title: Circadian variations in behaviors, BDNF and cell proliferation in depressive mice.
abstract: Neurotrophic factors are well-known to be involved in the pathophysiology of depression and treatment of antidepressants. Brain-derived neurotrophic factor (BDNF), one of the most widely distributed and the most highly studied neurotrophic factors, has been demonstrated to play an important role in the pathophysiology of depression and the mechanism of antidepressants. According to the previous studies, we found that animal tissues were dissected for BDNF measurement mainly in daytime. Considering the circadian rhythm of BDNF expression, our present study evaluated the circadian variations in behaviors, serum corticosterone concentrations, hippocampal BDNF expression and neuronal cell proliferation in mice exposed to chronic mild stress (CMS), one of the most widely used depression-like animal models. Our results provided the first evidence that the difference of BDNF expression and neuronal cell proliferation between CMS and control mice underwent an oscillation related to the circadian variations (maximum at 20:00 h, minimum at 12:00 h or 16:00 h), while the difference of sucrose preference and first feeding latency was not affected by circadian rhythm. This oscillation difference was attributed to the relative constant BDNF expression and cell proliferation in CMS mice and the fluctuating BDNF expression and cell proliferation in control mice. CMS exposure might destroy the circadian rhythm of BDNF expression and cell proliferation in hippocampus of normal individual. Our present study suggests that animal decapitation at 20:00 h is the best time for BDNF-related measurement in CMS experiment, since the difference reaches the maximum.
authors.affiliation: Department of Chemical and Pharmaceutical Engineering, College of Chemical Engineering, Huaqiao University, Xiamen, 361021, Fujian province, People's Republic of China. litao.yi@yahoo.com.|Institute of Pharmaceutical Engineering, Huaqiao University, Xiamen, 361021, Fujian Province, People's Republic of China. litao.yi@yahoo.com.
authors.forename: Li-Tao
authors.initials: LT
authors.lastname: Yi
authors.affiliation: Department of Chemical and Pharmaceutical Engineering, College of Chemical Engineering, Huaqiao University, Xiamen, 361021, Fujian province, People's Republic of China.
authors.forename: Liu
authors.initials: L
authors.lastname: Luo
authors.affiliation: Department of Chemical and Pharmaceutical Engineering, College of Chemical Engineering, Huaqiao University, Xiamen, 361021, Fujian province, People's Republic of China.
authors.forename: Yong-Jing
authors.initials: YJ
authors.lastname: Wu
authors.affiliation: Department of Chemical and Pharmaceutical Engineering, College of Chemical Engineering, Huaqiao University, Xiamen, 361021, Fujian province, People's Republic of China.
authors.forename: Bin-Bin
authors.initials: BB
authors.lastname: Liu
authors.affiliation: Department of Chemical and Pharmaceutical Engineering, College of Chemical Engineering, Huaqiao University, Xiamen, 361021, Fujian province, People's Republic of China.
authors.forename: Xiao-Long
authors.initials: XL
authors.lastname: Liu
authors.affiliation: Department of Chemical and Pharmaceutical Engineering, College of Chemical Engineering, Huaqiao University, Xiamen, 361021, Fujian province, People's Republic of China.|Institute of Pharmaceutical Engineering, Huaqiao University, Xiamen, 361021, Fujian Province, People's Republic of China.
authors.forename: Di
authors.initials: D
authors.lastname: Geng
authors.affiliation: Department of Chemical and Pharmaceutical Engineering, College of Chemical Engineering, Huaqiao University, Xiamen, 361021, Fujian province, People's Republic of China.|Institute of Pharmaceutical Engineering, Huaqiao University, Xiamen, 361021, Fujian Province, People's Republic of China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Liu
mesh_terms: D059445:Anhedonia; D000818:Animals; D001522:Behavior, Animal; D001835:Body Weight; D019208:Brain-Derived Neurotrophic Factor / Q000378:metabolism*; D049109:Cell Proliferation; D002940:Circadian Rhythm; D003345:Corticosterone / Q000097:blood; D003863:Depression / Q000378:metabolism* / Q000523:psychology*; D006624:Hippocampus / Q000378:metabolism; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D009474:Neurons; D013315:Stress, Psychological / Q000378:metabolism / Q000523:psychology; D013395:Sucrose
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D013395:Sucrose; D003345:Corticosterone
keywords: Brain-derived neurotrophic factor; Cell proliferation; Chronic mild stress; Circadian rhythm; Depression