The study of biological clock responsible for suprachiasmatic nucleus-independent circadian rhythm induced by restricted feeding

限食引起的视交叉上核非依赖性昼夜节律的生物钟研究

• 批准号: 14540635
• 负责人: CHIBA Atsuhiko
• 金额: $ 2.3万
• 依托单位: Sophia University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-14540635/
• 关键词: restricted feeding; Cry; gene knockout; suprachiasmatic nucleus; mouse; Cryptochrome; ノックアウト; 行動リズム

1.Effects of phase-shift of LD(light-dark) cycle and feeding time (Comparison between Wild-type mice(WT) and Cry 1&2 double mutant, behaviorally arrhythmic mice (DKO))After phase-shift of LD cycle, WT reentrained to the new LD cycle after several transient cycles while DKO immediately showed active phase during the dark period of the new LD cycle. In constant darkness (DD), both WT and DKO showed the anticipatory activity rhythm in response to restricted feeding, although in WT, suprachiasmatic nucleus(SCN)-dependent free-running component was also observed in their actograms. After phase-shift of the feeding time, the activity rhythm in response to the new feeding time was established within a couple of days in both WT and DKO. The rhythm which had established by the former feeding time, however, was also maintained for several cycles in both types of mice. This suggests that the molecular basis of the mechanisms for generation and entrainment of restricted feeding-induced rhythm is a … More t least in part different from that of SCN-dependent circadian rhythm.2.The entrainable range of SCN-dependent rhythm and restricted feeding-induced rhythm (WT vs.Cry1 mutant, short-period mice (SP))The actogram from both WT and SP showed SCN-dependent free-running component in DD irrespective of the period of given restricted feeding rhythms. Restricted feeding period ranging from 26h to 34h entrained all WT (N=6) and SP (N=8) mice except the fact that a half of SP mice failed to show clear feeding-induced rhythm when they were subjected to the 34 h feeding rhythm. This may suggest that upper entrainable limit of restricted feeding-induced rhythm of SP tends to be shorter than that of WT. LD cycles with the periods ranging from 26 h to 31 h under free access to food entrained all WT and SP mice. Further study using LD cycles with longer period is required to examine if upper entrainable limit of the period of LD cycle is shorter in SP mice than that in WT mice. Entraining mechanism of SCN-dependent activity rhythm of SP mouse, however, may be at least in part different from that in WT because, in the present study, the activity phase tended to be advanced as the period of LD cycle increases in SP mice. Less

1.LD（明暗）周期相移和喂养时间的影响（野生型小鼠（WT）与Cry 1&2双突变、行为心律失常小鼠（DKO）的比较）LD周期相移后，WT在几个短暂周期后重新进入新的LD周期，而DKO在新LD周期的暗期立即表现出活跃期。在持续黑暗（DD）中，WT和DKO均表现出响应限制进食的预期活动节律，尽管在WT中，在其活动图中也观察到视交叉上核（SCN）依赖性自由运行成分。饲喂时间相移后，WT 和 DKO 均在几天内建立了响应新饲喂时间的活动节律。然而，在这两种类型的小鼠中，由前一个喂食时间建立的节律也维持了几个周期。这表明，限制性进食诱导节律的产生和夹带机制的分子基础至少部分不同于 SCN 依赖性昼夜节律。 2. SCN 依赖性节律和限制性进食诱导节律的可夹带范围（WT 与 Cry1 突变体，短周期小鼠（SP））WT 和 SP 的活动图均显示 DD 中依赖于 SCN 的自由运行成分，与给定的限制喂养节律的周期无关。所有WT（N=6）和SP（N=8）小鼠均接受26h至34h的限制喂养期，但有一半的SP小鼠在接受34h喂养节律时未能表现出明显的喂养诱导节律。这可能表明 SP 的限制摄食诱导节律的可诱导上限往往比 WT 短。所有WT和SP小鼠在自由获取食物的情况下进行LD循环，周期范围为26小时至31小时。需要使用更长周期的LD循环进行进一步研究，以检查SP小鼠的LD循环周期上限是否比WT小鼠短。然而，SP 小鼠的 SCN 依赖性活动节律的诱导机制可能至少部分不同于 WT 中的机制，因为在本研究中，随着 SP 小鼠 LD 周期周期的增加，活动阶段趋于提前。较少的

项目成果

D.Nakahara: "Bimodal circadian secretion of melatonin from the pineal gland in a living CBA mouse."Proceedings of the National Academy of Sciences of the United States of America. 100. 9584-9589 (2003)

D.Nakahara：“活体 CBA 小鼠松果体褪黑激素的双峰昼夜分泌。”美国国家科学院院刊。

A.Chiba: "Dissociation between the circadian rhythm of locomotor activity and the pineal clock in the Japanese newt."J.Comp.Physiol.A. 189. 655-659 (2003)

A.Chiba：“日本蝾螈运动活动的昼夜节律与松果体钟之间的分离。”J.Comp.Physiol.A.