新生大鼠海马分区培养神经元对N-甲基-D-天冬氨酸反应的差异

目的 探讨海马不同区域神经元对N-甲基-D天冬氨酸(NMDA)的反应.方法 取新生大鼠CA区和DG区脑组织细胞培养9d.利用活细胞工作站,用四甲基罗丹明乙酯观察NMDA对来自不同区域神经元线粒体膜电位的影响.同时采用全细胞模式的膜片钳记录技术检测来自海马不同区域的神经元NMDA诱导电流.结果 与DG区的神经元比较,NMDA更易引起CA区神经元线粒体膜电位的下降,同时NMDA诱导电流强度明显增强.结论 DG、CA区来源的海马神经元对NMDA反应具有明显差异.     

抗N-甲基-D-天冬氨酸受体脑炎

抗N-甲基-D-天冬氨酸受体(anti-N-methyl-D-aspartate receptor,NMDAR)脑炎是与NMDAR的亚单位NR1相关的一种脑炎,其特点为病程呈多阶段性,主要表现为精神异常、记忆障碍、癫痫发作、意识水平降低等,常伴有运动障碍、自主神经功能紊乱和呼吸节律异常。     

记忆网络中的N-甲基-D-天冬氨酸受体

N-甲基-D-天冬氨酸(NMDA)受体属谷氨酸离子型受体,其与突触的可塑性和学习记忆密切相关。中枢神经系统中与学习记忆相关的,如以胆碱受体、谷氨酸受体、腺苷A1受体等为代表的诸多受体及递质,以谷氨酸(Glu)/GABA为代表的氨基酸能神经通路,以长时程增强(LTP)等为代表的脑内神经电活动,以脑源性神经营养因子(BDNF)等为代表的基因蛋白遗传信息改变,甚至许多神经退行性疾病中Glu的神经毒性,等等,都与NMDA受体相关,通过NMDA受体功能的改变调控学习记忆功能,进而对整个中枢神经系统产生影响。换句话说,如果把学习记忆的信息传递系统看做一个庞大的信息网络,那么NMDA受体就是学习记忆相关神经网络中一个相对中心的关键位点。因此,以探讨NMDA受体在学习记忆错综复杂网络中的关联为切入点,以微观深入研究为基础、以宏观视野分析为引领,全方位评价NMDA受体在学习记忆网络中的作用,或许可以引领未来脑功能及相关疾病系统的研究。     

苯环壬酯对N-甲基-D-天冬氨酸诱导的原代培养的大鼠海马神经细胞损伤的保护作用

目的　观察苯环壬酯对N 甲基 D 天冬氨酸(NMDA)诱导的原代培养大鼠海马神经细胞损伤的保护作用。方法　建立NMDA诱导的原代培养大鼠海马神经细胞损伤模型 ,采用乳酸脱氢酶 (LDH )法及噻唑蓝 (MTT)比色法 ,以特异性NMDA受体拮抗剂MK 80 1作为阳性对照药 ,观察抗胆碱药苯环壬酯、东莨菪碱对NMDA诱导的原代培养大鼠海马神经细胞损伤的保护作用。结果　NMDA (4 0 0μmol·L- 1)可明显降低海马神经细胞的存活率 ,表现为细胞LDH释放量明显增高 ,MTT比色后的吸光值明显降低。苯环壬酯 (1,2 .5 ,10 ,2 0和 5 0 μmol·L- 1)对NMDA所致的LDH升高有明显对抗作用 ,MTT比色后的吸光值明显增高 (P <0 .0 1) ,其作用类似于MK 80 1(1,10 μmol·L- 1) ;而另外一种抗胆碱药东莨菪碱 (1,10 ,10 0 0 μmol·L- 1)对损伤细胞的LDH释放及MTT比色后的吸光值无明显影响。结论　苯环壬酯对NMDA诱导的大鼠海马神经细胞损伤有明显保护作用 ,其作用机制可能与其对NMDA受体的拮抗作用有关     

N-甲基-D-天冬氨酸受体与抑郁障碍

越来越多研究表明,除单胺神经递质外,谷氨酸及相关受体在抑郁症病因中也扮演了重要的角色,特别是N-甲基-D-天冬氨酸(NMDA)受体,有证据表明NMDA受体的过度激活是抑郁障碍的病理生理机制之一。本文总结了谷氨酸及相关受体与抑郁障碍的关系,对NMDA受体成为潜在抗抑郁药靶点做一简要讨论。     

N-甲基-D-天冬氨酸型谷氨酸受体的调节与氰化物中枢毒作用

氰化物可通过间接与直接两条途径激活(N-甲基-D-天冬氨酸型)NMDA受体，首先氰化物引起的能量障碍能通过促使细胞外谷氨酸(Glu)浓度增高和细胞内Ca^2 稳态失调，间接地激活NMDA受体，其次氰化物可能作为NMDA受体直接的调节剂，通过调节NMDA受体中NR1或NR2亚型等半胱氨酸残基的氧化还原位点，提高NMDA受体的活性，随着间接和直接NMDA受体的激活，产生一系列由NMDA受体介导的中枢毒作用，最终导致神经元细胞损伤、凋亡及死亡。由此认为NMDA受体的激活在氰化物诱导的神经损伤机制中可能起关键的作用。     

N-甲基-D-天冬氨酸受体与全身麻醉药对发育期大脑的神经毒性

N-甲基-D-天冬氨酸(NMDA)受体是一类对Ca2+高度通透性配体门控离子通道。NMDA受体在脑发育突触可塑性、学习记忆方面都起到重要作用,也是全身麻醉药作用的主要靶点之一。全身麻醉药诱导发育期大脑神经毒性,进而影响成年期认知功能发育,这是否由NMDA受体介导,尚待进一步研究予以证实。     

(-)-S·R-蝙蝠葛苏林碱对N-甲基-D-天门冬氨酸引起大鼠皮层神经元损伤的保护作用

蝙蝠葛苏林碱（ｄａｕｒｉｓｏｌｉｎｅ，Ｄａｕ）是从防己科植物蝙蝠葛根茎中提取的生物碱，（－）－Ｓ·Ｒ－Ｄａｕ是其人工合成非对映异构体．研究表明它的药理活性比天然品强很多［１］．我们最近报道（－）－Ｓ·Ｒ－Ｄａｕ能抑制谷氨酸（Ｇｌｕ）对原代培养的大鼠皮...     

丙泊酚对N-甲基-D-天冬氨酸所致PC12细胞损伤的保护作用

目的　探讨静脉麻醉药丙泊酚 (PPF)脑保护作用的可能机制。方法　乳酸脱氢酶 (LDH)法及MTT比色法判断细胞损伤程度及细胞存活率 ,Fura 2 /AM荧光标记法测定细胞内Ca2 + 浓度 ( [Ca2 + ]i)的变化 ,分光光度法测定细胞一氧化氮合酶 (NOS)活性。结果　N 甲基 D 天冬氨酸 (NMDA) 3 0 0 μmol·L-1处理4h可明显导致PC1 2细胞的损伤 ,表现为LDH释放量明显增加 ,吸光度值A570nm明显降低 ,细胞存活率降低 ,同时 [Ca2 + ]i 和NOS活性则明显增加。PPF6.2 5 ,2 5 ,1 0 0 ,40 0 μmol·L-1与NMDA同时处理PC1 2细胞则使LDH释放量显著降低 ,细胞存活率增加。PPF 1 2 .5和 1 2 5 μmol·L-1可显著降低NMDA诱导的[Ca2 + ]i 水平及NOS活性的提高。结论　PPF对NMDA所致的PC1 2细胞损伤有明显的保护作用 ,其机制可能与其抑制NMDA受体的功能 ,降低 [Ca2 + ]i,减弱Ca2 + 超载 ,并降低NMDA诱导的NOS活性增加有关。提示PPF可能是通过抑制NMDA受体 Ca2 + NOS通路的功能而产生细胞保护效应     

儿童抗N-甲基-D-天冬氨酸受体脑炎19例临床分析

目的:总结儿童抗N-甲基-D-天冬氨酸受体(NMDAR)脑炎临床特点,以提高临床医师对该病的认识。方法:回顾性分析2015年12月至2017年3月于江西省儿童医院神经内科就诊的19例抗NMDAR脑炎患儿的临床表现、辅助检查、治疗、预后。结果:临床主要表现为精神行为异常、抽搐、运动障碍、睡眠障碍;10例头颅MRI异常;17例脑电图异常,主要表现为背景活动慢;5例脑脊液常规异常,淋巴细胞增高为主;2例血清抗NMDAR抗体IgG阴性,17例血清抗NMDAR抗体阳性及19例脑脊液抗体阳性;17例予一线免疫治疗,15例好转;随访16例,15例均好转,其中2例复发。结论:儿童抗NMDAR脑炎无明显性别差异,临床主要表现为精神异常、抽搐、运动障碍、睡眠障碍,出现中枢性通气障碍及合并肿瘤较少见,约半数头颅MRI表现异常,主要为颞叶受损;脑电图主要表现为背景活动慢,脑脊液无明显特异改变,少部分血清免疫抗体可为阴性;多数一线免疫治疗有效,大部分预后良好,复发率低于成人。     

Neurotoxicity of heroin–cocaine combinations in rat cortical neurons

Cocaine and heroin are frequently co-abused by humans, in a combination known as speedball. Recently, chemical interactions between heroin (Her) or its metabolite morphine (Mor) and cocaine (Coc) were described, resulting in the formation of strong adducts. In this work, we evaluated whether combinations of Coc and Her affect the neurotoxicity of these drugs, using rat cortical neurons incubated with Coc, Her, Her followed by Coc (Her + Coc) and Her plus Coc (Her:Coc, 1:1). Neurons exposed to Her, Her + Coc and Her:Coc exhibited a decrease in cell viability, which was more pronounced in neurons exposed to Her and Her + Coc, in comparison with neurons exposed to the mixture (Her:Coc). Cells exposed to the mixture showed increased intracellular calcium and mitochondrial dysfunction, as determined by a decrease in intracellular ATP levels and in mitochondrial membrane potential, displaying both apoptotic and necrotic characteristics. Conversely, a major increase in cytochrome c release, caspase 3-dependent apoptosis, and decreased metabolic neuronal viability were observed upon sequential exposure to Her and Coc. The data show that drug combinations potentiate cortical neurotoxicity and that the mode of co-exposure changes cellular death pathways activated by the drugs, strongly suggesting that chemical interactions occurring in Her:Coc, such as adduct formation, shift cell death mechanisms towards necrosis. Since impairment of the prefrontal cortex is involved in the loss of impulse control observed in drug addicts, the data presented here may contribute to explain the increase in treatment failure observed in speedball abusers.     

(-)-S·R-蝙蝠葛苏林碱对N-甲基-D-天门冬氨酸引起大鼠皮层神经元损伤的保护作用

Cultured neurons obtained from rat cortex were used to examine the protective effect of (-)-S·R-daurisoline (Dau) against N-methyl-D-aspartate (NMDA) induced neurotoxicity. Cell viability was estimated by using trypan blue dye exclusion and MTT assay.Intracellular free Ca²⁺ concentration (［Ca²⁺］_i) was measured by using AR-CM-
MIC cation measurement system with Fura-2/AM as Ca²⁺-senstive fluorecent indicator. It was found that Dau could significantly inhibit NMDA-induced neurotoxicity and block NMDA-elicited increase of ［Ca²⁺］_i in concentration-dependent manner with IC₅₀ value of 7.1 and 6.4 μmol·L^-1 respectively. It is suggested that Dau has a significant protection against NMDA-induced neurotoxicity,the mechanism underlying the protection might be related to it antagonism against Ca²⁺ influx into cells via-NMDA-mediated ligand-gated ion channels.     

米诺环素对脑缺血后的神经保护作用及其机制

目的综述米诺环素在多种动物模型中对脑缺血后神经功能的保护作用及其可能的机制。方法根据近年来发表的文献共31篇,对米诺环素单独应用和与其他药物联合应用的效果进行阐明,并从分子水平论述其可能的作用机制。结果米诺环素可以抗脑缺血,其作用显著。在多种模型中均可见其神经保护作用,且与组织型纤维蛋白溶酶原活化剂、细胞周期蛋白激酶抑制剂夫拉平度等其他药物合用时可见抗脑缺血作用加强,并对新生儿的脑缺血模型显示出一定的治疗作用,其作用强度也显示出与剂量的相关性。其涉及的机制包括抑制细胞凋亡、抗氧化应激、抑制小胶质细胞活化、抑制金属蛋白酶的活性等。结论对于米诺环素抗脑缺血及其机制的研究,可为了解脑血管病的病因及开发新药提供依据。     

Determination of the toxicity of intravitreal minocycline in rabbit eyes

Purpose: To evaluate the retinal toxicity of intravitreal minocycline in rabbit eyes.

Methods: Intravitreal injection of minocycline with concentrations of 1000, 500, 250, 125 and 62.5?μg in 0.1?ml was performed in 10 New Zealand albino rabbits. Each concentration was injected into two rabbit eyes. For each dose, normal saline was injected in one contralateral eye and the other fellow eye remained non-injected. Electrophysiologic testing was performed before and 4 weeks after injections. The eyes were enucleated 4 weeks after injections and examined using light microscopy.

Results: The clinical examination was unremarkable after injections. Electroretinography recordings were significantly affected at all doses in at least one of the a- or b-waves of photopic or scotopic responses. Histopathologic examination revealed marked atrophy and loss of integrity in all retinal layers in all minocycline injected eyes. Contralateral eyes were normal.

Conclusion: In our study, intravitreal minocycline was toxic to the retina in albino rabbits even at a concentration of 62.5?µg/0.1?ml.     

Study of the protective effect of calcium channel blockers against neuronal damage induced by glutamate in cultured hippocampal neurons

BackgroundThe aim of this study was to examine the putative protective effect of calcium channel blockers on hippocampal neurons in the experimental model of excitotoxic damage.MethodsSeven-day old primary dissociated cultures of rat hippocampal neural cells containing one of the following calcium channel blockers: cinnarizine, flunarizine or nimodipine were exposed to glutamate-induced injury. Quantitative assessments of neuronal injury were accomplished by measuring lactate dehydrogenase (LDH) activity in the media 24 h after exposure to glutamate and by counting and establishing the apoptotic and necrotic cells in flow cytometry with Annexin V-FITC/PI staining.ResultsIn our experiment, glutamate induced a 339% elevation of apoptotic cells and a 289% increase of necrotic cells in hippocampal neurons as compared to control cultures without drugs. In cultures containing flunarizine, glutamate-induced cell apoptosis was suppressed by 62% while necrosis showed no significant alternation. Cinnarizine exerted no anti-apoptotic effects on glutamate-injured cultured hippocampal neurons, while nimodipine intensified the apoptotic pathway of cell death and promoted an increase in the number of apoptotic neurons by 26%. When cinnarizine or nimodipine were used, the percentage of necrotic cells was significantly lower when compared with glutamate-injured cultures and it amounted to 44% and 24% for cinnarizine and nimodipine, respectively.ConclusionsThe obtained results suggest the beneficial anti-apoptotic potential of flunarizine and the anti-necrotic potential of cinnarizine against glutamate-induced death of cultured hippocampal neurons. Nimodipine can protect neurons against necrosis, but has an intensified adverse pro-apoptotic effect on cultured neurons in the experimental model of excitotoxic injury.     

木犀草素对大鼠皮层神经元氧化损伤的保护作用

目的研究木犀草素对于皮层神经元氧化损伤的保护作用及其机制。方法用200μmol·L-1H2O2处理皮层神经元造成神经元的氧化损伤,用LDH活性检测细胞死亡,MTT测定线粒体活性,荧光分光检测神经元线粒体膜电位,细胞内ROS的积累以及过氧化氢酶和谷胱甘肽的含量变化。结果20μmol·L-1的木犀草素能有效的保护H2O2导致的神经元死亡,有效维护线粒体膜电位和线粒体活性,减少细胞内ROS的累积,并能通过提高细胞内谷胱甘肽的含量有效对抗氧化损伤,同时对于H2O2造成的过氧化氢酶活力和谷胱甘肽含量的急剧下降也有很好的保护作用。结论木犀草素是一种比较有效的对抗神经元氧化损伤的保护剂,它很可能通过维持线粒体的活性而达到神经保护作用,并通过提高细胞内谷胱甘肽的水平,增强神经元抗氧化损伤的能力。     

羟丁酸钠对大鼠原代培养皮层神经元缺氧复氧损伤的保护作用与GABAA受体的关系

目的 :探讨羟丁酸钠 (SO)对大鼠皮层神经元缺氧复氧损伤的保护作用与GABAA 受体的关系。方法 :采用原代培养大鼠皮层神经元建立缺氧复氧损伤模型 ,观察细胞的形态学 ,测定其LDH漏出率、MDA含量、SOD、GPx活力。结果 :缺氧复氧可引起神经元损伤 ,LDH漏出率增加 ,MDA含量升高 (P <0 .0 1) ,SOD、GPx活力降低 (P <0 .0 1)。SO能显著减少损伤神经元的LDH漏出率及MDA的生成 (P <0 .0 1) ,升高SOD、GPx(P <0 .0 1)的活力 ,这种作用可被GABAA 受体阻断剂seurinine减弱 (P <0 .0 1)。结论 :SO对缺氧复氧神经元损伤的保护作用可能与其激动GABAA 受体有关。     

新鲜分离的新生大鼠皮层神经元的钙振荡

目的:研究新鲜分离的新生大鼠皮层神经元胞内钙离子浓度([Ca~(2 )]_i)发生振荡的机制。方法:采用酶解结合机械分离法从6—7日龄大鼠分离皮层神经元,用M40钙离子测量系统(PTI)测量细胞内钙离子浓度的变化。用Fura-2作为钙离子指示剂。结果:在观察到的82个神经元细胞中,47个产生了自发钙振荡。自发钙振荡依赖于胞外钙离子浓度。去除外钙后自发钙振荡立即停止。四乙铵1mmol/L引起钙振荡振幅增大,频率变快。CsCl 1mmol/L主要引起频率增加。BaCl_2 1mmol/L可使振幅、频率增高,并有明显的高台样基线增加。结论:皮层神经元在无突触联系的情况下具有产生自发[Ca~(2 )]_i振荡的特性,K~ 通道在决定钙振荡的幅值和频率方面起重要作用。     

远志皂苷元对新生大鼠皮质神经元的营养作用

目的 研究远志皂苷元(senegenin)对新生大鼠皮质神经元的神经营养作用.方法 原代培养新生24 h内SD大鼠皮质神经元,采用0.4% B27+DMEM/F12培养基制备营养缺乏模型.远志皂苷元0.5,1 和2 μmol·L-1及阳性对照组碱性成纤维细胞生长因子(bFGF)10 μg·L-1.倒置显微镜下观察各组皮...     

鞘内注射米诺环素减轻大鼠佐剂性关节炎性痛觉过敏

目的研究鞘内注射(it)米诺环素(minocycline,M)对大鼠完全氟氏佐剂(complete Freunds adjunvant,CFA)性关节炎性痛觉过敏的作用。方法蛛网膜下腔置管成功的♂SD大鼠,在右踝关节外侧皮下注射50μlCFA前30min分别it生理盐水(NS)或12.5、25、50μg的米诺环素,it每天1次,持续7d,观察热刺激回缩潜伏期(paw withdrawal thermal latency,PWTL)14d。CFA致炎后2d、6d,it米诺环素50μg,观察24h的PWTL变化;右踝关节外侧皮下注射50μlNS前30minit米诺环素50μg、NS20μl,观察24h的PWTL变化。结果米诺环素it不改变无炎症大鼠的PWTL;CFA致炎后PWTL缩短,米诺环素抑制致炎后PWTL的减少似呈剂量依赖性;预先及CFA致炎后2d米诺环素it可抑制PWTL的减少,d6则无明显影响。结论米诺环素it可减轻炎性痛觉过敏;对已存在的痛觉过敏,早期it作用较强,后期it则无明显作用。