NMDAR1和GABA_A受体的α_1及α_3亚单位在成年猫小脑的定位分布

用免疫组织化学反应及 Nissl染色探讨了 NMDAR1及 GABAA受体α1 和α3亚单位在成年猫小脑皮质及小脑核的定位分布。结果表明 ,NMDAR1免疫反应产物主要分布在 Purkinje细胞胞质和分子层的树突 ,分子层的星形细胞和篮细胞以及颗粒细胞层的颗粒细胞和胶质细胞呈中等强度的阳性反应 ,小脑核的神经元胞质和部分突起着色明显。 GABAA受体的α1 亚单位免疫反应产物主要分布在 Purkinje细胞胞质和树突 ,分子层的星形细胞和胶质细胞呈弱阳性 ,小脑核的神经元阳性反应明显。GABAA 受体的α3亚单位免疫反应产物主要分布在 Purkinje细胞胞质和树突 ,分子层的星形细胞和篮细胞着色明显 ,胶质细胞呈免疫反应弱阳性 ,小脑核神经元及纤维着色明显。在 Purkinje细胞层 NMDAR1、GABAA受体α1 及α3亚单位免疫阳性神经元分别占 Purkinje细胞总数的 80 % ,61% ,88%。结论 :NMDAR1、GABAA受体的α1 及α3亚单位在成年猫小脑具有广泛的分布。这些受体在介导小脑的复杂功能中可能发挥重要的作用。     

Lasting changes in NMDAR1 mRNA level in various regions of cerebral cortex in epileptogenesis of amygdaloid-kindled rat

The involvement of NMDA receptor subunit, NR1, with kindling phenomenon has been reported, but the role of NR1 in epileptogenesis is still unknown. We have examined the expression levels of NR1 mRNA in the cerebral cortices of amygdaloid-kindled rats. Northern blot analysis showed a significant increase in NR1 mRNA expression level in the ipsilateral frontal and temporal cortices at 4 weeks after the last generalized seizure. At the same time, NR1 mRNA decreased in the bilateral piriform cortices. These data suggest that NR1-mediated transmission may have an impact in the neurobiological basis of enduring epileptogenesis.     

越鞠甘麦大枣汤增强突触可塑性产生抗抑郁样作用＊

目的 研究越鞠甘麦大枣汤的抗抑郁样作用并分析其对小鼠海马突触可塑性的影响。方法 昆明小鼠随机分为对照组和越鞠甘麦大枣汤组，给药24 h和7 天后进行悬尾测试（Tail suspension test，TST）和强迫游泳测试（Forced swimming test，FST）。运用电生理（electrophysiological experiment）技术检测小鼠海马区Schaffe侧枝-CA1的长时程增强（long term potentiation，LTP），利用western blot方法分析海马脑区α-氨基-3-羟基-5-甲基-4-异恶唑丙酸受体（α-amino-3-hydroxy-5-methyl-4-isoxazole-propionicacid receptor，AMPAR）和N-甲基-d-天冬氨酸受体（N-methyl-D-aspartate receptor， NMDAR）相关突触蛋白的表达水平。结果 给药24 h和7天后，与对照组小鼠相比，越鞠甘麦大枣汤给药组小鼠在TST（P <0.001）和FST（P <0.01）中的不动时间均明显降低，氯胺酮在给药24 h后显示出抗抑郁作用，但到第7天不能降低小鼠不动时间，越鞠甘麦大枣汤显示出更持久的抗抑郁样作用。电生理实验中，越鞠甘麦大枣汤可增强小鼠海马区的LTP（P < 0.001）。Western blot结果显示，GluR1、NR2B以及NR1的表达水平在给药后均明显增加（P < 0.05）。结论 越鞠甘麦大枣汤可能通过增强昆明小鼠海马脑区LTP，以及增加AMPA和NMDA受体相关突触蛋白的表达水平以提高突触传递效能，从而产生抗抑郁样作用。     

姜黄素对氯化铝染毒的NG108 - 15细胞凋亡及PKC - NMDAR通路表达的影响

目的 探讨姜黄素对氯化铝染毒所致NG108 - 15细胞凋亡的影响及其机制,为铝致学习记忆损伤的治疗提供参考。方法 取对数生长期NG108 - 15细胞,随机分为空白对照组、DMSO组（溶剂对照）、姜黄素组（16 μmol/L姜黄素）、铝组（160 mg/L氯化铝染毒 ）、铝+姜黄素组（160 mg/L氯化铝染毒24 h后,给予16 μmol/L姜黄素处理24 h）。收集各组细胞,采用吖啶橙/嗅化乙锭（AO/EB）双荧光染色观察细胞凋亡形态,计数凋亡细胞数并计算凋亡率;流式细胞术检测细胞凋亡率, qRT - PCR检测细胞中PKC、NMDAR1、NMDAR2B 的mRNA表达水平,western blot检测细胞中凋亡相关蛋白（caspase3、Bax）和PKC、NMDAR1、NMDAR2B的蛋白表达水平。多组间均数的比较采用单因素方差分析（one - way ANOVA）,组间两样本均数的比较采用LSD法。结果 与空白对照组相比,铝染毒组的caspase3、Bax蛋白表达水平升高（t = - 5.547、 - 4.948,P＜0.001）,PKC、NMDAR1、NMDAR2B的mRNA（t = 4.926,P = 0.003;t = 6.330,P＜0.001;t = 4.224,P = 0.019）和蛋白（t = 20.638,P＜0.001;t = 4.509,P＜0.001;t = 17.388,P = 0.002）表达水平降低, AO/EB染色和流式细胞术结果均表明细胞凋亡率升高（t = - 5.153、 - 7.390,P＜0.001）;加入姜黄素处理后,与铝染毒组相比,铝+姜黄素组的caspase3、Bax蛋白表达水平降低（t = 2.930,P = 0.006;t = 4.907,P＜0.001）,PKC、NMDAR1、NMDAR2B 的mRNA（t = - 10.337、 - 6.621、 - 6.847,P＜0.001）和蛋白（t = - 30.551、 - 7.451、 - 26.294,P＜0.001）表达水平升高,AO/EB染色和流式细胞术结果均表明细胞凋亡率降低（t = 2.707,P = 0.01;t = 4.632,P＜0.001）。结论 上调PKC - NMDAR信号通路表达,可能是姜黄素减轻氯化铝染毒所致NG108 - 15细胞凋亡的机制之一。     

Rats classified as low or high cocaine locomotor responders: A unique model involving striatal dopamine transporters that predicts cocaine addiction-like behaviors

Individual differences are a hallmark of drug addiction. Here, we describe a rat model based on differential initial responsiveness to low dose cocaine. Despite similar brain cocaine levels, individual outbred Sprague-Dawley rats exhibit markedly different magnitudes of acute cocaine-induced locomotor activity and, thereby, can be classified as low or high cocaine responders (LCRs or HCRs). LCRs and HCRs differ in drug-induced, but not novelty-associated, hyperactivity. LCRs have higher basal numbers of striatal dopamine transporters (DATs) than HCRs and exhibit marginal cocaine inhibition of in vivo DAT activity and cocaine-induced increases in extracellular DA. Importantly, lower initial cocaine response predicts greater locomotor sensitization, conditioned place preference and greater motivation to self-administer cocaine following low dose acquisition. Further, outbred Long-Evans rats classified as LCRs, versus HCRs, are more sensitive to cocaine's discriminative stimulus effects. Overall, results to date with the LCR/HCR model underscore the contribution of striatal DATs to individual differences in initial cocaine responsiveness and the value of assessing the influence of initial drug response on subsequent expression of addiction-like behaviors.     

Novel nootropic drug sunifiram enhances hippocampal synaptic efficacy via glycine‐binding site of N‐methyl‐D‐aspartate receptor

Sunifiram is a novel pyrrolidone nootropic drug structurally related to piracetam, which was developed for neurodegenerative disorder like Alzheimer's disease. Sunifiram is known to enhance cognitive function in some behavioral experiments such as Morris water maze task. To address question whether sunifiram affects N‐methyl‐D ‐aspartate receptor (NMDAR)‐dependent synaptic function in the hippocampal CA1 region, we assessed the effects of sunifiram on NMDAR‐dependent long‐term potentiation (LTP) by electrophysiology and on phosphorylation of synaptic proteins by immunoblotting analysis. In mouse hippocampal slices, sunifiram at 10–100 nM significantly enhanced LTP in a bell‐shaped dose‐response relationship which peaked at 10 nM. The enhancement of LTP by sunifiram treatment was inhibited by 7‐chloro‐kynurenic acid (7‐ClKN), an antagonist for glycine‐binding site of NMDAR, but not by ifenprodil, an inhibitor for polyamine site of NMDAR. The enhancement of LTP by sunifilam was associated with an increase in phosphorylation of α‐amino‐3‐hydroxy‐5‐methylisozazole‐4‐propionate receptor (AMPAR) through activation of calcium/calmodulin‐dependent protein kinase II (CaMKII) and an increase in phosphorylation of NMDAR through activation of protein kinase Cα (PKCα). Sunifiram treatments at 1–1000 nM increased the slope of field excitatory postsynaptic potentials (fEPSPs) in a dose‐dependent manner. The enhancement was associated with an increase in phosphorylation of AMPAR receptor through activation of CaMKII. Interestingly, under the basal condition, sunifiram treatments increased PKCα (Ser‐657) and Src family (Tyr‐416) activities with the same bell‐shaped dose‐response curve as that of LTP peaking at 10 nM. The increase in phosphorylation of PKCα (Ser‐657) and Src (Tyr‐416) induced by sunifiram was inhibited by 7‐ClKN treatment. The LTP enhancement by sunifiram was significantly inhibited by PP2, a Src family inhibitor. Finally, when pretreated with a high concentration of glycine (300 μM), sunifiram treatments failed to potentiate LTP in the CA1 region. Taken together, sunifiram stimulates the glycine‐binding site of NMDAR with concomitant PKCα activation through Src kinase. Enhancement of PKCα activity triggers to potentiate hippocampal LTP through CaMKII activation. © 2013 Wiley Periodicals, Inc.     

NMDAR/PSD-95/nNOs复合体及其解偶联剂在治疗缺血性卒中的应用

缺血性脑卒中是一种高死亡率、高致残率、高复发率的疾病。目前认为,脑卒中是由各种血管性病因引起的急性或局灶性脑功能障碍,且持续时间超过24 h或引起死亡的临床症候群。随着对脑卒中发病机制的深入研究,其治疗药物也日新月异,该文综合国内外文献,根据NMDAR/PSD-95/nNOs复合体结构特点及其如何在缺血性脑卒中产生病理作用,阐明新型解偶联药物在治疗缺血性卒中的应用前景。     

Neurologic Autoimmunity in the Era of Checkpoint Inhibitor Cancer Immunotherapy

Neurologic autoimmune disorders in the context of systemic cancer reflect antitumor immune responses against onconeural proteins that are autoantigens in the nervous system. These responses observe basic principles of cancer immunity and are highly pertinent to oncological practice since the introduction of immune checkpoint inhibitor cancer therapy. The patient’s autoantibody profile is consistent with the antigenic composition of the underlying malignancy. A major determinant of the pathogenic outcome is the anatomic and subcellular location of the autoantigen. IgGs targeting plasma membrane proteins (eg, muscle acetylcholine receptor -IgG in patients with paraneoplastic myasthenia gravis) have pathogenic potential. However, IgGs specific for intracellular antigens (eg, antineuronal nuclear antibody 1 [anti-Hu] associated with sensory neuronopathy and small cell lung cancer) are surrogate markers for CD8⁺ T lymphocytes targeting peptides derived from nuclear or cytoplasmic proteins. In an inflammatory milieu, those peptides translocate to neural plasma membranes as major histocompatibility complex class I protein complexes. Paraneoplastic neurologic autoimmunity can affect any level of the neuraxis and may be mistaken for cancer progression. Importantly, these disorders generally respond favorably to early-initiated immunotherapy and cancer treatment. Small cell lung cancer and thymoma are commonly associated with neurologic autoimmunity, but in the context of checkpoint inhibitor therapy, other malignancy associations are increasingly recognized.     

谷氨酸转运体与疼痛

谷氨酸是N-甲基-D-天门冬氨酸(N-methyL-D-aspartate,NMDA)受体的天然配体,如果持续激动就会产生细胞毒性.谷氨酸转运体能从胞外向胞内摄取谷氨酸,以减少对NMDA受体的激动,保护神经元不受谷氨酸毒性影响.新近的研究表明,谷氨酸转运体通过调节细胞外谷氨酸浓度在疼痛过程中也发挥着重要作用.