PURPOSE: Status epilepticus (SE) was previously found to induce damage in the mediodorsal nucleus of the thalamus (MD) in both adult and immature rats. This study was designed to describe age-related changes of SE-induced neuronal degeneration in this part of the brain. METHODS: SE was induced by LiCl/pilocarpine in five age groups of rats (P12-P25). Distribution of degenerating neurons was studied at various time intervals from 4 h up to 1 week using Fluoro Jade B (FJB) staining. For P12 and P25 rats, an interval of 3 months was added. RESULTS: Damaged neurons were found in all age groups during a 1-week period after SE. Patterns of neuronal degeneration, however, changed in an age-related manner. In animals at P12 and P15, FJB-labeled neurons were located in the central and lateral segment of the MD. In the P18 group, degenerating neurons occurred in all three segments of the MD, with a prevalence in central and lateral subdivisions. In contrast, in P21 and P25 rats, FJB-labeled neurons were predominantly located in the central and medial segments. Degenerating neurons were still present 3 months after SE in the medial segment in P25 animals, whereas no labeled neurons were detected in the P12 group at this time. CONCLUSIONS: Our data demonstrate that the pattern of neuronal degeneration in MD is mainly related to age at SE onset. In addition to damage occurring during the acute phase of SE, a population of degenerating neurons was detected in P25 animals during the chronic period 3 months after SE.

• MeSH
• barvení a značení MeSH
• degenerace nervu patologie   MeSH
• fluoresceiny MeSH
• fluorescenční barviva MeSH
• krysa rodu Rattus MeSH
• Nisslova tělíska patologie   MeSH
• novorozená zvířata růst a vývoj   MeSH
• nucleus medialis dorsalis thalami patologie   MeSH
• organické látky MeSH
• potkani Wistar MeSH
• stárnutí fyziologie   MeSH
• status epilepticus patologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• fluoresceiny MeSH
• fluorescenční barviva MeSH
• fluoro jade MeSH Prohlížeč
• organické látky MeSH

Status epilepticus (StE) in immature rats causes long-term functional impairment. Whether this is associated with structural alterations remains controversial. The present study was designed to test the hypothesis that StE at an early age results in neuronal loss. StE was induced with lithium-pilocarpine in 12-d-old rats, and the presence of neuronal damage was investigated in the brain from 12 hr up to 1 week later using silver and Fluoro-Jade B staining techniques. Analysis of the sections indicated consistent neuronal damage in the central and lateral segments of the mediodorsal nucleus of the thalamus, which was confirmed using adjacent cresyl violet-stained preparations. The mechanism of thalamic damage (necrosis vs apoptosis) was investigated further using TUNEL, immunohistochemistry for caspase-3 and cytochrome c, and electron microscopy. Activated microglia were detected using OX-42 immunohistochemistry. The presence of silver and Fluoro-Jade B-positive degenerating neurons in the mediodorsal thalamic nucleus was associated with the appearance of OX-42-immunopositive activated microglia but not with the expression of markers of programmed cell death, caspase-3, or cytochrome c. Electron microscopy revealed necrosis of the ultrastructure of damaged neurons, providing further evidence that the mechanism of StE-induced damage in the mediodorsal thalamic nucleus at postnatal day 12 is necrosis rather than apoptosis. Finally, these data together with previously described functions of the medial and lateral segments of the mediodorsal thalamic nucleus suggest that some functions, such as adaptation to novelty, might become compromised after StE early in development.

• MeSH
• antigeny nádorové * MeSH
• antigeny povrchové metabolismus   MeSH
• apoptóza MeSH
• basigin MeSH
• CD antigeny * MeSH
• chlorid lithný MeSH
• cytochromy skupiny c metabolismus   MeSH
• elektronová mikroskopie MeSH
• imunohistochemie MeSH
• kaspasa 3 MeSH
• kaspasy metabolismus   MeSH
• koncové značení zlomů DNA in situ MeSH
• krevní proteiny * MeSH
• krysa rodu Rattus MeSH
• membránové glykoproteiny metabolismus   MeSH
• mikroglie metabolismus   patologie   MeSH
• modely nemocí na zvířatech MeSH
• nekróza MeSH
• neurony metabolismus   patologie   MeSH
• nucleus medialis dorsalis thalami metabolismus   patologie   MeSH
• pilokarpin MeSH
• potkani Wistar MeSH
• progrese nemoci MeSH
• ptačí proteiny * MeSH
• status epilepticus chemicky indukované   patologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antigeny nádorové * MeSH
• antigeny povrchové MeSH
• basigin MeSH
• Bsg protein, Gallus gallus MeSH Prohlížeč
• Bsg protein, rat MeSH Prohlížeč
• Casp3 protein, rat MeSH Prohlížeč
• CD antigeny * MeSH
• chlorid lithný MeSH
• cytochromy skupiny c MeSH
• kaspasa 3 MeSH
• kaspasy MeSH
• krevní proteiny * MeSH
• membránové glykoproteiny MeSH
• pilokarpin MeSH
• ptačí proteiny * MeSH

The aim of this study was to examine the influence of unilateral dorsal root section at the cervicothoracic level of the spinal cord on the spontaneous neuronal activity of medial thalamic nuclei in the rat. Single unit extracellular recordings from thalamic nuclei, nc. parafascicularis and nc. centralis lateralis, were obtained with glass micropipettes. The abnormal bursting activity of these nuclei following deafferentation was registered, although a correlation between the occurrence of this activity and the degree of autotomy behavior was not found. Such bursts were never observed in the studied thalamic nuclei of control rats.

• MeSH
• chování zvířat MeSH
• elektrofyziologie MeSH
• krysa rodu Rattus MeSH
• neurony fyziologie   MeSH
• nucleus medialis dorsalis thalami cytologie   fyziologie   MeSH
• pooperační období MeSH
• potkani Wistar MeSH
• rizotomie * MeSH
• sebepoškozování psychologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH