Social approach to pain: the effects of maternal relatedness

Recent behavioral research suggests that there is a sex-specific effect for social\ud approach behaviors in mice. Females will approach familiar female cagemates who\ud are expressing pain-related behaviors. In contrast, females do not approach\ud unfamiliar mice expressing similar behaviors. This approach pattern indicates that\ud familiarity is an important factor in predicting social approach behaviors in female\ud mice. Males do not exhibit this type of social behavior. Furthermore, female mice are\ud known to engage in a variety of social and maternal behaviors towards their genetic\ud offspring, and unrelated mice pups. Therefore, varying degrees of familiarity, such\ud as biological relatedness and maternal relationships may elicit different social\ud approach patterns in females. This study investigated the ways in which maternalrelatedness\ud and familiarity with mice pups expressing pain-related behaviors\ud affected social approach behaviors in adult female mice. We grouped mothers and\ud their offspring into five different categories based on familiarity and relatedness. We\ud tested each female in a double approach paradigm, with two pups that she reared,\ud gave birth to, or a pup she had no prior contact or relationship with. In each trial,\ud mesh wire confined a pup not in pain and a pup in pain at opposite ends of the\ud testing apparatus. We then placed the female in the middle of the apparatus and\ud recorded her proximity to each pup for a set time. After recording and analyzing\ud multiple tests and conditions, we found that familiarity, relatedness, and the\ud genders of the pups tested with, affected social approach behaviors towards pups in\ud female mice