Lack of social touch increases anxiety and alters social behaviors in mice

The importance of social interactions has been reported in different animal species. During the pandemic, although people can communicate through other sensory cues, social touch is mostly prohibited under different levels of social distance policies, which inspired us to explore the necessity of physical contact in mouse social interaction. In this study, we first conducted a long-term observation showing that pair-housed mice in a standard laboratory cage spent nearly half the day in direct physical contact with each other. Furthermore, isolation experiments demonstrated that, even with access to other sensations, prevention of social touch for one month significantly induced anxiety levels, changed social behaviors and increased interleukin-6 cytokine in the hippocampus and the serum of mice. Our study demonstrated the necessity of social touch for the maintenance of mental health in mice. This information could have important implications for human social interactions, especially the social policies during a pandemic crisis.