Comparative neurobiology and genetics of mammalian social behavior

Abstract

Despite advances in our understanding of the ecological and evolutionary factorsthat drive sociality, relatively little is known about the genetic and neurobiological mechanisms underlying group living. Decades of laboratory investigations into the neural substrates supporting parental behavior and social bond formation between mates have yielded important insights into how those specific social behaviors are reinforced and maintained (reviewed in McGraw & Young 2010; Young et al. 2011). This has laid the groundwork for recent studies of the mechanisms supporting social behavior between non-mate peers, particularly relationships found in group-living species. This chapter will present an overview of the current scientific understanding of genes, brains, and social behaviors with an emphasis on mammals, and with special attention paid to caviomorph rodents. Section 3.2 surveys the molecules implicated in a range of social behaviors, particularly the neuropeptides oxytocin (OT) and arginine vasopressin (AVP), and the neural circuits in which they act. We then turn to the neurobiology of parenting, monogamy, and sociality. Section 3.3 discusses the genetic underpinnings of these pathways. The study of sociality is a topic for which research on caviomorphs may be particularly helpful, as several species exhibit sociality in the absence of monogamy. This offers a valuable opportunity to study the mechanisms supporting social bonds between group-living peers. Thus, Section 3.4 details what is known about the aforementioned pathways in caviomorph rodents, including new data on degus (Octodon degus). Finally, we discuss the types of data needed to improve inferences about the connections between behavior and neurobiology.