Evaluating social defeat as a model for psychopathology in adult female rodents

Social conflict is a predominant stressor in humans and is associated with increased risk for developing psychological illnesses including depression and anxiety. Overwhelmingly, more women suffer from these disorders, which may be due to increased stress sensitivity. Like humans, rodents experience a myriad of physiological and behavioral sequelae due to prolonged stress exposure. Although the motivation for social conflict may differ between humans and rodents, female rodents may provide an opportunity to explore the underlying mechanisms by which stress confers risk for psychopathology in women. Because most female rodents do not express spontaneous aggression, the majority of basic research examines the physiological and behavioral outcomes of social conflict in male rodents. However, there are instances where female rodents exhibit territorial (California mice and Syrian hamsters) and maternal aggression (rats, mice, and hamsters) creating a venue to examine sex differences in physiology and behavior in response to stress. While many studies rely upon nonsocial behavioral assays (e.g., elevated plus maze, forced swim test) to assess the impact of stress on emotionality, here we primarily focus on behavioral outcomes in social-based assays in rodents. This is critically important given that disruptions in social relationships can be a cause and consequence of neuropsychiatric diseases. Next, we briefly discuss how sex differences in the recruitment of neural circuitry and/or neurochemistry in response to stress may underlie sex differences in neuroendocrine and behavioral stress responses. Finally, the translational value of females in rodent stress models and considerations regarding behavioral interpretations of these models are discussed. © 2016 Wiley Periodicals, Inc.