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

Diverse functions of perineuronal nets

100%
Karetko M., Skangiel-Kramska J.
Acta Neurobiologiae Experimentalis
|
2009
|
tom 69
|
nr 4
Perineuronal nets represent well-organised components of the extracellular matrix, which are surrounding cell bodies, dendrites, and axon segments of a particular class of neurones as well as forming lattice-like structures. The role of perineuronal nets is not fully elucidated yet. Perineuronal nets may play a beneficial role by stabilizing the extracellular milieu assuring the characteristic features of enveloped neurons and protecting them from the influence of harmful agents. On the other hand, perineuronal nets create a barrier which limits neuronal plasticity and counteracts regeneration. This review examines recent evidence concerning the significance of the occurrence of perineuronal nets.
2

Loss and restoration of perineuronal nets after cortical photothrombotic stroke in rats

81%
Karetko M., Nowicka D., Skangiel-Kramska J.
Acta Neurobiologiae Experimentalis
|
2009
|
tom 69
|
nr 3
The distribution and density of cells enwrapped with perineuronal nets (PNs) were examined in the neocortex after unilateral photothrombotic stroke. After different survival times PNs was visualized using Wisteria fl oribunda aglutinin (WFA) staining in the infarct core, peri-infarct and remote cortical areas. Sham operated rats and contralateral hemisphere to the stroke site from experimental rats served as controls. In the infarct core, 4 h after stroke only few cells enwrapped with PNs could be detected and none of numerous dying cells present showed PNs, as revealed by double staining (WFA and FJ-C). No cells with PNs were found 24 h after stroke. In the peri-infarct area, dramatic loss of PNs-enwrapped cells occurred (96%) as compared with the contralateral site, and such cells were almost absent after 24 h. However, 30 days after stroke, a signifi cant number of cells with PNs reappeared. In remote cortical areas, 4h after stroke a reduction in the number of cells with PNs was observed. After 24 h the loss of PNs-enwrapped cells was profound (63%) in comparison to intact hemisphere. However, 7d after stroke complete restoration of the number of cells enwrapped with PNs took place. The density of cells with PNs was similar to that found in the contralateral site and in sham operated rats. These results showed the wide spreading and transient effect of photothrombosis on PNs in remote cortical areas. Supported by MNiSW Grant N3030300832/0474 and statutory funds.
3

How photothrombotic stroke affects extracellular matrix?

81%
Nowicka D., Karetko M., Aleksy M., Skangiel-Kramska J.
Acta Neurobiologiae Experimentalis
|
2009
|
tom 69
|
nr 3
Perineuronal net (PN), a lattice-like structure surrounding certain neurons, represents a special form of extracellular matrix of the brain. The role of this structure remains elusive. It has been suggested to regulate neuronal plasticity, accumulate trophic molecules and protect neurons from damaging factors. Here we studied whether PN-enwrapped neurons are protected against ischemic injury. To this aim we performed cortical photothrombotic stroke in rats and investigated PNs and their co-localization with Fluoro Jade C (FJ), a marker of rapid cell death. We found that in the ischemic core 4 h after the stroke still PNs were observable, none of them around FJ-positive neurons. No PNs were detected after 24 h. In the peri-infarct area, a huge loss of PNs was observed 24 h after stroke, followed by a partial restoration 30 days post-infarct. Similar effect was found in remote cortical areas, except that in this case the restoration was almost complete already 7 days after stroke. No FJ staining was observed outside ischemic core. These results suggest that in areas that are not directly damaged, ischemic insult disrupts PNs but the neurons survive this disruption. Supported by MNiSW Grant N3030300832/0474.
4

Comparison of developmental composition pattern of perineuronal nets in the visual and the barrel cortex

81%
Karetko M., Nowicka D., Skangiel-Kramska J., Glazewski S.
Acta Neurobiologiae Experimentalis
|
2009
|
tom 69
|
nr 1
The barrel and visual cortices are primary model systems to study cortical plasticity. The ability to undergo experience dependent plastic changes depends on brain region, cortical layers, pattern of activity and is altered during development. For instance in mice, a critical period for barrels formation occurs during the fi rst postnatal days whereas in the visual cortex a critical period for ocular dominance plasticity ends about one month after birth. It has been suggested that formation of perineuronal nets (PNNs) during postnatal development may limit cortical plasticity. The aim of this study was to compare developmental patterns of distribution and composition of PNNs in the visual and somatosensory cortex of mice. For this purpose we used monoclonal antibody against chondroitin sulfate proteoglycans to visualized aggrecan (a major component of PNNs) and Wisteria fl oribunda agglutinin (WFA), which selectively recognizes N-acetylo-galactosamine residues within PNNs. At all time points examined in both cortices the highest density (cells/mm2 ) of WFA stained cells occurred in the layer IV. In the barrel cortex, WFA staining fi rst appeared at P10 whereas in the visual cortex WFA stained cells were seen not before P20. In both cortices, the adult like pattern was evident by P30. A composition of PNNs differed between the visual and barrel cortex. Number of aggrecan expressing cells was signifi cantly higher in the visual cortex than in the barrel cortex. Moreover, in the visual cortex aggrecan expressing cells were seen earlier during development than WFA staining. These data seemed to support a view that PNNs are involved in determination of specifi c critical period.
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.