Effects of Early Enriched Environment on Expressed of Growth Associated Protein 43 in Hippocampus of White Matter Damaged Neonatal Rats

Objective To study the effects of early enriched environment on expression of growth associated protein 43(GAP-43) in hippocampus of white matter damaged(WMD) neonatal rats.Methods Two days old postnatal SD rats (n=29) were collected and randomly divided into normal control group(n=9),intervention group(n=10) and non-intervention group(n=10).The latter 2 groups were subjected to WMD at first.The right common carotid artery was dissected and ligated,and after 2 hours rest,exposed to 60 mL·L-1 oxygen 940 mL·L-1 nitrogen gas mixture.After that,intervention group received the neonatal handling and was kept in an enriched environment for 27 days.Neonatal handling was applied from the 4th day to the 10th day after WMD.Then intervention group was put into enriched environment from the 11th day to the 30th day after WMD.The other 2 groups were fed in normal environment.The abilities of sensorimotor function (hanging test and inclined plane test) were observed after intervention,and Western blot was used to examine the expression of GAP-43 in hippocampus at the 7th day and the 27th day after intervention.Results The sensorimotor function abilities of intervention group were much higher than those in non-intervention group (P0.01).Compared with that in control group,expressions of GAP-43 in intervention group and non-intervention group were higher on the 7th day after intervention (P0.01).The expression of GAP-43 was up-regulated on the 27th day in intervention group (P0.01).Conclusions Early enriched environment can improve the motion ability of WMD neonatal rats,changing the expression of GAP-43 in hippocampus is a possible cause.