Department of Cellular and Molecular Pharmacology, The Chicago Medical School, Rosalind Franklin University, North Chicago, IL 60064, USA.
Behav Brain Res. 2013 Jul 1;248:12-24. doi: 10.1016/j.bbr.2013.03.028. Epub 2013 Mar 26.
Affective disorders are believed to involve dysfunction within the amygdala, a key structure for processing emotional information. Chronic stress may contribute to affective disorders such as depression and anxiety via its effects on the amygdala. Previous research has shown that chronic stress increases amygdala neuronal activity in an age-dependent manner. However, whether these distinct changes in amgydala neuronal activity are accompanied by age-dependent changes in amygdala-dependent affective behavior is unclear. In this study, we investigated how chronic stress impacts amgydala-dependent auditory fear conditioning in adolescent and adult rats in a repeated restraint model. We found that repeated restraint enhanced conditioned freezing in both adolescent and adult rats. But repeated restraint led to impaired acquisition of fear extinction only in adolescent rats. Along with previous findings, these results suggest that chronic stress may precipitate affective disorders via differential mechanisms, with different outcomes at different ages.
情感障碍被认为与杏仁核功能障碍有关，杏仁核是处理情绪信息的关键结构。慢性应激可能通过其对杏仁核的影响导致情感障碍，如抑郁和焦虑。先前的研究表明，慢性应激以年龄依赖的方式增加杏仁核神经元的活性。然而，这些不同的杏仁核神经元活性变化是否伴随着与年龄相关的杏仁核依赖性情感行为的变化尚不清楚。在这项研究中，我们在重复束缚模型中研究了慢性应激如何影响青少年和成年大鼠的杏仁核依赖性听觉恐惧条件反射。我们发现，重复束缚增强了青少年和成年大鼠的条件性冻结。但是，重复束缚仅导致青少年大鼠的恐惧消退获得受损。结合先前的研究结果，这些结果表明，慢性应激可能通过不同的机制引发情感障碍，在不同的年龄阶段产生不同的结果。
