From the Department of Neurobiology and Anatomy (Osako, Tanaka, Yuri), Kochi Medical School, Kochi University, Oko-cho, Nankoku, Kochi, Japan; Multidisciplinary Pain Centre, Aichi Medical University, School of Medicine (Nobuhara, Arai, Nishihara), Nagakute, Aichi, Japan; Center for Translational Social Neuroscience, Silvio O. Conte Center for Oxytocin and Social Cognition, Department of Psychiatry and Behavioral Sciences (Young), Yerkes National Primate Research Center, Emory University School of Medicine, Atlanta, GA; Center for Social Neural Networks, University of Tsukuba (Young), Tsukuba, Japan; and Department of Rehabilitation Sciences (Mitsui), Gunma University Graduate School of Health Sciences, Showa-machi, Maebashi, Gunma, Japan.
Psychosom Med. 2018 Jan;80(1):62-68. doi: 10.1097/PSY.0000000000000524.
Pain is modulated by psychosocial factors, and social stress-induced hyperalgesia is a common clinical symptom in pain disorders. To provide a new animal model for studying social modulation of pain, we examined pain behaviors in monogamous prairie voles experiencing partner loss.
After cohabitation with novel females, males (n = 79) were divided into two groups on the basis of preference test scores. Half of the males of each group were separated from their partner (loss group), whereas the other half remained paired (paired group). Thus, males from both groups experienced social isolation. Open field tests, plantar tests, and formalin tests were then conducted on males to assess anxiety and pain-related behaviors.
Loss males showing partner preferences (n = 20) displayed a significant increase in anxiety-related behavior in the open-field test (central area/total distance: 13.65% [1.58%] for paired versus 6.45% [0.87%] for loss; p < .001), a low threshold of thermal stimulus in the plantar test (withdrawal latencies: 9.69 [0.98] seconds for paired versus 6.15 [0.75] seconds for loss; p = .037), and exacerbated pain behaviors in the formalin test (total number of lifts: 40.33 [4.46] for paired versus 54.42 [1.91] for loss; p = .042) as compared with paired males (n = 20). Thermal thresholds in the plantar test significantly correlated with anxiety-related behavior in the open-field test (r = 0.64). No such differences were observed in the males that did not display partner preferences (r = 0.15).
Results indicate that social bonds and their disruption, but not social housing without bonding followed by isolation, modulate pain and emotion in male prairie voles. The prairie vole is a useful model for exploring the neural mechanisms by which social relationships contribute to pain and nociceptive processing in humans.
疼痛受心理社会因素的调节，社会应激引起的痛觉过敏是疼痛障碍的常见临床症状。为了提供一种研究疼痛的社会调节的新动物模型，我们检查了经历伴侣丧失的单配制草原田鼠的疼痛行为。
在与新雌性共同生活后，根据偏好测试分数将雄性（n = 79）分为两组。每组的一半雄性与伴侣分离（损失组），而另一半保持配对（配对组）。因此，两组雄性都经历了社会隔离。然后对雄性进行旷场测试、足底测试和福尔马林测试，以评估焦虑和与疼痛相关的行为。
表现出伴侣偏好的损失雄性（n = 20）在旷场测试中表现出明显的焦虑相关行为增加（中央区域/总距离：配对为 13.65%（1.58%），损失为 6.45%（0.87%）；p <.001），足底测试中热刺激的阈值较低（潜伏期：配对为 9.69（0.98）秒，损失为 6.15（0.75）秒；p =.037），福尔马林测试中疼痛行为加剧（总提举次数：配对为 40.33（4.46），损失为 54.42（1.91）；p =.042）与配对雄性（n = 20）相比。足底测试中的热阈值与旷场测试中的焦虑相关行为显著相关（r = 0.64）。在没有表现出伴侣偏好的雄性中没有观察到这种差异（r = 0.15）。
结果表明，社会联系及其破坏，而不是没有建立联系后隔离的社会住房，调节了雄性草原田鼠的疼痛和情绪。草原田鼠是探索社会关系如何促进人类疼痛和伤害性感受处理的神经机制的有用模型。
