Sterlemann Vera, Ganea Karin, Liebl Claudia, Harbich Daniela, Alam Stephanie, Holsboer Florian, Müller Marianne B, Schmidt Mathias V
Max Planck Institute of Psychiatry, Munich, Germany.
Horm Behav. 2008 Feb;53(2):386-94. doi: 10.1016/j.yhbeh.2007.11.001. Epub 2007 Nov 19.
The period of adolescence is characterized by a high vulnerability to stress and trauma, which might result in long-lasting consequences and an increased risk to develop psychiatric disorders. Using a recently developed mouse model for chronic social stress during adolescence, we studied persistent neuroendocrine and behavioral effects of chronic social stress obtained 12 months after cessation of the stressor. As a reference, we investigated immediate effects of chronic stress exposure obtained at the end of the chronic stress period. Immediately after the 7 week chronic stress period stressed animals show significantly increased adrenal weights, decreased thymus weight, increased basal corticosterone secretion and a flattened circadian rhythm. Furthermore, stressed animals display an increased anxiety-like behavior in the elevated plus maze and the novelty-induced suppression of feeding test. Hippocampal mineralocorticoid receptor (MR) and the glucocorticoid receptor (GR) mRNA levels were significantly decreased. To investigate persistent consequences of this early stressful experience, the same parameters were assessed in aged mice 12 months after the cessation of the stressor. Interestingly, we still found differences between formerly stressed and control mice in important stress-related parameters. MR expression levels were significantly lower in stressed animals, suggesting lasting, possibly epigenetic alterations in gene expression regulation. Furthermore, we observed long-term behavioral alterations in animals stressed during adolescence. Thus, we could demonstrate that chronic stress exposure during a crucial developmental time period results in long-term, persistent effects on physiological and behavioral parameters throughout life, which may contribute to an enhanced vulnerability to stress-induced diseases.
青春期的特点是极易受到压力和创伤的影响,这可能会导致长期后果,并增加患精神疾病的风险。我们使用最近开发的一种青春期慢性社会压力小鼠模型,研究了应激源停止12个月后慢性社会压力产生的持续神经内分泌和行为影响。作为对照,我们研究了慢性应激期结束时慢性应激暴露的即时影响。在7周的慢性应激期结束后,应激动物立即表现出肾上腺重量显著增加、胸腺重量减轻、基础皮质酮分泌增加以及昼夜节律变平。此外,应激动物在高架十字迷宫和新奇诱导摄食抑制试验中表现出焦虑样行为增加。海马盐皮质激素受体(MR)和糖皮质激素受体(GR)的mRNA水平显著降低。为了研究这种早期应激经历的持续后果,在应激源停止12个月后,对老年小鼠的相同参数进行了评估。有趣的是,我们仍然发现曾经应激的小鼠和对照小鼠在重要的应激相关参数上存在差异。应激动物的MR表达水平显著较低,这表明基因表达调控中存在持久的、可能是表观遗传的改变。此外,我们观察到青春期应激动物存在长期行为改变。因此,我们可以证明,在关键发育时期的慢性应激暴露会对一生的生理和行为参数产生长期、持久的影响,并可能导致对应激诱导疾病的易感性增加。