The Role Of Inflammation In Epileptogenesis Of Mesial Temporal Lobe Epilepsy In The Immature Rats

Objective:To investigate the dynamic expression changes of TLR4, MRP8and IL-lbeta in hippocampus of the immature epileptic rats during the development of epilepsy, and to explore whether they induced the pathogenisis of MTLE.Methods:90male3-week-old healthy Sprague-Dawley rats were divided randomly into control group and LiCl-Pilocarpine experimental group. The experimental rats were intraperitoneally injected with LiCl (127mg/kg) and Pilocarpine (50mg/kg) to induce status epilepticus (SE). SE was stopped with10%chloral hydrate intraperitoneally injecting90minutes later. Survival rats were continuously observed for onset and recurrence of spontaneous seizures every day and were grouped and sacrificed at2h (acute group),3w (latent group) and8w (chronic group) after the last pilocarpine injection respectively. The control rats were mitted tales doses of0.9%saline and grouped and sacrificed at2h,3w,8w after the saline injection. And all groups were executed for behavioral score and EEG scanning to identify the model. Then, by using immunohistochemistry, western-blotting and RT-PCR analysis, we examined the dynamic expression of TLR4, MRP8and IL-lbeta in the subfields of each gourps’hippocampus.Results:In control rats, behavioral and EEG manifestations were normal. And in experimental group,93.3%of the rats had successfully induced SE with a little high mortality of30.8%;62.8%of the survival rats were observed for spontaneous recurrent seizures, which were quite consistent with the features of human MTLE.Compared with control group, the expression of TLR4, MRP8and IL-lbeta increased in all of the model group (p<0.05).Both of TLR4and MRP8elevated at the areas of CA3, CA1, DG. In all of model group, the expression of TLR4,MRP8and IL-lbeta increase more significantly in acute stage and chronic stage than the latent stage (p<0.05).Conclusion:We used lithium chloride and pilocarpine to establish an immature rat chronic MTLE model that is quite consistent with the features of human MTLE.The evelated expressions of TLR4and MRP8in MTLE model rat indicate they could be responsible for the epileptogensis of MTLE. The TLR4/MRP8/IL-lbeta pathway may play an important role in the pathogenisis of MTLE.