Evaluating the rewarding nature of social interactions in laboratory animals

Abstract

Positive social interactions are essential for emotional well-being, healthy development, establishment and maintenance of adequate social structures and reproductive success of humans and animals. Here, we review the studies that have investigated whether forms of social interaction that occur in different phases of the lifespan of animals, i.e., maternal behavior, social play and sexual interaction are rewarding in rodents and non-human primates. We show that these three forms of social interaction can be used as incentive for place conditioning, lever pressing and maze learning, three setups that have been extensively used to study the rewarding properties of food and drugs of abuse and their neural underpinnings. The experience of positive social interactions during key developmental ages has profound and long-lasting effects on brain function and behavior in emotional, motivational and cognitive domains. For instance, pup interaction is more rewarding than cocaine for early postpartum dams and rats deprived of the opportunity to play during adolescence show social and cognitive impairments at adulthood. Furthermore, sexual behavior is only overtly rewarding when animals can control the rate at which the sexual interaction occurs. Last, we discuss how animal models contributed to our understanding of social reward mechanisms and its psychological components throughout development.

Contrasting Roles of Dopamine and Noradrenaline in the Motivational Properties of Social Play Behavior in Rats

“…To the best of our knowledge, however, the present study is the first to show that rats are willing to lever press for social play reinforcement. This demonstration fits into a larger literature that has described reinforcing properties of a wide variety of social behaviors, including maternal, sexual, and aggressive behavior (Everitt, 1990;Fish et al, 2002;Trezza et al, 2011).…”

“…During this developmental period, a characteristic, highly vigorous form of social interaction, ie, social play behavior, is abundantly expressed in most mammalian species (Panksepp et al, 1984;Vanderschuren et al, 1997;Pellis and Pellis, 2009). Social play behavior is highly rewarding (Vanderschuren, 2010;Trezza et al, 2011) and its expression is modulated through neural systems also implicated in other types of reward, such as food, sex, and drugs of abuse (Trezza et al, 2010;Siviy and Panksepp, 2011). Reward processes consist of pleasurable, incentive motivational, and learning components, which are mediated through different neural mechanisms (Berridge et al, 2009).…”

Investigating the motivation to play in lambs

“…Learning allows animals to make associations, representations, and predictions about future rewards based on past experiences (Trezza et al, 2011). Walking and butting had the highest frequency during the 2nd week which could be interpreted as evidence of learning during the training period and the 1st week in the test, resulting in better prediction of the upcoming possibility to play and, thus, increased motivation for play in week 2.…”

Maternal neglect with reduced depressive-like behavior and blunted c-fos activation in Brattleboro mothers, the role of central vasopressin

“…This region is a known brain center of reward (Gardner, 2011) and social interactions, like maternal behavior, are rewarding (Trezza et al, 2011). Indeed, mPOA regulated activation of mesolimbic dopamine system, especially the AcbSh, has a crucial role in the immediate onset and maintenance of maternal behavior after parturition (Afonso et al, 2009;Numan and Stolzenberg, 2009;Stolzenberg et al, 2010).…”