| Background: Epilepsy is a complex clinical syndrome that has high incidence and does great harm to patients. Therefore, the etiology and therapeutics of epilepsy has become important subjects to study in the medical field. Previously, the cortex is often emphasized as the site of seizure origin, and more investigations on epilepsy focus on brain cortex and hippocampus. Recently, accumulating evidence indicates that the cerebellum plays a crucial role in controlling and modulating epileptic seizures; on the other hand, chronic epilepsy can impair cerebellum and induce cerebellar atrophy. So, it is believed that there is some relationship between epilepsy and cerebellum. To find out the effects of cerebellum on epilepsy may provide new view for the etiology and therapeutics of epilepsy. Objective: In this study, we observe the change of behavior, EEG, and immunoreactivity for glial fibrillary acidic protein (GFAP) in cerebellum of lithium-pilocarpin seizures (LPS) rats. We hope to find some clues about relationship between epilepsy and cerebellum and evaluate effects of ginkgo biloba extract (GBE) on epileptic seizure. Objective: We selected healthy male adult Sprague-Dawley rats as research animal, and made LPS rat model. The changes of behaviors were observed, the EEG of rats were recorded, and the cerebellum section were Nissl-stained and immumohistochemistry-stained by c-Fos protein and GFAP. We also observed the effects of GBE on the cerebellum of LPS rats. Results: 1. LPS rats total to 40, the mortality rate is 10%. In the survival 36 rats, 33(91.67%) rats developed seizure of stage 4 or greater, according to Stewart 10-stage classification system. After silence period, all of the LPS rats appeared spontaneous recurrent seizures, about 2-4 times per week. The EEG of LPS rats were also abnormal. The frequency was increased, and the amplitude was elevated. Multiple spikes waves discharges or paroxysmal and continual spikes clusters discharges were recorded on the EEG of LPS rats. Then, we can recognize the LPS model is successful. 2. In the cerebellum of LPS rats, no c-Fos protein immunoreactivity (IR) positive neurons were observed. In Nissl-stained sections, the neurons of LPS rat were not obviously lost, compared with control. 3. GFAP immunohistochemistry staining showed there were so many GFAP-IR positive cells in granule layer of anterior lobe of LPS rats cerebellum, and statistical difference is significant, compared with control group. The GFAP immunoreactivity increased to peak value at 1 day, and decreased to normal level at 60 day after administration of pilocarpine. 4. Pre-treatment with GBE significantly reduced seizure stage, efficiently prevented spike discharges on EEG, and greatly inhibited activation of astrocytes induced by seizure in cerebellum. Conclusion: 1. Epileptic seizure can active astrocytes in cerebellum by some way, but has little effects on neurons. The activation of astrocytes in cerebellum may indicate the injury of cerebellum.2. Epilepsy mainly affects anterior lobe of cerebellum, namely spinocerebellum, which may be due to the special physiological function and anatomical structure of the lobe. 3. GBE maybe has some anti-epileptic effects, and can protect cerebellum from impairment induced by epileptic seizure.
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