The Plexus Chorioideus in the Adult Goat: A Scanning Electron Microscope Study

Rajtová V. : The Plexus Chorioideus in the Adult Goat: A Scanning Electron Microscope Study. Acta Vet. Brno 2000, 69: 167–171. The surface of plexus chorioideus of the fourth, third and lateral ventricle and in the region of the foramen interventriculare of adult goats of both sexes was studied using scanning electron microscopy. It was found that the convex apical membranes on the whole surface of the plexus chorioideus are covered with microvilli or microvillus-like structures. The presence of cilia was not recorded. Abundant spherical protrusions occurred in the region of lateral cerebral ventricle, and were almost absent in the region of the foramen interventriculare. The epiplexal cells occurred in the fourth and lateral ventricle only sporadically; they could be seen in higher number in the third ventricle and in the region the foramen interventriculare. Some epiplexal cells had a large number of filiform processes; most of these macrophage-like cells had only 3-5 pseudopodia with “ruffled” membranes. No differences which would be connected with sex or season were found in the structure of the plexus chorioideus. Central nervous system, plexus chorioideus, cerebral ventricles, microvilli, secretory protrusions, epiplexal cells, adult goat The plexus chorioideus (PCH) is situated in the cerebral ventricles and produces the greater part of the cerebrospinal fluid. It is a part of pial blood vessels invaginated into the ventricular space, villi formly arranged and covered with one layer of predominantly cuboid epithelial cells. Their apical membranes have a characteristic structure, which is very similar to the apical membranes of ependymal cells of the cerebral ventricular system (presence of microvilli, spherical protrusions or macrophage-like cells). The PCH surface was studied by the scanning electron microscope in various species of mammals in their prenatal or postnatal life (in the rat – Chamberlain 1973; Hosoya and Fuji ta 1973; Peters 1974; Peters and Swan 1979, in the dog – Allen 1975; Persky 1980, in the cat – Clementi and Marini 1972, in the macaque – Coates 1977; Ling 1983, in humans – Scot t et al. 1972, 1974; O’Rahil ly and Müller 1990; Otani and Tanaka 1988). Some authors focused on the description of the structure of epiplexal (Kolmer’s) cells (EPC) or their classification and origin (Carpenter et al. 1970; Kitamura 1973; Sturrock 1978; Maxwell and McGadey 1988). There is no record on the plexus chorioideus in the adult goat in the literature. The aim of the work was to study the plexus chorioideus surface in adult goats by scanning electron microscope. Materials and Methods Twelve adult goats of both sexes (9 females and 3 males) were used. They were killed between spring and autumn. Immediately after exsanguination, the heads of animals were perfused through a. carotis communis with 0.2 mol/l phosphate buffer solution and prefixed with Karnovsky solution. The specimens of the plexus chorioideus from the fourth, third and lateral ventricles and from the region of the foramen interventriculare were postfixed in ACTA VET. BRNO 2000, 69: 167–171 Address for correspondence: Prof. MVDr. Viera Rajtová, DrSc. Department of Anatomy and Histology University of Veterinary Medicine Komenského 73, 041 81 Ko‰ice, Slovak Republic Phone: +421 95 6229 924 Fax: +421 95 6323 666 E-mail: anatomia@uvm.sk http://www.vfu. cz/acta-vet/actavet.htm 3 % glutaraldehyde in cacodylate buffer (temperature of all solutions was 4 0C, pH 7.4) and then processed by the method of Murakami et al. (1977). After dehydration in an increasing ethanol series, the specimens we dried by the critical point method, coated with gold in vacuum and studied by the Tesla BS 340 scanning electron