Abstract: ObjectiveTo study the impact of early intervention on proliferation of neural stem cells in brain damage rats after intrauterine infection.
MethodsTotally 36 Wistar pregnant rats were randomly divided into two groups:LPS(n=30) and saline(n=6).Pregnant rats were consecutively injected with LPS(450 μg/kg) or saline on gestation 17 d.Saline neonatal rats were randomly selected as saline group N(n=30),LPS neonatal rat as training group T(n=30) and injury group I(n=30).The 1 d T group rats were interfered by early interventiont.At the same time,the N,I group rats were fed in the routine way.The expression of bromodeoxyuridind(BrdU) were determined by immunohistochemistry at 1，7，14，28 d of all groups.BrdU was used to mark dividing neural stem cells（NSCs) in hippocamp dentate gyrus subgranular zone（SGZ).
Results（1）BrdUlabeled cells could be observed in all groups；I groups and T groups were markedly less than N group（P<0.01）.(2)The number of positive cells of N group increased at 3 day（P<0.05）,approximately six fold with a peak at 7 day,markedly decreased at 28 day and approched normal level of mature rats.(3)Compared with the N group,the number of positive cells of T group increased strikingly at 3 day（P<0.01）,exceeding N group and approximately six fold with a peak at 14 day,then gradually decreased,but still higher than N group at 28 day.The appearance of increasing peak in T group was lengthened，value ascended.
ConclusionsOur results indicate that the brain damage caused by intrauterine infection can lead to the decrease of proliferation of inherent NSCs.The damage will not recover itself.Early intervention can stimulate the proliferation of inherent NSCs.Early period enriched environment can prolong the development window phase of inherent NSCs.

Key words: Brain damage;Intrauterine infection;Glial proliferation;Intervention；Rat；Animal, experiment