大鼠脑脊髓不同部位室管膜上皮的超微结构特征

目的：研究大鼠脑和脊髓不同部位室管膜上皮超微结构的区域性差异,并探讨其相应的功能。方法：应用透射电子显微镜法。结果：室管膜上皮衬于脑室、中脑水管和脊髓中央管的内表面,不同部位可见单层扁平、立方或假复层柱状各型上皮。细胞游离缘均具有纤毛、微绒毛及分泌泡,但其形态数量因部位而不同。结论：室管膜是脑脊髓腔面具有复杂功能的一层衬里,在脑脊液的跨越质膜转运及参与驱动脑脊液循环过程中具有重要作用。     

家兔前髓帆的解剖和扫描电镜观察

本研究通过20只家兔前髓帆的解剖,发现家兔与其他动物明显不同,可分为下丘隐窝膜性后壁部、第四脑室顶前部和二者之间的移行部。通过10只动物前髓帆室管膜面的扫描电镜观察,见该部室管膜面除有密集的微绒毛和纤毛外,在下丘隐窝膜性后壁部和移行部,还有典型的球泡样分泌颗粒和室管膜上细胞。微绒毛密集而不规则如毡状。在微绒毛之间,纤毛呈束状分布,弯曲倒伏且方向一致,部分区域形成旋涡状。大部分纤毛干部粗细均匀,个别呈串珠状,纤毛顶端尖细,偶可见球形小泡。在纤毛束之间,有球泡样分泌颗粒,大小不等,最大者直径为10μm,大部分颗粒表面粗糙不平,个别较光滑。室管膜上细胞位于纤毛束之间,有梭形、     

第四脑室外侧隐窝室管膜与哺乳关系的形态学观察

目的观察哺乳期雌性小鼠第四脑室外侧隐窝室管膜形态的变化与哺乳之间的关系.方法HE染色和扫描电镜法.结果光镜下对照组外侧隐窝室管膜细胞单层稀疏排列,哺乳早、中期外侧隐窝室管膜细胞密集,常呈双层或多层排列,在室管膜细胞增厚区上可见均质的絮状物,以哺乳中期最明显,此改变与对照组比较具有显著的差异（P〈0.05）.扫描电镜下对照组外侧隐窝处纤毛稠密,呈簇状分布;哺乳早期纤毛黏连成束,纤毛肿胀增粗,室管膜表面可见到密集的、大小不一的分泌囊泡;哺乳中期分泌囊泡比早期小,囊泡在室管膜表面黏连在一起,成层分布;哺乳末期室管膜细胞的纤毛和微绒毛与对照组相似.结论小鼠第四脑室外侧隐窝室管膜细胞有旺盛的分泌现象,这种改变与哺乳周期密切相关.     

ZnT7及游离锌离子在小鼠室管膜和脉络丛细胞的分布

目的 研究锌转运体7（ZnT7）和游离锌离子在小鼠脊髓室管膜和脉络丛上皮细胞中的分布.方法 应用ZnSe金属自显影技术（AMG）检测硒酸钠注射1.5h后小鼠脊髓室管膜细胞及脑室脉络丛上皮细胞的游离锌离子;应用免疫组织化学SABC法检测小鼠脊髓室管膜细胞及脑室脉络丛上皮细胞中ZnT7的表达.结果 光镜下观察AMG染色的切片,小鼠脊髓室管膜细胞及脑室脉络丛上皮细胞中均有游离锌离子的分布;免疫组织化学结果表明,脊髓室管膜细胞及脉络丛上皮细胞中均有ZnT7的表达,且与游离锌离子分布区域基本一致.结论 锌离子可能在脊髓室管膜细胞及脉络丛上皮细胞内发挥重要作用,脊髓室管膜细胞及脉络丛上皮细胞可能在脑脊液锌转运过程中发挥重要的作用.     

人胎儿脑室系统接触脑脊液神经元的扫描电镜观察

用扫描电镜较全面地观察了人胎儿脑室系统－侧脑室、第三脑室和第四脑室壁的超微结构。结果发现人和某些动物一样，几个脑室室管膜表面都覆盖着大量的纤毛和微绒毛。纤 的分布在区域上有一定的差别。并证实了３个脑室内存在着接触脑脊液神经元的胞体、树突和轴突该神经元的胞体为梭形或球形，可见到一个或两个以上的突起。室管膜上神经纤维发自神经细胞或自室腔外穿入而来。另外，在室管膜下还观察到了神经胶质样细胞和类组织细胞。     

猫、兔、鼠侧脑室脉络丛的扫描电镜观察

本文报道用扫描电镜观察猫、兔和大白鼠侧脑室脉络丛的微细结构。3种动物侧脑室脉络丛表面均可见密集的微绒毛、散在的纤毛簇、单个的纤毛、球样突起和花样结构。在高倍镜下,微绒毛又可分为两型,即尖细的指样绒毛和末端膨大成泡样的微绒毛。并发现有呈花样密集排列的微绒毛簇。同时在3种动物的侧脑室脉络丛表面均可见kolmer细胞,根据突起的多少可将此类细胞分成为单极、双极,多极、无伪足样突起四型。猫的侧脑室脉络丛的球样突起和大白鼠的纤毛簇较多。     

血管性痴呆小鼠第三脑室室管膜扫描电镜特征观察

目的:观察血管性痴呆(VD)小鼠第三脑室正中隆起室管膜表面扫描电镜特征变化并探讨其意义.方法:采用双侧颈总动脉线结、反复缺血-再灌注法,制作小鼠VD动物模型,并设假手术组作为对照.应用扫描电镜对两组小鼠上述区域进行观察.结果:(1)假手术组:室管膜上皮细胞表面可见较多的纤毛和大量的微绒毛.分泌颗粒丰富,呈圆球形.室管膜上神经元样细胞较多,胞体饱满,呈梭形或锥体形,突起较多.(2)VD模型组:纤毛和微绒毛均明显减少,且室管膜细胞表面凹凸不平.室管膜细胞分泌颗粒明显减少,且形态各异,有皱缩现象.室管膜上神经元样细胞数量减少,胞体不饱满,树突减少.结论:VD小鼠正中隆起室管膜细胞和室管膜上神经元样细胞存在着超微结构的损伤;本研究发现的上述改变是VD发生的重要病理学改变之一.     

大白鼠脊髓中央管室管膜的超微结构——透射电镜和扫描电镜观察

本文通过对12只大白鼠脊髓中央管室管膜的透射电镜和扫描电镜观察表明:室管膜主要由室管膜细胞、伸张细胞和神经细胞组成。室管膜细胞为柱状或立方状,表面有纤毛和微绒毛,纤毛可与Reissner氏纤维接触。室管膜细胞之间借粘着小带和闭锁小带连接,胞浆内有丰富的线粒体及泡状结构。伸张细胞胞体细长,嵌于室管膜细胞之间,其顶部有微绒毛,但无纤毛;底部发出基突伸向灰质并靠近毛细血管;胞浆内有丰富的微丝和微管。本文报告大白鼠脊髓中央管的室管膜含有接触脑脊髓液的神经元,它们属于室管膜上或室管膜下型,为小型多极神经元,其树突和轴突均可见于中央管腔内,偶尔可见神经纤维的末梢与“触液”树突接触。上述资料提示室管膜可能具有感受、吸收、分泌和调整的功能,并为神经一体液调节的途径提供了新的形态学依据。     

兔眼睫状体超微结构特征

目的：研究兔眼睫状体的超微结构特征，并探讨其功能。方法：采用扫描和透射电子镜观察兔眼睫状体。结果：睫状突的游离面隆起呈袢状，上皮细胞游离面具有大量粗而短的微绒毛及散在的微顶浆分泌小泡。睫状环游离面也存在纵行的微嵴，该处上皮细胞表面的微绒毛及分泌泡数量均较睫状突上皮者少。睫状上皮由两层立方形上皮细胞构成。表层(即腔面)为非色素细胞，内含丰富的细胞器，面向后房的细胞质膜呈高度褶叠，并可见微绒毛及分泌泡；深层的色素上皮细胞面向睫状体基质面的细胞质膜也有褶叠。睫状体基质的疏松结缔组织内可见大量有窗孔的毛细血管。结论：睫状体与房水的选择性通透分泌有关，构成“血-房水屏障”。     

血管性痴呆小鼠第四脑室外侧隐窝与外侧孔之间室管膜扫描电镜特征

目的：观察血管性痴呆(VD)小鼠第四脑室外侧隐窝与外侧孔之间室管膜游离面扫描电镜特征。方法：采用双侧颈总动脉结扎、再灌注法，制作小鼠VD模型；用扫描电镜进行观察。结果：VD模型组小鼠病变较轻的部位纤毛和微绒毛明显减少，纤毛扭曲僵折、排列紊乱、倒伏在室管膜细胞表面；重者纤毛枯缩、粘连成团，微绒毛消失。室管膜细胞分泌颗粒明显增多，成堆分布。室管膜上神经元样细胞数目减少，胞体扁平、皱缩不饱满，树突减少。巨噬细胞样细胞胞体变小，表面突起减少。结论：VD小鼠上述区域室管膜细胞和室管膜上结构存在着超微结构的损伤，提示以上形态学的改变是VD发生的重要病理学基础之一。     

The choroid plexus of the mature and aging rat: the choroidal epithelium.

The choroid plexus of mature and old rats has been examined by both scanning and transmission electron microscopy. It has been shown that the macrophages lying upon the ventricular surface of the choroid plexus have a close association with burr-like protrusions that extend from the apical surfaces of the choroidal epithelial cells. These protrusions have a dark cytoplasm filled with vesicles and tubules, and projecting from them are thin, shrunken microvilli. It is suggested that these protrusions are phagocytosed by the macrophages and that they are the source of some of the inclusions which become increasingly common within the cytoplasm of macrophages in older rats. The lateral surfaces of the choroidal epithelial cells have also been examined in the scanning electron microscope after exposure of the surfaces by dissection. In such preparations it is apparent that the elaborate interdigitations between adjacent cells are effected by irregular and vertically arranged folds confined to the basal portions of the lateral cell surfaces. Lastly, it has been shown that at the junction between the choroid plexus and the ependyma in the lateral ventricle, there are two modes of transition between the choroidal and ependymal epithelia. In one, typical choroidal and ependymal epithelial cells lie next to each other to produce a distinct and continuous bondary. In the other mode the boundary is also continuous, but there are modified ependymal cells present. These modified cells have short, relatively sparsely distributed microvilli and not more than one or two cilia.     

The choroid plexus of the mature and aging rat: The choroidal epithelium

The choroid plexus of mature and old rats has been examined by both scanning and transmission electron microscopy. It has been shown that the macrophages lying upon the ventricular surface of the choroid plexus have a close association with burr-like protrusions that extend from the apical surfaces of the choroidal epithelial cells. These protrusions have a dark cytoplasm filled with vesicles and tubules, and projecting from them are thin, shrunken microvilli. It is suggested that these protrusions are phagocytosed by the macrophages and that they are the source of some of the inclusions which become increasingly common within the cytoplasm of macrophages in older rats. The lateral surfaces of the choroidal epithelial cells have also been examined in the scanning electron microscope after exposure of the surfaces by dissection. In such preparations it is apparent that the elaborate interdigitations between adjacent cells are effected by irregular and vertically arranged folds confined to the basal portions of the lateral cell surfaces. Lastly, it has been shown that at the junction between the choroid plexus and the ependyma in the lateral ventricle, there are two modes of transition between the choroidal and ependymal epithelia. In one, typical choroidal and ependymal epithelial cells lie next to each other to produce a distinct and continuous boundary. In the other mode the boundary is also continuous, but there are modified ependymal cells present. These modified cells have short, relatively sparsely distributed microvilli and not more than one or two cilia.     

The surface ultrastructure of the habenular complex of the rat

Summary The surface features of the ependymal lining of the habenular complex in rats, aged between three weeks and nine months, were studied by means of scanning and transmission electron microscopy.The ependyma of the medial habenular nucleus is heavily ciliated, the cilia obscuring underlying substructure in SEM — preparations. On the habenular commissure most cilia are arranged in tufts. Cilia are provided with segmental indentations and occasional apical thickenings. Vesicular protrusions of the ependymal cytoplasm into the ventricular lumen and the frequent occurrence of homogeneous supraependymal globules were interpreted as signs of ependymosecretory activity of nucl. hab. med. Supraependymal cells are most numerous on the anterior and superior surface of the habenular commissure. Cells presenting features identical to Kolmer (epiplexus) cells were identified on the ventricular surface of nucl. hab. med. in one specimen showing degenerative changes of undetermined aetiology in the habenular nuclei. It is therefore suggested that such cells need not necessarily be restricted to the choroid plexus.Supraependymal unmyelinated axons are particularly numerous on both nucl. hab. med. and commiss. hab. They make desmosome contacts (maculae adherentes) with the ependymal plasmalemma. Contacts presenting all features of typical synapses were not encountered. The vesicle population of the axonal profiles mainly comprises 35–50 nm translucent round vesicles besides small numbers of 60–100 nm dense-cored vesicles and large pleiomorphic vesicles. Most probably the axons belong to the well-established dense population of serotonergic axons in the dorsal part of the third ventricle.     

A comparative ultrastructural study of the choroid plexuses of the immature pig

The fine structure of the choroid plexus of the immature pig consists of an epithelial layer of cells contiguous with a subepithelial region containing fibrillar elements. The apical surface is extended as numerous digitiform microvilli. At irregular intervals, apical tufts of cilia occur that contain 10–14 cilia with a typical 9+2 subfibrillar arrangement. The cytoplasm is composed of randomly distributed smooth tubular endoplasmic reticulum, apically concentrated cisternae of rough endoplasmic reticulum, Golgi areas, glycogen and numerous mitochondria. Lateral cell membranes are typically tortuous, interdigitating and possess an apical tight junction. Various vesicles are found including pinocytotic vesicles, lipoid inclusions and lysosomes. A comparative ultrastructural study of the choroid plexuses from the lateral, third and fourth ventricles failed to demonstrate significant differences between these structures of different embryological origin.     

Third ventricle suprachoroidal cells

Using transmission electron microscopy two types of cells on the choroid plexus of the third ventricle of the frog Rana esculenta have been located. They lie on the microvilli and cilia of the choroid epithelium. Their free surface is in contact with the cerebrospinal fluid. One type, Kolmer-like, has large, dense bodies in its cytoplasm. The cytoplasm of the other type is completely filled by large, ovoidal structures which have a limiting membrane and a polymorphic filamentous content. Their functional significance is unknown.     

The ependyma and subependymal layer of the young rat: A new contribution with freeze-fracture

The subependymal layer underlying the external wall of the lateral ventricle has been studied with freeze-fracture in 3-week-old rats. Membrane specializations corresponding to gap junction and attachment plates were found on ependymal cells, as well as the characteristic features of cilia and microvilli. Hexagonal arrays of particles previously found in the membrane of astrocytes were also present in ependyma. The membranes of subependymal cells were characterized by a paucity of intramembranous particles, when compared to ependymal and other mature glial cells. Specialized regions corresponding to areas of close membrane apposition seen on the sections were tentatively identified as clustering of particles on the protoplasmic face, corresponding with a cobbly texture on the exoplasmic face. Their possible significance, if they are not artifactual, is discussed.The analysis of replicas obtained from freeze-fractured material provides an additional tool for the study of cell differentiation and maturation, in our case gliogenesis. The comparison of membrane characteristics of neuroepithelial cells—precursors of glia—with those of mature glial cells and intermediate forms may contribute to a better understanding of the mechanism of their maturation.