Laboratory of Behavioral Genetics, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne (EFPL), Lausanne, Switzerland.
Neuropsychopharmacology. 2011 Oct;36(11):2349-56. doi: 10.1038/npp.2011.125. Epub 2011 Jul 13.
Exposure to stress can affect the establishment of dominance hierarchies. In our model, a social hierarchy established by two male rats during a first encounter is not maintained 1 week later. If one of the two rats is stressed, the stressed rat becomes subordinate and the hierarchy that is formed is maintained. In this study, we investigated the changes in the expression of oxytocin (Otr) and vasopressin (V1aR) receptor genes in the medial amygdala (MeA) and the lateral septum (LS) in the hours following hierarchy establishment under both stressed and basal conditions. We found that the potentiation of a social hierarchy induced by stress is accompanied by social status- and region-specific changes in the expression of Otr mRNA in the MeA 3 h after the social encounter. At this time point, no evidence was found for the regulation of V1aR mRNA in any of the brain regions examined. Results from pharmacological experiments involving the microinfusion of a specific OTR antagonist immediately after the acquisition of a subordinate status under basal, non-stress conditions suggested a role for this receptor in the MeA on the long-term establishment of the subordinate status. Altogether, these findings highlight a role for the oxytocinergic system in the mechanisms through which stress facilitates the long-term establishment of a social hierarchy.
应激暴露会影响优势等级制度的建立。在我们的模型中，两只雄性大鼠在第一次相遇时建立的社会等级制度在 1 周后不再维持。如果其中一只大鼠受到压力，受压大鼠会成为从属者，并且形成的等级制度会维持下去。在这项研究中，我们研究了在基础和应激条件下，等级制度建立后数小时内，内侧杏仁核（MeA）和外侧隔核（LS）中催产素（Otr）和血管加压素（V1aR）受体基因表达的变化。我们发现，应激增强的社会等级制度伴随着社会地位和区域特异性的变化，即在社交接触后 3 小时，MeA 中 Otr mRNA 的表达增强。在这个时间点，没有证据表明任何被检查的脑区中 V1aR mRNA 的调节。在基础非应激条件下，在获得从属地位后立即对特定 OTR 拮抗剂进行微注射的药理学实验结果表明，该受体在 MeA 中对从属地位的长期建立具有作用。总之，这些发现强调了催产素系统在应激促进社会等级制度长期建立的机制中的作用。
