Objective:To study the dynamic expression of Nogo-A in hippocampus of rats after carbon monoxide poisoning,and to explore the effect and influence of Nogo-A in the damage to nervous system after carbon monoxide poisoning.Methods:Thirty male SD rats were randomly divided into NC group(n=6),CO group(n=6),CO-24 h group(n=6),CO-48 h group(n=6),CO-7d group(n=6).The method of injection CO gas was used to establish the carbon monoxide poisoning model.Then immunohistochemical (IHC) and Western blot (WB) techniques were used to observe dynamic expression of Nogo-A in hippocampus of rats at several time intervals after carbon monoxide poisoning and to analyze its change law.Results:IHC results showed that the average optical density value of expression of Nogo-A in NC group,CO group,CO-24 h group,CO-48h group and CO-7d group were 0.0928± 0.0038,0.01172± 0.0042,0.1452± 0.0056,0.1271 ± 0.0057,0.1088± 0.0055.WB results showed that the expression of Nogo-A in hippocampus after carbon monoxide poisoning was significantly higher than that in NC group(P＜0.05),and reached the highest level at 24 h,then had a gradual recovery after 24h.The expression of Nogo-A decreased obviously,but still higher than that of NC group by day 7 (P＜0.05).Conclusions:In this study,the increase of expression of Nogo-A was associated with carbon monoxide poisoning.The expression of Nogo-A reached the highest level at 24h,then had a gradual recovery after 24 h.