Effect of maternal deprivation on learning and memory ability and hippocampal nerve regeneration in rats with hypoxic-ischemic brain damage / 中华实用儿科临床杂志

ABSTRACT

Objective To observe the effect of maternal deprivation(MD)on learning and memory ability and hippocampal pathology and nestin expression in rats with hypoxic -ischemic brain damage (HIBD).Methods The models of HIBD SD male rats were established by the method of Rice,and were randomly divided into 2 groupsMD group and control group.In addition,the sham -operation group(sham group)models were established.The MD group rats were separated from their mother 3 hours per day from the second day after modeling to the 21 st postnatal day.After 28 postnatal days,Morris water maze was used to evaluate the learning and memory ability of the rat models.HE stai-ning was employed to observe the hippocampal pathological change in the rats.Then,the expression of nestin in the hip-pocampus was measured by the method of immunohistochemistry.Results Their body mass changes showed that quali-ty of sham group was higher than that of the control and the MD groups,and quality was improved in the control group, compared with the MD group,and the differences were statistically significant(q =9.860 8,3.880 7,5.980 1 ,all P <0.05).The water maze scores of the MD group in place navigation test and spatial probe test were much lower than that of the control group and the sham group,and the scores of the sham group were higher than that of the control group,the differences were statistically significant(all P <0.05 ).The findings of HE stain showed that the pathology in the right -sided hippocampus of the sham group was normal and neurons were well -arranged,and that of control group was minimally abnormal,and the neurons were almost arranged orderly and remained normal.While,the pathomorpholo-gy of the MD group was obviously abnormal,the neurons were arranged disorderly,many of the neurons lost.According to the immunohistochemical findings,the number of nestin -positive cells in right -sided hippocampus of the MD group was significantly less than that of the control group,and the number of nestin -positive cells of the sham group was less than that of the MD group,which showed significant differences among the groups(all P <0.05).Conclusions MD aggravated injury to learning and memory ability of neonatal rats with HIBD,and decrease the number of nestin -posi-tive cells of MD markedly,which is not good for the recovery of brain injury.