Pentylenetetrazole kindling induces neuronal cyclin B1 expression in rat hippocampus

The purpose of the study was to explore the involvement of cell cycle events in the neuronal death induced by repeated seizures. Pentylenetetrazole (PTZ) kindling was used as a model of seizure-induced hippocampal neurodegeneration. Immunohistochemical approach was applied to detect cell cycle markers (cyclins and cycline-dependent kinases) in hippocampus. PTZ-kindling in rats induced moderate neuronal cell loss in hippocampal fields CA1, CA 3, CA 4, and dentate gyrus. The majority of damaged cells in hippocampi of PTZ-kindled rats were cycline B1 positive, while no expression of either other cell cycle markers or TUNEL-positive (apoptotic) nuclei could be revealed. Since cycline B1 expression has been described in hippocampal neurons of patients with temporal lobe epilepsy by [Z. Nagy, M.M. Esiri, Neuronal cyclin expression in the hippocampus in temporal lobe epilepsy, Exp. Neurol. 150 (1998) 240-247], it is suggested that PTZ-kindling may be a suitable model to study the mechanisms of seizure-induced neuronal death.