Effect of Enriched Environment Early Intervention on Periventricular Leukomalacia of Premature Rats

Objective To explore the protective effects of the early enriched environment stimulation in the periventricular leucomalacia (PVL) of the premature rats and the expression of growth-associated protein-43(GAP-43).Methods Two days old postnatal of PVL SD rats models were established.Then they were randomly divided into intervention (n=40) and non-intervention groups (n=40). The sham-operation rats served as control group (n=40). Then the enriched environment intervention was administrated to the intervention groups.Non-intervention groups and the sham-operation groups were breeded in standard environment,and did not intervent by enriched environment. On the fifth week, the abilities of sensorimotor movement (hanging test and inclined plane test), learning and memory function were evaluated. On the 4th,11th,18th,25th,32th day, the expression of GAP-43 in the hippocampus was measured by the method of reverse transcription-polynerase chain reaction(RT-PCR).Results The abilities of sensorimotor movement [hanging test:(4.5±1.5)min vs (3.1±0.9)min;inclined plane test:(2.3±0.7)s vs (3.9±1.1)s] and the learning and memory ability[escaped latent period:(4.86±2.94)s vs (15.0±11.23)s;Space learning and memory test:(62.89±8.69)% vs (43.99±8.29)%] of intervention group were improved compared with non-intervention group(Pa0.05). And those abilities of non-intervention group reduced and was much lower than that of sham group.RT-PCR analysis showed that expression of GAP-43 on the 11th,18th,25th,32th day in the hippocampus of intervention group significantly increased compared with that of non-intervention group [(3.21±0.45) vs (2.63±0.32);(2.74±0.34) vs (2.47±0.25);(2.14±0.29) vs (1.75±0.19);(1.96±0.25) vs (1.63±0.15) Pa0.01].Conclusions Early enriched environment can improve brain function of PVL in premature rats. The enriched environment stimulation could increase the expression of GAP-43, and it may be mec-hanism of the recovery of PVL in the premature rats.