大鼠纹状体边缘区内P物质阳性终末的突触特征

本文用免疫电镜方法研究了大鼠纹状体边缘区内P物质阳性终末的突触特征。边缘区内可见4种P物质免疫反应阳性(SPIR)的突触,即轴树、轴棘、轴轴和复合突触。轴树和轴棘突触较常见,轴轴突触和复合突触较少。轴树和轴棘突触的突触后靶区为小或大的树突或棘,复合突触含两种以上突触成份。在边缘区内可观察到对称型和非对称型两种突触。SPIR突触前终扣内的小泡大部分是多形性的,很少为圆形。这些突触特征均和纹状体其它部位不同,提示边缘区内SPIR终末的来源可能和纹状体其它部位不同,同时也说明边缘区的功能可能和纹状体其它区不同。     

Ultrastructural characteristics of substance P-immunoreactive terminals in marginal division of rat striatum.

In our previous work using immunocytochemical method combined with tract tracing techniques a new subdivision was described in the striatum of the rat. This "marginal division" is more densely filled with substance P, enkephalin and dynorphin B terminals than the rest of the striatum. In the present study, the synaptic organization of the substance P immunoreactive (SPIR) terminals in the marginal division of the rat striatum was studied using electron microscopy and immunocytochemistry for substance P (SP). Four major types of SPIR synapses were identified in the marginal division: axodendritic, axospinous, axo-axonal, and compound synapses. Axodendritic and axospinous synapses, in which the postsynaptic targets were small or large dendrites or spines, were the most common. A few axo-axonic synapses were observed as were several subtypes of compound synapses with more than two synaptic components. SPIR axon terminals formed the presynaptic components of all these synaptic types, but in one case an unlabeled bouton was observed making a synaptic connection onto a SPIR dendrite. Both symmetric and asymmetric SPIR synapses were observed in the marginal division. The vesicles in the SPIR presynaptic boutons were mostly pleomorphic although a few of them were round. The existence of asymmetric synapses, round synaptic vesicles and small postsynaptic dendrites distinguishes the ultrastructure of the marginal division from that of the other parts of the striatum. The complex characteristics of the synaptic organization in the marginal division implies that the SPIR terminals in the marginal division originate from a different source than those in the rest of the striatum. The complexity of the synaptic organization further suggests that the function of the marginal division is different from that of the rest of the striatum.

     

Ultrastructure of the marginal division in the rat striatum.

The discovery of a new subdivision in the striatum of the rat, the marginal division, has recently been reported. The marginal division is located at the caudal extent of the striatum, surrounding the rostrolateral border of the globus pallidus, and has different cellular morphology, immunohistochemistry and an efferent projection pattern from those of the main body of the striatum. In the present study, the ultrastructural organization of the marginal division was investigated. Most neuronal somata in the marginal division were fusiform in shape and had a large pale oval nucleus without in-foldings. There were four types of synapses in the marginal division: axo-somatic, axo-dendritic, axo-spinous and axo-axonic. Both symmetric and asymmetric synapses were observed on the somata, dendrites, or dendritic spines. Most of the symmetric synapses contained pleomorphic vesicles, whereas the asymmetric ones contained mainly round vesicles. Individual axo-axo-spinous synapses, which were first described in the striatum, were also observed in the marginal division. These ultrastructural characteristics distinguish the marginal division from the rest of the striatum.

     

学习记忆过程中磷酸化的CREB在大鼠脑纹状体内的表达

目的探讨大鼠在学习记忆过程中磷酸化的转录因子环磷酸腺苷反应单元结合蛋白 (cAMPresponsiveelementbindingprotein ,CREB)在脑纹状体内的表达。 方法将动物首先在Y迷宫中进行学习记忆训练 ,然后应用免疫组织化学方法检测磷酸化的CREB ( phosphorylatedCREB ,pCREB)在脑纹状体内的表达。结果大鼠经电Y迷宫训练后 ,脑纹状体内侧的边缘区内即有明显的 pCREB阳性表达 ,而假训练组或对照组的边缘区内均无明显的pCREB阳性表达。此外 ,在海马、前额叶皮质和扣带回等处也有较多的 pCREB阳性表达。结论大鼠进行电Y迷宫厌暗学习时 ,脑纹状体边缘区内磷酸化的转录因子pCREB参与学习记忆的信号转导过程。     

缺氧对大鼠纹状体边缘区AChE和NADPH—d含量的影响及其与学习记忆的关系

目的 观察大鼠缺氧后纹状体边缘区（MrD)的病理改变及乙酰胆碱酯酶（AChE）和还原型尼克酰胺腺嘌呤二核苷酸脱氢酶（NADPH－d）的含量改变，探讨缺氧对纹状体边缘区的损害及与学习记忆的关系。方法 建立40只大鼠缺氧模型（予氧含量为8％、氮气含量为92％的混合气，4h/d，连续5d）并对其进行Y迷宫实验，缺氧5d后处死动物观察其脑组织切片HE染色和AChE和NADPH－d组织化学染色情况并与对照组比较。结果 （1）大鼠缺氧前后Y迷宫实验成绩差异显著。（2）AChE组化结果显示，正常大鼠纹状体可见大量AChE阳性反应纤维和少量阳性细胞，MrD内AChE染色略谈；缺氧后纹状体其他部分AChE染色无明显变化，而MrD则明显加深。（3）NADPH－d组化反应显示，MrD内NADPH－d阳性细胞多呈梭形，纹状体内阳性细胞数较其他区域多；缺氧后阳性细胞形态变化不明显，但数目明显少于正常对照。结论 缺氧可导致大鼠学习记忆功能下降以及MrD内AChE、NADPH－d染色的明显改变。这些改变较纹状体其他区域更为明显，表明MrD对于缺氧较敏感，缺氧后AchE和NSADPH的减少可能与学习记忆功能的下降有关。     

边缘区损伤与认知功能下降关系的临床分析(附20例报告)

目的探讨脑边缘区损伤与认知功能下降的关系。方法搜集20例因各种原因造成脑边缘区损伤在我院住院的病例,男14例,女6例;全部病例均行常规MRI检查,对每病例进行认知功能测定,并与MRI表现对比分析;同时,还与10例老年性痴呆患者进行MRI改变及认知功能下降程度的对比研究。结果(1)边缘区损伤的原因多以缺血性损伤为主,MRI表现为长T1长T2异常信号灶,而对照组主要表现为颞叶、海马及大脑皮层的萎缩;(2)20例患者的MMSE评分介于13~25分之间,平均19.7分,以记忆力及计算力下降为主;对照组的MMSE评分为6~15分,平均11分,定向力、记忆力、注意力和计算力、回忆力及语言能力的评分全面下降;(3)单纯边缘区损伤组的认知障碍程度与边缘区合并了豆状核其它部位损伤组无明显差异。结论边缘区是人脑与学习及记忆功能相关的一个新区,脑边缘区的损伤可引起认知功能的下降。     

降钙素基因相关肽在大鼠纹状体边缘区内分布及其纤维联系的研究

应用免疫细胞化学ABC法对降钙素基因相关肽（CGRP）在大鼠纹状体边缘区内的分布以及与杏仁核、终纹床核等边缘系统结构之间的联系进行了研究。结果发现：（1）CGRP免疫阳性纤维在纹状体内存在于纹状体的中部和尾侧,位于尾壳核和苍白球之间,即相当于纹状体边缘区的部位,形成一条明显的背腹方向走行的带状。CGRP免疫阳性纤维分布越靠纹状体尾,则纤维越密集,且阳性带越宽;（2）在纹状体的最尾侧,除边缘区外,尾壳核的外侧缘也出现一条致密的阳性纤维带,与边缘区走向一致。并与边缘区的CGRP阳性纤维带之间存在较多的横向联系纤维;（3）纹状体边缘区的CGRP阳性纤维向背侧通过终纹与吻侧的终纹床核联系,向腹侧与杏仁核的CGRP阳性纤维相连,向尾侧和中脑黑质外侧部及其背外侧区的CGRP阳性胞体相连;（4）边缘区的CGRP阳性纤维主要与杏仁中央核相联系,少量与杏仁内侧核相联系;尾壳核外侧缘的CGRP阳性纤维也主要与杏仁中央核相联系。结果提示：CGRP阳性纤维在纹状体边缘区、杏仁核、终纹床核以及黑质背外侧区之间形成了一个相互联系的神经网络,纹状体边缘区与边缘系统之间存在密切的纤维联系。     

Effects of kainic acid that damages the marginal division of rat striatum on hippocampal long-term potentiation]

OBJECTIVE: To investigate the relationship between the marginal division (MrD) of the striatum and other brain regions associated with learning and memory. METHODS: Long-term potentiation (LTP) was induced by high-frequency stimulation of the perforant path-dentate gyrus, and changes in hippocampal LTP after destruction of the marginal division with kainic acid were observed. RESULTS: High-frequency stimulation of the perforant path produced significant increases in the peak amplitudes of the population spike (PS) in normal rats and those receiving saline treatment. In rats with damaged MrD, the increase in PS and the excitatory postsynaptic potential were less obvious compared with normal or saline-treated rats, indicating that the LTP of the hippocampus was attenuated by damage of the MrD. CONCLUSION: Damage of the MrD impacts the LTP formation in the hippocampus.     

边缘区损伤与认知功能下降关系的临床分析（附20例报告）

目的 探讨脑边缘区损伤与认知功能下降的关系。方法 搜集20例因各种原因造成脑边缘区损伤在我院住院的病例。男14例，女6例；全部病例均行常规MRI检查，对每病例进行认知功能测定，并与MRI表现对比分析；同时，还与10例老年性痴呆患者进行MRI改变及认知功能下降程度的对比研究。结果 (1)边缘区损伤的原因多以缺血性损伤为主，MRI表现为长T1长T2异常信号灶，而对照组主要表现为颞叶、海马及大脑皮层的萎缩；(2)20例患者的MMSE评分介于13-25分之间，平均19．7分，以记忆力及计算力下降为主；对照组的MMSE评分为6-15分，平均11分，定向力、记忆力、注意力和计算力、回忆力及语言能力的评分全面下降；(3)单纯边缘区损伤组的认知障碍程度与边缘区合并了豆状核其它部位损伤组无明显差异。结论 边缘区是人脑与学习及记忆功能相关的一个新区，脑边缘区的损伤可引起认知功能的下降。     

大鼠孤束核内含NT神经元的超微结构观察

用免疫电镜法对大鼠孤束核内侧亚核内NT-LI神经元的超微结构进行了观察。NT-LI产物可见于核周体、树突、轴突及终末内。标记轴突与树突构成轴-树突触最多见,轴-轴和轴-体突触少见。可见一些复合型突触和轴-树型自调节突触。此外一些NT-LI树突紧邻毛细血管。结果提示:(1)NT在孤束核调节心血管内脏活动中可能起着重要作用。(2)孤束核内NT神经元与血管之间可能存在神经-血管回路。     

Double Labeling Immulloelectron Microscopic Study on the Synaptic Connections between Glutamic Acid Neurons and GABA Neurons in the Hippocampus of Rats

The pathogenesis of epilepsy is a very complicated process, In which neurotransmltters play important roles. The hippocamplls is a frequently attacked site and an ideal model tissue for epilepsy' l]. In general, the seizure results from the imbalance of excitation and inhibition, i. e., increased effect of excltatory neurotransmltters ordecreased effect of inhlbitory neurotransrnlttersL =' ']. However, there was no nlorphologlcal, eel)eclally at the ultrastructural level, evidenceic identify …     

P物质和受体在纹状体边缘区内的分布及其与学习记忆功能的关系

目的 研究纹状体边缘区内的P物质和受体的分布特点及其与学习记忆功能的关系。方法 用免疫组化。原位杂交方法研究纹状体边缘区内P物质及其受体的分布特点，再用受体基因封闭方法结合迷宫行为试验研究P物质受体与边缘区学习记忆功能的关系。结果 纹状体边缘区内有大量的P）物质免疫阳性纤维及受体蛋白和NK1mRNA的分布，封闭纹状体边缘区内的P物质受体基因后，大鼠的学习记忆能力显著下降。结论 纹状体边缘区内的P物质和受体对纹状体边缘区的学习记忆功能有重要作用。推测这种作用是P物质通过其受体NK1调节边缘区中的5-HT等神经递质来实现的。     

Expression of c-fos and c-jun proteins in the marginal division of the rat striatum during learning and memory training

Background A new brain region, the marginal division (MrD) , was discovered at the caudal margin of the neostriatum. The MrD was shown to be involved in learning and memory in the rat. The aim of this study was to investigate the expression of the immediate-early genes c-fos and c-jun in the MrD of the striatum during learning and memory processes in the rat, immunocytochemical and Western blot methods were used to examine Y-maze trained rats.Methods The rats were divided into three groups, namely the training, pseudotraining, and control groups. After Y-maze training, the expression of the immediate-early genes c-fos and c-jun in the MrD of the rats was investigated using immunocytochemical and Western blot methods.Results After one hour of Y-maze training, the expression of c-jun and c-fos proteins was significantly enhanced in the MrD; the c-jun protein, in particular, was more intensely expressed in this region than in other parts of the striatum. The expression of these two proteins in the training group was significantly higher than in the pseudotraining and control groups. In addition, positive expression was also found in the hippocampus,cingulum cortex, thalamus, and in other areas. Western blot disclosed two immunoreactive bands for the anti-c-fos antibody (47kD and 54kD) and two immunoreactive bands for the anti-c-jun antibody (39kD and 54kD). Conclusions These results indicate that the immediate-early genes c-fos and c-jun participate in signal transduction during the learning and memory processes associated with Y-maze training in rats.     

Double labeling immunoelectron microscopic study on the synaptic connections between glutamic acid neurons and GABA neurons in the hippocampus of rats

Summary In order to explore the roles of different neurotransmitters in epileptic pathogenesis, the synaptic connections between glutamic acid (Glu) neurons and GABA neurons in normal rat hippocampus were studied by pre-embedding double labeling immunoelectron microscopy. The GABA immunoreaction was first demonstrated by chromogen DAB, then the Glu immunoreaction was demonstrated by molybdic acid-TMB method. After being stabilized by DAB-cobalt chloride, the sections were processed for electron microscopic embedding. Under electron microscope, there were many Glu immunoreaction-positive neurons in the pyramidal layer of hippocampal CA₁ area and some GABA immunoreaction-positive neurons with pyramidal or polygonal perikarya in the pyramidal, polymorphic and radiant layer of CA₁ area. There were also symmetric dendro-axonic synapses formed by GABA-positive dendrites and Glu-positive axons in the polymorphic layer and symmetric axo-dendritic synapses formed by GABA-positive axons and Glu-positive dendrites in the radiant layer. In addition, there were symmetric autoregulatory axo-dendritic synapses between Glu-positive axons and dendrites and autoregulatory axo-axonic synapses (both symmetric and asymmetric) between GABA-positive axons. Above mentioned results, for the first time, showed that there were complex synaptic regulatory relationships between excitatory Glu neurons and inhibitory GABA neurons in the hippocampal CA₁ area, thereby, providing ultrastructural evidence for different neurotransmitters participating in epileptic pathogenesis. This project was supported by a grant from the National Nature Scientific Foundation of China (No. 39330210).     

N-甲基-D-门冬氨酸2B受体mRNA在纹状体边缘区的表达

目的 通过研究N-甲基-D-门冬氨酸（N-methyl-D-asparate, NMDA）2B受体是否在纹状体边缘区表达,从而在基因分子方面确定边缘区在学习记忆过程中的作用。方法 用地高辛标记多相探针方法,原位检测大鼠纹状体边缘区内NMDA 2B受体表达。结果 原位杂交结果发现NMDA 2B受体mRNA阳性信号在纹状体内分布不均匀,主要见于尾壳核,在尾壳核和苍白球间的边缘区部位可见中等大小梭形神经元,呈密集的带状分布,而苍白球只有少量的阳性胞体。结论 大鼠纹状体边缘区可以合成NMDA 2B受体,推测边缘区的学习记忆功能与NMDA受体有关。     

学习记忆过程中即刻早期基因c—fos、c—jun在纹状体边缘区的表达

OBJECTIVE: To study the expression of immediate-early genes c-fos and c-jun in the marginal division (MrD) of rat striatum during learning and memory. METHODS: After Y-maze training in rats, the expression of immediate-early genes c-fos and c-jun in the MrD was investigated immunocytochemically. RESULTS: After 1 h of Y- maze training, the expression of c-Fos and c-Jun proteins was significantly enhanced in the MrD, where c-Jun protein in particular was more intensely expressed than in other parts of the striatum. The training group showed significantly higher expressions of the 2 proteins than pseudotraining group (P<0.01). In addition, positive expression was also observed in the hippocampus, cingulum cortex and other parts of the brain. CONCLUSION: Immediate-early genes c-fos and c-jun in the MrD participate in the signal transduction during learning and memory processes in the courses of Y-maze training of the rats.     

大鼠纹状体边缘区与海马学习记忆功能的行为学比较研究

目的 探讨MrD与海马这两个不同脑区在大脑学习记忆功能上的区别和作用地位。方法 在Y迷宫训练大鼠后即刻或24h后化学损毁大鼠双侧MrD或切断双侧穹窿海马伞(fornix/fimbria，FF)，训练后6d再观察化学损毁双侧MrD组、MrD对照组、切断双侧FF组和FF对照组大鼠在Y迷宫中学习记忆的行为表现；或在化学损毁大鼠双侧MrD或切断双侧FF下后7d，在Morris水迷宫中检测上述各组的学习记忆能力。结果 在Y迷宫测试的正确反应次数方面，训练后即刻或24h后损毁双侧MrD组与MrD对照组比较均明显减少；训练后即刻切断双侧FF组与FF对照组比较也明显减少，但训练24h后切断双侧FF组与FF对照组比较则无显著意义的差别。在Morris水迷宫试验中，损毁双侧MrD组和切断双侧FF组与各自的对照组比较，平均逃避潜伏期延长，穿环次数减少，但两者之间则无显著意义的差别。结论 MrD与海马均与大鼠的空间学习记忆功能有密切关系；但在Y迷宫逃避性学习方面，海马仅参与陈述性记忆的早期阶段，而MrD则与早、晚两个阶段均有关。提示MrD和海马在学习记忆功能方面可能不同，MrD可能涉及更复杂的记忆过程。     

人脑纹状体边缘区参与听觉数字工作记忆的功能磁共振研究

目的本实验拟通过正常人的功能磁共振研究,检测人脑纹状体边缘区是否参与了听觉数字工作记忆的过程。方法选取13名健康志愿者分别进行听觉数字工作记忆和听觉非记忆任务作业,同时进行功能磁共振检查,检测脑区在不同任务下的激活情况。结果11名受试者通过了数字工作记忆任务作业。功能磁共振结果显示受试者在进行听觉数字工作记忆时具有左侧优势的双侧前额叶皮层和左侧纹状体边缘区均有激活,出现高信号区,其他脑区激活不明显。而在进行听觉非记忆任务作业时,受试者的前额叶和边缘区均无明显激活。结论左侧纹状体边缘区与前额叶一起参与了人脑的听觉数字工作记忆过程,边缘区可能是一个联系着其他学习记忆相关脑区的皮层下中枢。     

人脑纹状体边缘区参与听觉数字工作记忆的功能磁共振研究

目的：本实验拟通过正常人的功能磁共振研究，检测人脑纹状体边缘区是否参与了听觉数字工作记忆的过程。方法：选取13名健康志愿者分别进行听觉数字工作记忆和听觉非记忆任务作业，同时进行功能磁共振检查，检测脑区在不同任务下的激活情况。结果：11名受试者通过了数字工作记忆任务作业。功能磁共振结果显示受试者在进行听觉数字工作记忆时具有左侧优势的双侧前额叶皮层和左侧纹状体边缘区均有激活，出现高信号区，其他脑区激活不明显。而在进行听觉非记忆任务作业时，受试者的前额叶和边缘区均无明显激活。结论：左侧纹状体边缘区与前额叶一起参与了人脑的听觉数字工作记忆过程，边缘区可能是一个联系着其他学习记忆相关脑区的皮层下中枢。     

帕金森病模型大鼠纹状体肾上腺髓质移植后突触结构的观察

目的 :对移植到帕金森病模型大鼠纹状体内的嗜铬细胞与脑细胞之间形成的突触结构进行观察。方法 :实验用Wistar大鼠 4 0只 ,注射 6羟多巴胺 ( 6 -OHDA)破坏大鼠一侧黑质纹状体系统 ,制成实验性帕金森病 (PD)动物模型。将肾上腺髓质植入PD模型大鼠纹状体内 ,移植后定期检测大鼠阿朴吗啡诱发旋转行为 ,并用电镜观察嗜铬细胞与脑细胞之间形成的突触结构。结果 :移植组大鼠的阿朴吗啡诱发旋转行为明显改善 (P <0 0 5)。电镜观察发现嗜铬细胞与脑细胞之间形成突触结构 ,以嗜铬细胞为突触前膜的占 72 88% ;以嗜铬细胞为突触后膜的占 2 7 12 %。结论 :移植肾上腺髓质后 ,模型大鼠阿朴吗啡诱发旋转行为明显改善 ,嗜铬细胞与宿主脑细胞之间形成突触联系 ,并以嗜铬细胞为突触前膜的为多。