Neurosciences CEDD, GlaxoSmithKline Medicine Research Centre, via Alessandro Fleming 4, 37135 Verona, Italy.
Behav Brain Res. 2011 Jan 1;216(1):100-8. doi: 10.1016/j.bbr.2010.07.014. Epub 2010 Jul 21.
Social stress may precipitate psychopathological disorders in susceptible individuals. The present experiments were focused on the biology beyond the differential susceptibility to social stress. Social defeat, an ethologically relevant stressor known to elicit different coping strategies, was used in two mouse strains differing for baseline emotionality, such as C57BL6/J and BalbC. In separate experiments, in both strains a single social defeat decreased home-cage activity without altering social aversion; it diminished body weight only in defeated BalbC mice. In longitudinal experiments, mice experienced repeated social defeats that induced multiple long-term consequences. Defeated C57BL6/J increased their body weight and food intake; defeated BalbC mice diminished their metabolic efficiency. Only defeated BalbC subjects exhibited increased social avoidance levels; no differences from controls were seen on forced swim test response in defeated mice of either strain. No long-term effects of social defeat were detected in peripheral biomarkers of stress, metabolic, and immune responses, although the analysis of selected internal organs revealed decreases in abdominal fat and gonadal organs in all defeated subjects. These results demonstrated a strain-distinctive profile in the susceptibility to social defeat stress, either acutely or chronically, with metabolic consequences more consistently found in C57BL6/J while social aversion induced predominantly in BalbC subjects.
社会压力可能会促使易患精神病理障碍的个体发病。本实验主要关注的是易感性差异之外的社会压力生物学。社会挫败，一种具有生态学相关性的应激源，已知会引发不同的应对策略，被用于两种基线情绪不同的小鼠品系，如 C57BL6/J 和 BalbC。在单独的实验中，在这两种品系中，单次社会挫败都会降低动物的笼内活动而不改变对社会的回避；只有在被击败的 BalbC 小鼠中，它才会导致体重减轻。在纵向实验中，小鼠经历了多次社会挫败，引发了多种长期后果。被击败的 C57BL6/J 增加了它们的体重和食物摄入量；被击败的 BalbC 小鼠则降低了它们的代谢效率。只有被击败的 BalbC 小鼠表现出更高的社交回避水平；在两种品系的被击败的小鼠中，强迫游泳测试的反应与对照组没有差异。社会挫败对压力、代谢和免疫反应的外周生物标志物没有产生长期影响，尽管对选定的内脏器官的分析表明，所有被击败的动物的腹部脂肪和性腺器官都减少了。这些结果表明，无论是急性还是慢性，两种品系对社会挫败应激的易感性存在明显的差异，代谢后果在 C57BL6/J 中更为一致，而社交回避主要在 BalbC 品系中诱导。
