Number, Volume and Size Distribution of Nucleoli in Rat Neurosecretory Cells with Suppressed and Stimulated Secretion

Andersen, Lotte Bøgh

doi:10.1159/000146900

Cited by 13 publications

(4 citation statements)

References 7 publications

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“…Scale bar ϭ 4 m. nucleolar accumulation of processing pre-rRNA-protein complexes (Shaw and Jordan, 1995). In agreement with this view, there is extensive literature demonstrating that hyperosmolar activation of SON neurons produces a significant increase in the nucleolar size (Edström and Eichner, 1958;Russell, 1980;Andersen, 1990a;Lafarga et al, 1991;Beagley and Hatton, 1992), which reverts to control values after the cessation of the osmotic stimulation by the rehydration of animals.…”

Section: Changes In the Size And Structural Configuration Of Nucleolisupporting

confidence: 55%

Structural and functional compartmentalization of the cell nucleus in supraoptic neurons

Berciano

Villagra

Pena

et al. 2002

Microscopy Res & Technique

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It is well-established that the neuronal cell nucleus is organized in discrete compartments involved in transcription and RNA processing. The main nuclear compartments in neurons include the chromosome territories, the nucleolus, nuclear speckles of splicing factors, Cajal bodies, and nuclear rodlets. The supraoptic nucleus (SON) neurons provide a powerful model in vivo to study the organization of these nuclear compartments in response to variations of cellular activity. The upregulation of transcription in SON neurons under chronic hyperosmolar conditions is associated with 1) nuclear and nucleolar enlargement, 2) dispersion of chromatin, 3) reduction in the size of nuclear speckles, 4) increase in the number of Cajal bodies implicated in the maturation of splicing small nuclear ribonucleoproteins, and 5) proliferation of the fibrillar centers of the nucleolus, the sites of nucleolar transcription of ribosomal genes. These changes revert after the cessation of the activation by rehydration of animals. Under conditions of neuronal stress induced by hypertonic saline injection, SON neurons exhibit an early response of downregulation of transcription. This is accompanied by chromatin condensation, redistribution of splicing factors, reduction in the number of Cajal bodies, and microsegregation of the fibrillar and granular components of the nucleolus and disruption of its fibrillar centers, all of which are associated with a transitory expression of c-Fos. These changes progressively revert and at 24 hours after the stress induction a rebound upregulation of transcription is observed. These findings illustrate the transcription-dependent organization and behavior of nuclear compartments in the neuronal model of magnocellular neurosecretory cells of the hypothalamus.

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Section: Changes In the Size And Structural Configuration Of Nucleolisupporting

confidence: 55%

Structural and functional compartmentalization of the cell nucleus in supraoptic neurons

Berciano

Villagra

Pena

et al. 2002

Microscopy Res & Technique

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“…Andersen [1990] determined the average nucleolar volume per cell in SON in water-deprived, water-ad-libitum and water-loaded rats. These volumes are given in the first column of table 2, and they are in the next columns allocated to the centres and components of the nucleoli using their relative volumes determined in the present investigation.…”

Section: Resultsmentioning

confidence: 99%

Electron Microscopy and Morphometry of Nucleoli in Rat Neurosecretory Cells with Stimulated and Suppressed Secretion

Andersen

1990

Cells Tissues Organs

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The nucleoli in the neurons of the supraoptic nucleus in the rat were analyzed by electron microscopy and morphometry after the secretion of vasopressin had been fully suppressed by water load, after the secretion had been stimulated by water deprival and in normal rats which had water ad libitum. Suppression of the secretion increased the proportion of fibrillar centres in the nucleoli 2-fold. Stimulation of the secretion increased the proportion of the granular component by 22%. The overall nucleolar organization did not change very much with the secretory activity. The results show that an increased proportion of fibrillar centres in nucleoli is an indicator of decreased secretory activity and, moreover, that an increased volume of the nucleolar fibrillar and granular components per cell indicates an increased secretory activity.

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“…The functional state of nonapeptidergic cells of SON and PVN was assessed by the content of c-Fosimmunoreactive cells and by the content of so-called polynucleolar neurosecretory cells, bearing in mind that the size of the neurosecretory cell nucleolus correlates with the hltensity of protein synthesis [7,9]. We determined the nucleolus size in 35 oxytochl-and vasopressinergic cells of SON and PVN in each rat.…”

Section: Methodsmentioning

confidence: 99%

Thein vitro effect of thyreostimulating hormone on the functional state of nonapeptidergic cells in rat hypothalamus

Глазова

Krasnovskaya

1998

Bull Exp Biol Med

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In persistent rat hypothalamic slices thyreostilnulating hormone activates only the oxytocinergic cells of the supraoptic and paraventricular nuclei. This effect manifests itself in increased volume of nucleoli in oxytocinergic cells and in markedly increased content of c-Fos-immunoreactive cells in both nuclei. Key Words: thyreostimulating hormone; vasopressin; oxytocin; paraventricular and supraoptic nuclei of the hypothalamusThe interactions between the nonapeptidergic neurosecretory system of the hypothalamus and the hypothalamus-hypophysis-thyroid gland system, which produces thyroliberin, thyreostimulating hormone (TSH), and the thyroid gland hormones, have been extensively investigated [1,5,13]. It was demonstrated that vasopressin stimulates the thyroid gland both in vivo and in vitro. There is evidence that thyroid hormones modify the activity of nonapeptidergic cells [6]. The effects of thyroliberin on the function of neurosecretory cells in the supraoptic (SON) and paraventricular (PVN) nuclei of rat hypothalalnus were studied [2][3][4]11,17].The interactions between the nonapeptidergic neurosecretory system of the hypothalamus and TSH-cells of the adenohypophysis have not been studied in sufficient detail. Nevertheless, it is known that vasopressin and oxytocin affect TSH secretion [12,14]. It remains unclear whether TSH has any effect on the activity on nonapeptidergic cells. In the in vivo experiments TSH increased blood concentration of nonapeptide hormones and it was impossible to distinguish between its effects and Laboratory of Neuroendocrinology, M. I. Setchenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Pete~bur9 those of the thyroid gland hormones. We managed to demonstrate a direct effect of TSH on vasopressin-and oxytocinergic cells in experiments on hypothalamic slices. MATERIALS AND METHODSExperiments were performed oll adult male Wistar rats weighing 120-140 g. The animals were mahltahmd under the standard vivarium conditions. All the experiments were started at 12:00-13:00. The rats were decapitated, the brain was rapidly isolated under stenle conditions, and hypothalalnic slices (400-g lhick) containing SON and/or PVN were prepared. Tlle slices were preincubated for 90 rain at 37~ in Earle's growth medium or in medium 199 with Hanks' balanced salts saturated with carbogen (95% O~+5% CO2). The cells were then transferred to the culture medium containing 50x10 -~ U/ml TSH and incubated for 30 or 60 min under the same conditions.After the incubation the slices were fixed in Bouin's fluid and processed according to the standard histological techniques.Parallel hypothalamic sections were incubated with unlabeled antivasopressin or antioxytocin antibodies and the peroxidase-antiperoxidase complex, using 3,3'-diaminobenzidine for visualization of the 0007-4888/98/0010-0977520.00 9Kluwer Aceademic/Ptenum Puhtishers

show abstract

Number, Volume and Size Distribution of Nucleoli in Rat Neurosecretory Cells with Suppressed and Stimulated Secretion

Cited by 13 publications

References 7 publications

Structural and functional compartmentalization of the cell nucleus in supraoptic neurons

Structural and functional compartmentalization of the cell nucleus in supraoptic neurons

Electron Microscopy and Morphometry of Nucleoli in Rat Neurosecretory Cells with Stimulated and Suppressed Secretion

Thein vitro effect of thyreostimulating hormone on the functional state of nonapeptidergic cells in rat hypothalamus

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