Effects of early intervention on functional outcome and content of GAP- 43 in the brain of rats with hypoxic-ischemic brain damage

Objective To study the effects of early intervention on functional outcome and content of growth associated protein (GAP- 43) in the brain of rats with hypoxic-ischemic brain damage (HIBD). Methods The animal model of intra-uterus HIBD was established in 30 pregnant Sprague-Dawley rats, who were then divided randomly into 4 groups: the intervention HIBD group (HIBD-IT),the non-intervention HIBD group (HIBD-NIT),the intervention control group(control-IT),the non-intervention control group(control-NIT). From the second day after the operation, the rats of the HIBD-IT and control-IT groups were kept in an enriched environment and administered with the neonatal handling including massage for 14 days. On the 28th day, jumping stand test was administered to all the rats, at the same time, the expression of GAP- 43 in brain of the rats in different groups were measured by immunohistochemical method. Results On the jumping stand test, the performance of control-IT and HIBD-IT groups were significantly better than that of the control-NIT and HIBD-NIT groups(P0.05), respectively. Immunohistochemical analysis showed that expression of GAP- 43 in prefrontal cortex and CA3 region of hippocampus, was significantly stronger in the HIBD-IT and control-IT groups as compared with that of the HIBD-NIT and the control-NIT groups (P0.05), respectively. Conclusion Early intervention could effectively improve learning and memory and relieve the neuron behavior sequela in HIBD rats, and the intervention could also improve the brain function of the normal rats. The up-regulated GAP- 43 expression in the brain may contributed to the amelioration of brain function treated by early intervention.