树Qu脑β—内啡肽能神经元胞体和纤维分布的研究

本文用免疫组织化学方法和免疫电镜方法对１４只树Ｑｕβ－内啡肽能神经元胞体和纤维的分布及其在细胞器的定位进行了研究。结果表明,本文首次报道在Ｂｒｏｃａ斜角带观察到β－内啡肽免疫反应阳性神经元胞体,电镜观察到β－内啡肽免疫反应物质定位于大颗粒囊泡内的小颗粒上和粗面内质网上。下丘脑弓状核及其附近区域观察到β－内啡肽免疫反应阳性神经元胞体。在室周区、室旁核、第３脑室室管膜下层及室管膜上皮细胞间、内侧基底下     

树脑β－内啡肽能神经元胞体和纤维分布的研究

本文用免疫组织化学方法和免疫电镜方法对１４只树脑β－内啡肽能神经元胞体和纤维的分布及其在细胞器的定位进行了研究。结果表明，本文首次报道在Ｂｒｏｃａ斜角带观察到β－内啡肽免疫反应阳性神经元胞体，电镜观察到β－内啡肽免疫反应物质定位于大颗粒囊泡内的小颗粒上和粗面内质网上。下丘脑弓状核及其附近区域观察到β－内啡肽免疫反应阳性神经元胞体。在室周区、室旁核、第３脑室室管膜下层及室管膜上皮细胞间、内侧基底下丘脑及其外侧区、正中隆起内带和外带部可见到β－内啡肽免疫反应阳性纤维和串珠状的膨体。对β－内啡肽的释放途径及其调节因素作了探讨。     

在胚胎发育中第三脑室室管膜细胞表达乙酰胆碱转移酶

目的在研究胚胎14天（E14）大鼠端脑放射状胶质细胞与胆碱能前体细胞的关系时发现,第三脑室室管膜细胞和侧脑室脉络丛上皮细胞均表达胆碱能神经元标志性蛋白,即乙酰胆碱转移酶（Choline acetyltransferase,ChAT）。方法E14大鼠端脑冠状连续切片,采用免疫组织化学染色法,分别对放射状胶质细胞标志性蛋白,即波形蛋白（Vi men-tin）和乙酰胆碱转移酶进行免疫组织化学染色。结果E14大鼠端脑室管膜细胞呈单层衬于第三脑室,在背中侧的室管膜细胞由单层增殖为复层。上皮基底部与邻近组织分界不清,这些细胞的游离面胞质呈乙酰胆碱转移酶免疫反应阳性,在邻近的第三脑室周围局部形成乙酰胆碱转移酶阳性细胞群。在相邻切片的同一区域内复层室管膜细胞波形蛋白免疫反应阴性。结论第三脑室背中侧室管膜细胞作为神经干细胞分裂、增殖,产生胆碱能前体细胞,并向第三脑室周围组织迁移,形成基底前脑神经核团的Ch5,Ch6胆碱能神经细胞群。     

大鼠第三脑室室管膜NADPH-d阳性伸展细胞的形态与分布

应用 Ｎ Ａ Ｄ Ｐ Ｈｄ 组织化学方法研究了大鼠第三脑室视前区室管膜的伸展细胞⒚结果表明：１）第三脑室视前区室管膜存在 Ｎ Ａ Ｄ Ｐ Ｈｄ 阳性的伸展细胞,其基突伸向视前区并与神经元或毛细血管相接触;２） Ｎ Ａ Ｄ Ｐ Ｈｄ 阳性的伸展细胞在第三脑室侧壁常见、室底少见、室顶未发现其存在;３） Ｎ Ａ Ｄ Ｐ Ｈｄ 阳性的伸展细胞的形态与分布,在雌、雄大鼠间不存在明显的性别差异⒚尽管 Ｎ Ａ Ｄ Ｐ Ｈｄ 阳性的伸展细胞的生理功能不十分清楚,但本研究为伸展细胞作为脑脑脊液环路的一部分,介导下丘脑对脑脊液中化学变化的感受提供了形态学依据,并提示一氧化氮可能参与了这一过程⒚     

细胞大型内吞囊泡快速标记方法的改进和应用

为了研究细胞内大型内吞囊泡的快速动态变化,本文借鉴了诱导神经元轴突诱导转向的方法,通过脉冲压力从微电极释放诱导因子,在细胞周围形成稳定的浓度梯度,诱导细胞产生胞饮泡,并通过局部染料释放进行快速标记和洗脱。同时利用活细胞成像技术,对胞饮泡标记过程以及标记后胞饮泡动态变化进行实时记录。该方法大大缩短了标记和洗脱的时间,从而实现了对细胞囊泡的快速标记和同步观察记录,可用于胞饮泡、溶酶体等细胞囊泡的动态标记和观察,是研究细胞大型内吞囊泡动态变化的一种实用且高效的手段。     

囊泡膜谷氨酸转运体阳性纤维在大鼠三叉神经运动核内的分布

目的观察I、Ⅱ型囊泡膜谷氨酸转运体阳性纤维在大鼠三叉神经运动核内的分布。方法首先采用免疫荧光三重标记I、Ⅱ型囊泡膜谷氨酸转运体和神经元核蛋白以观察I、Ⅱ型囊泡膜谷氨酸转运体阳性纤维在大鼠三叉神经运动核内的分布;接着注射四甲基罗达明人下颌舌骨肌神经逆行标记三叉神经运动核开口神经元,再采用免疫荧光双重标记I型囊泡膜谷氨酸转运体和神经元核蛋白以观察I、Ⅱ型囊泡膜谷氨酸转运体阳性纤维在大鼠三叉神经运动核开口神经元区和闭口神经元区内的分布差异。结果I型囊泡膜谷氨酸转运体阳性纤维仅在三叉神经运动核背外侧部分布,而Ⅱ型囊泡膜谷氨酸转运体阳性纤维在整个三叉神经运动核内分布;开口神经元区未观察到I型囊泡膜谷氨酸转运体阳性终末。结论闭口神经元接受I、Ⅱ型囊泡膜谷氨酸转运体阳性纤维支配,开口神经元仅仅接受Ⅱ型囊泡膜谷氨酸转运体阳性纤维支配。     

成年鼠脑中神经干细胞的纯化

神经干细胞具有自我复制和多向分化的潜能 ,它可分化为成熟神经元和神经胶质细胞 ,人们希望利用神经干细胞的分化潜能治疗帕金森病等神经系统疾病 ,但首先必须分离纯化这些细胞。以往 ,人们从发育外周神经系统中纯化神经干细胞 ,而脑中干细胞纯化率从未超过 5 %。最近 ,ＲｏｄｎｅｙＬ .Ｒｉｅｔｚｅ等以 80 %的纯化率分离成年鼠脑干细胞并检测这些细胞的特性。他们发现 ,其中一种可在室管膜和脑室下腔区域找到的干细胞活性很强 ,在 ｑｕｅｒｋｏｐｆ变异鼠 (一种嗅觉神经元缺陷的鼠 )中 ,这种细胞选择性缺失 ,提示它可能是离体主要的功能性…     

神经元细胞器和囊泡运输

神经元是高度极化的细胞,典型的神经元由胞体、轴突及树突构成。神经元的胞体和神经末梢之间的物质和信息传递以及神经元之间的通讯都依赖于胞内的细胞器和囊泡运输。神经元中的运输系统对于神经元形态和功能的建成和维持以及突触的功能和可塑性至关重要。胞内运输的调控机制是细胞神经生物学领域的重大科学问题。该文重点总结了近年来关于神经元内细胞器和囊泡运输的研究进展,并对神经活性依赖的运输调控机制进行了初步探讨。此外,该文还简要介绍了神经元胞内运输与人类疾病之间的关系。     

囊泡转运复合物Retromer和SNX蛋白家族在发育和疾病中的作用

逆向囊泡转运复合物Retromer主要负责介导货物蛋白从内体向反式高尔基体或细胞表面逆向转运,是细胞内囊泡转运分选系统的重要成员.Retromer复合物主要含有两个亚复合体:货物选择复合体VPS26-VPS29-VPS35和膜结合复合体SNX-BAR.本文着重综述了Retromer复合物和SNX蛋白家族参与囊泡转运过程的分子机制以及它们在发育中对Wnt信号的调控作用;并讨论了Retromer复合物在细胞极性形成、细胞凋亡、神经元信号传递中的重要作用;以及该复合物与帕金森和阿尔茨海默病等退行性疾病之间的关系.     

中华大蟾蜍多种组织内5-羟色胺免疫染色细胞的分布

用过氧化物酶-抗过氧化物酶(PAP)法,对中华大蟾蜍消化道(冬眠期与非冬眠期),脑及其他组织的5-HT分布进行了研究。5-HT免疫染色细胞位于脑干中缝核区和间脑的第Ⅲ脑室腹侧的室管膜细胞区。阳性神经元呈圆形或卵圆形,细胞常有突起与其他阳性细胞突起相连,上述部位中还有一些阳性神经纤维。消化道的免疫染色细胞密度在胃幽门、胃体和胃贲门处最高,食道和十二指肠次之,大肠和小肠最低。非冬眠期蟾蜍消化道内免疫染色细胞密度明显高于冬眠期的(P<0.05)。阳性细胞位于粘膜上皮或腺上皮细胞间,细胞有一个或一个以上呈阳性反应的突起,有的突起伸入肠腔面或腺腔面,有的穿过基膜到达固有层,表明这些细胞兼有内、外分泌的功能。在甲状旁腺的主细胞间,肺呼吸性细支气管上皮和肺泡管上皮细胞间都有5-HT免疫染色细胞,细胞呈立方形、圆形、卵圆形或不规则形,常有几个细胞成簇分布。     

Supraependymal cells and fibers in the third ventricle of the domestic chicken. A scanning electron microscopic study

Supraependymal cells, fibers and what are presumed to be neuronal bulb-like projections were found in the third ventricle of the domestic chicken with a scanning electron microscope. At least two types of supraependymal cells were found: neuron-like cells and phagocyte-like cells. The former were predominantly seen in the area of the paraventricular organ and infundibular recess. The latter were abundant on the ventricular surface of the median eminence and subfornical organ. Bulb or club-like projections thought to be the dendritic terminals of CSF-contacting neurons were observed in the area of the paraventricular organ and infundibular recess. Similar structures were observed at the preoptic recess as well. The supraependymal neuronal components found in the domestic chicken differed from those of mammals in several respects: 1. the wall of the third ventricle was devoid of supraependymal fibrous plexus except for that of the paraventricular organ; 2. bulb-like projections were abundant in the area of the paraventricular organ; 3. supraependymal neuron-like cells were unipolar or bipolar in appearance. These data underline the dissimilarity of the CSF-contacting neuronal system of birds and mammals.     

A scanning electron microscopic survey of the brain ventricular system of the female armadillo

Summary The scanning electron microscope was used to survey the brain ventricular system of the female armadillo (Dasypus novemcinctus) with emphasis on the third ventricle. The walls of the lateral ventricles, aqueduct, and fourth ventricle are covered by long cilia. In the lateral ventricle, the cilia are arranged in groups; but in the aqueduct and fourth ventricle, they are evenly placed over the cellular surfaces. The ependymal cells of the third ventricle are densely ciliated except for the organum vasculosum and infundibular recess. The non-ciliated luminal surface of these areas has a pebblestone appearance punctuated by numerous microvilli and two types of supraependymal cells.Supported by Edward G. Schlieder Foundation GrantThe authors would like to thank Jacqueline Skaggs for her secretarial assistance and Garbis Kerimian for his photographic work     

The third ventricle of monkeys

Summary Surface features of the ependymal lining of the third ventricle in mature male and female monkeys have been investigated with scanning electron microscopy (SEM). Broad aspects of third ventricular morphology from three species of monkey are similar regardless of sex. The lateral walls are heavily ciliated whereas the ventral floor and most ventral parts of the lateral walls are not. Clumps of cilia on the lateral walls are so dense that underlying surface details are usually obscured. There is a transition zone between the ciliated lateral wall and nonciliated ventral floor. The floor and lower part of the lateral walls of the third ventricle exhibit a characteristic polygonal pattern upon which surface specializations such as microvilli, blebs and polymorphous membrane protrusions are superimposed. Ependyma of the choroid plexus of the third ventricle also display membrane specializations. Supraependymal cells are more visible in nonciliated regions.Supported by USPHS Grants RR-05432, GM-16598 and HD-10010 from the National Institutes of Health and GSRF 171 funds from the University of Washington Graduate School. Portions of this work have been reported previously in abstract form in Anat. Rec. 175, 294 (1973) (before the 86th annual session of the American Association of Anatomists, New York, N.Y., April, 1973)     

Scanning electron microscopic analysis of the linings of the fourth ventricle in the domestic fowl

Summary Surface features of the ependymal linings of the fourth ventricle in the fowl were analyzed employing the scanning electron microscope (SEM). On the floor of the median sulcus, each ependymal cell has a solitary cilium, whereas on both sides of the sulcus, cilia are so densely distributed that the details of the underlying cell surface are usually obscured. On the roof of the fourth ventricle, except for the surface of the ciliated groove where numerous cilia are present, the ependymal cells are polygonal in shape, and the center of each cell possesses an aggregate of ten to twenty cilia. Cell surfaces of the choroid tela are entirely covered with delicate microvilli and possess clumped cilia. The ependymal cell surfaces of the area postrema are dome-like in shape. Each ependymal cell has a solitary cilium and shows a smooth surface free of microvilli.This work was supported by a Scientific Research Grant, No. 144017, from the Ministry of Education of Japan to Professor M. Yasuda     

Intraventricular neuronal complex of the lamina terminalis of the mouse

An intraventricular neuronal complex has been identified with scanning and transmission electron microscopy at the base of the lamina terminalis of the mouse. The raspberry-shaped complex protrudes from a thickened bulge on the ependymal surface of the lamina terminalis or adjacent rostral floor of the third ventricle. Neurons and occasional ependymal cells cover the surface of the complex. Its core is made up of neurons, ependymal cells, and neuronal processes, which are usually compactly arranged. The core is continuous, through a breach in the ependymal layers, with the subependymal neuropil of the lamina terminalis. Within the core of the complex are large numbers of axodendritic synapses. Axonal varicosities and synaptic terminals are filled with vesicles and mitochondria. Synaptic endings have one of two populations of vesicles: exclusively clear, small, round or flattened vesicles. In view of the known structural and functional characteristics of the lamina terminalis, it is possible that the neuronal complex may participate in neurohormonal regulatory systems of the hypothalamus and hypophysis or in the network of circumventricular organs mediating angiotensin effects.     

The ventricular system in neuroendocrine mechanisms

Summary This investigation has utilized a correlative scanning-transmission electron microscopic technique in the analysis of the primate cerebral ventricular system. This approach has demonstrated a complex network of supraependymal cellular elements upon the walls of the third cerebral ventricle in direct contact with the ventricular lumen. Type I neuronal-like cells and type II histiocytic-like cells with potential phagocytic capabilities have been observed in large numbers throughout the third ventricle. Type I neuron-like cells are discussed in the context that they may represent a population of receptor-cells which serve to assess ambient changes in the composition of bioactive peptides in the cerebrospinal fluid and may serve as a supraependymal network that integrates the endocrine hypothalamus with other circumventricular organs which may also be sites of neuroendocrine transduction.Supported by USPHS Program Project Grant NS-11642Career Development Awardee GM K04 70001     

Scanning electron microscopy of the third ventricle of sheep

Summary Scanning electron microscopy of the third ventricle of sheep demonstrates areas of ciliated ependymal cells at the dorsal and middle third. The cilia of the dorsal portion of the ventricle have biconcave discs that are attached to each cilium by a slender stalk. The lower third and floor of the ventricular wall, as well as the pineal recess, are largely covered by ependymal cells that possess numerous microvilli with only a few isolated cilia scattered along cell surfaces. The infundibular recess is papillated with apical blebs of the ependymal cells that project into the lumen of the recess. Measurements of these surface elements indicate an average diameter of 0.28 for cilia, 0.10 for microvilli and 0.50 for the apical blebs of the infundibular recess. The functional significance of the regional differences in surface structures is discussed in relation to cerebrospinal fluid movement, ependymoabsorption and ependymosecretion.Supported by U.S.P.H.S. Grant NS 08171.Career Development Awardee KO4 GM 70001.     

The surface fine structure of the walls of cerebral ventricles and of choroid plexus in cat

Summary The surface of ependymal cells bordering the brain ventricles, and that of the epithelial cells of choroid plexuses of the cat have been investigated by means of the scanning electron microscope. The ventricle walls are entirely covered with very long and numerous cilia and no regional differences have been observed regarding their number and disposition. Among the ciliated cells dome-shaped structures are present, possibly containing nervous elements. The ependymal cells of the third ventricle floor are mainly non ciliated but the surface thereof shows numerous small microvilli. Numerous round formations are present among these cells, their nature being difficult to interpret. Also present on the floor are small cells of triangular shape with long and tortuous protrusions, tentatively identified as small neurons. The choroid plexuses have a typical sinuous structure of long tortuous villi rich in cavities and convolutions. Details of the epithelial cells covering the plexus and their surface organization are also reported.Part of these results were presented to the Septième Congrès International de Microscopie Electronique, Grenoble 1970.     

The neurohypophysis of the crested newt

Summary In the median eminence of the newt a medial region and two lateral regions are described.In cross section, the medial region appears to be made up of 1) an outer or glandular zone (Zone I) containing aldehyde-thionine-positive and negative nerve fibres and blood capillaries. Nerve fibres appear aligned in palisade array along the capillaries. 2) An inner zone (Zone II) made up of a) a layer of aldehyde-thionine-positive nerve fibres (fibrous layer) belonging to the preoptic hypophyseal tract and b) a layer of ependymal cells lining the infundibular lumen and reaching the blood vessels with their long processes.The lateral regions display a less pronounced stratification and aldehyde-thionine positive nerve fibres are nearly absent.A slender lamina (ependymal border) containing mainly aldehyde-thionine-positive nerve fibres and ependymal cells connects the median eminence to the pars nervosa.At the ultrastructural level, in the outer zone of the medial region at least 4 types of nerve fibres and nerve endings are identified:Type I nerve fibres containing granular vesicles of 700–1000 Å and clear vesicles (250–400 Å).Type II nerve fibres containing granular vesicles and polymorphous granules of 900–1300 Å and clear vesicles (250–400 Å).Type III nerve fibres containing dense granules of 1200–2000 Å and clear vesicles of 250–400 Å.Type IV nerve fibres containing only clear vesicles of 250–400 Å. In the inner zone too, all these nerve fiber types are found among ependymal cells, while the fibrous layer consists of nerve fibres containing granules of 1200–2000 Å in diameter.In the lateral regions Type I, Type II and Type IV nerve fibres and their respective perivascular terminals are found; axons containing dense granules (1200–2000 Å) are scanty. In these regions typical synapses between Type I nerve fibres and processes rich in microtubules are visible.The classification and functional significance of nerve fibres in the median eminence are still unsolved, but it may be assumed that nerve fibres of the medial region belong to both the preoptic hypophyseal and tubero hypophyseal tract, while the lateral regions are characterized by nerve fibres of the tubero hypophyseal tract. Peculiar specializations of the ependymal cells in the median eminence of the newt are also discussed.Work supported by a grant from the Consiglio Nazionale delle Ricerche.The authors are indebted to Mr. G. Gendusa and P. Balbi for technical assistance.     

Scanning electron microscopy of the wall of the third ventricle in the brain of Rana temporaria. Part IV.

Summary The surface specializations of the wall of the third cerebral ventricle of Rana temporaria were investigated with the scanning electron microscope. These specializations can be divided into three types: cilia, large bulbous protrusions, and microvillus-like protrusions.Most parts of the ventricular surface are densely ciliated. In contrast, other regions are either scantily ciliated or devoid of cilia. Four areas of the ventricular surface are studded with numerous large bulbous protrusions. These large protrusions can be divided into two types: One type consists of intraventricular end bulbs of dendrites of secretory neurons. The other type is represented by large cytoplasmic extensions of ependymal cells.In the third ventricle of Rana, microvillus-like surface specializations of ependymal cells are ubiquitous structures. Generally, filiform protrusions of varying length are the predominant type. The microvillus-like specializations are transient structures, the number of which varies according to different physiological states of the ependymal cells.This investigation was supported by a grant from the Belgian Nationaal Fonds voor Geneeskundig Wetenschappelijk Onderzoek