Involvement of Gap Junctions in the Manifestation and Control of the Duration of Seizures in Rats In Vivo
| Autor: | Edit Hermesz, Zita Gajda, Erika Gyengesi, Magdolna Szente, K. Said Ali |
|---|---|
| Rok vydání: | 2003 |
| Předmět: |
Male
medicine.medical_specialty Carbenoxolone Gene Expression Connexin Biology Epileptogenesis Cell junction Connexins Methylamines Epilepsy Internal medicine medicine Animals Ictal RNA Messenger 4-Aminopyridine Rats Wistar Cerebral Cortex Reverse Transcriptase Polymerase Chain Reaction Gap junction Gap Junctions Electroencephalography medicine.disease Rats Disease Models Animal Endocrinology Neurology Connexin 43 Female Neurology (clinical) medicine.drug |
| Zdroj: | Epilepsia. 44:1596-1600 |
| ISSN: | 1528-1167 0013-9580 |
| DOI: | 10.1111/j.0013-9580.2003.25803.x |
| Popis: | Summary: Purpose: The possible role of gap junctions in the manifestation and control of the duration of seizures was tested on the 4-aminopyridine–induced epilepsy model in rats in vivo, by using electrophysiologic, pharmacologic, and molecular biologic techniques. Methods: In electrophysiologic experiments, the functional states of the gap junctions were manipulated with a specific blocker (carbenoxolone) or opener (trimethylamine) at the already active focus of adult, anesthetized rats, 60 min after the induction of the first seizure, which was repeated spontaneously thereafter. Semiquantitative reverse transcriptase–polymerase chain reaction (RT-PCR) amplification was used to measure the levels of connexin (Cx) 32, 43, and 36 messenger RNAs (mRNAs) prepared from the areas of the already active primary and mirror foci. Results: After repeated seizures, the expression levels of Cx32, Cx43, and Cx36 mRNAs at the epileptic foci were increased significantly. Blockade of the gap junctions with carbenoxolone shortened the duration of seizures and decreased the amplitude of the seizure discharges, whereas their opening with trimethylamine lengthened the duration and increased the amplitude. Secondary epileptogenesis was facilitated when the gap junctions were opened. Conclusions: Our findings support the idea that, in epileptic foci, the gap junctions are involved in the expression of rhythmic ictal discharges and in the control of the duration and propagation of the individual seizures in vivo. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Plný text