Effects of cross-fostering experience on emotion in adolescent Kunming mice

Parent–infant bonds are critical early postnatal environment in mammals. Unstable parent–infant bonds, such as maternal separation, paternal deprivation, and neonatal social isolation have negative effects on emotion, cognition, addiction, and social behaviours in the animal’s whole lifespan. Another unstable parent–infant bond, cross-fostering, in which pups were randomly exchanged to other parents has mostly focused on kin recognition and anxiety-like behavioural changes in adult. But its effects on adolescence, particularly on autism spectrum disorder, are poorly understood. Whole cross-fostering model was used in the present study. The results showed that with cross-fostering, adolescent Kunming mice buried more marbles, expressed higher levels of anxiety and depression. Cross-fostering attenuated prosocial behaviours and reduced the activity of adolescence when encountering another individual in social interaction test. Taken together, our results demonstrate that experiencing whole cross-fostering in early life is more likely to induce autism-, anxiety-, and depression- like behaviours in adolescence.