Neuroplasticity Of Lamotrigine And Ethosuximide On Temporal-lobe Epilepsy Induced By Pilocarpine

Objective:to elvaluate the effects (ethology, EEG and mossy fiber sprouting) of lamotrigine and ethosuximide on temporal-lobe epilepsy induced by lithium-pilocarpine.Methods:(1) Use lithium-pilocarpine to make chronic temporal-lobe epilepsy:status epilepticus was induced using the lithium-pilocarpine intraperitoneally injection. An aqueous solution of lithium chloride3mmol/kg was injected i.p.18-24h prior to injection of pilocapine in dose of30mg/kg. Add10mg/kg pilocarpine every15min to achieve4or5grade status epilepticus if animals don't achieve4or5grade status epilepticus after30min first injection of pilocarpine. After pilocapine injection,seizure activity was monitored behaviorally and graded according to Racine's criterion (Racine,1972).Only rats that displayed continuous and convulsive seizure activities of stage4or5after pilocapine injection were used in the experiments,seizures were terminated with sodium pentobarbital10mg/kg when rats experienced stage4or5seizures for60min. The animal who survive after above operation is regard as the success one.(2) Randomly divide into6groups:the normal control group, the model control group, the low-dose lamotrigine group(LTG10mg/kg), the high-dose lamotrigine group(LTG20mg/kg), the low-dose ethosuximide group(ESX25mg/kg), the high-dose ethosuximide group(ESX50mg/kg).(3) To appraise the ethology, EEG and mossy fiber sprouting with these two drugs on all the groups.(4) All results are expressed as mean±sem. Statistical analysis of the data was performed using standard one-way ANOVA, followed by the LSD-t between groups. Statistical significance was set at P<0.05.Results:(1) The low and high dose lamotrigine can control the spontaneous recurrent epileptic seizure (SRS),improve the appearance of EEG(reduce the frequency of spike wave or sharp wave and lower the amplitude of the epilepsy wave) and restrain the mossy fiber sprouting(MFS)in the dentate gyrus and CA3zone. There is statistically difference between the model control group and the lamotrigine groups, and there is statistically difference between the lamotrigine low-dose group and the lamotrigine high-dose group;(2) however ethosuximide without the above effects, ethosuximide can't control the spontaneous recurrent epileptic seizure (SRS), can't improve the appearance of EEG(reduce the frequency of spike wave or sharp wave and lower the amplitude of the epilepsy wave) and can't restrain the mossy fiber sprouting(MFS) in the dentate gyrus and CA3zone. There is no statistically difference between model control group and ethosuximide groups, and there is no statistically difference between the low-dose ethosuximide group and the high-dose ethosuximide group.Conclusion:Lamotrigine can prevent the temporal-lobe epilepsy induced by pilocarpine, Lamotrigine can control SRS, improve EEG and restrain MFS of the chronic model; Ethosuximide can't prevent the temporal-lobe epilepsy induced by pilocarpine, ethosuximide can't control SRS, improve EEG and restrain MFS on this model.