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Objective:To investigate the effects of hippocampal injection of tyrosine kinase receptor binding protein B3(Ephrin-B3) agonist on spontaneous seizures and the expression of hippocampal secretory glycoprotein (Reelin) and phosphorylated adaptor protein (p-Dab1) in epileptic model rats.Methods:Seventy-eight rats were randomly divided into control group and model group according to body mass matching with 39 rats in each group.The rats in control group were fed normaly, and the rats in model group were established epilepsy model by intraperitoneal injection of lithium chloride pilocarpine. The hippocampal tissues were taken in the acute phase (7 days), quiescent phase (14 days) and chronic phase (60 days) after the successful induction of status epilepticus. The levels of Reelin protein and p-Dab1 protein in the hippocampal tissues of epileptic model rats and normal rats were detected by immunohistochemistry and Western blot.And thirteen rats were randomly selected at each time point. Another 48 rats were randomly divided into normal Fc-control group, normal EphB3-Fc group, epilepsy Fc-control group and epilepsy EphB3-Fc group, with 12 rats in each group. Rats in the first two groups were fed normally, and those in the latter two groups were established epileptic model. Seven days after modeling, all rats were injected into bilateral hippocampus with EphB3-Fc (Ephrin-B3 agonist) and FC control (control agent of Ephrin-B3 agonist) according to the grouping, once a day for 7 days. After administration, the changes of behavior and EEG were observed within two weeks. At the same time, the expression of Reelin protein and p-Dab1 protein were detected by immunohistochemistry and Western blot. SPSS 21.0 was used for statistical analysis, One-way ANOVA was used for multi group comparison, and Tukey's test was used for pairwise comparison.Results:The results of immunohistochemistry and Western blot showed that compared with the control group, the levels of Reelin and p-Dab1 protein in hippocampus of model group decreased significantly at 7, 14 and 60 days after epilepsy (all P<0.01). The results of immunohistochemistry showed that compared with epilepsy Fc-control group, the levels of p-Dab1 ((0.41±0.04), (0.58±0.06), P<0.05) in epilepsy EphB3-Fc group increased significantly.Western blot result showed that the level of p-Dab1 in epilepsy EphB3-Fc group increased compared with that of epilepsy Fc-control group (1.34±0.04), (2.26±0.10), P<0.01). Compared with epilepsy Fc-control group, epilepsy EphB3-Fc group showed less average seizure duration ((39.00±1.79)s, (26.50±1.87)s; t=23.21, P<0.01), less frequencies ((2.00±0.89), (0.50±0.55); t=2.32, P<0.01) and less latent period ((6.33±1.37)day, (12.50±1.87)day; t=2.52, P<0.01) in spontaneous recurrent seizures. Compared with epilepsy Fc-control group, epilepsy EphB3-Fc group showed lower average amplitude ((37.30±1.21)μV, (29.00±1.41)μV; t=25.14, P<0.01), less average seizure duration ((5.35±0.19)s, (2.35±0.19)s; t=3.13, P<0.01). Conclusion:Ephrin-B3 alleviated spontaneous recurrent seizures by upregulating Reelin and p-Dab1 in temporal lobe epilepsy rat.
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@#Objective To explore dynamic expression of Ephrin-B3 in hippocampus of pilocarpine induced epileptic rats and the role of Ephrin-B3 in the process of epileptogenesis.Methods We first established pilocarpine induced epileptic rat model and then detected Ephrin-B3 expression at 7,14 and 60 days post status epilepticus (SE) by real time qPCR,immunohistochemistry and Western blot.Results After pilocarpine injection,rats showed facial muscles,forelimb and tail clonus and ataxic lurching,head bobbing and wet dog shakes.Real time qPCR revealed that Ephrin-B3 mRNA expression in hippocampus decreased during spontaneous seizure period.Compared with controls,epileptic rats showed decreased Ephrin-B3 expression at 7 days,reached the lowest level at 14 days and then increased slightly at 60 days post-SE (P<0.001).Ephrin-B3 protein in hippocampus also decreased at 7,14 and 60 days detected by Western blot (P<0.001).Immunohistochemistry results showed that Ephrin-B3 mainly expressed in granule cells in dentate gyrus.Analysis of immunohistochemistry revealed decreased Ephrin-B3 expression in epileptic rats compared with controls (P<0.001).Conclusion The dynamic changes of Ephrin-B3 expression in hippocampus of epileptic rats indicated that Ephrin-B3 may participate in the process of spontaneous recurrent seizures.
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Background: Seizure is a commonly encountered problem in pediatric practice. Convulsive disorder constitutes a heterogeneous group with a varied etiology. Arriving at the cause of seizure is important as it plays a vital role in managing the child. Chances of recurrence to be analyzed, after the first episode of seizure for management. The aim was to study the etiology and the causes of recurrence after a first episode seizure.Methods: A prospective observational study was done on 135 children for a period of two months admitted in tertiary care center. Proper history, complete neurological and other systemic examinations was done. Blood investigations and imaging with EEG was done when indicated. All children were classified according to International League against epilepsy and followed up for recurrence rate and history leading to recurrence. Co- relation between recurrence and risk factors was analyzed.Results: Electroencephalogram tracing was abnormal in 62 out of 105 children. 19 out of 62 had recurrence while only 2 among 43 normal EEG had recurrence. This was statistically significant (P value 0.001). Children with remote symptomatic etiology constitutes the majority in those with abnormal EEG tracings. In children with remote symptomatic etiology, only one child had normal EEG. Remote symptomatic had higher number of abnormal EEG when compared to others and was found to have more recurrence.Conclusions: Children with EEG abnormalities after the first episode of afebrile seizure have more chance of recurrence. Children with seizure secondary to remote symptomatic etiology had more recurrences.
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This study aimed to determine the long-term change of seizure susceptibility and the role of nNOS on brain development following recurrent early-life seizures in rats. Video-EEG recordings were conducted between postnatal days 50 and 60. Alterations in seizure susceptibility were assayed on day 22 or 50 using the flurothyl method. Changes in nNOS expression were determined by quantitative immunoblotting on day 50. On average, rats had 8.4+/-2.7 seizures during 10 daily 1 hr behavioral monitoring sessions. As adults (days 50-60), all rats displayed interictal spikes in the hippocampus and/or overlying cortex. Brief electrographic seizures were recorded in only one of five animals. Rats appeared to progress from a period of marked seizure susceptibility (day 22) to one of lessened seizure susceptibility (day 50). Up-regulation of nNOS expression following early-life recurrent seizures was observed on day 50. In conclusion, these data suggested that recurrent early-life seizures had the long-term effects on seizure susceptibility late in life and up-regulatory nNOS expression on the hippocampus during brain development, and nNOS appeared to contribute to the persistent changes in seizure susceptibility, and epileptogenesis.
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Objective To explore the dynamic expression of a new phospholipid phosphatase, plasticity related gene 1 ( PRG-1 ) in cerebral cortex following recurrent neonatal seizures.Methods A seizure was induced by inhalant flurothyl daily in neonatal Sprague-Dawley rats from postnatal day 6 (P6).Rats were assigned into the recurrent-seizure group (seizures induced in six consecutive days) and the control group.At 3 h,12 h,48 h,14d after the last convulsion,PRG-1 protein level in cerebral cortex was detected by western blot method.Results At 3 h, 12 h,48 h, 14d after the last convulsion in control group, the expression of PRG-1 in cerebral cortex respectively was 1.363 ± 0.742,1.278 ± 0.687 ,0.763 ± 0.374,1.004 ± 0.113, in experimental group , the expression of PRG-1 in cerebral cortex respectively was 1.818 ± 1.093,1.562 ± 0.782,1.024 ± 0.510,1.378 ± 0.279.At 3 h, 12 h,48 h, the expression of PRG-1 in cerebral cortex was not significantly different between the experimental and control group( t = 0.843,0.668,1.011 ,all P ＞ 0.05 ).However, at 14 d, the level of PRG-1 protein in cerebral cortex of experimental group was significantly higher than that of control ( t = 3.041, P ＜ 0.05 ).Conclusion The up-regulated expression of PRG-1 in cerebral cortex may be associated with the recurrent neonatal seizure-induced brain damage.
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Objective To explore the expression of drug transporter organic anion transporting polypeptide2(Oatp2) and P-glycoprotein(P-gp) in brains of chronic epileptic rats induced by lithium-pilocarpine.Methods Chronic epilepsy modles were elicited after status epilepticus(SE) induced by lithium-pilocarpine in adult Wistar rats.The expressions of Oatp2 and P-gp were detected by immuno-histochemistry(SABC) method.Results Positive expression of Oatp2 was predominantly in the plexus epithelial cells and(blood-brain) barrier endothelial cells.Weak staining for Oatp2 was also detected in the neurocyte.In contrast,apparent expression of(P-gp) was seen in brain capillary and neurocyte only.Compared with normal control rats,expression of Oatp2 on the plexus epithelial cells and brain capillary in chronic epileptic rats was significantly decreased(P
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0.05).However,the level of PRG-1 protein in cerebral cortex of experimental group was significantly higher than that of control group at 7 d(t=2.347,P=0.041).Conclusion The up-regulated expression of PRG-1 in cerebral cortex may be associated with the recurrent neonatal seizure-induced brain damage.