Mitra Rupshi, Vyas Ajai, Chatterjee Garga, Chattarji Sumantra
National Centre for Biological Sciences, Tata Institute of Fundamental Research, GKVK P.O., Bangalore 560065, India.
Neurosci Lett. 2005 Aug 5;383(3):278-83. doi: 10.1016/j.neulet.2005.04.037. Epub 2005 Apr 26.
Stress facilitates emotionality and consolidation of aversive memories in male rodents. In addition, considerable sexual dimorphism has been observed in animal and clinical literature, both in response to stress and predisposition to anxiety disorders thought to be exacerbated by stress. In view of this, we investigated effects of chronic immobilization stress and chronic unpredictable stress on anxiety-like behavior exhibited by female Wistar rats, using the elevated plus-maze. Neither of the stress paradigms employed in this study significantly influenced anxiety, as manifested by similar open-arm exploration in control and treated animals. Previous studies have reported that in males, exposure to elevated plus-maze during an initial trial significantly reduces open-arm exploration in subsequent retesting, an effect attributed to consolidation of aversive experience of the initial exposure. Control female animals, during a second exposure to the maze 72 h after the first trial, displayed a similar shift to a state of enhanced anxiety. Furthermore, exposure to stress did not affect such consolidation of anxiety, as evidenced by similar reduction in open-arm exploration between control and stressed animals during retesting. We conclude that female rats are insensitive to chronic stress in terms of facilitation and consolidation of anxiety.
应激促进雄性啮齿动物的情绪反应以及厌恶记忆的巩固。此外，在动物和临床文献中均观察到了显著的性别差异，无论是对应激的反应，还是对应激加剧的焦虑症的易感性。鉴于此，我们使用高架十字迷宫研究了慢性束缚应激和慢性不可预测应激对雌性Wistar大鼠表现出的焦虑样行为的影响。本研究采用的两种应激模式均未显著影响焦虑，这在对照动物和处理动物相似的开臂探索中得到体现。先前的研究报道，在雄性动物中，初次试验期间暴露于高架十字迷宫会显著减少后续重新测试中的开臂探索，这种效应归因于初次暴露的厌恶经历的巩固。对照雌性动物在首次试验72小时后再次暴露于迷宫时，也表现出类似的向焦虑增强状态的转变。此外，应激暴露并未影响焦虑的这种巩固，这在重新测试期间对照动物和应激动物之间开臂探索的类似减少中得到证明。我们得出结论，就焦虑的促进和巩固而言，雌性大鼠对慢性应激不敏感。
