Chapter 22 - Dopamine Regulation of Pair Bonding in Monogamous Prairie Voles

Abstract

The field of behavioral neuroendocrinology has primarily focused on using traditional laboratory rodents. Data from these studies have provided valuable information for better understanding of the neuroanatomical, neurochemical, hormonal, and molecular genetic mechanisms underlying several types of classic social behaviors, including aggression, mating, and maternal care. It has been shown that species differences exist in animals' social behaviors and underlying mechanisms, and thus caution needs to be taken when data are extrapolated from one species to another. The mesolimbic dopamine (DA) circuit is important in mediating social reward associated with pair bonding in monogamous prairie voles. In fact, central DA has also been implicated in other types of natural reward including food intake, body weight homeostasis, mating, and parental behavior. In rats, for example, food seeking induces DA release in the nucleus accumbens (Nacc), and released DA activates D1-type receptors to facilitate this behavior, illustrating a receptor-specific DA regulation of natural motivation. Mating has also been shown to induce DA release in several brain regions including the NAcc, CP, and medial preoptic area (MPOA) in both male and female rats. In a series of elegant studies in male rats, mating was found to induce DA release in the MPOA before and during copulation Released DA then acts on postsynaptic DA receptors and interacts with other neurochemicals, such as glutamate and GABA, to facilitate genita/motor reflexes e.g., erection, mounting, and ejaculation and appetitive processing of the incentive value of potential mates. It has been shown that the MPOA has a direct anatomical and neurochemical connection with the mesolimbic DA system and can act synergistically with the VTA–NAcc circuit to regulate the motivational salience associated with mating.