Multisensory interaction mediates the social transmission of avoidance in rats: dissociation from social transmission of fear.

Social interaction enables animals to transmit various types of sensory information that can modulate learned avoidance behavior and fear responses, which are important to survival. We previously reported that, under a passive avoidance paradigm, avoidance behavior is facilitated when a rat observes another rat (demonstrator) receiving a shock when performing a specific behavior. However, the sensory mechanisms underlying this 'social facilitation of avoidance' are not well understood. The present study examined the role of sensory pathways for social transmission of avoidance, focusing on the olfactory and visual systems. The olfactory ability of observer rats was blocked by an intranasal application of ZnSO4, and their visual ability was blocked by an opaque partition placed between observer and demonstrator rats. We found that blocking either olfactory or visual input drastically diminished the social transmission of avoidance. Interestingly the social transmission of fear responses remained intact even when olfactory or visual information was blocked. These results indicate that the social transmission of avoidance is mediated not by any single sensory modality but by multisensory interaction in rats, suggesting a distinct sensory mechanism from that underlying the social transmission of fear.