Effect of paroxetine on a model of posttraumatic stress disorder in rats

To better understand neurochemical and psychopharmacological aspects of post-traumatic stress disorder (PTSD), it is necessary to establish an animal model of PTSD in which behavioral changes persist after the initial traumatization. We administered inescapable electric foot-shock (IS) to male Wistar rats in a shuttle-box with the gate closed. With or without paroxetine (PRX; belonging to selective serotonin reuptake inhibitors) treatment for 2 weeks after IS, we performed an avoidance/escape task session in the shuttle-box using signal lights as non-specific anxiogenic stimulants. Locomotor activity decreased before the task session and avoidance behavior increased during the session. Two weeks of PRX administration reduced hypervigilant behavior during the task session. We considered these behavioral changes as representative of numbing/avoidance and hypervigilance, referred to as bi-directional changes in PTSD.