Synchronized Control for Circadian Rhythm Based on the Central Clock Model of Drosophila

2006 ◽  
Author(s):  
Yuta Katakura ◽  
Hiromitsu Ohmori
Keyword(s):  
Circadian Rhythm ◽  
Clock Model ◽  
Central Clock ◽  
Synchronized Control

Circadian rhythm, sleep pattern, and metabolic consequences: an overview on cardiovascular risk factors

2014 ◽  
Vol 18 (1) ◽  
Author(s):  
Roberta Marcondes Machado ◽  
Marcia Kiyomi Koike
Keyword(s):  
Risk Factors ◽  
Cardiovascular Disease ◽  
Circadian Rhythm ◽  
Sleep Pattern ◽  
Metabolic Effects ◽  
Environmental Cues ◽  
Suprachiasmatic Nuclei ◽  
Peripheral Tissues ◽  
The Central Nervous System ◽  
Central Clock

AbstractSleep duration is a risk factor for cardiovascular disease. Alteration in sleep pattern can induce the loss of circadian rhythmicity. Chronically, this desynchronization between endogenous rhythm and behavioral cycles can lead to an adverse metabolic profile, a proinflammatory condition and can increase the risk of cardiovascular disease. The circadian cycle can vary due to environmental cues. The circadian pacemaker is located in the suprachiasmatic nuclei; this central clock coordinates the circadian rhythm in the central nervous system and peripheral tissues. The mechanisms involved in sleep disturbance, circadian misalignment and adverse metabolic effects have yet to be fully elucidated. This review looks over the association among sleep alteration, circadian rhythm and the development of risk factors implicated in cardiovascular disease.

scholarly journals Drosophila clock cells use multiple mechanisms to transmit time-of-day signals in the brain

2021 ◽  
Vol 118 (10) ◽  
pp. e2019826118
Author(s):  
Annika F. Barber ◽  
Shi Yi Fong ◽  
Anna Kolesnik ◽  
Michael Fetchko ◽  
Amita Sehgal
Keyword(s):  
Circadian Rhythm ◽  
Time Of Day ◽  
Pars Intercerebralis ◽  
Insulin Producing Cells ◽  
Output Neurons ◽  
Central Clock ◽  
Circadian Behavior ◽  
And Control ◽  
The Brain

Regulation of circadian behavior and physiology by the Drosophila brain clock requires communication from central clock neurons to downstream output regions, but the mechanism by which clock cells regulate downstream targets is not known. We show here that the pars intercerebralis (PI), previously identified as a target of the morning cells in the clock network, also receives input from evening cells. We determined that morning and evening clock neurons have time-of-day–dependent connectivity to the PI, which is regulated by specific peptides as well as by fast neurotransmitters. Interestingly, PI cells that secrete the peptide DH44, and control rest:activity rhythms, are inhibited by clock inputs while insulin-producing cells (IPCs) are activated, indicating that the same clock cells can use different mechanisms to drive cycling in output neurons. Inputs of morning cells to IPCs are relevant for the circadian rhythm of feeding, reinforcing the role of the PI as a circadian relay that controls multiple behavioral outputs. Our findings provide mechanisms by which clock neurons signal to nonclock cells to drive rhythms of behavior.

scholarly journals Circadian Clock, Sleep, and Diet

2021 ◽  
Author(s):  
Junichiro Irie
Keyword(s):  
Circadian Rhythm ◽  
Circadian Rhythms ◽  
Metabolic Regulation ◽  
Biological Clocks ◽  
Metabolic Alterations ◽  
Sleep Homeostasis ◽  
Peripheral Clocks ◽  
Central Clock ◽  
The Impact

Circadian rhythm is a fundamental process of sustaining metabolic homeostasis by predicting changes in the environment. This is driven by biological clocks, which operate within a 24-h period to orchestrate daily variation of metabolism and sleep. The central clock in the hypothalamus is the master keeper of the circadian rhythm and is primarily reset by light, while the feeding-fasting rhythm, that is, nutritional stimulus, entrains peripheral clocks in peripheral organs such as the intestine and liver. Nutritional stimuli are important modulators of peripheral circadian rhythms and may affect the central clock and sleep homeostasis through metabolic alterations. In this chapter, I will summarize the significance of circadian rhythm and sleep in metabolic regulation as well as discuss the impact that diet has on circadian rhythm and sleep.

scholarly journals Chronobiology and Metabolism: Is Ketogenic Diet Able to Influence Circadian Rhythm?

2021 ◽  
Vol 15 ◽  
Author(s):  
Elena Gangitano ◽  
Lucio Gnessi ◽  
Andrea Lenzi ◽  
David Ray
Keyword(s):  
Gene Expression ◽  
Circadian Rhythm ◽  
Circadian Clock ◽  
Ketogenic Diet ◽  
Clock Genes ◽  
The Body ◽  
Acid Oxidation ◽  
Metabolic Switch ◽  
Peripheral Tissues ◽  
Central Clock

Circadian rhythms underpin most physiological processes, including energy metabolism. The core circadian clock consists of a transcription-translation negative feedback loop, and is synchronized to light-dark cycles by virtue of light input from the retina, to the central clock in the suprachiasmatic nucleus in the hypothalamus. All cells in the body have circadian oscillators which are entrained to the central clock by neural and humoral signals. In addition to light entrainment of the central clock in the brain, it now emerges that other stimuli can drive circadian clock function in peripheral tissues, the major one being food. This can then drive the liver clock to be misaligned with the central brain clock, a situation of internal misalignment with metabolic disease consequences. Such misalignment is prevalent, with shift workers making up 20% of the working population. The effects of diet composition on the clock are not completely clarified yet. High-fat diet and fasting influence circadian expression of clock genes, inducing phase-advance and phase-delay in animal models. Ketogenic diet (KD) is able to induce a metabolic switch from carbohydrate to fatty acid oxidation, miming a fasting state. In recent years, some animal studies have been conducted to investigate the ability of the KD to modify circadian gene expression, and demonstrated that the KD alters circadian rhythm and induces a rearrangement of metabolic gene expression. These findings may lead to new approaches to obesity and metabolic pathologies treatment.

A circadian rhythm in adult idiopathic epistaxis?

1998 ◽  
Vol 23 (3) ◽  
pp. 280-280 ◽  
Author(s):  
Mehanna ◽  
Robinson ◽  
Gatehouse ◽  
Mcgarry
Keyword(s):  
Circadian Rhythm ◽  
Idiopathic Epistaxis

Lights Beat Melatonin for Circadian Rhythm Shift

2005 ◽  
Vol 38 (10) ◽  
pp. 19
Author(s):  
SHERRY BOSCHERT
Keyword(s):  
Circadian Rhythm

Light and Melatonin Can Reset Circadian Rhythm

2008 ◽  
Vol 36 (5) ◽  
pp. 48
Author(s):  
JANE SALODOF MACNEIL
Keyword(s):  
Circadian Rhythm

18F-sodium fluoride bone deposition quantitation with PET in Mice: Variation with age, sex, and circadian rhythm

2020 ◽  
Vol 59 (06) ◽  
pp. 428-437
Author(s):  
Viktoria Dorau-Rutke ◽  
Kai Huang ◽  
Mathias Lukas ◽  
Marc O. Schulze ◽  
Christian Rosner ◽  
...  
Keyword(s):  
Circadian Rhythm ◽  
Sodium Fluoride ◽  
Bone Growth ◽  
Bone Volume ◽  
Sleep Phase ◽  
Median Percentage ◽  
Bone Uptake ◽  
Pooled Data ◽  
Uptake Studies ◽  
Bone Deposition

Abstract Aim The aim of this study was to establish a data base for normal 18F-sodium fluoride (18F-NaF) bone uptake as a function of age, sex and circadian rhythm in mice. Methods In 12 female (F) and 12 male (M) C57BL/6N mice PET images were acquired 90 min after intravenous injection of 20 MBq 18F-NaF for 30 minutes. Each mouse was imaged in follow-up studies at 1, 3, 6, 13 and 21 months of age. In order to assess for physiologic changes related to circadian rhythm, animals were imaged during light (sleep phase) as well as during night conditions (awake phase). Bone uptake is described as the median percentage of the injected activity (%IA) and in relation to bone volume (%IA/ml). Results A significant smaller bone volume was found in F (1.79 ml) compared to M (1.99 ml; p < 0.001). In sex-pooled data, highest bone uptake occurred at an age of 1 month (61.1 %IA, 44.5 %IA/ml) with a significant reduction (p < 0.001) at age 3 months (43.6 %IA, 23.6 %IA/ml), followed by an increase between 13 (47.3 %IA, 24.5 %IA/ml) and 21 months (52.2 %IA, 28.1 %IA/ml). F had a significantly higher total uptake (F 48.2 %IA, M 43.8 %IA; p = 0.026) as well as a higher uptake per ml bone tissue (F 27.0 %IA/ml; M 22.4 %IA/ml; p < 0.001). A significant impact of circadian rhythm was only found for F at ages of 3 and 6 months with a higher uptake during the sleep phase. Conclusion Circadian rhythm had a significant impact on uptake only in F of 3 and 6 months. Regarding sex, F showed generally higher uptake rates than M. The highest uptake values were observed during bone growth at age 1 month in both sexes, a second uptake peak occurred in elderly F. Designing future bone uptake studies with M, attention must be paid to age only, while in F circadian rhythm and age must be taken into account.

Obesity-associated alterations in the circadian rhythm of the myokine irisin

2014 ◽  
Vol 9 (S 01) ◽  
Author(s):  
D Löffler ◽  
U Müller ◽  
K Scheuermann ◽  
I Wagner ◽  
D Friebe ◽  
...  
Keyword(s):  
Circadian Rhythm
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