Maternal aggression in mice: Influence of the young

Recent research concerning maternal aggression in mice is reviewed and a model describing the events controlling the behavior is proposed. It appears that hormones secreted during pregnancy produce growth in the nipples. This growth enables the female to receive suckling stimulation from her young following parturition. Suckling-induced changes, of which hypothalamic alterations are strongly suspected, may be responsible for the initiation of aggression. The frequency of suckling and exteroceptive stimuli from young maintain the hypothalamic changes responsible for aggression. Suggestions for future research in maternal aggression are proposed. The relevance of this work to other areas of psychobiology is also considered.