Ling Travis J, Forster Gina L, Watt Michael J, Korzan Wayne J, Renner Kenneth J, Summers Cliff H
Department of Biology, University of South Dakota, 414 East Clark St, Vermillion, SD 57069, USA.
Physiol Behav. 2009 Feb 16;96(2):218-32. doi: 10.1016/j.physbeh.2008.10.004. Epub 2008 Oct 17.
Male Anolis carolinensis that win aggressive interactions mobilize neuroendocrine responses to social stress more rapidly than defeated lizards. We initially examined temporal patterns of neuroendocrine response to restraint stress in lizards of unknown status, and then investigated whether winning males respond more rapidly to this non-social stressor. Size-matched male pairs interacted to establish social status, and then were returned to individual home cages for 3 days. Plasma and brains were collected from non-restrained dominants and subordinates, and from a non-interacting control group. Additional groups of dominants and subordinates underwent 90 s restraint stress, with plasma and brains collected either immediately or 300 s after restraint. In lizards of unknown social status restraint stimulated rapid monoaminergic responses in nucleus accumbens, hippocampus, amygdala, and locus ceruleus, with delayed responses seen in VTA and raphé. Non-restrained dominants and subordinates had lower levels of raphé serotonergic activity and lower hippocampal dopaminergic activity 3 days after interacting, compared to controls. Dominants had higher corticosterone levels, both immediately and 300 s after restraint, than either non-restrained dominants or restrained subordinates. Restraint induced higher raphé serotonergic activity in dominants. However, subordinates also showed rapid responses to restraint; exhibiting lower hippocampal dopamine (DA) levels than non-restrained subordinates. At 300 s after the stress, amygdalar serotonin levels increased in dominants, while subordinates showed higher amygdalar DA levels. These results suggest that stressful aggressive interactions will not only alter basal neurochemical activity, but also influence neuroendocrine responses to non-social stressors according to individual social status.
在攻击性互动中获胜的雄性卡罗来纳安乐蜥比战败的蜥蜴更快地调动神经内分泌对社会压力的反应。我们首先研究了未知状态蜥蜴对束缚应激的神经内分泌反应的时间模式，然后调查了获胜雄性对这种非社会应激源的反应是否更快。体型匹配的雄性配对进行互动以确定社会地位，然后回到各自的家笼中3天。从无束缚的优势个体和从属个体以及一个非互动对照组中采集血浆和大脑样本。另外的优势个体和从属个体组经历90秒的束缚应激，在束缚后立即或300秒后采集血浆和大脑样本。在社会地位未知的蜥蜴中，束缚刺激了伏隔核、海马体、杏仁核和蓝斑中的快速单胺能反应，而在腹侧被盖区和中缝核中则出现延迟反应。与对照组相比，无束缚的优势个体和从属个体在互动3天后中缝核的血清素能活性较低，海马体的多巴胺能活性也较低。优势个体在束缚后立即和300秒时的皮质酮水平均高于无束缚的优势个体或受束缚的从属个体。束缚诱导优势个体中缝核的血清素能活性升高。然而，从属个体对束缚也表现出快速反应；其海马体多巴胺（DA）水平低于无束缚的从属个体。在应激后300秒时，优势个体杏仁核中的血清素水平升高，而从属个体杏仁核中的DA水平较高。这些结果表明，有压力的攻击性互动不仅会改变基础神经化学活性，还会根据个体社会地位影响对非社会应激源的神经内分泌反应。
