Neuropediatrics 2006; 37 - THP39
DOI: 10.1055/s-2006-945862

CORRELATIVE FACTORS OF NEURONAL APOPTOSIS IN HIPPOCAMPUS AFTER STATUS CONVULSION

Y Hu 1, L Jiang 1, X Li 1
  • 1Children's Hospital, Chongqing University of Medical Sciences, Chongqing, P.R. China

Objectives: To explore the influences of age and duration of status convulsion (SC) on hippocampal neuron apoptosis by observing the dynamic change of neuron apoptosis in rats with different age after SC termination.

Methods: Seizures were induced in infant and adult rats (IRs, ARs) with lithium and pilocarpine injected intraperitoneally. They were sacrificed at 6 time points (3h 6h 12h 1d 3d 7d) after 30min of SC termination, or 2 time points (3h 1d) after 3h of SC termination respectively. The location and type of apoptotic cells was assessed by using terminal deoxynucleotidyl dUTP nick end-labeling (TUNEL) of brain sections in situ. The proportion of apoptotic cells was quantified by the Annexin V-FITC apoptosis detection and analysed by flow cytometer.

Results: (1) SC induced neuronal apoptosis and necrosis mainly in the CA1 and CA3 regions of hippocampus. (2) Compared to the time point before SC, the proportion of apoptotic cells in the IRs and ARs hippocampus was increased obviously at 3h after 30min of SC (IRs 0.55±0.21%, ARs 0.53±0.06%), with a maximal induction at 12h and 1d respectively (IRs 0.67±0.18%, ARs 0.98±0.38%). The apoptotic process continued at least 3–7d. (3) In IRs, the proportion of apoptotic cells was lower than in ARs at the different time points after 30min of SC, except 3h point. There was the significant difference between the two age groups at 1d and 7d after SC respectively. The age-related difference was more obvious for the longer duration of SC. (4) Excluding the effect of the age-related difference, there was the positive correlation between the duration of SC and proportion of hippocampal apoptotic cells by partial correlation analysis. Conclusion: (1) Severe seizure could induce neuronal apoptosis in hippocampus. (2) Age and duration of SC were the important factors to influence neuronal apoptosis. The neuronal apoptosis in hippocampus after SC had the positive correlation with age and duration of seizure.