title: Diurnal Expression of the Per2 Gene and Protein in the Lateral Habenular Nucleus.
abstract: The suprachiasmatic nucleus plays an important role in generating circadian rhythms in mammals. The lateral habenular nucleus (LHb) is closely linked to this structure. Interestingly, the LHb shows a rhythmic firing rate in vivo and in vitro, and sustained oscillation of rhythmic genes in vitro. However, under the in vivo condition, whether rhythmic gene expression in the LHb has circadian rhythms remains unknown. In this study, we examined LHb tissue in rats to determine Period2 (Per2) gene and protein expression at six zeitgeber time points (ZT2, ZT6, ZT10, ZT14, ZT18, and ZT22) in a 12-h light and 12-h dark (LD) environment. We found that in the LD environment, Per2 gene expression and PER2 protein levels in the LHb were higher in the day and lower in the night, showing periodic oscillation, with a peak at ZT10 and a trough at ZT22 (Per2 mRNA) and ZT18 (PER2 protein). We conclude that Per2 expression and PER2 protein levels in the LHb have rhythmic oscillation in vivo. This study provides a basis for further study on the role of the LHb in the circadian rhythm system.
authors.affiliation: Department of Physiology, College of Basic Medical Sciences, Jilin University, 126 Xinmin Street, Changchun 130021, China. studayhard518@sina.com.
authors.forename: Zhigong
authors.initials: Z
authors.lastname: Zhao
authors.affiliation: Department of Physiology, College of Basic Medical Sciences, Jilin University, 126 Xinmin Street, Changchun 130021, China. hyxu@jlu.edu.cn.
authors.forename: Haiyan
authors.initials: H
authors.lastname: Xu
authors.affiliation: Department of Physiology, College of Basic Medical Sciences, Jilin University, 126 Xinmin Street, Changchun 130021, China. lymmm8338@sina.com.
authors.forename: Yongmao
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Physiology, College of Basic Medical Sciences, Jilin University, 126 Xinmin Street, Changchun 130021, China. muli_xf@126.com.
authors.forename: Li
authors.initials: L
authors.lastname: Mu
authors.affiliation: Department of Physiology, College of Basic Medical Sciences, Jilin University, 126 Xinmin Street, Changchun 130021, China. zacshaw@outlook.com.
authors.forename: Jinyu
authors.initials: J
authors.lastname: Xiao
authors.affiliation: Department of Physiology, College of Basic Medical Sciences, Jilin University, 126 Xinmin Street, Changchun 130021, China. zhua@jlu.edu.cn.
authors.forename: Hua
authors.initials: H
authors.lastname: Zhao
mesh_terms: D000818:Animals; D002940:Circadian Rhythm / Q000235:genetics*; D005786:Gene Expression Regulation; D019262:Habenula / Q000378:metabolism*; D008297:Male; D056950:Period Circadian Proteins / Q000235:genetics* / Q000378:metabolism; D017440:Photoperiod; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017208:Rats, Wistar
chemical_list: C513311:Per2 protein, rat; D056950:Period Circadian Proteins; D012333:RNA, Messenger
keywords: circadian rhythm; lateral habenular nucleus; period2 gene; running-wheel activity; suprachiasmatic nucleus