title: Differential effect of lithium on the circadian oscillator in young and old hamsters.
abstract: Lithium is one of the most commonly used drugs in the prophylaxis and treatment of bipolar disorder. It is also known to lengthen circadian period in several organisms. Previously, we reported that there was the association between lengthening circadian period by lithium and GSK-3 protein and its enzyme activity in the mouse suprachiasmatic nucleus (SCN). In this study, we show that lithium affects the circadian oscillator in young and old hamster SCN, in an age-dependent manner. We found that basal levels of phosphorylated GSK-3 (pGSK-3) protein expression in old hamsters are much lower than that in young hamsters. Furthermore, in the old hamsters, lithium did not affect the period of the locomotor activity rhythm or pGSK-3 expression, while changing period and pGSK-3 in the younger animals. These results indicate that the content of pGSK-3 in the SCN has an important role in age-dependent effects of lithium on the circadian oscillator.
authors.affiliation: Department of Pharmacology, School of Science and Engineering, Waseda University, 3-4-1 Ohkubo, Shinjuku-ku 169-0072, Japan.
authors.forename: Eiko
authors.initials: E
authors.lastname: Iwahana
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Hamada
authors.forename: Ayumi
authors.initials: A
authors.lastname: Uchida
authors.forename: Shigenobu
authors.initials: S
authors.lastname: Shibata
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D001714:Bipolar Disorder / Q000188:drug therapy; D002940:Circadian Rhythm / Q000187:drug effects* / Q000502:physiology; D006224:Cricetinae; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects* / Q000502:physiology; D038362:Glycogen Synthase Kinase 3 / Q000235:genetics / Q000378:metabolism*; D008094:Lithium / Q000494:pharmacology*; D008297:Male; D013493:Suprachiasmatic Nucleus / Q000187:drug effects* / Q000378:metabolism; D013997:Time Factors
chemical_list: D008094:Lithium; D038362:Glycogen Synthase Kinase 3