EN
INTRODUCTION: Prosocial behaviors may be broadly defined as actions that benefit others. While these behaviors are intuitively simple, the underlying mechanism driving prosocial actions are only partly understood, and the methods to observe them under laboratory conditions remain limited. AIM(S): Here, we describe a novel task that assesses prosocial choices in mice and tests the frequency of prosocial behaviors in male and female C57BL/6 animals. METHOD(S): The test measures prosocial behavior towards a familiar conspecific. The tested mouse (actor) is placed in the starting compartment of the cage, from which it may enter two feeding compartments. The stimulus mouse (partner) is placed in the compartment adjacent to both actor’s feeding compartments. The wall between actor’s and partner’s compartments is transparent and perforated. Entering the compartment that was designated as “prosocial” by the actor results in the reward delivery to both actor and partner. Entering the “asocial” compartment results in a reward only for the actor. Pilot experiments were also carried out on an automated version of the test using a Skinner box‑based setup. RESULTS: We found that, on average, male mice had no significant preference for the prosocial choice (n=10, 47.5% ± 9.2% without a partner vs. 47.8±4.9% with a partner). In the case of females, we initially observed a trend towards increased preference of the prosocial decision, but the result did not reach significance when all experiments were pooled (n=14, 46.9±8.0% without a partner vs. 50.8±8.0% with a partner). CONCLUSIONS: Further experiments are required to conclude whether C57BL/6 mice show prosocial behavior towards conspecific cagemates. The results so far suggest that prosocial behavior may possibly be exhibited by females, which is consistent with observations in wild mice.