Working memory in posttraumatic stress disorder: trauma cue reactivity

Posttraumatic stress disorder involves a constellation of neural and behavioral alterations in response to trauma exposure. Aside from symptoms involved in posttraumatic stress disorder diagnosis, patients frequently present with working memory impairments. Working memory training has been established as an effective intervention to reduce posttraumatic stress symptoms. Working memory is associated with posttraumatic stress disorder in that it is commonly impaired in patients and that training can reduce the severity of posttraumatic stress symptoms. Taken together, these points suggest the possibility of a shared mechanism between working memory and posttraumatic stress disorder but working memory has not been studied thoroughly in rodent models of posttraumatic stress disorder. The present study utilizes footshock trauma to induce a posttraumatic stress state in rats and evaluates the effect of trauma and trauma-paired cues on working memory performance. Results demonstrate the emergence of chronic deficits in working memory among traumatized animals three weeks post-trauma. Presentation of trauma-paired cues caused further decrement in working memory performance. Regression analysis indicates that the degree of working memory impairment in response to a trauma-paired cue can be significantly predicted by behavioral phenotypes typic of diagnostic symptoms for posttraumatic stress disorder. This study enhances existing animal models by replicating the clinical observations of working memory deficits associated with posttraumatic stress disorder. This will pave the way for future work to probe underlying mechanistic dysregulation of working memory following trauma exposure and for future development of novel treatment strategies.