Lesions of nucleus accumbens shell abolish socially transmitted food preferences

Rats adapt their food choices to conform to their conspecifics' dietary preferences. The nucleus accumbens shell is a relevant brain region to process reward-related and motivated behaviours and social information. Here, we hypothesize that the integrity of the nucleus accumbens shell is necessary to show socially transmitted food preferences. We made excitotoxic and sham lesions of nucleus accumbens shell in male Long-Evans rats who performed a social transmission of food preference task. In this task, observer rats revealed their original preference for one out of two food options. Afterward, they were exposed to a demonstrator rat who was fed with the observer's originally non-preferred food, and the observer's food choices were sampled again. Sham lesioned observer rats changed their food preferences following interaction with the demonstrator, specifically by increasing the intake of their originally non-preferred food type. This interaction-related change in preference was not found after nucleus accumbens shell lesions. The lesion effects on choice were not the consequence of impaired social or non-social motivation, anxiety or sensory or motor function, suggesting that they reflected a genuine deficit in social reward revaluation. These results highlight the role of nucleus accumbens shell in revaluating food rewards to match a conspecific's preferences.