The potential subunits involved in two subtypes of α-Bgt-resistant nAChRs in cockroach dorsal unpaired median (DUM) neurons

The american cockroach (Periplaneta americana) dorsal unpaired median (DUM) neurons provide an native tool to analyze the functional and pharmacological properties of ion channels and membrane receptors, such as nicotine acetylcholine receptors (nAChRs). Here the imidacloprid-activated nAChR subtypes were examined in DUM neurons by the patch-clamp technique and the potential subunits involved in important subtypes were analyzed by combining with RNA interference (RNAi) technique. Imidacloprid exerted agonist activities on one subtype in α-Bgt-sensitive nAChRs and another subtype in α-Bgt-resistant nAChRs, in which the α-Bgt-resistant subtype showed much higher sensitivity to imidacloprid than the α-Bgt-sensitive subtype, with the difference close to 200-fold. In α-Bgt-resistant nAChRs, nicotine exerted the agonist activity on two subtypes (nAChR1 and nAChR2), although imidacloprid only activated nAChR1. RNAi against Paα3, Paα8 and Paβ1 significantly reduced both imidacloprid- and nicotine-activated currents on nAChR1. In contrast, RNAi against Paα1, Paα2 and Paβ1 decreased nicotine-activated currents on nAChR2. The results indicated that, in α-Bgt-resistant nAChRs, Paα3, Paα8 and Paβ1 might be involved in the subunit composition of nAChR1, and Paα1, Paα2 and Paβ1 in nAChR2. In summary, from the present study and previous reports, we deduced that there are at least three nAChR subtypes that are sensitive to imidacloprid in the cockroach DUM neurons.     

秀丽隐杆线虫固有免疫功能神经调控机制研究进展

固有免疫系统是动植物个体应对外来微生物侵入感染时非常重要的抵御防线。秀丽隐杆线虫(Caenorhabditis elegans,简称线虫)作为研究宿主与病原菌之间相互作用的经典模式动物,近年来在神经和免疫之间相互作用的分子与遗传机制等方面的研究取得了长足进展。研究表明,线虫神经元通过释放神经递质与神经多肽(如多巴胺、NLP-20)等,激活相关信号通路途经,参与线虫对病原菌的识别、逃避、调节物理屏障防御能力和激活固有免疫反应,并表达分泌抗菌肽以清除病原菌等的调控进程。本文综述了线虫神经系统调控固有免疫功能机制的最新研究进展,为人们深入了解神经与免疫系统间相互作用的功能分子及其调控机制和揭示人类神经与免疫系统相关疾病的病理机理提供了重要信息。     

用激光共聚焦扫描技术研究昆虫触角叶的雌雄异构性

【目的】本研究探讨用激光共聚焦扫描显微镜对昆虫触角叶内结构的扫描技术。【方法】选取鳞翅目斜纹夜蛾Spodoptera litura, 蜚蠊目美洲大蠊Periplaneta americana和鞘翅目松墨天牛Monochamus alternatus, 仔细解剖得到昆虫完整脑组织, 经过Lucifer yellow染色、戊二醛固定、梯度酒精脱水和透明等一系列处理后, 用激光共聚焦扫描显微镜对昆虫触角叶结构进行分层扫描。【结果】结果显示: 经该方法处理后在激发光488 nm下能清晰扫描出昆虫触角内典型结构神经纤维球, 并且可清晰看到这3种昆虫雄性触角叶结构内的扩大型神经纤维球复合体(macroglomerular complex, MGC), 而在相应雌性昆虫体内都没有此复合体。另外通过5 μm分层扫描得到斜纹夜蛾、美洲大蠊和松墨天牛的触角叶平均厚度分别为130, 235和115 μm, 神经纤维球数量分别为35, 59和39个。【结论】激光共聚焦扫描技术是获得昆虫触角叶内部结构的一个可行方法。     

The complement cascade in the regulation of neuroinflammation,nociceptive sensitization,and pain

The complement cascade is a key component of the innate immune system that is rapidly recruited through a cascade of enzymatic reactions to enable the recognition and clearance of pathogens and promote tissue repair. Despite its well-understood role in immunology, recent studies have highlighted new and unexpected roles of the complement cascade in neuroimmune interaction and in the regulation of neuronal processes during development, aging, and in disease states. Complement signaling is particularly important in directing neuronal responses to tissue injury, neurotrauma, and nerve lesions. Under physiological conditions, complement-dependent changes in neuronal excitability, synaptic strength, and neurite remodeling promote nerve regeneration, tissue repair, and healing. However, in a variety of pathologies, dysregulation of the complement cascade leads to chronic inflammation, persistent pain, and neural dysfunction. This review describes recent advances in our understanding of the multifaceted cross-communication that takes place between the complement system and neurons. In particular, we focus on the molecular and cellular mechanisms through which complement signaling regulates neuronal excitability and synaptic plasticity in the nociceptive pathways involved in pain processing in both health and disease. Finally, we discuss the future of this rapidly growing field and what we believe to be the significant knowledge gaps that need to be addressed.     

银杏内酯对胚基底前脑NOS、AChE阳性神经元发育的影响

目的 探讨银杏内酯对胚基底前脑NOS和AChE阳性神经元发育的影响。方法 实验分成银杏组,NGF组,BDNF组和单纯对照组。取孕17dSD大鼠胚基底前脑原基制成细胞悬液接种于96孔培养板和2块24孔培养板中,分别加入含银杏内酯,NGF,BDNF及不含上述成份的DMEM培养液,于体外培养18d后,96孔培养板行MTT比色分析测定光吸收值（OD值）,以检测培养的神经元活力,2块24孔培养板分别行NADPH-d和AChE组化染色,显微镜下计数各组每了忆中的NOS和AChE阳性神经元数,并用CMM-301图像分析系统对两种神经元的细胞面积和细胞周长进行处理。数据用方差分析和SNK检验进行统计学处理。结果 银杏组MTT比色分析的OD值和NOS,AChE阳性神经元数,细胞面积,细胞周长等指标均明显地好于单纯对照组,达到或仅稍差于NGF组或BDNF组的指标。结论 银杏内酯在促进胚基底前脑NOS和AChE阳性神经元发育方面具有类似NGF和BDNF的作用。     

昆虫神经生物学研究技术:细胞内记录

细胞内记录是昆虫神经生物学研究中的常用技术。它用来获得神经元兴奋和抑制过程及神经脉冲产生机制的信息。该技术的特点是把一根微电极的顶尖插入到神经细胞内进行电生理记录 ,这根电极还能用于向膜内输入电流。作者以对蝗虫Schistocercagregaria后胸神经节内的 2个运动神经元的活性记录为例介绍了这一技术     

Immunocytochemical Study of the Distribution of hcs2 Gene Products in Command Neurons of the Helix lucorum Snail

The distribution of the putative protein products of gene hcs2 in giant command neurons of the parietal ganglia of the terrestrial snail Helix lucorum has been studied using light- and electron-microscopic immunocytochemistry. The product of the hcs2 gene is a hybrid protein belonging to the EF-hand family of Ca²⁺-binding proteins and is a precursor of several neuropeptides. Polyclonal antibodies to neuropeptides CNP3 and CNP4 and the C-terminal Ca²⁺-binding domain of the precursor protein have been used to determine their intracellular localization. The targets for all three types of antibodies have been found in cytoplasmic secretory granules. The label (colloidal gold) density in the secretory granules is two times higher in the case of neuropeptides CNP3 and CNP4 than in the case of the Ca²⁺-binding domain. Thus, a specific association between the putative products of the hcs2 gene and the cell secretory apparatus has been demonstrated. This agrees with the earlier hypothesis that hcs2 products may serve as neurotransmitters or neuromodulators.     

一种新的氧合球蛋白——神经球蛋白

神经球蛋白 (neuroglobin ,NGB)是最近发现的一种新的可以和氧可逆性结合的血红蛋白家族成员 ,主要表达于脊椎动物的脑中 .NGB蛋白是由 151个氨基酸组成的单体蛋白 ,有着古老的进化起源 .迄今为止 ,已证明它具有储存、转运氧气和保护神经细胞的功能 .NGB基因的表达调节至少有两条信号转导途径参与 .NGB的发现为中风等缺氧相关疾病的治疗提供了新的方向     

人同源框基因Lhx4 cDNA序列的获得,染色体定位和基因组分析

Lhx4基因是LIM同源框基因家族的一员 ,它在运动神经元的发育过程中发挥着重要的作用 .从人脊髓cDNA文库中筛选到了 1个人源性Lhx4基因的cDNA全长序列 ,它与鼠源性的Lhx4基因的cDNA序列有 92 %同源性 .它的基因被定位在 1号染色体 1q 2 4 .1- 1q 2 4 .3的位置 ,并包含有 6个外显子 .其中同源框结构域由外显子 4和 5表达 ,LIM结构域 1由外显子 2表达 ,LIM结构域2由外显子 3表达 .     

JNK3 contributes to c-Jun activation and apoptosis but not oxidative stress in nerve growth factor-deprived sympathetic neurons

The stress activated protein kinase pathway culminates in c-Jun phosphorylation mediated by the Jun Kinases (JNKs). The role of the JNK pathway in sympathetic neuronal death is unclear in that apoptosis is not inhibited by a dominant negative protein of one JNK kinase, SEK1, but is inhibited by CEP-1347, a compound known to inhibit this overall pathway but not JNKs per se. To evaluate directly the apoptotic role of the JNK isoform that is selectively expressed in neurons, JNK3, we isolated sympathetic neurons from JNK3-deficient mice and quantified nerve growth factor (NGF) deprivation-induced neuronal death, oxidative stress, c-Jun phosphorylation, and c-jun induction. Here, we report that oxidative stress in neurons from JNK3-deficient mice is normal after NGF deprivation. In contrast, NGF-deprivation-induced increases in the levels of phosphorylated c-Jun, c-jun, and apoptosis are each inhibited in JNK3-deficient mice. Overall, these results indicate that JNK3 plays a critical role in activation of c-Jun and apoptosis in a classic model of cell-autonomous programmed neuron death.