Effects of neonatal recurrent seizures on glucocorticoid receptor expression in the rat brain

Objective To investigate the effets of flurothyl-induced neonatal recurrent seizures on glucocorticoid receptor (GR) expression in the rat brain.Methods Forty-eight seven-day-old Sprague-Dawley rats were randomly divided into two groups:control and seizure.Seizures were induced by inhalant flurothyl daily for six consecutive days.Brains were sampled on postnatal days 13,15 and 19.The expression of GR protein in the cerebral cortex was detected by Western blot and immunohistochemical method.Results The expression of GR in the cerebral cortical plasma protein was significantly lower in the seizure group than in the control group on postnatal day 15.The expression of GR protein in the cerebral cortical nuclear protein decreased significantly in the seizure group compared with that in the control group on postnatal days 15 and 19 (P0.05).Compared to the control group,the accumulated optical density (AOD) of GR immunoreactivity (IR) decreased significantly in the parietal cortex on postnatal day 13 (P0.05),the AOD of GR IR decreased significantly in the parietal cortex and the temporal cortex on postnatal day 15 (P0.05),and the AOD of GR IR decreased significantly in the parietal cortex,temporal cortex and the frontal cortex in the seizure group on postnatal day 19 (P0.05).Conclusions Recurrent seizures in neonatal rats result in abnormal GR expression in the cerebral cortex which might play an important role in short-term brain injury induced by early recurrent seizures.