不同应激范式对大鼠行为和脑神经颗粒素含量的影响

为探讨慢性情绪应激、生理应激对大鼠旷场行为和脑神经颗粒素（Neurogranin，NG）含量的不同作用，以及NG含量变化与应激性行为效应之间的相互关系。分别以不确定性空瓶刺激和饮水剥夺，建立情绪应激和生理应激动物模型。将40只雄性SD大鼠随机分为情绪应激组（ES）、生理应激组（PS）、定时饮水组（C1）和正常对照组（C2）（n=10）。以旷场行为任务来评定大鼠应激后的行为变化，Western blotting方法测定海马和前脑皮层中的NG含量。结果表明：应激后四组大鼠海马的NG含量差异无显著性；ES组前脑皮层的NG含量低于C2组，差异具有显著性，p<0.01；PS组的前脑皮层NG含量也下降，但与C2组相比差异无显著性; 应激后ES组、PS组修饰行为多于C2组，差异具有显著性，分别为p<0.01,p<0.05;前脑皮层NG含量与修饰行为之间的相关达显著水平。提示慢性情绪和生理应激均能导致前脑皮层NG含量下降，修饰行为增加，情绪应激作用更显著。修饰行为可能是反映情绪状态的较敏感行为指标，前脑皮层NG水平可能是预测情绪应激所致焦虑或抑郁行为的较敏感生物学指标。

The Effects of Different Stressors on Behavior and Protein Levels of Neurogranin in Rats

The aim of study was to investigate the effects of chronic emotional stress and physical stress on behavior and protein levels of neurogranin in brain,and the correlation between protein levels of neurogranin and stress-induced behavioral changes.Forty rats were randomly divided into emotional stressed group(ES),physical stressed group(PS),regular drinking group(C1) and handled-controls(C2),with ten in each.Randomly giving empty water bottles was used as emotional stressor,and physical stress is induced by water-deprivation.Behavioral changes in rats after stress were observed by open-field test,and neurogranin level of hippocampus and forebrain were determined by Western blotting.The results showed that there is no significantly difference in neurogranin levels of hippocampus among four groups.Neurogranin level of forebrain in ES was significantly lower than that in C1 and C2 groups(p<0.05,p<0.01;separately). Neurogranin level of forebrain in PS was significantly lower than that in C1(p<0.05).Grooming in open-field test in both ES and PS groups was more increased than that in C2 group(p<0.01,p<0.05;separately).Correlation is significant at 0.01 level betweengrooming and neurogranin level in forebrain.These results suggested that chronic emotional stress can induce more significant decrease in neurogranin levels of forebrain and increase in grooming than physical stress.Grooming may be a sensitive behavioral index,and neurogranin levels of forebrain may be an effective biological predictor for anxiety and/or depression induced by emotional stress.