Licht- und elektronenmikroskopische Untersuchungen des Saccus vasculosus und des Nervus und Tractus sacci vasculosi

Vígh, B.; Vigh-Teichmann, I.; Aros, B; Varjassy, P.

doi:10.1007/bf00316746

Cited by 20 publications

(25 citation statements)

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“…The existence of this saccofugal tract was first observed using silver staining in the trout [Dammerman, 1910] and confirmed in other teleosts by AChE histochemistry [Vigh et al, 1972]. Tract-tracing studies in trout revealed experimentally that this tract is only saccofugal and that it projects massively to the NSV [Yáñez et al, 1997].…”

Section: The Gabaergic System Of the Svmentioning

confidence: 99%

“…Histochemical studies of the SV in teleosts have revealed acetylcholinesterase activity (AChE) in CSF-c neurons [Vigh-Teichmann et al, 1970;Zimmermann and Altner, 1970;Jansen and West, 1971;Vigh et al, 1972]. Immunoreactivity to choline acetyltransferase, the acetylcholine-synthesizing enzyme, has been reported in these SV cells in sturgeon [Adrio et al, 2000], but not in trout or dogfish [Pérez et al, 2000;Anadón et al, 2000].…”

mentioning

confidence: 99%

“…In teleosts, the conspicuous saccofugal tract (SV tract; tractus sacci vasculosi) coursing to the posterior tubercle is AChE positive [Zimmermann and Altner, 1970;Vigh et al, 1972]. These saccofugal projections were experimentally investigated with tract-tracing methods and shown to contain GABA-, GAD-and NPY-immunoreactive fibers in trout [Yáñez et al, 1997].…”

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New Insights on Saccus vasculosus Evolution: A Developmental and Immunohistochemical Study in Elasmobranchs

et al. 2007

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The saccus vasculosus (SV) is a circumventricular organ of the hypothalamus of many jawed fishes whose functions have not yet been clarified. It is a vascularized neuroepithelium that consists of coronet cells, cerebrospinal fluid-contacting (CSF-c) neurons and supporting cells. To assess the organization, development and evolution of the SV, the expression of glial fibrillary acidic protein (GFAP) and the neuronal markers γ-aminobutyric acid (GABA), glutamic acid decarboxylase (GAD; the GABA synthesizing enzyme), neuropeptide Y (NPY), neurophysin II (NPH), tyrosine hydroxylase (TH; the rate-limiting catecholamine-synthesizing enzyme) and serotonin (5-HT), were investigated by immunohistochemistry in developing and adult sharks. Coronet cells showed GFAP immunoreactivity from embryos at stage 31 to adults, indicating a glial nature. GABAergic CSF-c neurons were evidenced just when the primordium of the SV becomes detectable (at stage 29). Double immunolabeling revealed colocalization of NPY and GAD in these cells. Some CSF-c cells showed TH immunoreactivity in postembryonic stages. Saccofugal GABAergic fibers formed a defined SV tract from the stage 30 and scattered neurosecretory (NPH-immunoreactive) and monoaminergic (5-HT- and TH-immunoreactive) saccopetal fibers were first detected at stages 31 and 32, respectively. The early differentiation of GABAergic neurons and the presence of a conspicuous GABAergic saccofugal system are shared by elasmobranch and teleosts (trout), suggesting that GABA plays a key function in the SV circuitry. Monoaminergic structures have not been reported in the SV of bony fishes, and were probably acquired secondarily in sharks. The existence of saccopetal monoaminergic and neurosecretory fibers reveals reciprocal connections between the SV and hypothalamic structures which have not been previously detected in teleosts.

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Section: The Gabaergic System Of the Svmentioning

confidence: 99%

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confidence: 99%

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confidence: 99%

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New Insights on Saccus vasculosus Evolution: A Developmental and Immunohistochemical Study in Elasmobranchs

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“…According to this author, the coronet cells (named in reference to their apical crown of globule-tipped cilia) give rise to saccofugal projections to the posterior tubercle and possibly to the thalamus. Electron-microscopic studies, however, have demonstrated a third cell type in the SV, namely CSFcontacting (pseudocoronet) cells (Murakami and Yoshida 1967;Jansen and Flight 1969;Zimmermann and Altner 1970;Vigh et al 1972;Zimmermann 1972;Rodríguez-Moldes and Anadón 1988;Corujo et al 1990). According to these studies, the CSF-contacting cells give rise to the saccofugal axons of the tract of the SV.…”

Section: Introductionmentioning

confidence: 99%

“…According to these studies, the CSF-contacting cells give rise to the saccofugal axons of the tract of the SV. Histochemical studies in a few teleosts (Vigh-Teichmann et al 1970;Zimmermann and Altner 1970;Jansen and West 1971;Vigh et al 1972) have indicated that these cells and/or the SV tract are acetylcholinesterase (AChE)-positive. These studies have also confirmed the existence of saccular projections to the nucleus sacci vasculosi (NSV) in the posterior tubercle and to the thalamus, although the possible targets in the thalamus are still to be characterized.…”

Section: Introductionmentioning

confidence: 99%

The neuronal system of the saccus vasculosus of trout (

et al. 1997

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The neuronal system of the saccus vasculosus of two species of trout was studied with immunocytochemical methods and carboindocyanine-dye (DiI) tract-tracing. The cerebrospinal-fluid-contacting neurons of the saccus were immunoreactive for gamma-aminobutyric acid (GABA), glutamic acid decarboxylase (GAD), and neuropeptide Y (NPY). Immunostaining of alternate sections of the saccus vasculosus of fry with anti-GAD and anti-NPY indicated that these substances were colocalized. The tractus sacci vasculosi and the neuropil of the nucleus sacci vasculosi were also immunoreactive to these substances. The GABA, GAD, and neuropeptide Y immunoreactivity of the saccus vasculosus system appeared early in trout ontogeny. After applying DiI to various levels of the tractus sacci vasculosi of adult trout, we observed massive bilateral saccular projections to the nucleus sacci vasculosi and could follow the course of the sacco-thalamic tract. This tract extended in the subependymal region of the thalamus rostral to the nucleus sacci vasculosi and split into two small tracts that reached the subhabenular-preoptic region. Sacco-thalamic fibers formed extensive periependymal plexuses along their trajectory. Interestingly, no clear evidence of the existence of a saccopetal system was obtained. On the basis of these results, we postulate that the saccus vasculosus system modulates the function of centers of the posterior tubercle and periventricular thalamus.

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Actual problems of the cerebrospinal fluid-contacting neurons

Vígh

Vigh-Teichmann

1998

Microsc. Res. Tech.

133

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Cerebrospinal fluid (CSF)‐contacting neurons form a part of the circumventricular organs of the central nervous system. Represented by different cytologic types and located in different regions, they constitute a CSF‐contacting neuronal system, the most central periventricular ring of neurons in the brain organized concentrically according to our concept. Because the central nervous system of deuterostomian echinoderm starfishes and the prochordate lancelet is composed mainly of CSF‐contacting‐like neurons, we hypothesize that this cell type represents ancient cells, or protoneurons, in the vertebrate brain. Neurons may contact the ventricular CSF via their dendrites, axons, or perikarya. Most of the CSF‐contacting nerve cells send their dendritic processes into the ventricular cavity, where they form ciliated terminals. These ciliated endings resemble those of known sensory cells. By means of axons, the CSF‐contacting neurons also may contact the external CSF space, where the axons form terminals of neurohormonal type similar to those known in the neurohemal areas. The most simple CSF‐contacting neurons of vertebrates are present in the terminal filum, spinal cord, and oblongate medulla. The dendritic pole of these medullospinal CSF‐contacting neurons terminates with an enlargement bearing many stereocilia in the central canal. These cells are also supplied with a 9 × 2 + 2 kinocilium that may contact Reissner's fiber, the condensed secretory material of the subcommissural organ. The Reissner's fiber floating freely in the CSF leaves the central canal at the caudal open end of the terminal filum in lower vertebrates, and open communication is thus established between internal CSF and the surrounding tissue spaces. Resembling mechanoreceptors cytologically, the spinal CSF‐contacting neurons send their axons to the outer surface of the spinal cord to form neurosecretory‐type terminals. They also send collaterals to local neurons and to higher spinal segments. In the hypothalamic part of the diencephalon, neurons of two circumventricular organs, the paraventricular organ and the vascular sac, of the magnocellular neurosecretory nuclei and several parvocellular nuclei, form CSF‐contacting dendritic terminals. A CSF‐contacting neuronal area also was found in the telencephalon. The CSF‐contacting dendrites of all these areas bear solitary 9 × 2 + 0 cilia and resemble chemoreceptors and developing photoreceptors cytologically. In electrophysiological experiments, the neurons of the paraventricular organ are highly sensitive to the composition of the ventricular CSF. The axons of the CSF‐contacting neurons of the paraventricular organ and hypothalamic nuclei terminate in hypothalamic synaptic zones, and those of magno‐ and parvocellular neurosecretory nuclei also form neurohormonal terminals in the median eminence and neurohypophysis. The axons of the CSF‐contacting neurons of the vascular sac run in the nervus and tractus sacci vasculosi to the nucleus (ganglion) sacci vasculosi. Some hypothalamic CSF‐contacti...

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Licht- und elektronenmikroskopische Untersuchungen des Saccus vasculosus und des Nervus und Tractus sacci vasculosi

Cited by 20 publications

References 12 publications

New Insights on Saccus vasculosus Evolution: A Developmental and Immunohistochemical Study in Elasmobranchs

New Insights on Saccus vasculosus Evolution: A Developmental and Immunohistochemical Study in Elasmobranchs

The neuronal system of the saccus vasculosus of trout (

Actual problems of the cerebrospinal fluid-contacting neurons

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