Modeling specific phobias and posttraumatic stress disorder in rodents: the challenge to convey both cognitive and emotional features

Aberrant emotional memory processing is a core, disabling feature of both specific phobias and posttraumatic stress disorder (PTSD), two psychiatric diseases of significant prevalence and morbidity whose cognitive symptoms cannot be adequately treated by current psychopharmacological tools. Elucidating the neurobiological mechanisms involved in the etiology of these diseases is of great interest for the identification of new therapeutics that improve not only the symptomatology but also the full recovery from the pathology. To this aim, several animal models have been proposed based on substantial resemblance between the behavioral alterations seen in animals and the human pathology. The purpose of this review is to describe and comment on the most commonly used rodent models of specific phobias and PTSD. A particular focus will be reserved to the cued version of fear conditioning, as the highly specific stimulus-bound conditioned fear response seems to fit well with clinical descriptions of phobic fear. Moreover, animal models of PTSD will be evaluated by referring to three elements that are considered essential in a valid model of this disease: stressor exposure, memory for the stressor, and anxiety-related behaviors. Finally, current therapeutic directions, with a focus on cannabinoid and glucocorticoid compounds, will be briefly outlined.