Association of epileptiform activity with neuronal death in the CA3 subfield of the hippocampus following focally evoked limbic seizures.

Objective To investigate the relationnship between epileptiform activity and cell death in the CA3 subfield of the hippocampus following focally evoked limbic seizures through a quantitative study. Methods Wistar rats used in this study received intra-amygdaloid injection of kainic acid to induce type IV epileptiform activity of different duration with continuous electroencephalographic (EEG) monitoring Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) was used to detect apoptotic cells. The number of CA3 neurons survived and TUNEL-positive cells were counted to estimate the number of necrotic cells. Results Epileptiform activity induced cell death in the major form of apoptosis of the cells in CA3 subfield of the hippocampus following focally evoked limbic seizures. The longer the type IV epileptiform activity lasted, the less neurons survived, with consequent increase in the number of both necrotic and apoptotic cells. Conclusion Prolongation of type IV seizures dose-dependently causes increase in apoptotic and necrotic cells in CA3 subfield of the hippocampus.