大豆磷脂酰胆碱提高幼年大鼠学习记忆能力及海马突触素的表达

目的:观察大豆磷脂酰胆碱(SB-pc)对幼年大鼠海马结构突触素(SYN)的免疫表达和空间辨别性学习记忆能力的影响. 方法:5 wk龄雄性Wistar大鼠21只,随机分为3组:①SB-pc添加喂养组(PC,n=8);②迷宫对照组(MC, n=7);③正常对照组(NC, n=6). 喂养8 wk,PC组和MC组大鼠在Morris水迷宫中进行连续4 d的空间辨别性学习记忆能力检测,计算机分析系统自动记录逃避潜伏期(escape latency, EL)等相关参数,分析大鼠行为变化. 用免疫组织化学方法检测PC、MC和NC各组大鼠海马结构SYN的免疫表达. 结果:逃避潜伏期(EL):PC组与MC组比较,差异有统计学意义(P<0.01). SYN免疫表达:PC组与MC组比较,大鼠海马结构各区SYN免疫反应阳性产物的吸光度值差异有统计学意义(P<0.01); MC组与NC组比较,差异有统计学意义(P<0.01). 结论:添加SB-pc喂养幼年大鼠,可促进其海马结构突触的增长,使SYN的免疫表达增强,提高了突触的可塑性,从而提高幼年大鼠的空间辨别性学习记忆能力.     

剥夺异相睡眠对大鼠海马结构突触囊泡膜蛋白表达的影响

目的: 观察剥夺异相睡眠对大鼠海马结构突触囊泡膜蛋白表达的影响. 方法: 34只雄性Wistar大鼠随机分为4组:①剥夺异相睡眠组(PSD, n＝9),采用"小平台水环境法"(Flower Pot Technique)剥夺大鼠异相睡眠;②大平台对照组(TC, n＝8)置于"平台水环境",平台直径为20㎝;③普通鼠笼对照组(CC, n＝9);④非游泳对照组(NC, n＝8). 除NC组外,其余3组大鼠在Morris水迷宫中进行游泳训练对比,水迷宫记录分析系统自动记录游泳速度、游泳距离、逃避潜伏期等相关参数. 通过免疫组织化学方法检测大鼠海马结构突触囊泡膜蛋白(synaptophysin, SYN)的表达. 结果: 从第2日开始到第4日,PSD组大鼠游泳距离大于CC组和TC组,有显著性差异(P<0.05). PSD组和NC组大鼠海马结构突触囊泡膜蛋白阳性产物的光密度值较CC组和TC组低(P<0.05). 结论: 剥夺异相睡眠可能通过影响海马结构突触的增长使大鼠的空间辨别性学习记忆能力下降.     

新生鼠脑缺血再灌注后海马CA1区突触素的表达及意义

目的 :观察新生Wistar大鼠脑缺血再灌注后海马CA1区突触素的表达 .探讨中枢神经系统的可塑性 .方法 :应用免疫组化方法观察新生鼠脑缺血再灌注后不同时点脑组织突触素的表达 .结果 :缺血再灌注 3d突触素表达开始增高 ,7d达高峰 ,1 4d时免疫活性仍高 ,其矫正吸光度值与对照组比较有显著性差异 (P <0 .0 1 ) .结论 :新生Wistar大鼠脑神经细胞损伤后具有修复的可塑性 ,其时间持续至缺血再灌注后 1 4d .突触素检测能较好地反映神经元和轴突的代偿再生情况     

Neurotransmitter segregation: functional and plastic implications

Synaptic cotransmission is the ability of neurons to use more than one transmitter to convey synaptic signals. Cotransmission was originally described as the presence of a classic transmitter, which conveys main signal, along one or more cotransmitters that modulate transmission, later on, it was found cotransmission of classic transmitters. It has been generally accepted that neurons store and release the same set of transmitters in all their synaptic processes. However, some findings that show axon endings of individual neurons storing and releasing different sets of transmitters, are not in accordance with this assumption, and give support to the hypothesis that neurons can segregate transmitters to different synapses. Here, we review the studies showing segregation of transmitters in invertebrate and mammalian central nervous system neurons, and correlate them with our results obtained in sympathetic neurons. Our data show that these neurons segregate even classic transmitters to separated axons. Based on our data we suggest that segregation is a plastic phenomenon and responds to functional synaptic requirements, and to 'environmental' cues such as neurotrophins. We propose that neurons have the machinery to guide the different molecules required in synaptic transmission through axons and sort them to different axon endings. We believe that transmitter segregation improves neuron interactions during cotransmission and gives them selective and better control of synaptic plasticity.     

意向运动疗法对大鼠局灶性脑缺血后GFAP和SYP表达的影响

目的探讨意向运动疗法对大鼠局灶性脑缺血2 h后再灌注缺血周围脑组织GFAP和SYP表达的影响及其对神经再生修复作用的可能机制。方法采用线栓法建立(middle cerebral artery occlusion,MCAO)大鼠模型,缺血2 h后进行再灌注;再灌注24 h后根据Longa神经功能缺损评分选择实验模型,随机分为模型组(MCAO组)、环境改变组(environmental modification,EM)、意向运动组(willed movement,WM),每组再分为3、7、15 d三个亚组;大鼠处死前再进行Longa评分;通过免疫组织化学及免疫荧光观察缺血周围脑组织GFAP和SYP的表达。结果再灌注15 d时,WM组大鼠神经功能缺损评分低于MCAO组、EM组(P<0.05);再灌注7、15 d时,WM组大鼠GFAP和SYP的表达量均高于MCAO组、EM组(P<0.05);MCAO组与EM组比较:任一时间点的GFAP和SYP表达均无统计学差异(P>0.05)。结论意向运动疗法促进了MCAO大鼠神经功能缺损的恢复;可能与其促进缺血周围脑组织GFAP和SYP的表达有关。     

Involvement of GPR12 in the induction of neurite outgrowth in PC12 cells

GPR12, an orphan G protein-coupled receptor, constitutively activates the Gs signaling pathway and further increases intracellular cyclic AMP. GPR12 overexpression has been reported to promote neurite extension in neurons or transform neuro2a neuroblastoma cells into neuron-like cells. However, the possible effects and mechanisms of GPR12 in the differentiation of PC12 cells are still unknown. The present study shows that GPR12 overexpression induced PC12 cells differentiation into neuron-like cells with enlarged cell sizes and neuritogenesis possibly via activation of Erk1/2 signaling and significantly increased the expression of several neurite outgrowth-related genes, including Bcl-xL, Bcl-2 and synaptophysin. These findings indicate that GPR12 may play a role in neurite outgrowth during PC12 cell differentiation.     

Lateral ventricular liponeurocytoma: Review of literature and case illustration

BackgroundLiponeurocytoma is an uncommon tumor of the central nervous system. It is very rare for this tumor to originate within the lateral ventricle. In the context of the rarity of this tumor entity, this review article aims to summarize the clinical, radiological, and pathological features of lateral ventricular liponeurocytoma to facilitate its diagnosis and management.MethodsHere, we conduct a systematic literature review using the Pubmed, Scopus, and Cochrane Library database for all cases of lateral ventricular liponeurocytoma. A case illustration complements this review.ResultsThe described cases from 1997 onward include 14 cases that have been published in full papers in the English literature. Six additional cases are reported in short English abstracts in full non-English papers, and one case was described in a central neurocytoma report. There is a definite male predominance of 70% (14 male) and a mean age of 37 years (range 24–62). Heterogenous enhancement and signals in magnetic resonant images (MRI) are the radiological characteristics. In all reported cases, the presence of lipocytes and fat vacuoles is considered the paramount histopathological feature. Total surgical resection was achieved in 80% (12 out of 15) of the cases. Only two cases (including ours) received radiation therapy. Recurrence was seen in two patients during follow-up that was treated by radiation therapy in one and surgery in the other. The proliferation index is mostly below 5% in all cases, with the Ki-67 range between < 1% to 10%.ConclusionsLateral ventricular liponeurocytoma has been treated effectively by surgical resection in a limited number of cases. The decision for radiation therapy is based on a high proliferation index and tumor recurrence.     

碱性成纤维细胞生长因子对谷氨酸毒性损伤豚鼠视网膜内突触小泡蛋白表达的影响

目的:探讨过量谷氨酸毒性损伤豚鼠视网膜内突触小泡蛋白(SYP)的表达及碱性成纤维细胞生长因子(bFGF)对其表达的影响。方法:豚鼠随机分成谷氨酸钠损伤组、对照组和bFGF治疗组。采用免疫组织化学方法和图像分析技术,对各组豚鼠视网膜内SYP免疫反应产物的表达进行检测。结果:对照组豚鼠视网膜内SYP的表达为强阳性,主要定位于外网状层和内网状层,损伤组视网膜相应区域内阳性反应产物的光密度值明显低于对照组,bFGF治疗后SYP的阳性表达明显高于损伤组,且与对照组相比,无显著性差异。结论:bFGF可抑制过量谷氨酸钠诱发的视网膜内SYP的表达减少,上调SYP的表达,对视神经损伤有显著地促功能修复作用。     

突触囊泡膜蛋白及神经多肽的神经内动力学

神经递质的释放是一复杂的过程，它受若干种囊泡胰蛋白和突触前膜蛋白的调控、本文综述了作者近年来对两类突触囊泡膜蛋白和神经多肽在大鼠坐骨神经内的转运及分布。坐骨神经在结扎以后，正常转运中的各种蛋白及多肽便积聚于结扎的近侧端（表示该物质从周围内细胞体转运）。囊泡膜镶嵌蛋白（Ｓｙｎａｐｔｏｐｈｙｓｉｎ，ＳＶ２，ＳｙｎａｐｔｏｌａｇａｉｎⅠ和ＳｙｎａｎｔｏｂｒｅｖｉｎⅡ）和表面粘附囊泡膜蛋白（ＳｙｎａｐｓｉｎⅠ，Ｒｅｂ３ａ与Ｒａｂｎｈｉｌｉｎ－３Ａ）在神经结扎后一小时即可在结扎的近侧端被检测到，其后，随着时间的延长（至八小时），积聚量不断增加，说明该二类蛋白被快相转运。但是５０％～８０％的囊泡镶嵌蛋白同时积聚在结扎处的远侧端，仅１０％～３０％的表面粘附膜蛋白积肥聚在结扎的远侧端，显示绝大部分表面粘附膜蛋白在神经终末被解，而大部分囊泡膜镶嵌蛋白参于蛋白的再循环。除此之外，本文还研究了神经多肽在周围神经内的转运．位于致密核心囊泡内的神经多肽快速从细胞体向周围转运。但仍有３０％～４０％的神经多肽积聚于结扎处的远侧端，参与再循环．本文显示囊泡膜镶嵌蛋白、表面粘附膜蛋白以及神经多肽各有其独特的神经内转运模式。     

Expression of synaptic proteins in the developing rat cerebellum following ionizing radiation

Various proteins regulating neurotransmission release and synaptic vesicle exocytosis have been implicated in axonal elongation and synaptic maturation. In the present study, immunohistochemistry to the presynaptic membrane proteins syntaxin-I and synaptosomal-associated protein of 25 kDa (SNAP-25) synaptic vesicle-associated proteins synaptophysin and synapsin-I and the neuronal maturation and axonal growth-related protein GAP-43, has been carried out in the normal developing cerebellum and following a single dose of ionizing radiation (2 Gy gamma-rays) at postnatal day 1. Our aim has been to learn about the morphological and possible functional modalities that occur during the progression of neuronal connectivity in normal and abnormal development. Expression of all these proteins is associated with the arrival of afferents in the subcortical white matter and with the maturation of the internal granule cell layer and molecular layer during normal development. In addition, SNAP-25 and GAP-43 are strongly expressed in granule cells of the external granule cell layer, thus suggesting that these proteins are involved in cell elongation of granule cells. Apoptosis appears at 3 h and peaks at 6 h following ionizing radiation. Radiation-induced apoptosis in the external granule cell layer produces a transient decrease in the expression of SNAP-25 and GAP-43 in the external granule cell layer. The external granule cell layer recovers at 48 h and external granule cells of proliferating cells also express SNAP-25 and GAP-43, thus indicating that proliferating cells in this layer are equipped with proteins involved in cell elongation. Furthermore, expression of synaptophysin, synapsin-I, syntaxin-I and SNAP-25 is the same in the cerebellum of irradiated and normal rats from this time to adulthood (3 months). These results point to the likelihood that recovery of the cerebellar cortex occurs following a single exposure of ionizing radiation during postnatal development.