One relatively simplistic and widely used model of depression is the forced-swimming paradigm originally adopted by Porsolt et al. (1978). Naïve rats and mice forced to swim in an aversive and confined environment innately fight to escape the apparatus. Following failed attempts to escape, they become immobile (i.e. float), a behavior generally considered as despair, “depressive-like” behavior. Prior treatment with antidepressants decreases the time spent immobile and increases the latency to reach the first immobility episode.