Using social rank as the lens to focus on the neural circuitry driving stress coping styles

Abstract

Social hierarchy position in humans is negatively correlated with stress-related psychiatric disease risk. Animal models have largely corroborated human studies, showing that social rank can impact stress susceptibility and is considered to be a major risk factor in the development of psychiatric illness. Differences in stress coping style is one of several factors that mediate this relationship between social rank and stress susceptibility. Coping styles encompass correlated groupings of behaviors associated with differential physiological stress responses. Here, we discuss recent insights from animal models that highlight several neural circuits that can contribute to social rank-associated differences in coping style.

Figure: 1. Neural Circuitry Implicated in Social Hierarchy, Stress Coping and Aggression.

A simplified schematic showing connections between the medial prefrontal cortex (mPFC), nucleus accumbens (NAc), Amygdala (Amy), hypothalamic nuclei including the lateral hypothalamus (LH) ventral medial hypothalamus (MH) premammillary nucleus dorsal (PMD), lateral habenula (LHb) ventral tegmental area (VTA), periaqueductal gray (PAG), and the dorsal raphe nucleus (DRN) with glutamatergic projections in red, dopaminergic in green, GABAergic in blue and orexinergic in yellow. Each of these projections has been demonstrated to play a causal role in behaviors related to active or passive stress coping, such as social dominance, aggression, immobility or struggling in the forced swim test or tail suspension, response to an aggressive resident or intruder, as well as exposure to shock or other aversive stressors.