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1.
J. Fleury B. Bellon J. F. Bernaudin C. Bouchaud M. C. Pinchon J. Kuhn J. Poirier 《Cell and tissue research》1984,238(1):177-182
Summary The localization of autologous antiperoxidase immunoglobulin G (IgG) was studied in the choroid plexus of Lewis rats immunized against horseradish peroxidase (HRP). This experiment was performed to study the permeability of the choroid plexus to intravascular IgG. It was shown that autologous IgG was present in the extravascular spaces. The transendothelial transfer appeared to occur mainly via the fenestrations and some interendothelial junctions. No transfer of IgG at the level of epithelial cells toward the cerebrospinal fluid was demonstrated. Interstitial spaces in contact with the connective-tissue cells of the choroid stroma were strongly labeled. The significance of these spaces remains hypothetical and raises the question of the fate of IgG from the interstitial space.This work has been partly supported by Crédits Recherche Universitaire, Paris-val de Marne. 相似文献
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Summary The pineal gland of the rat receives a rich nervous supply originating from the superior cervical ganglia. These fibers contain serotonin in addition to their neurotransmitter, noradrenaline. Cytochemical studies at the ultrastructural level have shown that both amines are present in the cores of the granular vesicles that are characteristic of these nerves. It is presently shown that the bilateral electrical stimulation of the preganglionic fibers innervating the ganglia markedly reduces the number of small sites reacting cytochemically for both noradrenaline and serotonin, these sites corresponding to the cores of small granular vesicles, while the larger reactive sites (cores of large vesicles) remain unaltered. The vesicles are retained in nerve terminals after stimulation, as observed in conventionally processed tissues, although with altered sizes and shapes. Apart from these cytochemical and structural changes, nerve stimulation also reduces the endogenous noradrenaline content of the pineal gland. Thus, both noradrenaline and serotonin are released from their storage sites in pineal sympathetic nerves after electrical stimulation in vivo. This suggests the possibility that several substances with presumed transmitter or modulatory functions might be simultaneously released by nerve impulses from a given nerve terminal. 相似文献
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Notch family molecules are transmembrane receptors that play various roles in contact-dependent cell–cell interactions in
a wide range of organs. In the brain, Notch2, but not the other members of Notch, is expressed in the choroid plexus at an
exceptionally high level. We immunohistochemically examined the cellular and subcellular localization of Notch2 protein in
the choroid plexus using confocal and electron microscopy. Unexpectedly, Notch2 was asymmetrically localized on the microvillous
surface of epithelial cells in the choroid plexus of both postnatal and adult rats. This localization pattern of Notch2 suggests
its novel and unknown role independent of contact with adjacent cells in the choroid plexus. In organotypic cultures of the
choroid plexus, the addition of anti-Notch2 antibody resulted in deformation of microvilli in epithelial cells, which suggests
a role of Notch2 in the maintenance of the microvillous structure in choroid plexus epithelial cells. 相似文献
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Summary Changes in the proximal stump of axons of divided rat sciatic nerves in the first 6 weeks after nerve section were studied, particularly in terms of alterations in the organelle content, axoplasmic ultrastructure and the diameter of the axons. A variety of organelle types were observed; quasi-membranous structures, multivesicular bodies, dense bodies, vesicles and tubules, dense cored vesicles and alveolate vesicles: their identification and the functional implications of their presence are discussed. Alterations in the ultrastructure of the stained elements of the axoplasm are described. Axons containing excess organelles were divided into classes, comprising myelinated axons; and supergiant, giant and conventional non-myelinated axons. Temporal changes in these axons are described. The characteristics of the various classes of apparently non-myelinated axon are considered in terms of their identification as regenerating terminal sprouts of myelinated axons, segmentally demyelinated axons, sections through abnormal nodes of Ranvier or merely non-myelinated axons. The structure of axons in regenerating units is described. Changes in the neurofilament microtubule ratio of small axons without excess organelles are demonstrated, and spiralling of neurofilaments in some myelinated and non-myelinated axons with normal axoplasmic ultrastructure is illustrated and discussed.Medical Research Council Scholar.McLoughlin Fellow.The authors have great pleasure in acknowledging the expert technical assistance of Mrs. Frances Burton. G. W. would also like to thank the British Medical Research Council, the Wellcome Trust and LEPRA (British Leprosy relief association) for financial assistance without which this work could not have been completed. 相似文献