| Part Ⅰ Establishment the chronic rat epilepsy model induced by lithium chloride pilocarpine, and evaluate the model by Video monitoring and the electroencephalogram (EEG)Objective:Establish the chronic rat epilepsy model induced by lithium chloride and pilocarpine, and evaluate the model by Video monitoring and the electroencephalogram (EEG).Methods:20 Sprague-Dawley rats(6-8 weeks, male)were divided into SRS group (n=14)and control group(n=6), rats of SRS group were injected lithium chloride(127mg/kg) 24 hours before scopolamine methyl bromide and pilocarpine (45mg/kg) was administered to establish the model of pilocarpine induced status epilepticus(SE), and diazepam (10mg/kg) was administered to terminate seizures 30min later. And the rats of the control group were injected lithium chloride, scopolamine methyl bromide and physiological saline, the status epilepticus(SE) were recorded by a Video monitoring system. After 12±2 days spontaneous recurrent seizures (SRS) were recorded by the same Video-monitoring system for 120h. Then during the chronic phase all the rats were recorded the encephlogram to study epilepsy.Results:13 rats of the SRS group developed the signs of eholinergic stimulation bilateral forelimb myoelonic movements with rearing and episodes of head and falling stared and progressed to SE in around 20-35min after the injection of pilocarpine (45mg/Kg).The 30min of SE were characterized by long-lasting, sustained clonic seizure activity that reached stage 4 and stage 5 based on Racine classfication.30 min after onset of SE, diazepam were injected. During the following 1 week,3 rats of the SRS group were dead, the success ratio of SE model was 71.4%. During the 12d-56d chronic phase, in the pilocarpine induced chronic rat epilepsy model,7 rats showed signs of seizure activity reaching 3 or 4 degree by Racine classification, while the other 3 rats of the SRS group showed signs of seizure activity reaching 2 degree by Racine classification. There were no sign of seizure activity in the control group. The success ratio of SRS model was 50%.3 rats of the SRS group and 1 rat of the control group died during the following 3 days after the surgical operation burying electrode for encephalograms, the results of the EEG presented changes between the SRS group and the control group in the shares of α wave,β wave,θ wave,σ wave. Those of the SRS group showed increasing shares of the θ wave and σ wave as well as decreasing shares ofa wave and β wave compared with those of the control group. And the EEG of the SRS group showed sharp wave which never showed of the EEG of the control group.Conclusion:The success ratio of SE model was 71.4%, and the success ratio of SRS model was50%, the establishment of the chronic rat epilepsy model induced by lithium chloride and pilocarpine was successful.Part Ⅱ The study of the changes of the white mater of hippocampus of the chronic rat epilepsy model induced by lithium chloride and pilocarpine by Diffusion Tensor Imaging (DTI)Objects:The present study aims to estimate these changes of the chronic phases of the pilocarpine rat model by the Diffusion Tensor Imaging (DTI) to evaluate the changes of the white mater of hippocampus of the chronic rat epilepsy model induced by lithium chloride and pilocarpine.Methods:The stablishment of the chronic rat epilepsy model induced by lithium chloride and pilocarpine was the same with the part Ⅰ. MR scanss were performed 7days before (baseline),56±4days after SE onset in chronic phases of epileptogenesis. MR examinations wore carried out on a 3.0 Tesla scanner made by GE company. Image J software were adapt to measure the FA value and ADC value of hippocampus in the region of interest (ROI) The data of FA value and ADC value of different time points and different groups were compared.Results:The data of ADC value and FA value of the hippocampus of the SRS group (n=7) obtained 7 days before the onset of SE of the rats of the SRS group showed no significant difference compared with those of the control group(n=5) obtained at the same time point,P>0.05.The data of ADC value of the hippocampus of the SRS group (n=7) obtained 56±4days after SE onset in the chronic phases:10.686E-10±3.121E-10 appeared significant difference of that,6.493E-10±1.451E-10, obtained 7 days before the onset of SE of the same group (n=7), P<0.01. The data of FA value of the hippocampus of the SRS group (n=7) obtained 56±4 days after SE onset in the chronic phases:0.370±0.127 appeared significant difference of that,0.459±0.080, obtained 7 days before the onset of SE of the same group (n=7), P<0.01.The data of ADC value and FA value of the hippocampus of the control group group (n=5) obtained 56±4 days after SE onset of the SRS group appeared no significant difference of those obtained 7 days before the onset of SE of the SRS group of the control group group(n=5), P>0.05.The data of ADC value of the hippocampus of the SRS group (n=7) obtained 56±4 days after SE onset in the chronic phases 10.686E-10±3.121E-10 appeared difference compared with that,7.258E-10±0.576E-10, of the same time point of the control group group(n=5), P<0.01. The data of FA value of the hippocampus of the SRS group(n=7) obtained 56±4 days after SE onset in the chronic phases 0.370±0.127 appeared difference compared with that,0.419±0.135, of the same time point of the control group group (n=5), P<0.05.Conclusions:The results of DTI study ensured changes of the white mater of hippocampus of the lithium chloride and pilocarpine induced epilepsy rat model in the chronic phases by the changes of FA value and ADC value of the hippocampus of the SRS group of the tow time points and the significant difference compared with those of the control group of the tow time points.Part Ⅲ The study of the changes of oligodendrocyte of hippocampus of chronic epilepsy modelObjective:The present study aims to study the damage of the oligodendrocyte of the hippocampus to provide evidence for possible oligodendrocyte damages in the hippocampus of the rats of lithium chloride pilocarpin induced chronic epilepsy model and to further study its effects in the DTI.Methods:The stablishment of the chronic rat epilepsy model induced by lithium chloride and pilocarpine was the same with the part Ⅰ. By means of immunofluorescence technique and Image Pro Plus software, flurorescence intensity was used to analyze the expression of myelin basic protein (MBP) and chondroitin sulfate proteoglycan NG2(NG2) in the hippocampus of rats brain tissue frozen sections to study oligodendrocyte damages of hippocampus of lithium chloride and pilocarpine induced chronic epilepsy model of rats compared with the control group.Results:The flurorescence intensity results showed that MBP expression in the CA1 of hippocampus of lithium chloride and pilocarpine induced chronic epilepsy group, which was 0.0235 ± 0.000842, was significantly decreased compared with that of the control group which was 0.0315±0.000780, P<0.01. MBP expression in the CA3 of hippocampus of lithium chloride and pilocarpine induced chronic epilepsy group, which was0.0190±0.000947, was significantly decreased compared with that of the control group which was 0.0271 ± 0.00104, P<0.01. MBP expression in the DG of hippocampus of lithium chloride and pilocarpine induced chronic epilepsy group, which was 0.0149±0.000901, was significantly decreased compared with that of the control group which was 0.0282±0.000862, P<0.01.The flurorescence intensity results showed that NG2 expression in the CA1 of hippocampus of lithium chloride and pilocarpine induced chronic epilepsy group, which was 0.00456±0.000291, was significantly increased compared with that of the control group which was 0.00320±0.000390, P<0.05. NG2 expression in the CA3 of hippocampus of lithium chloride and pilocarpine induced chronic epilepsy group, which was 0.00319±0.000178, was significantly increased compared with that of the control group which was 0.00196±0.000170, P<0.01. NG2 expression in the DG of hippocampus of lithium chloride and pilocarpine induced chronic epilepsy group, which was 0.00923±0.000591, was significantly increased compared with that of the control group which was 0.00257±0.000273, P<0.01.Conclusions:Oligodendrocytes were damaged in the hippocampus of lithium chloride and pilocarpine induced chronic epilepsy rats which was ensured by the increasing flurorescence intensity of myelin basic protein (MBP) and the decreasing flurorescence intensity of chondroitin sulfate proteoglycan NG2 compared with those of the control group.Conclusions1. The success ratio of SRS model was50%, the establishment of the chronic rat epilepsy model induced by lithium chloride and pilocarpine was successful.2. The results of DTI study ensured changes of the white mater of hippocampus of the lithium chloride and pilocarpine induced epilepsy rat model in the chronic phases by the changes of FA value and ADC value of the hippocampus of the SRS group of the tow time points and the significant difference compared with those of the control group of the tow time points.3. Oligodendrocytes were damaged in the hippocampus of lithium chloride and pilocarpine induced chronic epilepsy rats which was ensured by the increasing flurorescence intensity of myelin basic protein (MBP) and the decreasing flurorescence intensity of chondroitin sulfate proteoglycan NG2 compared with those of the control group. |
PDF Full Text Request