The neurobiology of social recognition, approach, and avoidance.

Rodent models of social behavior provide powerful experimental tools for elucidating the molecular, cellular, and neurobiological mechanisms regulating social behavior. Here I discuss several rodent models that have been particularly useful in understanding the neurobiology of the discrimination of social verses nonsocial stimuli, affiliative behavior, and social avoidance. The oxytocin knockout mouse model has been useful for understanding how, in the context of social recognition, the brain may process social stimuli differently from nonsocial stimuli. Vole species that are either highly social and monogamous or solitary and promiscuous have provided a model for investigating the brain mechanisms involved in promoting social interactions. Comparative studies in these species strongly implicate the neuropeptides oxytocin and vasopressin in the regulation of affiliative behavior as well as social attachment. A conditioned defeat model in hamsters may provide a useful model to understand how adverse social experiences may facilitate social avoidance. These models have yielded valuable insights into the regulation of social behaviors, and the findings of these studies may prove useful in understanding the neural mechanisms that underlie individual differences in human personality traits.