Expression of neuron-specific enolase protein in rats after intermittent hypoxia and its influence on learining and memory function / 中华行为医学与脑科学杂志

ABSTRACT

Objective To observe the changes of learning function and neuron-specific enolase (NSE)protein of both brian and serum in rats after intermittent hypoxia,and explore the relation between NSE protein and learning and memory function.Methods Male Wistar adult rats(n=48)were randomly divided into control group (UC group) and 7.5％ chronic intermittent hypoxia group (7.5％CIH group).7.5％ chronic intermittent hypoxia model in rats were simalated by using the self-made cabin of intermittent hypoxia.At the 2nd,4th,6th,and 8th week respectively,learning and memory function in rat was tested by Morris water maze in two groups.The level of NSE protein in hippocampal CA1 region was detected by immunohistochemical method,and was detected in serum of rats by using enzyme-linked immunosorbent adsorption method.Results Compared with the control group,7.5％ CIH group at the 2nd,4th,6th,and 8th week in rats from the second week of the escape latency time was 44.13± 2.84) s,(50.35 ± 1.96) s,(57.47 ± 1.66) s,(62.85 ± 1.80) s,and across the target quadrant time was 48.81 ± 2.09) s,(42.04± 1.84) s,(36.82± 2.07) s,(31.81 ± 1.68) s.From the first two weeks,the longer the hypoxia time prolonged,the longer the rat's escapedlatency (P＜0.05) and the shorter the rats acrossed the target quadrant (P ＜0.05).7.5％ CIH group of hippocampal CA1 neurons NSE protein at the 2nd,4th,6th,and 8th week was (9.69±1.37),17.10± 1.87),(24.79± 3.51),(34.16±5.35),respectively,and serum NSE protein at the 2nd,4th,6th,and 8th week respectively was (6.03±0.91) μg/L,(11.04± 1.89) μg/L,(16.39± 1.00) μg/L,(24.22±3.73) μg/L,both of which were more than the control group.The difference was statistically significant (P＜0.05).7.5％ CIH group of hippocampal CA1 neurons and serum NSE protein expression were significant time differences,and gradually increased over time.The difference was statistically significant (P＜0.05).Positive NSE protein expression in hippocampal CA1 region relative NSE and serum protein expression values were positively correlated (r=0.94,P ＜0.01).But in control group NSE protein expression did not exist time difference (P＞0.05).Conclusion Intermittent hypoxia can cause NSE levels significant increase in serum and brain tissue,and the dynamic changes of them can reflect severity of learning and memory impairement in rat.