Effects of early enriched environment intervention on neurofilament protein expression in rats with hypoxic-ischemic brain injury

Objective To investigate effect of enriched environment on neurofilament protein (NF) expression in the rats with hypoxic-ischemic brain injury (HIBI). Methods Totally 52 7-day-aged rats were divided into normal control group (n=12), and the left 40 into HI non-intervention group(n=20) and EE intervention group(n=20) after establishment of HIBI model. EE intervention group received touch and enriched environment stimulus for 28 d. After determination of ethology, the expression of NF protein was observed in the hippocampus and the results were analyzed quantitatively with image analysis system. Results Compared with normal control group and EE intervention group, the NF expression and the ratio of integrated optical density of NF in right to left brain (L∶R_ NF ) were decreased in HI non-intervention group, while no difference was seen in the normal control group and EE intervention group. Morris water maze indicated that long-term memory of HI non-intervention group was much lower than that of normal control group and EE intervention group (P0.01) , but EE intervention group was similar in normal control group. Conclusion Touch and enriched environment stimulus conduce to attenuate HIBI, probably by the mechanism of promoting neural network’s re-establishment.