Prediction of Susceptibility/Resilience Toward Animal Models of Post-traumatic Stress Disorder (PTSD)

In the western countries, the lifetime prevalence of experiencing high stressful events is estimated to be about 75–80%; however, only a small proportion of those individuals (about 10%) exposed to stress ultimately develops PTSD. This represents a critical aspect that must be considered when modeling PTSD-like symptomatology in animal models. The vulnerability toward the development of PTSD may be conferred by exposure to risk factors and individual predisposition, and both factors can be incorporated in animal models. Here we describe an animal model for PTSD-like symptomatology that combines to the traumatic experience (footshock), exposure to risk factors (i.e., social isolation), and behavioral profiling to enable the differentiation between susceptible and resilient phenotypes to the development of long-lasting trauma-induced cognitive and emotional alterations. Notably, this model allows an early post-trauma identification of a reliable predictor (i.e., exploratory activity in a novel environment) of susceptibility and resilience. The present animal model provides a relevant behavioral tool to understand the neurobiology of PTSD and, most importantly, the neurobiology of resilience and susceptibility toward the development of the psychiatric disorder. Understanding the mechanisms of resilience and susceptibility will unravel new targets for prophylactic and/or therapeutic interventions aiming at promoting resilience or reduce vulnerability.