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Results for “EPENDYMA”

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At least 127 records · Page 7Linked to original sources

PubMed1986

[Involutional changes in the epithelium of the human cerebral vascular plexuses and ependyma based on scanning electron microscopy data].

Vascular plexi and cerebral ependyma were studied using scanning electron microscope for young, adult and elderly patients. In the elderly the formations mentioned had a number of structural peculiarities, thus, the majority of the epithelial cells in vascular plexus were lacking microvilli, the intercellular spaces were widened having deep grooves in them. Ependymal changes with age were characterized by the disappearance of villi in some groups of cells resulting in the appearance of large zones lacking superficial structures. Special characteristics of Biondi rings in the epithelium of vascular plexus of the elderly is given, as well as their relationship with other structural components. The age-related changes may lead to dysfunction of the hemato-encephalic barrier, that may be significant for the development of aging process.

Adolescent↗

PubMed1973

Parainfluenza virus Sendai infection in macrophages, ependyma, choroid plexus, vascular endothelium and respiratory tract of mice.

Immunofluorescent observations showed that after intranasal instillation of parainfluenza 1 (Sendai) virus into adult mice, infection is confined to the epithelial lining of the larger airways. Alveolar macrophages were not significantly involved, although they could be infected in vitro. In suckling mice, the infection was more acutely lethal and extended into the terminal air spaces. The intranasal susceptibility of adult mice was not reproducibly affected by treatment with potent antithymocyte serum, and there were no obvious pathogenic effects when heterologous antiserum was instilled intranasally into infected mice. Peritoneal macrophages were infected by intraperitoneally injected Sendai virus, with production of a highly viscous peritoneal exudate. Kupffer cells of the liver and endothelial cells in large veins and auricles were infected by intravenously injected virus. When injected intracerebrally, Sendai virus infected ependyma and choroid plexus epithelium. Adult mice often survived, in spite of ependymal destruction and changes in ventricular morphology. Astrocytes were activated but not infected.

Animals↗

PubMed1977

The ependyma of the ventriculus mesencephali in the rat.

The ventriculus mesencephali in the rat proceeds in the colliculi posterior region from the mesencephalic aqueduct in the dorsal direction. The ependymal lining is formed by flat, cuboid and cylindrical cells. The cylindrical cells, which occur in all parts of the ventriculus mesencephali, are the most numerous. The cuboid cells are localized mainly in the anterior part, the flat ones in the posterior part of the ventriculus mesencephali. Some cuboid and cylindrical cells have short basal processes. Among the ependymal cells, there are cells with long basal processes. The ependyma is at sites interrupted by flocks of ependymal cells. On the cell surface, there area cilia, microvilli and protoplasmic extrusions. The cell nuclei are spherical to oval. Supraependymally, there are homogeneous globules and intraventricular fibres. The histological variability of ependymal cells may point to the active participation of these cells in functional processes, even within such a small part of the ventricle system as the ventriculus mesencephali.

Animals↗

PubMedDate not supplied

[Incorporation of labeled sex hormones into the ependyma of the mediobasal hypothalamus of rats after intraperitoneal and intraventricular administration].

Histoautoradiography was used to demonstrate the ability of ependyma element of the 3d brain ventricle to incorporate the label after intraperitoneal and intraventricular injection of labeled sexual hormones. The least label incorporation after intraventricular injection of 3H-estradiol and 3H-testosterone and the maximal label incorporation after intraperitoneal injection of 3H-estradiol was demonstrated by beta 1-tanicytes. The basal processes of these cells terminate in the lateral part of the external zone of the median eminence where gonadoliberin is released to the portal capillaries of the hypophysis. The data obtained warrant an assumption that beta 1-tanicytes are responsible for the transport of sexual hormones primarily from the pericapillary space of the median eminence of the hypothalamus to the cerebrospinal fluid, thereby possibly taking part in the regulation of gonadoliberin release to the portal circulation of the hypophysis.

Animals↗

PubMed1984

A goniometrical study of mitochondrial cristae in rat heart muscle and ependyma of the choroid plexus after application 2,4-DNP in vivo.

We have sought a method capable of detecting small changes in mitochondrial cristae thickness under normal and experimental conditions. Using conventional electron microscopy and goniometry, we studied changes in mitochondria of rat heart muscle and of choroid plexus ependyma caused by treatment with 2,4-dinitrophenol (DNP). Calculation of real thickness was made using goniometric data (formula shown) and the results checked by the method of Casley-Smith and Davy. DNP produced a thickness increase of low statistical significance in choroid plexus ependymal mitochondrial cristae, but a decrease for heart muscle cristae. Although our findings do not resolve the problem of DNP-induced cristae changes, our modified goniometric method may be useful for other studies.

2,4-Dinitrophenol↗

PubMedDate not supplied

[Serotoninergic nerve fibers in the area of the substantia grisea and the ependyma of the cerebral aqueduct].

An electron microscopic study of the midbrain gravy with the help of degeneration caused by serotonin-like neurotoxin 5,7-dihydroxytryptamine has shown that serotonergic terminals are responsible for the innervation of dendrites, neuron bodies and ependyma cells of the cerebral aqueduct. The detection of light, dark with prevailing fine transparent or large granular synaptic vesicles as well as vacuole degeneration evidences of the existence of several sources of serotonergic innervation of the central gray substance. Continuous damage of perivascular astrocytes of the central gray by neurotoxin allows a suggestion to be made that they are also the object of serotonergic innervation. Immunomorphological data on the presence of serotoninergic neurons in the cerebral gray are confirmed.

5,7-Dihydroxytryptamine↗

PubMed1978

[Enzyme-histochemical behaviour of the tanycyte ependyma in the III. ventricle of the rat with thiamin deficiency (author's transl)].

The influence of experimental thiamine deficiency in rats on enzyme-histochemical parameters was carried out in the diencephalon. The degree of thiamine deficiency was measured by the activity coefficient of transketolase in the red blood cells. The alpha-ETK of thiamine deficient animals was 1,45 +/- 0,36, of equal-fed animals 1,04 +/- 0.04 and of control animals 1,08 +/- 0,04. We got the following results: Lactatdehydrogenase, acid phosphatases and thiamine pyrophosphatase did not indicate any difference in enzyme activity between the groups of control, equal-fed and thiamine deficient rats. However, the enzyme activity of nonspecific lysosome-bound esterases in the tanycyte ependyma and in the investigated nuclear regions (nucleus supraopticus, ncl. paraventricularis, ncl. ventromedialis) of the thiamine deficient animals was significantly decreased in comparison to control and equal-fed animals. The possibility of a restriction of the hypophyseal-adrenal-cortex-system is discussed, since the results are similar to those obtained with bilaterally adrenalectomized rats.

Acid Phosphatase↗

PubMed1985

Cytochemical localization of alkaline phosphatase in the ependyma of the rat medulla oblongata.

The ependyma of the IVth ventricle and the central canal of the rat medulla oblongata was investigated using the cytochemical technique for alkaline phosphatase (A1Pase) which revealed two types of ependymal cells in the medulla. The central canal type of the ependymal cell occupying the dorsal part of the central canal in the lower medulla exhibited intense A1Pase activity with light microscopy. These cells had reaction products in all plasma membranes, including the microvilli and the cilia at the luminal cell surface. Some cells appeared to be tanycytes, since the process reached the basement membrane of the parenchymal blood vessel. The ventricular type of ependymal cells, which form the floor of the IVth ventricle and the central canal, contained no reaction products in any structure of the luminal cell surface. The possible relationship between the cerebrospinal fluid and the nervous tissues through the ependymal linings is discussed.

Alkaline Phosphatase↗

PubMed1991

Transient expression of glial-fibrillary acidic protein (GFAP) in the ependyma of the regenerating spinal cord in adult newts.

In the homeotherms the presence of glial-fibrillary acidic protein (GFAP) and that of neurofilaments (NF) are used as specific molecular markers associated with intermediate filaments (IF) of the glial and neuronal elements respectively. On this basis a comparison was made between trends in the immunohistochemical response to these markers of the ependyma of a both a normal and a regenerating spinal cord in Triturus carnifex (Urodele Amphibian) adults, whose high spinal cord regenerative capacity is due to the ependymal epithelium cells. Under normal conditions, the ependymal cells are vimentin positive and negative for GFAP and the IF, respectively, while GFAP and NF positivity is found in the grey and white matter. During regeneration, by about day 10, vimentin positivity begins to decrease in the ependymal epithelium of the caudal stump and GFAP positive elements appear (subsequently, this was observed also in the ependymal epithelium of the cephalic stump). High GFAP positivity is found also in the newly formed apical ampullae. From day 20 to after day 30 these patterns develop both in the stumps and in the regenerating spinal cord. NF positivity is always restricted to the grey matter alone and to the axonal processes of the white matter. At about day 60, by which time the regenerative processes may be considered as having terminated and the spinal cord has virtually regained its original structure, the immunohistochemical features typical of the rest state are restored in the ependymal epithelium.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1964