Effects Of Recurrent Neonatal Seizures On Expression Of Glucocorticoid Receptor In The Rat Cerebral Cortex

Objective:To investigate the short-term effects of flurothyl-induced neonatal recurrent seizures on glucocorticoid receptor(GR)expressions in rat brain.Methods:48 of postnatal(PN-)7d Sprague-Dawley rats were divided randomly into two groups:the control group and the seizure group.Seizures were induced by inhalant flurothyl daily in six consecutive days.The brains of rats were sampled on after-recurrent-seizure(ARS)- ld(PN-13d),ARS-3d(PN-15d)and ARS-7d(PN-19d).The expressions of GR protein in cerebral cortex were detected by immunohistochemistry and Western blots methods.Results:The expression of GR in the cerebral cortex of rat pup has been found by western blot and immunohistochemistry method since PN-13d.The expression of GR was found in the cellular plasma on PN-13d,and that was found in the cellular nucleus and plasma on PN-15d and PN-19d.By western blot method,we found that the expressions of GR in the cellular plasma of cerebral_Ⅱcortex were similar in between two group on ARS-1d(PN-13d)and ARS-7d(PN-19d)(P＞0.05),but the expressions of GR in the cellular plasma of cerebral cortex decreased significantly in seizure rats than those in control rats on PRS-3d(PN-15d) (P＜0.05);the GR proteins were hardly expressed in the nucleus of seizure rat cortex on ARS-1d and ARS-3d,and the expressions of GR in the cellular nucleus of cerebral cortex decreased significantly in seizure rats than those in control rats on ARS-7d(PN-19d)(P＜0.05).On ARS-1d (PN-13d),the immunochemical accumulate optical densify(AOD)of GR protein in the parietal cortex decreased significantly in seizure rats than those in the control rats(P＜0.05),but the immunochemical AODs of GR protein were similar between two groups in the temporal cortex and frontal cortex(P＞0.05).On ARS-3d(PN-15d),the immunochemical AOD of GR protein in the parietal cortex and temporal cortex decreased significantly in seizure rats than those in control rats(P＜0.05),but the immunochemical AODs of GR protein were similar between two groups in the frontal cortex(P＞0.05).On ARS-7d(PN-19d),the immunochemical AODs of GR protein in the parietal cortex,temporal cortex,and frontal cortex were decreased significantly in seizure rats than those in control rats(P＜0.05).Conclusions:Recurrent seizures in neonatal rats modify GR expression in the developmental rat brain.This phenomenon raised the possibility that abnormal GR expression might play an important role in developmental brain injury.