Depression and/or potentiation of cortical responses after status epilepticus in immature rats
Language English Country Czech Republic Media print-electronic
Document type Journal Article, Research Support, Non-U.S. Gov't
PubMed
16925471
DOI
10.33549/physiolres.931047
PII: 1047
Knihovny.cz E-resources
- MeSH
- Time Factors MeSH
- Lithium Chloride MeSH
- Long-Term Potentiation * MeSH
- Long-Term Synaptic Depression * MeSH
- Electric Stimulation MeSH
- Electroencephalography MeSH
- Evoked Potentials MeSH
- Rats MeSH
- Disease Models, Animal MeSH
- Cerebral Cortex physiopathology MeSH
- Pilocarpine MeSH
- Rats, Wistar MeSH
- Status Epilepticus chemically induced physiopathology MeSH
- Animals MeSH
- Check Tag
- Rats MeSH
- Male MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- Lithium Chloride MeSH
- Pilocarpine MeSH
Lithium-pilocarpine status epilepticus (SE) resulted in delayed changes of single cortical interhemisperic (transcallosal) responses in immature rats. Low-frequency stimulation inducing depression and/or potentiation was studied to analyze possible dynamic changes in cortical responses. Status was elicited in 12-day-old (SE12) or 25-day-old (SE25) rats. Control siblings received saline instead of pilocarpine. Interhemispheric responses were elicited by stimulation of the sensorimotor region of the cerebral cortex 3, 6, 9, 13, or 26 days after status. A series of 5 biphasic pulses with intensity equal to twofold threshold were used for stimulation. The interval between pulses was 100, 125, 160, 200 or 300 ms, eight responses were always averaged. Peak amplitude of the first positive, first negative and second positive waves was measured and responses to the second, third, fourth and fifth pulse were compared with the first one. Animals after status epilepticus as well as lithium-paraldehyde controls exhibit a frequency depression at nearly all the intervals studied. An outlined increase of responses in SE rats in comparison with the controls three days after SE stayed just below the level of statistical significance. In addition, animals in the SE12 group exhibited potentiation of responses at this interval after SE. With longer intervals after SE, the relation between SE and control animals changed twice resulting in a tendency to lower amplitude of responses in SE than in control rats 26 days after SE. Rats in the SE25 group exhibited higher responses than controls 13 days after status, but this difference was not present at the longest interval after SE. Low-frequency stimulation did not reveal increased cortical excitability as a long-lasting consequence of status epilepticus induced in immature rats. In addition, the outlined differences between SE and control rats changed with the time after SE.
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