Effects of Kainic Acid-induced Seizures on c-fos Protein Expression in the Rat Hippocampus

J Korean Neurol Assoc > Volume 14(1); 1996 > Article

Journal of the Korean Neurological Association 1996;14(1): 102-113.

Kainic Acid로 유발된 경련이 백서 해마에서 c-fos 단백의 발현에 미치는 영향

유경무, 김광수, 조무연*, 박병채**

고신대학교 의학부 신경과학교실, 생화학교실*, 내과학교실**

Effects of Kainic Acid-induced Seizures on c-fos Protein Expression in the Rat Hippocampus

Kyung My Yoo, Kwang Soo Kim, Moo Youn Cho*, Byung Chae Park**

Department of Neurology, Biochemistry*, Internal Medicine**, Kosin Medical College

Abstract

C-fos protein is a gene regulatory third messenger involved in long-term responses of cells to various stimuli. Kainic acid(KA) , a powerful excitatory analogue, induces seizures and damages the hippocampus and other limbic regions in rats. KA treatment induces c-fos protein production in the hippocampus. This study was undertaken to investigate the expression of c-fos protein in the hippocampus according to seizure stage induced by systemic injection of KA. Twenty-three adult male Sprague-Dawley rats experienced convulsions by a single intraperitoneal injection of convulsive dose (20-40 mg/Kg) of KA. Seven control rats received normal saline. Animals were sacrificed 3 hr after KA treatment. The expression of c-fos protein was tested in the hippocampus by immunohistochemical staining using polyclonal anti-Fos. Most of the rats exhibited limbic motor epileptic activity. C-fos protein immunoreactivity increased in the CA1, CA3 and dentate gyrus at stage 1-2, and not only in the CA1, CA3 and dentate gyrus but also in the CA4 at stage 3-4. At stage 5, c-fos protein immunoreactivity increased in all areas of the hippocampus. C-fos protein immunoreactivity increased progressively with increasing severity of convulsions. These results show that KA produces limbic motor seizure associated with a rise in the c-fos protein in the hippocampus, and that the expression of c-fos protein may has some relevance to the progressive and permanent brain changes occurring during epilepsy.