Dopamine Neuron Activity and Stress Signaling as Links Between Social Hierarchy and Psychopathology Vulnerability.

Background: Social status in humans, generally reflected by socioeconomic status, has been associated, when constrained, with heightened vulnerability to pathologies including psychiatric diseases. Social hierarchy in mice translates into individual and interdependent behavioral strategies of animals within a group. The rules leading to the emergence of a social organization are elusive, and detangling the contribution of social status from other factors, whether environmental or genetic, to normal and pathological behaviors remains challenging.

SWI/SNF chromatin remodeler complex within the reward pathway is required for behavioral adaptations to stress.

Enduring behavioral changes upon stress exposure involve changes in gene expression sustained by epigenetic modifications in brain circuits, including the mesocorticolimbic pathway. Brahma (BRM) and Brahma Related Gene 1 (BRG1) are ATPase subunits of the SWI/SNF complexes involved in chromatin remodeling, a process essential to enduring plastic changes in gene expression. Here, we show that in mice, social defeat induces changes in BRG1 nuclear distribution.