Prefrontal circuits of active avoidance under social conditions in rats

PROJECT SUMMARY: DIEHL PROJECT Individuals suffering from post-traumatic stress disorder (PTSD) and anxiety disorders show excessive fear and persistent avoidance of activities, places, or people associated with their emotional trauma. Not only does emotional trauma impair one’s ability to appropriately assess dangerous situations, but may also lead to deficits in social interactions. The goal of this project is to understand the neural mechanisms of avoidance under social conditions. To study the effect of social conditions on avoidance circuits, rats undergo platform- mediated avoidance (PMA), in which rats avoid a tone-signaled shock by stepping onto a nearby platform, in the presence of another rat. This social partner will have one of three trauma-related experiences: PMA- conditioned, fear-conditioned, or naïve (no previous conditioning). Single-unit electrophysiological recordings combined with optogenetic approaches will be used to identify prefrontal regions whose activity correlates with behaviors during PMA under the different social conditions. We will first characterize behavioral differences in the acquisition and expression of PMA under social conditions versus alone (Aim 1), then measure single unit activity in the anterior cingulate (ACC) or prelimbic (PL) prefrontal cortex during the same conditions of the task (Aim 2), and finally determine whether ACC activity is necessary for the social partner PMA task using optogenetics (Aim 3). These findings will further our understanding of the differences between the neural circuits of active avoidance under social versus solo conditions and their relevance to PTSD and other anxiety disorders.