The Dynamic Changes Of Cofilin And Mossy Fiber Sprouting In Hippocampus In The PTZ Kindling Model

Background and object Cofilin is a member of the actin depolymerizing factor (ADF/ cofilin), it exists in all eukaryotic cells, and its function is to combine and depolymerize F-actin.Recently,the research on RhoGTP ases superfamily and the signaling pathway they participate in is attractive , and cofilin plays a very important role in this pathway. Through the observation of the relationship of the dynamic changed expression of np- cofilin and the mossy fiber sprouting in the PTZ kindling model's hippocampus ,and use fasudil to intervene these models ,to investigate the role of the RhoGTP ases superfamily and the signaling pathway they participate in in mossy fiber sprouting, so as to provide new ideas on epilepsy.Methods 210 healthy male Sprague-Dawley rats were divided randomly into control(42), PTZ treated (84)and Fasudil intervened (84 ) groups.The rats from PTZ treated group were intraperitoneally injected PTZ (30mg/kg) every 24 hours and were stopped injection once kindled.The rats from Fasudil intervened group were intraperitoneally injected fasudil 30 minutes before the injection of PTZ,and the control group received 0.9% saline injection instead of PTZ at the same time.At 1d, 3d, lw,2w,4w,6w,8w after the first injection, the three groups were then divided into two subgroups evenly.Timm staining were scored at different time in the CA3 region of hippocampus and dentate gyrus.The non-phosphorylated cofilin was analyzed in the various subfields of hippocampus by immunohistochemistry at different time points.Results 1.Animal modelPTZ chronic kindling model After the 24-26 days' consecutive injection of PTZ,most rats were kindled,and the kindled rate is 83.33%,the mortality is 3.57%. Seizure-form discharges were recorded on the EEG in the kindled rats and we can oberserve spontaneous seizures in these rats.While they were given the same subthreshold stimulation of PTZ may induce seizures and epileptic EEG wave.The Fasudil intervened model Most rats were kindled after 24-27 days of consecutive injection, and the manifestation was alike with the PTZ chronic kindling model.The kindled rate is 86.11% and the mortality is 3.57%.Control group Neither seizures nor seizure-form discharges on the EEG were discovered in these rats.2.The dynamic changes of mossy fiber sprouting PTZ and fasudil intervened groups showed no statistical difference in the Timm scores on the CA3 rigion. While these two groups' Timm scores were significantly different compared with the control group at different time points except ld(P<0.05) .With daily injection of PTZ and fasudil ,the Timm scores on the CA3 region increased from 3d and reached peak in two weeks' injection, and then maintained high levels. There were no significant difference in the scores on supragranular region of the dentate gyms ,it was only 0 to 1 point, and no significant difference between the three groups at different time points.As the control group, CA3 region and supragranular of the DG, the scores were only 0 to 1 point and there were no significant difference at different time points too.3. The dynamic changes of np-cofilin Pentylenetetrazol and fasudil intervened groups showed no statistics difference in the expression of non-phosphorylated cofilin in hippocampus.The expression was significantly higher of 3d,1w,2w,and 4w than that of control. Thereafter,the expression was decreased to the level of control.Conclusion1. The expression change of non-phosphorylated cofilin wasconsistent with mossy fiber sprouting's trend,and may be through the participation in the course of mossy fiber sprouting, promote the occurrence of epilepsy.2. Fasudil had no significant effect on the expression of non-phosphorylated cofilin and mossy fiber sprouting in the PTZ kindling model's hippocampus.