title: Depression-like behaviors in tree shrews and comparison of the effects of treatment with fluoxetine and carbetocin.
abstract: Tree shrews, a species phylogenetically close to primates, are regarded as a suitable and naturalistic animal model for depression studies. However, psychological symptoms that are essential for depression diagnosis and treatment, such as helplessness and social withdrawal, have not been studied in this model. Therefore, in this study, we first investigated learned helplessness, social interaction and sucrose preference induced by two chronic stress paradigms: uncontrollable foot shocks (1-week foot shocks) and multiple unpredictable stimuli (1-week foot shocks and 3-week unpredictable stressors) in tree shrews. Our results showed that uncontrollable foot shocks could only induce learned helplessness in animals; whereas animals treated with multiple unpredictable stimuli exhibited more depression-like behaviors including social withdrawal, anhedonia and learned helplessness. These findings suggested that multiple unpredictable stimuli could effectively induce various depression-like behaviors in tree shrews. More importantly, we compared the antidepressant effects of fluoxetine and carbetocin, a long-acting oxytocin analog, on specific depression-like behaviors. Our present data displayed that, compared with fluoxetine, carbetocin was also effective in reversing learned helplessness, elevating sucrose preference and improving social interaction behaviors in depression-like animals. Therefore, carbetocin might be a potential antidepressant with applications in humans.
authors.affiliation: Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China; Institute of Psychology, University of Chinese Academy of Sciences, Beijing, China.
authors.forename: Xiaolu
authors.initials: X
authors.lastname: Meng
authors.affiliation: Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China. Electronic address: shenf@psych.ac.cn.
authors.forename: Fang
authors.initials: F
authors.lastname: Shen
authors.affiliation: Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China; Institute of Psychology, University of Chinese Academy of Sciences, Beijing, China.
authors.forename: Chunlu
authors.initials: C
authors.lastname: Li
authors.affiliation: Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Yonghui
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Orthopedic Surgery, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Xuewei
authors.initials: X
authors.lastname: Wang
mesh_terms: D059445:Anhedonia / Q000187:drug effects; D000818:Animals; D000928:Antidepressive Agents / Q000494:pharmacology / Q000627:therapeutic use; D003863:Depression / Q000188:drug therapy*; D004597:Electroshock; D005473:Fluoxetine / Q000494:pharmacology / Q000627:therapeutic use*; D006380:Helplessness, Learned; D008297:Male; D010121:Oxytocin / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use; D012919:Social Behavior; D013315:Stress, Psychological / Q000188:drug therapy / Q000523:psychology; D014418:Tupaiidae / Q000523:psychology*
chemical_list: D000928:Antidepressive Agents; D005473:Fluoxetine; D010121:Oxytocin; C020731:carbetocin
keywords: Carbetocin; Chronic unpredictable stress; Depression-like behaviors; Tree shrews; Uncontrollable foot shocks