title: Chronic unpredictable stress induces a reversible change of PER2 rhythm in the suprachiasmatic nucleus.
abstract: Many clinical studies have shown that circadian rhythm abnormalities are strongly associated with major depression. The master clock of the circadian system in mammals is located in the suprachiasmatic nucleus (SCN) within the anterior hypothalamus, where Per1 and Per2 are essential core components of circadian rhythm oscillation. Chronic unpredictable stress (CUS) is a reliable animal model of depression with good face, predictive, and constructive validity. In the present study, we investigated the effects of CUS on the circadian expression of PER1 and PER2 in the SCN. We found that CUS led to depressive-like behavior and reduced the amplitude of PER2 oscillation in the SCN, which were blocked by 3 weeks of desipramine (DMI) treatment. 2 weeks after termination of CUS, the decreased peak of PER2 expression returned to control levels, whereas depressive-like behavior remained unchanged. Our findings suggest that the dampened amplitude of PER2 expression in the SCN may participate in the development of depressive-like behavior induced by CUS but is unlikely involved in the long-lasting effects of CUS on depressive-like behavior.
authors.affiliation: National Institute on Drug Dependence, Peking University, 38, Xue Yuan Road, Beijing 100191, China. jiangwg@bjmu.edu.cn
authors.forename: Wen-Gao
authors.initials: WG
authors.lastname: Jiang
authors.forename: Su-Xia
authors.initials: SX
authors.lastname: Li
authors.forename: Shuang-Jiang
authors.initials: SJ
authors.lastname: Zhou
authors.forename: Yan
authors.initials: Y
authors.lastname: Sun
authors.forename: Jie
authors.initials: J
authors.lastname: Shi
authors.forename: Lin
authors.initials: L
authors.lastname: Lu
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D000929:Antidepressive Agents, Tricyclic / Q000494:pharmacology / Q000627:therapeutic use; D002908:Chronic Disease; D002940:Circadian Rhythm / Q000502:physiology*; D003891:Desipramine / Q000494:pharmacology / Q000627:therapeutic use; D004195:Disease Models, Animal; D005106:Exploratory Behavior / Q000187:drug effects / Q000502:physiology; D005518:Food Preferences / Q000187:drug effects / Q000502:physiology; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology*; D008297:Male; D056950:Period Circadian Proteins / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013315:Stress, Psychological / Q000188:drug therapy / Q000473:pathology* / Q000503:physiopathology; D013395:Sucrose / Q000008:administration & dosage; D013493:Suprachiasmatic Nucleus / Q000187:drug effects / Q000378:metabolism*; D013997:Time Factors
chemical_list: D000929:Antidepressive Agents, Tricyclic; C539024:Per1 protein, rat; C513311:Per2 protein, rat; D056950:Period Circadian Proteins; D013395:Sucrose; D003891:Desipramine