| BackgroundIn recent years,studies based on animal or cell epilepsy models have shown that acid-sensing ion channel 1a(ASIC1a),TWIK-related Acid-Sensitive K+ channel 1 and 3(TASK-1 and TASK-3)in the central nervous system play an important role in the occurrence and development of epilepsy.In some studies,ASIC la is believed to promote the occurrence of chronic epilepsy,while in other studies,ASIC1a is believed to contribute to the termination of epilepsy.The results of these studies are inconsistent and need to be confirmed by further study.The expression of TASK-1 and TASK-3 and their effects on epileptic behavior and electrophysiology have not been reported.In this study,we will analyze the expression of ASIC1a,TASK-1,and TASK-3 in the hippocampus of rats and observe their effects on electrophysiology through the model of status epilepticus induced by lithium-pilocarpineObjectiveUnder the condition of status epilepticus(SE),by observing the expression of ASIC la,TASK-1,and TASK-3 at different time points,the effects on glial cells and neurons,and the effects of ASIC1a,TASK-1,and TASK-3 on the electrophysiology of pyramidal cells,the role of ASIC1a,TASK-1,and TASK-3 in epileptic seizures was exploredMethods1.SE model was induced by intraperitoneal injection of lithium-pilocarpine,then the expression levels of ASIC1a,TASK-1,and TASK-3 mRNA in the hippocampus of Sprague-Dawley(SD)rats in the control group and at 0,1,2,and 3 h after SE were detected by Quantitative Real-time PCR(q-PCR)2.SE model was induced by intraperitoneal injection of lithium-pilocarpine,then the expression levels of ASIC la,TASK-1,and TASK-3 protein in hippocampus of SD rats in the control group and at 0,1,2,and 3 h after SE were detected by Western Blot3.SE model was induced by intraperitoneal injection of lithium-pilocarpine,then the changes of astrocytes,microglia and neurons in the hippocampus of SD rats in the control group and at 1,2,and 3 h after SE were detected by immunofluorescence4.The SE model was induced by intraperitoneal injection of lithium-pilocarpine.24 h later,the whole cell patch clamp technique was used to record the frequency changes of action potential(AP)of pyramidal cells in CA1 area of hippocampus in SD rats in the SE control group and treated with ASIC la,TASK-1,and TASK-3 inhibitors respectivelyResults1.After SE,contrasted to the control group,the expression of ASIC la mRNA was significantly reduced at 2 and 3 h,that of TASK-1 mRNA at 1 h,and that of TASK-3 mRNA at 3 h2.After SE,compared with the control group,the expression of ASICla,TASK-1,and TASK-3 protein decreased significantly at 3 h time point3.After SE,contrasted with the control group,the expression level of glial fibrillary acidic protein(GFAP)in CA1,CA3,and dentate gyrus(DG)area of hippocampus was significantly increased at 3 h time point,but there was no significant change at any time point in CA2 area;the expression level of ionized calcium binding adapter molecule 1(IBA-1)in all areas of hippocampus was significantly increased at 3 h time point;neuron specific nuclear protein(NeuN)was no significant change in all regions of hippocampus at all time points4.24 h after SE,the frequency of AP was significantly lower than that of SE group after ASIC la inhibitor PcTx1 was given,and the frequency of AP was significantly higher than that of SE group after TASK-1 and TASK-3 inhibitors ML365 and PK-THPP were given,respectivelyConclusionAfter SE,ASIC la,TASK-1,and TASK-3 were down regulated while astrocytes and microglia were activated,but had no obvious effect on neurons;after SE,ASIC la,TASK-1,and TASK-3 increased the excitability of pyramidal cells,which may participate in the process of status epilepticus. |
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