Prolactin-mediated restraint of maternal aggression in lactation

Abstract

Significance Heightened intruder-directed aggressive behavior in female mice is displayed during lactation to enable a mother to protect her offspring. Although recent work has identified that the ventromedial nucleus of the hypothalamus plays an important role in governing aggressive behavior, it is unknown how the changing hormones of pregnancy and lactation might regulate this behavior during specific reproductive states. Here, we show that prolactin-responsive neurons are activated during aggression and project to multiple brain regions with known roles in regulating behavior. Through neuron-specific and region-specific deletion of the prolactin receptor, our data reveal that prolactin is an important modulator of maternal aggression. By acting on glutamatergic neurons in the ventromedial nucleus, prolactin restrains maternal aggression, specifically in lactating female mice.