强迫性冷水游泳应激对大鼠行为和海马神经颗粒素的影响

THE EFFECT OF FORCED COLD-WATER SWIMMING STRESS ON BEHAVIOR AND NEUROGRANIN LEVEL OF BRAIN IN RATS

为考察应激对海马神经颗粒素含量和磷酸化水平的影响,以及神经颗粒素是否涉及应激所致行为效应的脑机制,采用强迫性冷水游泳应激模型,选取40只Sprague-Dawley大鼠,随机分为应激组、装置对照组和正常对照组1和正常对照组2。以旷场试验法测定应激前后大鼠行为的变化,以Westernblotting技术测定大鼠海马区域神经颗粒素的总含量和磷酸化水平,并分析两者之间的相互关系。结果表明:应激组动物活动增加,表现出焦虑行为;而海马区域神经颗粒素含量降低,与对照组相比差异具有显著性;且多项行为指标的变化与海马神经颗粒素含量的改变呈显著相关。这些结果提示神经颗粒素有可能在应激所致焦虑行为中起作用,可作为预测应激所致焦虑行为的较为敏感的指标之一。慢性应激过程中海马区域没有发现神经颗粒素的磷酸化反应。

To explore the effects of stress on the hippocampal protein and phosphorylation levels of neurogranin, and the possible role of neurogranin involving in the brain mechanisms underlying stress-induced behavioral changes, in this present study, forced cold-water swimming was used as a stressor, and 40 male Sprague-Dawley rats were randomly distributed into four groups: swimming group, apparatus controls and two cage control groups in the present study. Behavioral changes in rats after stress were observed by open-field test, and neurogranin level of hippocampus was determined by Western blotting. The results showed that neurogranin level of hippocampus in swimming rats was significantly lower than that in apparatus controls or cage controls although changes in phosphorylation of neurogranin on hippocampus was not detected. Moreover, activity of the swimming group also significantly increased. Almost all of the behaviors observed were negatively correlated with the level of neurogranin of hippocampus. These results suggested that neurogranin may play a role in stress-induced anxious behaviors, and could be a sensitive predictor of anxiogenic effect of stress.