Brain vasopressin signaling modulates aspects of maternal behavior in lactating rats

The brain vasopressin system mediates various social behaviors as has been studied mostly in males. Only recently, advances in social neuroscience revealed that central vasopressin signaling via its V1a and V1b receptors also facilitates female social behavior, including maternal behavior. In this review, we show how maternal care, maternal motivation and maternal aggression of lactating rat mothers are modulated in a V1 receptor subtype- and brain region-specific manner. Measuring local release pattern of vasopressin via intracerebral microdialysis in the behaving rat mother as well as using pharmacological approaches to activate or block vasopressin receptors with subsequent behavioral observation provide detailed insight into the functional role of the vasopressin system in maternal behavior. In this context, the complementary rat animal model of high (HAB) and low anxiety-related behavior (LAB) is particularly helpful due to the genetically determined high activity of the vasopressin gene in HAB rats, which also underlies their high levels of maternal behavior. Furthermore, first studies in humans indicate that the vasopressin system in general and the V1a receptor in more particular might mediate mothering.