Dexmedetomidine alleviates anxiety-like behaviors and cognitive impairments in a rat model of post-traumatic stress disorder.

Post-traumatic stress disorder (PTSD) is a psychiatric disease that has substantial health implications, including high rates of health morbidity and mortality, as well as increased health-related costs. Although many pharmacological agents have proven the effects on the development of PTSD, current pharmacotherapies typically only produce partial improvement of PTSD symptoms. Dexmedetomidine is a selective, short-acting α2-adrenoceptor agonist, which has anxiolytic, sedative, and analgesic effects. We therefore hypothesized that dexmedetomidine possesses the ability to prevent the development of PTSD and alleviate its symptoms. By using the rat model of PTSD induced by five electric foot shocks followed by three weekly exposures to situational reminders, we showed that the stressed rats displayed pronounced anxiety-like behaviors and cognitive impairments compared to the controls. Notably, repeated administration of 20μg/kg dexmedetomidine showed impaired fear conditioning memory, decreased anxiety-like behaviors, and improved spatial cognitive impairments compared to the vehicle-treated stressed rats. These data suggest that dexmedetomidine may exert preventive and protective effects against anxiety-like behaviors and cognitive impairments in the rats with PTSD after repeated administration.