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

• Published in: Progress in neuro-psychopharmacology & biological psychiatry 2014-10, Vol.54, p.284-288
• Main Authors: Ji, Mu-Huo, Jia, Min, Zhang, Ming-Qiang, Liu, Wen-Xue, Xie, Zhong-Cong, Wang, Zhong-Yun, Yang, Jian-Jun
• Format: Article
• Language: English
• Subjects: Adrenergic alpha-2 Receptor Agonists - pharmacology; Adult and adolescent clinical studies; Animals; Anti-Anxiety Agents - pharmacology; Anxiety - drug therapy; Anxiety - physiopathology; Anxiety disorders. Neuroses; Anxiety-like behavior; Biological and medical sciences; Cognition; Cognition Disorders - drug therapy; Cognition Disorders - physiopathology; Conditioning (Psychology) - drug effects; Dexmedetomidine; Dexmedetomidine - pharmacology; Disease Models, Animal; Electroshock; Fear - drug effects; Freezing Reaction, Cataleptic - drug effects; Male; Medical sciences; Motor Activity - drug effects; Neuropharmacology; Nootropic Agents - pharmacology; Pharmacology. Drug treatments; Post-traumatic stress disorder; Post-traumatic stress disorder (PTSD); Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; Random Allocation; Rats, Sprague-Dawley; Spatial Memory - drug effects; Stress Disorders, Post-Traumatic - drug therapy; Stress Disorders, Post-Traumatic - physiopathology; Stress Disorders, Post-Traumatic - psychology
• ISSN: 0278-5846; 1878-4216
• DOI: 10.1016/j.pnpbp.2014.06.013

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. •We determined if dexmedetomidine can limit PTSD symptoms in a rat model.•Dexmedetomidine impaired fear conditioning memory in the stressed rats.•Dexmedetomidine reduced the anxiety behavior in the stressed rats.•Dexmedetomidine improved the spatial memory impairment in the stressed rats.