Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 4

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
1

Imaging method of neuronal nuclei in the mouse brain

100%
Czaban L., Broszkiewicz M., Magalska A., Ruszczycki B., Wilczynski G. M.
Acta Neurobiologiae Experimentalis
|
2013
|
tom 73
|
nr Suppl.1
Little is known about the relationship between neuronal gene expression and the architecture of the neuronal cell nucleus. We wanted to study the cell nuclei in neurons of the mouse cerebral cortex, using confocal microscopic immunocytochemistry. We used a segmentation algorithm, based on continuous boundary tracing, able to reconstruct the nucleus surface and to separate adjacent nuclei (Walczak et al. 2013). The algorithm did not use a rigid threshold what made it robust against variations in image intensity and poor contrast. However, when we analyzed mouse, but not rat, neuronal nuclei there have occurred a considerable problem with an appropriate segmentation. This problem was related to the presence of the discrete chromocenters, which are much more prominent in the mouse that in other species. Therefore, in order to assure the proper segmentation, we used sections co-immunostained for the lamin protein. Our refined program is an efficient segmentation tool for crowded and overlapping objects in 3D space, regardless of the particular species. It allows us to study quantitatively the architecture of the neuronal nucleus using confocal-microscopic approach.
2

Higher-order nuclear structure in epileptogenesis

86%
Szczepankiewicz A., Walczak A., Szczepinska T., Broszkiewicz M., Pawlowski K., Wilczynski G.
Acta Neurobiologiae Experimentalis
|
2009
|
tom 69
|
nr 3
Although the molecular mechanisms of gene-expression in neurons are comprehensively described in the literature, little is known about the relationship between these processes and the architecture of the neuronal cell nucleus. For example, it has never been examined whether bursts of transcriptional activity associated with seizures involve any regulation at the level of higher-order nuclear structure. Accordingly, we have performed studies on the structure of neuronal nucleus in epileptic animals. Using electron microscopy, we found the striking appearance of large interchromatin granule clusters (IGCs) in epileptic nuclei. We confi rmed this observation by immunofl uorescence-confocal analysis of IGC marker, a spliceosome assembly factor SC-35. Interestingly, there was also aggregation of spots immunoreactive for phophorylated and acetylated Histone H3, a marker of transcriptionally active chromatin. The fi ndings are consistent with the results of bioinformatic analysis of transcription profi ling in the rat kainate-induced status epilepticus (public gene expression data), showing tendency for coordinated expression of positional gene-clusters along chromosomes. Taken together, our results suggest that upon epileptogenesis there is prominent reorganization of neuronal nucleus, putatively involving formation of molecular factories, where transcription, splicing, and export of pre-mRNA are orchestrated.
3

Neuronal PML bodies are modulated by activity in adult murine brain

86%
Broszkiewicz M., Szczepankiewicz A., Yeghiazaryan M., Patel S., Ruszczycki B., Pawlak R., Wilczynski G.
Acta Neurobiologiae Experimentalis
|
2011
|
tom 71
|
nr S
PML is a tumor-suppresor protein involved in the pathogenesis of promyelocytic leukemia. In proliferating mammalian cells PML is a principal component of characteristic nuclear bodies, which contain other proteins but do not contain nucleic acids. There are several PML bodies per nucleus. The molecular function of PML protein is unclear, yet the majority of data points to its involvement in regulation of gene-expression and/or intranuclear protein storage and degradation. In the brain PML has been implicated in the pathogenesis of neurodegenerative disorders, glioma and in the control of embryonic neurogenesis. It is not clear whether the protein is expressed, and has a function, in the normal adult brain. Therefore we have investigated the expression and localization of PML at the cellular and subcellular levels, in the adult mouse brain. By immunofluorescence, typical PML bodies were found in a subset of neurons in the cerebral cortex, hippocampus and amygdala. In the cortex, the protein was present predominantly in layer II/III. Stimulation of neuronal activity by a) pentylenetetrazole seizures or b) immobilization stress, greatly increased the size and signal-intensity of the neuronal PML bodies. Our results suggest that function of PML protein in the brain can be associated with neuronal activity and plasticity.
4

Repositioning of selected genes in neuronal cell nucleus upon seizures

59%
Walczak A., Szczepankiewicz A., Szczepinska T., Ruszczycki B., Dabrowski M., Broszkiewicz M., Siudek M., Pyskaty M., Wilczek E., Szczerbal I., Switonski M., Pawlowski K., Wilczynski G.
Acta Neurobiologiae Experimentalis
|
2011
|
tom 71
|
nr S
Even though the molecular mechanisms of gene expression in neurons are quite broadly described in the literature, little is known about the relationship between these processes and the architecture of the neuronal cell nucleus. For example, it is firmly established that waves of gene expression occurring after neuronal stimulation comprise plenty of genes playing important roles in cognitive and epileptic phenomena. However, it has never been examined whether these bursts of transcriptional activity involve any regulation at the level of higher-order nuclear structure. Accordingly, we have performed studies on the structure of neuronal nucleus in epileptic animals. Based on the literature we chose the genes for BDNF and TRKB that play key roles in synaptic plasticity in the brain. We have investigated clustering of these genes in the nucleus by means of fluorescent in situ hybridization. We found that in hippocampal neurons the bdnf-trkb distance decreases 2 hours after seizure induction compared to control. Moreover, using bioinformatical approach we selected 2 linear clusters of the genes that are upregulated after seizures. One of them was selected on the chromosome 1 and the other one on chromosome 20. Those linear gene clusters appeared to associate 4 weeks after seizure compared to control. Our results suggest that upon epileptogenesis there is a reorganization of neuronal nucleus involving clustering of the genes in three-dimensional space. The phenomenon could occur also in other forms of synaptic plasticity, and should be a topic to follow up in the future.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.