禁锢应激对小鼠焦虑相关脑区c-Fos表达的影响

EFFECT OF REPEATED RESTRAINT STRESS ON THE EXPRESSION OF C-FOS IN ANXIETY-RELATED BRAIN REGIONS IN MICE

目的研究反复禁锢应激对小鼠焦虑相关脑区c-Fos表达的影响。方法将2月龄雄性C57BL6/J小鼠12只随机均分为对照组、禁锢后90 min组和禁锢后7 d组,对后两组小鼠进行反复禁锢应激。利用高架十字迷宫实验检测3组小鼠的焦虑水平,采用免疫荧光技术检测3组小鼠内侧前额叶皮质(mPFC)、下丘脑(HY)、腹侧海马(vHPC)、基底外侧杏仁核(BLA)等4个焦虑相关脑区c-Fos的表达情况。结果高架十字迷宫实验表明,反复禁锢应激后7 d,小鼠表现出明显的焦虑样行为(t=3.364、6.386,P<0.05),而禁锢应激后90 min的小鼠焦虑样行为不明显(P>0.05)。免疫荧光检测结果显示,与对照组相比,禁锢后90 min组小鼠各脑区c-Fos表达均明显增加(F=13.4~645.0,q=5.1~31.6,P<0.01),而禁锢后7 d组小鼠只有HY和BLA脑区c-Fos表达仍然明显增加(q=3.0、3.0,P<0.05)。结论反复禁锢应激导致HY和BLA脑区c-Fos表达持续增加,这可能与小鼠的焦虑样行为密切相关。

Objective To investigate the effect of repeated restraint stress on the expression of c-Fos in anxiety-related brain regions in mice.Methods A total of 12 male C57BL6/J mice,aged 2 months,were randomly divided into control group,90 min post-stress group,and 7 d post-stress group,and the mice in the latter two groups were given repeated restraint stress.The elevated plus maze test was used to evaluate the level of anxiety,and immunofluorescence assay was used to measure the expression of c-Fos in the four anxiety-related brain regions of the medial prefrontal cortex(mPFC),the hypothalamus(HY),the ventral hippocampus(vHPC),and the basolateral amygdala(BLA).Results The elevated plus maze test showed that the mice displayed significant anxiety-like behavior on day 7 after repeated restraint stress(t=3.364,6.386,P<0.05),while the mice in the 90 min post-stress group did not develop significant anxiety-like behavior(P>0.05).The results of immunofluorescence assay showed that compared with the control group,the 90 min post-stress group had a significant increase in the expression of c-Fos in each brain region(F=13.4-645.0,q=5.1-31.6,P<0.01),while the 7 d post-stress group had a significant increase in the expression of c-Fos in the HY and the BLA(q=3.0,3.0,P<0.05).Conclusion Repeated restraint stress leads to a continuous increase in c-Fos expression in the HY and the BLA,which may closely associated with anxiety-like behavior in mice.