Social buffering of acute early life stress sex-dependently ameliorates fear incubation in adulthood

Abstract

Social buffering may reduce the persistent impacts of acute early life stress (aELS) and, thus, has important implications for anxiety- and trauma-related disorders. First, we assessed whether aELS would induce maladaptive fear incubation in adult mice, a PTSD-like phenotype. Overall, animals showed incubation of fear memory in adulthood independent of aELS condition. Next, we investigated whether social interaction with the dam and/or the littermates following the aELS session would eliminate adult fear incubation. Males demonstrated social buffering only if the dam was present, and females demonstrated social buffering only if the littermates were present. Finally, we assessed whether social buffering following aELS exposure reduces consolidation of the associative fear learning that occurs during the aELS session. Animals received aELS followed by isolation or social interaction (dam + littermates). Over the next four consecutive days, they received 30-minute exposures to the context (test/extinction). There were no differences between isolation and social interaction on contextual fear memory expression or its extinction. Taken together, these results indicate that social buffering reduces the impact of non-associative processes during aELS on subsequent adult fear memory in a sex-dependent manner, and further supports social buffering as an important intervention following early trauma experiences.