Mossy Fiber Sprouting And Hilar Ectopic Granule Cells In Different Periods Of Li-Pilocarpine Induced Epilepsy

Object: The purpose of this study was to investigate the trends of mossy fibersprouting and hilar ectopic granule cells in different periods of temporal lobeepilepsy (TLE).Methods: We used Li-Pilocarpine to induce chronic model of temporal lobeepilepsy. Animals were killed in different periods (1hour,1week,2weeks,1month,2months,3months) after SE to observe MFS and HEGC. To label mossy fiberterminals and cell bodies of granule cells, Timm’s staining and Calbindine D-28k(CaBP) immunohistochemical staining was applied respectively. Then we comparedthe extent of MFS and HEGC in different periods of epileptogenesis throughobserving the results of staining with the light microscope (LM).Results:1. Intraperitoneal injections of pilocarpine to rats induced SE that canbe controlled by diazepam. After a latent period, rats represented spontaneousrecurrent seizures (SRS, chronic phase).2. The electroencephalogram (EEG) of ratswhich were in acute or chronic period showed abnormal waveforms.3. MFS emergedwithin1week after SE, and its extent was more obvious as time going until2monthsafter SE.4. We observed a small number of HEGCs2weeks after SE. In the rats thatkilled2months and3months after SE, the HEGCs tended to aggregated distributionin the hilar/CA3border.Conclusion: As the important pathological changes of granule cells, mossy fibersprouting and hilar ectopic granule cells exist in TLE. They perform the progressivecourses, and form the stable structures in chronic phase of TLE.