Motivational systems and the neural circuitry of maternal behavior in the rat

Jay Rosenblatt's approach-avoidance model of maternal behavior proposes that maternal behavior occurs when the tendency to approach infant stimuli is greater than the tendency to avoid such stimuli. Our research program has uncovered neural circuits which conform to such a model. We present evidence that the medial preoptic area (MPOA: located in the rostral hypothalamus) may regulate maternal responsiveness by depressing antagonistic neural systems which promote withdrawal responses while also activating appetitive neural systems which increase the attractiveness of infant-related stimuli. These MPOA circuits are activated by the hormonal events of late pregnancy. Preoptic efferents may suppress a central aversion system which includes an amygdala to anterior hypothalamic circuit. Preoptic efferents are also shown to interact with components of the mesolimbic dopamine (DA) system to regulate proactive voluntary maternal responses. We make a distinction between specific (MPOA neurons) and nonspecific motivational systems (mesolimbic DA system) in the regulation of maternal responsiveness.