RE的鉴别诊断的ROC下面积分别为0.801、0.853、0.812。RE患儿血清NSE、GM1-A与NPY的表达量呈显著负相关,而血清NSE与GM1-A水平呈显著正相关(均P0.05)。不同发作频率患儿血清NSE、NPY及GM1-A水平也存在统计学意义(均P0.05)。结论血清NSE、NPY及GM1-A表达情况与RE的发生密切相关,检测血清NSE、NPY及GM1-A水平有助于RE的鉴别。     

大麻素对大鼠三叉神经节神经元烟碱激活电流的抑制作用

目的在初级感觉神经元上探讨大麻素对神经元烟碱受体(nAChR)的影响.方法应用全细胞膜片钳技术在培养的三叉神经节神经元上观察人工合成大麻素(WIN55,212-2)对烟碱激活电流的调制作用.结果大部分受检细胞(82.5%,85/103)对外加烟碱(10～1 000 μmol/L)敏感,产生一浓度依赖性内向电流;与烟碱单独作用相比,同时给予WIN55,212-2(0.03～30μmol/L)和烟碱能明显抑制烟碱激活电流峰值;且此快速抑制作用呈可逆性、浓度依赖性和非电压依赖性;WIN55,212-2使烟碱激活电流量效曲线明显下移,但EC50值无明显改变.结论WIN55,212-2可直接作用于nAChR,且以非竞争性方式抑制烟碱电流发挥外周镇痛作用.     

Modulation of GABAA receptor-mediated inhibition by postsynaptic calcium in epileptic hippocampal neurons

Visualization of neurons during patch clamp recordings from slices provides concurrent neuroanatomical information for physiological studies. Although, the technique becomes increasingly popular in immature brains, it has not been fully utilized in aged/adult and diseased brains including post-surgical human specimen. In the present study, glutamatergic modulation of GABA_A receptor-mediated inhibition was investigated by whole-cell patch clamp recordings from visualized hippocampal dentate granule cells (DGCs) in slices that were prepared from surgically-removed human medial temporal lobe specimens and the rat pilocarpine model of temporal lobe epilepsy. GABA_A receptor-mediated synaptic inhibition was recorded by isolating inhibitory postsynaptic currents (IPSCs) at a membrane potential of 0 mV where glutamatergic excitatory postsynaptic currents are near equilibrium. Peak amplitude of GABA_A IPSC was not different between epileptic DGCs of both human and pilocarpine-treated rat hippocampi and those in the control rat DGCs. However, when high frequency stimulation (30 Hz for 10 s) preceded immediately before the generation of a GABA_A IPSC, its peak amplitude was significantly reduced in epileptic DGCs. The application of an NMDA receptor antagonist prevented this decrease indicating that the high frequency stimulation activated the NMDA receptor and that this activation is involved in the induction of response-decrement of GABA_A IPSCs in epileptic DGCs. In addition, intracellular application of a calcium chelator, BAPTA through a patch pipette was found effective in preventing the response-decrement of GABA_A IPSCs suggesting that postsynaptic calcium-increase is also involved in this process. It is proposed that activation of the NMDA receptor in epileptic DGC may trigger an epileptogenic increase of intracellular free calcium, and this calcium-increase plays a crucial role for the induction of the response-decrement of GABA_A IPSCs in epileptic hippocampus, which possibly leads to the initiation of epileptic seizures and ictal events.     

癫痫动物模型脑中神经肽Y的动态含量变化及意义

目的:探讨匹罗卡品(PILO)诱发的癫痫大鼠模型脑组织中神经肽Y(Neuropeptide Y,NPY)含量的动态变化及意义,进一步明确NPY与癫痫的关系,为抗癫痫治疗,研制抗癫痫药物提供新途径。方法:健康成年雄性SD大鼠120只,随机分为两组:单纯腹腔注射匹罗卡品组(癫痫模型组);单纯腹腔注射生理盐水组(对照组);注射后根据Racine制定的标准判定是否有癫痫发作,并行脑电图检查,观察有无癫痫样波(棘波,尖波,棘慢波,尖慢波)发放。两组大鼠分别于给药后1h,3h,6h,24h,3d,7d,15d,30d,60d将大鼠麻醉,取出脑组织,对脑组织中的NPY含量进行测定。结果:癫痫模型组60只大鼠中,2只死于癫痫持续状态,其余大鼠可观察到边缘发作行为表现,脑电图有典型的癫痫样波发放,对照组无癫痫发作及癫痫样波发放。癫痫模型组脑NPY含量与对照组相比,差异有显著性P<0.05;癫痫模型组急性期(1h-7d)与慢性期(15d-60d)比较差异有显著性P<0.05,对照组差异无显著性;癫痫模型组与对照组脑中的NPY含量在12h,24h,15d,30d,60d.差异有显著性P<0.05或P<0.01,癫痫模型组脑中的NPY含量各组(各时间段)比较有差异有显著性P<0.05,对照组差异无显著性,癫痫模型组大鼠Ⅳ-Ⅴ级发作与Ⅱ-Ⅲ级发作,脑NPY含量比较,差异有显著性P<0.05。结论:1.神经肽Y与癫痫密切相关,癫痫发作后?     

Caspase3基因克隆及在癫痫样放电海马神经元中的表达

目的 探讨海马神经元癫痫样放电引起神经元丢失的机制。方法 采用RT—PCR法克隆大鼠全长Caspase3cDNA，然后采用原位杂交和流式细胞技术检测了海马神经元癫痫模型中Caspase3基因表达和神经元凋亡情况。结果 得到了大鼠的全长Caspase3cDNA，发现海马神经元癫痫样放电后出现Caspase3基因表达和神经元凋亡的现象。结论 癫痫样放电启动Caspase3表达，继而介导神经元凋亡。     

Caspase3基因克隆及在癫痫样放电海马神经元中的表达

目的 探讨海马神经元癫痫样放电引起神经元丢失的机制。方法 采用RT-PCR法克隆大鼠全长Caspase3 cDNA，然后采用原位杂交和流式细胞技术检测了海马神经元癫痫模型中Caspase3基因表达和神经元凋亡情况。结果 获得了大鼠的全长CasPase3工业cDNA．发现海马神经元癫痫样放电后出现Caspase3基因表达和神经元凋亡的现象。结论 癫痫样放电启动Caspase3表达，继而介导神经元凋亡。     

The temporal and spatial expressions of neuropeptide Y induced by seizure in the hippocampal complex of gerbil

Recent studies reported changes in neuropeptide Y (NPY) expression induced by seizures in the experimental epileptic models. However, there have been few reports of the alteration of NPY expression in hippocampal complexes of genetic epilepsy models. In the present study, we performed spatial and temporal analyses of NPY expression in the hippocampal complexes of the seizure-resistant (SR) and seizure-sensitive (SS) gerbils, one of the genetic models. In SR gerbils, most NPY⁺ cells were located at the dentate hilus (DH) and the subiculum (SC). In the pre-seizure group of SS gerbils, neurons in the DH and SC were nearly devoid of NPY immunoreactivity. Interestingly, the acute NPY expressions were observed in these areas of the post-seizure group at 30 min, and its immunoreactivity was declined at 12 h after the onset of seizure. These findings suggest that in seizure, the deficiency of NPY in DH and SC may be one of the factors, and that the acute expression of NPY after seizure in these areas may be the compensatory response for reduction of seizure activity in this animal.     

Direct excitatory effects of neuropeptide Y (NPY) on rat hippocampal neurones in vitro

Intracellular recordings from granule cells of the rat dentate gyrus show neuropeptide Y (NPY) applied by pressure ejection from pipettes containing 1.2-12 microM by pressures of less than 200 kPa for 1-5 s in duration to consistently evoke membrane depolarisations accompanied by a reduction in membrane resistance. The depolarisations were accompanied by an increase in excitability. Since the depolarisations evoked by NPY were not attenuated by either tetrodotoxin or kynurenic acid a direct excitatory action of NPY is postulated.     

硬脑膜传入神经末梢敏化对初级感觉神经元电压门控型钙电流的影响

目的 探讨化学刺激硬脑膜传入神经末梢对大鼠三叉神经节神经元的高电压激活钙电流(HVA-ICa)的调控效应. 方法 雄性SD大鼠16只按随机数字表法分为生理盐水(NS)组和致炎剂(IS)+释放降钙素基因相关肽(CGRP)组(n=8),大鼠上矢状窦处脑膜给药造模1h后急性分离大鼠三叉神经节中小神经元,采用全细胞膜片钳技术记录电压门控钙离子通道(VGCC)电流. 结果 与NS组钙电流峰电流[(-49.5±5.18)pA/pF]比较,IS+CGRP组[(-80.48±4.43) pA/pF]增高,差异有统计学意义(P＜0.05);IS+CGRP组神经元钙电流激活曲线的半数激活电压Val/2为(-20.9±0.4)mV,较NS组[(-16.2±0.5)mV]向超级化方向移动了4.7 mV,差异有统计学意义(P＜0.05); IS+CGRP组神经元钙电流的半数失活电压V1/2为(-12.4±0.2) mV,较NS组[(-22.5±0.3)mY]向去极化方向移动了10.1 mV,差异有统计学意义(P＜0.05). 结论 激活硬脑膜传入神经末梢诱导初级感觉神经元的外周敏化过程,突出表现为钙电流的增高.     

Morphological differentiation of neuropeptide Y neurons in aggregate cultures of dissociated fetal cortical cells: a model system for glia-neuron paracrine interactions

The temporal changes in the morphological profiles of neuropeptide Y (NPY) neurons and their topographical relationship with glial cells (astrocytes) were characterized in aggregate cultures derived from fetal cortical tissue using immunocytochemical procedures. On day 6 of culture, structures labelled with NPY antibodies were small and uneven in size but many resembled neuronal cell bodies. On day 14, neuronal perikarya were well defined and several morphological types of NPY neurons could be distinguished most of which gave rise to beaded processes: unipolar or multipolar bitufted neurons whose processes branch in close proximity to the cell body; bipolar neurons; and multipolar neurons. On day 23, heavily punctate and asymmetrically labelled cell bodies were dispersed throughout the aggregate; neuronal processes were less conspicuous. At 14 and 23 days, cells expressing glial fibrillary acidic protein (GFAP) and neuronal specific enolase (NSE) were abundantly distributed throughout the aggregate. Using a double immunoreaction on 14-day-old aggregates revealed that GFAP + cells and their processes were in close apposition to and engulfing the NPY neurons. Thus, dissociated fetal NPY neurons undergo morphological differentiation in culture along with astrocytes (GFAP +) and other neuronal cell types (NSE +). Based on the topographical association of astrocytes and neurons, particularly NPY neurons, we propose that the aggregate culture system can serve as a model to study the role of paracrine interactions in the regulation of the expression of NPY.     

Changes of immunoreactive neuropeptide Y, somatostatin and corticotropin-releasing factor (CRF) in the brain of a novel epileptic mutant rat, Ihara's genetically epileptic rat (IGER)

Ihara's genetically epileptic rat (IGER) is a rat mutant with genetically scheduled spontaneous convulsions mimicking human limbic seizures. In the present study, the possible changes of three neuropeptides, neuropeptide Y (NPY), somatostatin (SRIF) and corticotropin-releasing factor (CRF), in the brains of IGER were investigated. Increased contents of immunoreactive (IR) NPY were found only in the hippocampus of 2-month IGERs before developing convulsive seizures, while similar increases of IR-NPY were discovered in the striatum and pyriform and entorhinal cortex as well as hippocampus in 8-month IGERs with repetitive seizures. There were no significant differences in the brain contents of IR-SRIF and IR-CRF between IGERs and the controls at both ages. These findings indicate an enhanced rate of NPY synthesis in this experimental model of epilepsy which may play a critical role in the development of epileptogenesis.     

The distribution of neuropeptide Y and brain-derived neurotrophic factor immunoreactivity in hippocampal formation of the monkey and rat

The distribution of neuropeptide Y (NPY) and Brain-Derived Neurotrophic Factor (BDNF) in the hippocampal formation of monkey and rat brains was studied immunohistochemically. The NPY-neuronal system is more highly developed in the monkey compared to that in the rat. The distribution of NPY-positive products was coincident with that of abundant BDNF-positive deposits. These observations suggest that the role of BDNF and the interaction of BDNF-NPY may differ between species.