Analysis of PDF-dependent microcircuits in the circadian clock of the Madeira cockroach

马德拉蟑螂生物钟中 PDF 相关微电路的分析

• 批准号: 36209371
• 负责人: Professorin Dr. Monika Stengl
• 金额: --
• 依托单位: Abteilung Tierphysiologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2007
• 资助国家: 德国
• 起止时间: 2006-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/36209371?language=en
• 关键词: Analysis; PDF; dependent; microcircuits; circadian

The neuropeptide pigment-dispersing factor (PDF) is an obligatory circadian coupling signal in insects which synchronizes circadian clocks distributed throughout the insect body. It shares astounding similarities in signaling on the molecular and cellular level with vasoactive intestinal polypeptide (VIP) the most important circadian coupling factor in mammals. Both, PDF and VIP signal via cAMP rises and are essential for the expression of large amplitude circadian rhythms in physiology and behavior in synchrony with external light-dark cycles. Nevertheless, our knowledge about the PDF/VIP-dependent neuronal circuits and their control via light is still limited.Our renewal proposal focuses further on cellular analysis of PDF-dependent circadian circuits in the clock of the night-active, long-lived Madeira cockroach, an established cellular model of circadian rhythm research. With intracellular and patch clamp electrophysiological analysis combined with Ca2+ imaging, multiple-label immunocytochemistry, and single-cell MALDI-TOF we examine the light input pathways to PDF neurons. Previous PDF-injections phase delayed locomotor activity rhythms during dusk and phase advanced during dawn comparably to cAMP- and light-stimuli. Furthermore, peaks in cAMP concentrations were measured in the cockroach circadian clock one at dusk and one at dawn. Thus, we propose and search for two PDF-dependent neuronal circuits in the cockroach clock locking either onto dusk or dawn to restrict locomotor activity rhythms to the night while photoperiod is changing during the course of the year.

神经肽色素分散因子(PDF)是昆虫体内必需的昼夜节律耦合信号，它同步分布在昆虫体内的昼夜节律时钟。它在分子和细胞水平上与哺乳动物中最重要的昼夜节律偶联因子血管活性肠多肽(VIP)有着惊人的相似之处。PDF和VIP信号都通过cAMP升高，对于与外部明暗周期同步的生理和行为大幅度昼夜节律的表达是必不可少的。然而，我们对依赖PDF/VIP的神经元回路及其对光的控制的了解仍然有限。我们的更新建议进一步关注夜间活动、长寿命的马德拉蟑螂生物钟中依赖PDF的昼夜回路的细胞分析，这是一个已建立的昼夜节律研究的细胞模型。通过细胞内和膜片钳电生理分析，结合钙离子成像、多标记免疫细胞化学和单细胞MALDI-TOF，我们研究了光输入到PDF神经元的途径。与cAMP和光刺激相比，注射PDF的黄昏时相延迟运动节律，黎明时相提前。此外，在蟑螂生物钟中测得cAMP浓度的峰值分别在黄昏和黎明。因此，我们提出并寻找了蟑螂时钟锁定到黄昏或黎明的两个依赖PDF的神经元回路，以将运动活动节律限制在夜间，而光周期在一年中发生变化。