Effects of environmental enrichment on the neonatal rat hippocampus neurons after hypoxia-ischemic brain damage mediated by Akt signaling passway

Objective To study the effects of environmental enrichment stimulation(EES)on the neonatal rat hippocampus(CA1)neurons after hypoxia-ischemic brain damage(HIBD)mediated by Akt signaling passway.Methods Ninety healthy SD rats of 7 days old were randomly divided into three groups with 30 rats each.The rats in group A were not treated with HIBD as the controls.The rats in group B were treated with HIBD using Sale technique and without EE.The rats in group C were given EES(2-h stimulation per day for 20 days)after HIBD model had been established.Ten rats were choosen from each group on the 3rd and 20th day after hypoxia-ischemia and then the brains of them were decapitated for detecting the phosphorylation of Akt and Bad(ser136)in the CA1 region by Western blot and neurons injury by Cresly violet-strained.Results Compared with group A,the phosphorylation level of Akt and Bad(ser136)was significantly lower on the 3rd day in group B(P0.05)and the injury of CA1 neurons was more severe on the 20th day(P0.05).The phosphorylation level of Akt and Bad(ser136)on the 3rd day was significantly higher in group C than that in group B(P0.05)and the injury of CA1 neurons on the 20th day was less severe in group C than that in group B(P0.05).Conclusion EES may promote the recovery and reduce the injury of CA1 neurons after HIBD.An increase of phosphorylation level of Akt and Bad(ser136)may be one of the mechanisms for that.