The Medial Prefrontal Regulation of Maternal Behavior Across Postpartum: A Triadic Model

Maternal behavior is a highly motivated and adaptive social behavior. Its frequency and pattern change across the postpartum period in response to the changing characteristics of the young and psychophysiological state of the mother. In rodents, maternal behavior peaks shortly after parturition, remains stable for a certain period of time, and then declines gradually until weaning. These dramatic behavioral changes all happen within a 3-to 4-week period. This article reviews evidence on the role of the medial prefrontal cortex (mPFC) in the regulation of the postpartum maternal behavior cycle in rats. Based on this review, a triadic model is proposed to explain how the mPFC, functioning as an executive control system, organizes different patterned maternal responses in different stages of postpartum via its interactions with the maternal excitatory approach system (centered around the medial preoptic area, the mesolimbic dopamine [DA] system) and the maternal inhibitory avoidance system (centered around the olfactory bulb-medial amygdala-ventromedial hypothalamus system). Dopamine and serotonin are hypothesized to operate in all three neural systems to regulate maternal behavior by influencing the motivational, executive control, and memory processes. This triadic model provides a useful framework for understanding dynamic changes of postpartum maternal behavior, as it integrates the evidence-supported approach–withdrawal model with the new prefrontal regulatory model of maternal behavior. Future research aimed at delineating the exact maternal neurocircuits and their interactions could benefit from the ideas derived from this model. Given that human maternal behavior is mainly cortical-driven, this model has significant implications for constructing neural models of human parental behavior.