创伤性应激障碍样大鼠海马GABA受体表达的变化

Changes of GABA receptors of different sub-regions of hippocampus in posttraumatic stress disorder-like rats

目的:使用单次延长刺激(SPS)模型,考察创伤后应激障碍对大鼠海马CA1和CA3亚区GABA受体蛋白表达的变化。方法:大鼠分为未造模组、SPS造模后1天和14天组。采用旷场测试中的中央区停留时间和高架十字测试中的开臂/(开臂+闭臂)指数来评价SPS模型诱发的创伤后应激障碍样行为,即焦虑和过度觉醒状态;并使用蛋白印迹检测大鼠海马CA1和CA3亚区的GABA_A和GABA_B受体的表达量。结果:和其他两组相比,SPS造模后14天组在旷场测试时中央区停留时间及高架十字测试时的开臂/(开臂+闭臂)指数均显著降低(P<0.05),同时在CA1和CA3区的GABA_A和GABA_B受体蛋白表达水平均降低(P<0.05)。结论:海马CA1区和CA3亚区的GABA_A和GABA_B受体蛋白表达异常可能参与了SPS模型诱发的大鼠创伤后应激障碍样行为。

Objective： To investigate the associations between posttraumatic stress disorder-like behaviors and changes of GABA receptors in the hippocampus CA1 and CA3 brain region of rats. Methods： Rats were divided in- to 3 groups： group of no SPS manipulation, group of 1 d after SPS manipulation, group of 14 d after SPS manipula- tion. PTSD-like behaviors, i. e. anxiety-like behaviors was measured by time spent in central area during open field （OF） test and open arms/（ open arms ＋ closed arm） index during elevated plus maze （EPM）. Western blot was used to detect protein levels of GABAA and GABAB receptors in CA1 and CA3 areas of the hippocampus. Results： The results showed that compared with the other two groups, group of 14 d after SPS exhibited significantly de- creased time Spent in central area during OF and decreased open arms/（open arms ＋ closed arm） index during EPM test （both P 〈0. 05）. Meanwhile, the results of Western blot analyses showed that GABAA and GABAB ex- pression level in both CA1 and CA3 of group of 14d after SPS groups were significantly decreased （P 〈 0. 05）, compared with that the other two groups. Conclusion： It suggests that single-prolonged stress could induce delayed onset of PTSD-like behaviors in rats, which may be associated with the decrease of GABAA and GABAB receptorsin hippocampus CA1 and CA3.