Physical contact is essential for effective social buffering of social fear in mice

Abstract Social buffering attenuates stress and fear responses, yet the sensory requirements for effectively buffering social fear remain unclear. Here, we established a paradigm combining social fear conditioning with social buffering to determine whether buffering efficacy depends on tactile, visual, and/or olfactory contact with a familiar conspecific. Adult female and male mice underwent social fear conditioning and were then housed for 24 h under one of three buffering conditions: full multisensory contact, visual and olfactory access, or olfactory access alone. Social fear was assessed thereafter, and mice without buffering served as controls. Conditioned mice without buffering showed impaired social preference and robust social fear, with a trend toward stronger fear expression in females. Only mice receiving full multisensory buffering retained normal social preference and showed no social fear in both sexes, with a more pronounced effect in females, whereas restricted sensory conditions were ineffective. Notably, only conditioned females without buffering showed extinction, while the lowest freezing levels were found in females exposed to full multisensory buffering. Together, these findings demonstrate that effective buffering requires full multisensory contact with a familiar conspecific and establish this paradigm as a framework for dissecting modality- and sex-dependent mechanisms of social buffering of social fear.