Chari Trishala, Hernandez Ariana, Portera-Cailliau Carlos
bioRxiv. 2023 Jan 13:2023.01.11.523491. doi: 10.1101/2023.01.11.523491.
Social touch, an important aspect of social interaction and communication, is essential to kinship across animal species. How animals experience and respond to social touch has not been thoroughly investigated, in part due to the lack of appropriate assays. Previous studies that examined social touch in freely moving rodents lacked the necessary temporal and spatial control over individual touch interactions. We designed a novel head-fixed assay for social touch in mice, in which the experimenter has complete control to elicit highly stereotyped bouts of social touch between two animals. The user determines the number, duration, context, and type of social touch interactions, while monitoring with high frame rate cameras an array of complex behavioral responses. We focused on social touch to the face because of their high translational relevance to humans. We validated this assay in two different models of autism spectrum disorder (ASD), the knockout model of Fragile X Syndrome and maternal immune activation mice. We observed increased avoidance, hyperarousal, and more aversive facial expressions to social touch, but not to object touch, in both ASD models compared to controls. Because this new social touch assay for head-fixed mice can be used to record neural activity during repeated bouts of social touch it should be of interest to neuroscientists interested in uncovering the underlying circuits.
社会接触作为社会互动和交流的一个重要方面，对所有动物物种的亲缘关系都至关重要。动物如何体验和回应社会接触尚未得到充分研究，部分原因是缺乏合适的检测方法。以往在自由活动的啮齿动物身上研究社会接触的实验，缺乏对个体接触互动必要的时间和空间控制。我们设计了一种用于小鼠社会接触的新型头部固定检测方法，在此方法中，实验者能够完全控制引发两只动物之间高度刻板的社会接触行为。使用者可以确定社会接触互动的次数、持续时间、背景和类型，同时用高帧率摄像机监测一系列复杂的行为反应。由于面部的社会接触与人类具有高度的转化相关性，我们将重点放在对面部的社会接触上。我们在两种不同的自闭症谱系障碍（ASD）模型，即脆性X综合征基因敲除模型和母体免疫激活小鼠模型中验证了这种检测方法。与对照组相比，我们在两种ASD模型中均观察到对社会接触的回避增加、过度觉醒以及更厌恶的面部表情，但对物体接触则没有这些表现。因为这种针对头部固定小鼠的新型社会接触检测方法可用于在重复的社会接触行为期间记录神经活动，所以它应该会引起对揭示潜在神经回路感兴趣的神经科学家的关注。
