In the wild over 90% of Mus musculus females will rear their offspring in communal nests. In the laboratory, the typical method of rearing is one dam with her litter. I have shown that rearing pups in large communal nests (three dams sharing litters) leads to profound changes in the maternal and social behavior of mouse offspring as well as the distribution of oxytocin and vasopressin receptors in several brain regions. Furthermore, these behavioral changes can be transmitted over generations through female offspring.
In collaboration with Dr. Igor Branchi, we have shown that male mouse pups reared in communal nests have increased social competency in that they are quicker to recognize their social status when tested in pairs as adults. This effect is only found for pups from older and younger litters who also receive higher levels of maternal care. Both forms of social enrichment (maternal care and peer socialization) appear to be necessary. Increased social competency is associated with higher protein levels of BDNF in the hippocampus, frontal cortex and hypothalamus.
Video showing three mouse dams communally rearing their ten day old pups.
Curley JP , Davidson S, Bateson P & Champagne FA, 2009, Social enrichment during postnatal development induces transgenerational effects on emotional and reproductive behavior in mice, Frontiers in Behavioral Neuroscience. 3(25): 1-14.
Branchi I, Curley JP, D’Andrea I, Cirulli F, Champagne FA & Alleva E, 2013, Early interactions with mother and peers independently build adult social skills and shape BDNF and oxytocin receptor brain levels, Psychoneuroendocrinology 38: 522-532.