The Expression Of Neurons Migrate Protein DCX And LIS1in Neonatal Rats Brain On Corticosterone

Objective:To investigate the alternation of neurons migrate protein DCX (doublecortin) and LIS1(microtubule binding lissencephaly1) expressions in neonatal rat pups brain after exposed to corticosterone.Methods:48of7-day-old Sprague-Dawley rats were assigned randomly into two groups:the control group and the corticosterone group. The rat pups in the corticosterone group were injected intraperitoneally corticosterone (1.5mg/kg) between8:00and9:00for consecutive six days. The pups in the control group were injected the same volume of normal saline at the same time. Brains were sampled on postnatal (PN-)14d,17d, and21d. The expressions of DCX and LIS1protein in cerebral cortex and hippocampus were detected by immunohistochemistry method and Western Blot method.Results:Compared to the control group, the accumulated optical density (AOD) of DCX immunoreactivity (IR) in the corticosterone group increased significantly both in the cerebral cortex and all regions of hippocampus on the PN-14d. PN-17d and PN-21d (P<0.05).The expression of DCX protein in the corticosterone group increased significantly than that in the control group in hippocampus by Western blotting. Compared to the control group, the AOD of LIS1IR in the corticosterone group decreased significantly both in the cerebral cortex and all regions of hippocampus on the PN-14d (P<0.05). Compared to the control group, the expression of LIS1protein in the corticosterone group decreased significantly in the cerebral cortex on the PN-14d and PN-21d and in the hippocampus on the PN-21d (P<0.05) by Western blotting.Conclusions:1.The expression of DCX and LIS1,in the normal brain of newborn rat pups show the temporal and spatial changes.2. Exogenous glucocorticoid may modify neuronal migration movements by up-regulating DCX expression and down-regulating LIS1expression.