Wood Gwendolyn E, Norris Erin H, Waters Elizabeth, Stoldt Jeremiah T, McEwen Bruce S
The Laboratory of Neuroendocrinology. The Rockefeller University, New York, NY 10065, USA.
Behav Neurosci. 2008 Apr;122(2):282-92. doi: 10.1037/0735-7044.122.2.282.
Chronic stress significantly alters limbic neuroarchitecture and function, and potentiates emotionality in rats. Chronic restraint stress (CRS) increases aggression among familiar rats, potentiates anxiety, and enhances fear conditioning. Chronic immobilization stress (CIS) induces anxiety behavior and dendritic hypertrophy in the basolateral amygdala, which persist beyond a recovery period. However, little else is known about the emotional impact of CIS as a model of chronic stress or depression. Therefore, the authors present two experiments examining emotional and learned responses to CIS. In Experiment I, the authors examine individual differences in behaviors during and after CIS, specifically: struggling, aggression, learned helplessness, inhibitory avoidance, and escape behavior. In Experiment II, the authors confirm the effects of CIS on aggression and struggling during immobilization, and correlate individual responses with aspects of conditioned fear. Here the authors report significant effects of CIS on aggression, inhibitory avoidance, escape, as well as learned aspects of fear (i.e., fear conditioning) and inescapable stress (i.e., struggling and helplessness). These results emphasize the emotional and learned responses to CIS evident during and after the stress treatment, as well as the importance of individual differences.
慢性应激会显著改变边缘系统的神经结构和功能，并增强大鼠的情绪反应。慢性束缚应激（CRS）会增加熟悉大鼠之间的攻击性，增强焦虑，并强化恐惧条件反射。慢性固定应激（CIS）会诱发焦虑行为以及基底外侧杏仁核中的树突肥大，且这些变化在恢复期后仍会持续。然而，对于CIS作为慢性应激或抑郁症模型所产生的情绪影响，人们所知甚少。因此，作者进行了两项实验，研究对CIS的情绪和学习反应。在实验一中，作者研究了CIS期间及之后行为的个体差异，具体包括：挣扎、攻击、习得性无助、抑制性回避和逃避行为。在实验二中，作者证实了CIS对固定期间攻击和挣扎的影响，并将个体反应与条件性恐惧的各个方面进行关联。在此，作者报告了CIS对攻击、抑制性回避、逃避以及恐惧的学习方面（即恐惧条件反射）和不可逃避应激（即挣扎和无助）的显著影响。这些结果强调了应激处理期间及之后对CIS明显的情绪和学习反应，以及个体差异的重要性。
