Neocortical c-fos mRNA transcription in repeated, brief, acute seizures: is c-fos a coincidence detector?
The effect of acute brief seizures on neocortical c-fos expression was investigated in rats injected with 5 mg/kg 4-aminopyridine. Electroencephalography in freely moving animals with implanted neocortical electrodes detected an average of 2.67 tonic-clonic convulsions within 1 h following the 4-AP treatment. Tissue samples of the somatosensory neocortex were collected at 30 min, 1 h, 3 h, 5 h and 8 h following the treatment for PCR and immunohistochemistry. The c-fos mRNA displayed the first significant rise at 1 h, and remained significantly higher through 3 h. The number of c-fos protein immunoreactive cells was significantly elevated already at 30 min, peaked at 1 h, and declined by 5 h. We conclude that in repetitive, brief seizures, the first convulsion does not increase c-fos RNA transcription, whilst the second causes a long-lasting gene expression and a large increase of c-fos protein synthesis. The phenomenon may have implications in the pathogenesis of human and animal epilepsies.
Mihály
András
A
Department of Anatomy, Faculty of Medicine, University of Szeged, H-6701 Szeged, Hungary. mihaly@anatomy.szote.u-szeged.hu
Borbély
Sándor
S
Világi
Ildikó
I
Détári
László
L
Weiczner
Roland
R
Zádor
Zsolt
Z
Krisztin-Péva
Beáta
B
Bagosi
Andrea
A
Kopniczky
Zsolt
Z
Zádor
Erno
E
D015761:4-Aminopyridine / Q000494:pharmacology; D000818:Animals; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism; D004594:Electrophysiology; D007150:Immunohistochemistry; D008297:Male; D019579:Neocortex / Q000378:metabolism* / Q000473:pathology*; D016760:Proto-Oncogene Proteins c-fos / Q000235:genetics* / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012640:Seizures / Q000139:chemically induced / Q000235:genetics* / Q000378:metabolism*; D013997:Time Factors; D014158:Transcription, Genetic / Q000235:genetics*
D016760:Proto-Oncogene Proteins c-fos; D012333:RNA, Messenger; D015761:4-Aminopyridine