Institute of Brain and Behavioral Sciences, College of Life Sciences, Shaanxi Normal University, Xi'an, 710062, China; College of Life Sciences, Nanyang Normal University, Nanyang, 473061, China.
Institute of Brain and Behavioral Sciences, College of Life Sciences, Shaanxi Normal University, Xi'an, 710062, China.
Psychoneuroendocrinology. 2019 May;103:14-24. doi: 10.1016/j.psyneuen.2018.12.238. Epub 2018 Dec 27.
Consolation, which entails comforting contact directed toward a distressed party, is a common empathetic response in humans and other species with advanced cognition. Here, using the social defeat paradigm, we provide empirical evidence that highly social and monogamous mandarin voles (Microtus mandarinus) increased grooming toward a socially defeated partner but not toward a partner who underwent only separation. This selective behavioral response existed in both males and females. Accompanied with these behavioral changes, c-Fos expression was elevated in many of the brain regions relevant for emotional processing, such as the anterior cingulate cortex (ACC), bed nucleus of the stria terminalis, paraventricular nucleus (PVN), basal/basolateral and central nucleus of the amygdala, and lateral habenular nucleus in both sexes; in the medial preoptic area, the increase in c-Fos expression was found only in females, whereas in the medial nucleus of the amygdala, this increase was found only in males. In particular, the GAD67/c-Fos and oxytocin (OT)/c-Fos colocalization rates were elevated in the ACC and PVN, indicating selective activation of GABA and OT neurons in these regions. The "stressed" pairs matched their anxiety-like behaviors in the open-field test, and their plasma corticosterone levels correlated well with each other, suggesting an empathy-based mechanism. This partner-directed grooming was blocked by pretreatment with an OT receptor antagonist or a GABA receptor antagonist in the ACC but not by a V1a subtype vasopressin receptor antagonist. We conclude that consolation behavior can be elicited by the social defeat paradigm in mandarin voles, and this behavior may be involved in a coordinated network of emotion-related brain structures, which differs slightly between the sexes. We also found that the endogenous OT and the GABA systems within the ACC are essential for consolation behavior in mandarin voles.
慰藉是一种指向痛苦一方的安慰性接触，是人类和其他具有高级认知能力的物种中常见的共情反应。在这里，我们使用社交挫败范式提供了经验证据，表明高度社交和一夫一妻制的布氏田鼠（Microtus mandarinus）增加了对社交挫败伴侣的梳理，但对仅经历分离的伴侣没有。这种选择性的行为反应存在于雄性和雌性中。伴随着这些行为变化，许多与情绪处理相关的大脑区域（如前扣带皮层（ACC）、终纹床核、室旁核（PVN）、基底/基底外侧和杏仁核中央核、以及两性的外侧缰核）中的 c-Fos 表达升高；在雌性中，仅在 medial preoptic area 中发现 c-Fos 表达增加，而在雄性中，仅在 medial nucleus of the amygdala 中发现 c-Fos 表达增加。特别是，ACC 和 PVN 中的 GAD67/c-Fos 和催产素（OT）/c-Fos 共定位率升高，表明这些区域中 GABA 和 OT 神经元的选择性激活。“受压力”的对配对在旷场测试中表现出类似焦虑的行为，并且它们的血浆皮质酮水平彼此很好地相关，表明存在基于同理心的机制。这种伴侣导向的梳理被 ACC 中的 OT 受体拮抗剂或 GABA 受体拮抗剂预处理阻断，但不能被 V1a 亚型血管加压素受体拮抗剂阻断。我们得出结论，安慰行为可以在布氏田鼠中通过社交挫败范式引发，并且这种行为可能涉及到情绪相关脑结构的协调网络，在性别之间略有不同。我们还发现，ACC 内的内源性 OT 和 GABA 系统对于布氏田鼠的安慰行为是必不可少的。
