J Korean Neurol Assoc.  1996 Mar;14(1):89-101.

Expression of c-fos mRNA in the Hippocampus of Pentylenetetrazol Kindling Rat

• Kim KS
• Yoo KM
• Suh SI
• Yi SD

Abstract

Kindling, induced by repeated subconvulsive electrical or chemical stimulations, leads to progressive and permanent amplification of seizure activity, resulting in permanent brain changes. It is a good animal model of epilepsy and neural plasticity. C-fos has been proposed as the gene responsible for turning on molecular events for these permanent brain changes underlying epilepsy and neural plasticity. But the role of c-fos in the development of kindling is controversial. This study was undertaken to investigate the role of c-fos mRNA in the plastic changes underlying kindling. Among 66 adult male Sprague-Dawley rats, 29 rats were kindled by repeated administrations of subconvulsive doses (IS-25 mg/kg) of pentylenetetrazol (PTZ), 25 rats experienced convulsions induced by a single injection of convulsive dose(30-60 mg/kg) of PTZ, and 12 rats experienced convulsions by a single electroconvulsive shock (ECS), Twelve control rats received normal saline only. Animals were sacrificed at various seizure stages. C-fos mRNA levels in the hippocampus were quantified using slot-blot hybridization analysis. In the experiment of PTZ kindling, c-fos mRNA expression 30 min after convulsion was elevated about 2-4 times at stage 1, 2 and 5, but wasn't increased at stage 3 and 4, compared with controls. C-fos mRNA expression 60 min after convulsion was elevated about 2 times at stage 1 and 5, but wasn't increased at stage 2, 3 and 4. In the experiment of PTZ-induced seizures, c-fos mRNA expression 30 min after convulsion was elevated 2.5, 2.2 and 6 times stage 1-2, 3-4, and 5, respectively. C-fos mRNA expression 60 min after convulsion was elevated 3.6 times at stage 3-4, but wasn't increased at stage 2 and 5. In the experiment of ECB-induced seizures, c-fos mRNA expression 1 min after mild convulsion was elevated 3,3 times, but wasn't increased generalized tonic-clonic seizure. C-fos mRNA expression 60 min after convulsion wasn't increased at any stage of convulsion. These results show that c-fos mRNA levels have no meaningful relationship with the stages of PTZ kindling, and PTZ or ECS-induced seizures, and that c-fos mRNA does not seem to play the crucial role in turning on a molecular program underlying kindling.

MeSH Terms

Adult
Animals
Brain
Electroshock
Epilepsy
Hippocampus*
Humans
Male
Models, Animal
Pentylenetetrazole*
Plastics
Rats*
Rats, Sprague-Dawley
RNA, Messenger*
Seizures
Stimulation, Chemical
Pentylenetetrazole
Plastics
RNA, Messenger