SUPPRESSION OF PILOCARPINE-INDUCED STATUS EPILEPTICUS AND THE LATE DEVELOPMENT OF EPILEPSY IN RATS

Status epilepticus (SE) has been related to subsequent development of epilepsy. The present work was aimed at elucidating the relationship b etween the duration of pilocarpine- (PILO)-induced SE and the subseque nt development of epilepsy in rats. The latency for the appearance of the first spontaneous seizure, the frequency of spontaneous seizures, the cell density in the hippocampal formation and the density of supra granular neo-Timm staining were monitored. At 30 min, 1, 2 and 6 h aft er the beginning of SE, animals were treated with diazepam plus pentob arbital. In non-treated rats, SE remitted spontaneously. Animals exhib iting 30 min of PILO-induced SE did not develop spontaneous seizures. Hippocampal cell counts and the density of neo-Timm staining in these animals were similar to those observed in control rats. In the other g roups longer SE durations were related to: shorter latency for the app earance of the first spontaneous seizure, increased number of the spon taneous recurrent seizures, severe cell loss in the hippocampal format ion, or increased supragranular neo-Timm staining. These data suggest that more than 30 min of SE is required to produce hippocampal damage with subsequent synaptic reorganization of the messy fibre pathway tha t could account for SRSs observed in the PILO model of epilepsy.