Scanning Electron Microscopy of Plexus Choroideus in Adult Sheep

Abstract

The outer morphology of the surface of the ependymal lining of the plexus choroideus was studied within the whole ventricular system of the brain in adult sheep using a scanning electron microscope. The more abundant occurrence of spherical secretory protrusions was found on the plexus choroideus (PCH) in the lateral cerebral ventricle. A frequent finding of the macrophagelike epiplexal cells was recorded on the PCH in the region of the lateral as well as the fourth ventricle. No differences were found in the structure of the PCH surface, which could be related to the sexual differentiation of the sheep. Our results are compared, above all, with those found in the adult goat and in the foetuses of both species of small ruminants. Central nervous system, plexus choroideus, cerebral ventricles, adult sheepLess attention has been paid to the study of the plexus choroideus as one of the structures of the ventricular system of the brain in different species of mammals using the scanning electron microscope than to the structure of the surface of the ependymal lining. In the prenatal but also in postnatal period, the surface of the PCH in laboratory rodents was observed by Yamadori (1972), Hosoya and Fujita (1973), Chamberlain (1974), Peters (1974), Mestres and Breipohl (1976), Peters and Swan (1979), in the dog (Allen 1975;Persky 1980), in the cat (Clementi and Marini 1972), in the rhesus macaque (Ling 1983), and in humans (Scott et al. 1972(Scott et al. , 1974Otani and Tanaka 1988, O'Rahilly andMüller 1990). In farm mammals the PCH was studied in the goat and sheep foetuses but also in the adult goat (R ajtová 1997, 2000). There is no record of the structure of the surface of epithelial cells that cover the PCH in adult sheep.The aim of the work was to describe the epithelial surface of the PCH in the lateral, third and fourth cerebral ventricles in adult sheep with the aid of a scanning electron microscope. Materials and MethodsTen healthy adult sheep (5 ewes and 5 rams) were used. The animals were killed in March and October by exsanguination following thiopental anaesthesia. Immediately after exsanguination, the heads of the animals were perfused through the a. carotis communis with 0.2 mol/l phosphate buffer solution and prefixed with Karnovsky solution. The specimens of the individual parts of the plexus choroideus were postfixed in 3% glutaraldehyde in 0.2 mol/l cacodylate buffer. The temperature of the solutions was 4 °C, pH 7.4. The specimens were processed by the method of Murakami et al. (1977), dehydrated, dried by the critical point method and coated with gold in vacuum. Then they were studied in the Tesla BS 340 scanning electron microscope with image analysis. ResultsThe plexus choroideus ventriculi lateralis forms low folds. The periphery of the ependymal cells is irregularly round, almost elongated. The apical membranes of most lining ependymal cells are convex, covered with thick, short, densely arranged microvillus-like structures. Among them on numerous sites are abundant, predominantly small and...

Microvasculature of the buffalo (Bubalus bubalis) choroid plexuses: Structural, histochemical, and immunocytochemical study

“…In general, SEM and TEM analyses of the CPs from buffalo brain showed morphological and structural features similar to those reported in other mammalian species (Adami et al, 2005;De Spiegelaere et al, 2008;Gomez and Potts, 1981;Miodonski et al, 1979;Peters and Swan, 1979;Rajtovà , 2002;Scala et al, 1994;Tamega et al, 2000;Webster, 1976). The blood microvasculature is the major component of the CPs responsible for the formation of the CSF.…”

“…The morphology, structure and function of mammalian CPs have been studied, but data regarding the CPs cellular elements, and the process that regulates the production of CSF are virtually nonexistent for domestic ruminants. The information in the literature consists of (1) a SEM study of sheep CPs (Rajtovà , 2002); (2) a microvascular description of the lateral ventricles in goat (Scala et al, 1994); (3) a scanning and transmission microscopy study of two heretofore unknown cellular types, i.e., elongated cells and cells with multiple protrusions, from the CPs of buffalo ; and (4) two immuno-histochemical studies in the CPs of buffalo Tafuri et al, 2009). As of yet there have been no morpho-structural studies of the blood vessels that comprise the CPs.…”

Electron Microscopic Study of the Porcine Choroid Plexus Epithelium

“…Cilia are present on the ependymal lining and on the CP epithelium of most mammalian species, except for adult goat and sheep in which the CP epithelium lacks cilia (Rajtova, 2000, 2002). When present, the number of cilia on the CP epithelium is small in comparison to those of the ependymal lining (Adami et al, 2005).…”

“…Although the ultrastructure of the CP has already been studied in a range of mammals (Rajtova, 2000, 2002; Adami et al, 2005), this has not been studied in the porcine CP. Nevertheless, the porcine CP is used for research on xenotransplantation in chronic disease models to study Huntington’s disease (Borlongan, 2004; Emerich, 2006).…”

Scanning Electron Microscopy of the Choroid Plexus of the Lateral Ventricle of the Horse

“…Studies investigating morphological aspects of the choroid plexuses of the cerebral ventricles have been performed on various animals, such as birds (Hilton, 1955), reptiles (Weiger and Lametschwandtner, 1988), sheep (Rajtová, 2002), dogs (Gomez and Potts, 1981), cats (Miodonski et al., 1979), rodents (Peters and Swan, 1979), and monkeys (Tamega et al., 2000).…”