Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Comparative immunohistochemical study of the effects of pilocarpine on the mossy cells, mossy fibres and inhibitory neurones in murine dentate gyrus

100%

Karoly N., Dobo E., Mihaly A.

Acta Neurobiologiae Experimentalis

2015

tom 75

nr 2

Treatment with pilocarpine (PILO) induces variable degrees of loss of mossy cells (MCs) and mossy fibre (MF) sprouting in rodents, the relationships of which have not been examined in individual animals. Our aim was to test whether the loss of MCs and MF sprouting are coupled processes in PILO-treated rodents. Animals which exhibited intense PILO-induced convulsions for at least 30 min were used in this study. After a 2-month survival period, the incidence of epileptic seizures was checked individually by neuropeptide-Y (NPY) immunohistochemistry, and the numbers of MCs were counted by means of immunohistochemistry, for calretinin (CR) in mice and calcitonin gene-related peptide (CGRP) in rats. MF sprouting was checked by using Timm's silver-sulphide method for zinc. In our comparative studies, NPY immunohistochemistry resulted in more positive animals than on zinc staining. The CR immunoreactivity remained unchanged even in those mice that displayed MF sprouting and greatly increased NPY immunoreactivity. CR immunoreactivity was also verified after transection of the fornix to exclude the extrahippocampal source of this peptide. However, the CGRP immunoreactivity was severely reduced in those rats that exhibited simultaneous increases in zinc content and NPY immunoreactivity in the supragranular layer and stratum lucidum. Our findings suggest that the MCs survive PILO treatment in mice, but not in rats. There is direct evidence of a close relationship between the loss of MCs and MF sprouting in rats, but not in mice. Thus, similar PILO seizures may result from different changes in the neuronal circuits of rodents.

Differential expression of the c‑fos protein and synaptophysin in zebrin II positive and zebrin II negative cerebellar cortical areas in 4‑aminopyridine seizures

100%

Krisztin-Peva B., Mihaly A., Toth Z.

Acta Neurobiologiae Experimentalis

2019

tom 79

nr 3

The present study examined temporal activation patterns of rat cerebellar cortical neurons in 4‑aminopyridine induced seizures, using c‑fos protein as a marker of neuronal activity. C‑fos‑containing cells were counted in each cerebellar cortical layer, and cell count was compared between zebrin II positive and zebrin II negative bands of the lobules of the vermis and cerebellar hemispheres. We found significant activation of granule cells and interneurons of the molecular layer in zebrin II positive bands. The Purkinje cells, in contrast, exhibited non‑significant, scattered c‑fos immunoreactivity across all bands. Fluctuation of synaptophysin expression in the mossy fibre rosettes of the granular layer was determined via light microscopic immunohistochemistry. We detected a transient, significant decrease in synaptophysin staining density following 4‑aminopyridine seizures, which may indicate short‑term synaptic depression. We also identified different timing of increased c‑fos expression in the neurons of the cerebellar cortex in different cortical zones. In particular, the activation pattern of the interneurons of the molecular layer reflected the climbing fibre distribution, reflecting the zonal olivo‑cortico‑nuclear organization. Seizure‑induced activation of the granule cells corresponded with the zebrin II positive zones. This observation raises the possibility that zebrin II positive compartments may be more susceptible to cerebellar convulsions.

Ograniczanie wyników

2 Acta Neurobiologiae Experimentalis

2 Mihaly A.

1 Dobo E.

1 Karoly N.

1 Krisztin-Peva B.

1 Toth Z.

1 2019

1 2015

Wyniki wyszukiwania

Comparative immunohistochemical study of the effects of pilocarpine on the mossy cells, mossy fibres and inhibitory neurones in murine dentate gyrus

Differential expression of the c‑fos protein and synaptophysin in zebrin II positive and zebrin II negative cerebellar cortical areas in 4‑aminopyridine seizures