scholarly journals Natural food intake patterns have little synchronizing effect on peripheral circadian clocks

BMC Biology ◽  
2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Xiaobin Xie ◽  
Ayaka Kukino ◽  
Haley E. Calcagno ◽  
Alec M. Berman ◽  
Joseph P. Garner ◽  
...  
Keyword(s):  
Food Intake ◽  
Circadian Rhythms ◽  
Submandibular Gland ◽  
Activity Cycle ◽  
Circadian Clocks ◽  
Dark Cycle ◽  
Liver And Kidney ◽  
Peripheral Clocks ◽  
Ad Libitum ◽  
Rest Activity

Abstract Background Circadian rhythms across mammalian tissues are coordinated by a master clock in the suprachiasmatic nucleus (SCN) that is principally entrained by light-dark cycles. Prior investigations have shown, however, that time-restricted feeding (TRF)—daily alternation of fasting and food availability—synchronizes peripheral clocks independent of the light-dark cycle and of the SCN. This has led to the idea that downstream peripheral clocks are entrained indirectly by food intake rhythms. However, TRF is not a normal eating pattern, and it imposes non-physiologic long fasts that rodents do not typically experience. Therefore, we tested whether normal feeding patterns can phase-shift or entrain peripheral tissues by measuring circadian rhythms of the liver, kidney, and submandibular gland in mPer2Luc mice under different food schedules. Results We employed home cage feeders to first measure ad libitum food intake and then to dispense 20-mg pellets on a schedule mimicking that pattern. In both conditions, PER2::LUC bioluminescence peaked during the night as expected. Surprisingly, shifting the scheduled feeding by 12 h advanced peripheral clocks by only 0–3 h, much less than predicted from TRF protocols. To isolate the effects of feeding from the light-dark cycle, clock phase was then measured in mice acclimated to scheduled feeding over the course of 3 months in constant darkness. In these conditions, peripheral clock phases were better predicted by the rest-activity cycle than by the food schedule, contrary to expectation based on TRF studies. At the end of both experiments, mice were exposed to a modified TRF with food provided in eight equally sized meals over 12 h. In the light-dark cycle, this advanced the phase of the liver and kidney, though less so than in TRF with ad libitum access; in darkness, this entrained the liver and kidney but had little effect on the submandibular gland or the rest-activity cycle. Conclusions These data suggest that natural feeding patterns can only weakly affect circadian clocks. Instead, in normally feeding mice, the central pacemaker in the brain may set the phase of peripheral organs via pathways that are independent of feeding behavior.

scholarly journals Oxyntomodulin regulates resetting of the liver circadian clock by food

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Dominic Landgraf ◽  
Anthony H Tsang ◽  
Alexei Leliavski ◽  
Christiane E Koch ◽  
Johanna L Barclay ◽  
...  
Keyword(s):  
Circadian Rhythm ◽  
Food Intake ◽  
Metabolic Disorders ◽  
Clock Genes ◽  
Circadian Clocks ◽  
Direct Link ◽  
Dark Cycle ◽  
The Core ◽  
Peripheral Clocks ◽  
Master Clock

Circadian clocks coordinate 24-hr rhythms of behavior and physiology. In mammals, a master clock residing in the suprachiasmatic nucleus (SCN) is reset by the light–dark cycle, while timed food intake is a potent synchronizer of peripheral clocks such as the liver. Alterations in food intake rhythms can uncouple peripheral clocks from the SCN, resulting in internal desynchrony, which promotes obesity and metabolic disorders. Pancreas-derived hormones such as insulin and glucagon have been implicated in signaling mealtime to peripheral clocks. In this study, we identify a novel, more direct pathway of food-driven liver clock resetting involving oxyntomodulin (OXM). In mice, food intake stimulates OXM secretion from the gut, which resets liver transcription rhythms via induction of the core clock genes Per1 and 2. Inhibition of OXM signaling blocks food-mediated resetting of hepatocyte clocks. These data reveal a direct link between gastric filling with food and circadian rhythm phasing in metabolic tissues.

scholarly journals Circadian rhythms of gastrointestinal function are regulated by both central and peripheral oscillators

2012 ◽  
Vol 303 (4) ◽  
pp. G461-G473 ◽  
Author(s):  
Jaclyn N. Malloy ◽  
Jiffin K. Paulose ◽  
Ye Li ◽  
Vincent M. Cassone
Keyword(s):  
Circadian Rhythms ◽  
Ex Vivo ◽  
Circadian Clocks ◽  
Constant Darkness ◽  
Restricted Feeding ◽  
Chemical Sympathectomy ◽  
Surgical Ablation ◽  
Peripheral Oscillators ◽  
Ad Libitum ◽  
6 Hydroxydopamine

Circadian clocks are responsible for daily rhythms in a wide array of processes, including gastrointestinal (GI) function. These are vital for normal digestive rhythms and overall health. Previous studies demonstrated circadian clocks within the cells of GI tissue. The present study examines the roles played by the suprachiasmatic nuclei (SCN), master circadian pacemaker for overt circadian rhythms, and the sympathetic nervous system in regulation of circadian GI rhythms in the mouse Mus musculus . Surgical ablation of the SCN abolishes circadian locomotor, feeding, and stool output rhythms when animals are presented with food ad libitum, while restricted feeding reestablishes these rhythms temporarily. In intact mice, chemical sympathectomy with 6-hydroxydopamine has no effect on feeding and locomotor rhythmicity in light-dark cycles or constant darkness but attenuates stool weight and stool number rhythms. Again, however, restricted feeding reestablishes rhythms in locomotor activity, feeding, and stool output rhythms. Ex vivo, intestinal tissue from PER2::LUC transgenic mice expresses circadian rhythms of luciferase bioluminescence. Chemical sympathectomy has little effect on these rhythms, but timed administration of the β-adrenergic agonist isoproterenol causes a phase-dependent shift in PERIOD2 expression rhythms. Collectively, the data suggest that the SCN are required to maintain feeding, locomotor, and stool output rhythms during ad libitum conditions, acting at least in part through daily activation of sympathetic activity. Even so, this input is not necessary for entrainment to timed feeding, which may be the province of oscillators within the intestines themselves or other components of the GI system.

scholarly journals The Effect of Circadian Alteration and Temperature on Reproductive Fitness in Cyanobacteria

2012 ◽  
Vol 8 ◽  
Author(s):  
Lowell A. Safren ◽  
Patrick Donahue ◽  
Tara Shrout ◽  
Aynalem Ameha ◽  
Hollie Black ◽  
...  
Keyword(s):  
Circadian Rhythms ◽  
Type Strain ◽  
Wild Type Strain ◽  
Reproductive Fitness ◽  
Circadian Clocks ◽  
Light Conditions ◽  
Wild Type ◽  
Dark Cycle ◽  
Adaptive Value ◽  
Pure Cultures

The reproductive fitness of cyanobacteria is altered by variation of temperature conditions and differential mutation of Kai genes that contribute to circadian rhythms. The degree and significance of these effects were tested in three distinct strains of Synechococcus elongatus cyanobacteria: a wild-type strain (AMC149) and two mutated strains with either an optimized or a disrupted circadian rhythm. These strains were allowed to compete in mixed cultures to determine the adaptive value of circadian clocks in relation to the reproductive fitness of cyanobacteria. Pure cultures served as controls, ensuring that growth rates were the same. Results illustrate that under constant light conditions at high temperatures, the strains with mutant circadian rhythms were both more reproductively fit than the wild-type strain. In conclusion, we found that circadian clocks do not confer a reproductive advantage for cyanobacteria when the cycle of the circadian clock does not match the light/dark cycle of the environment.

scholarly journals Differential impacts of the head onPlatynereis dumeriliiperipheral circadian rhythms

2019 ◽  
Author(s):  
Enrique Arboleda ◽  
Martin Zurl ◽  
Kristin Tessmar-Raible
Keyword(s):  
Circadian Rhythms ◽  
Circadian Clock ◽  
Clock Genes ◽  
Functional Model ◽  
Circadian Clocks ◽  
Constant Darkness ◽  
Dark Cycle ◽  
Peripheral Tissues ◽  
Platynereis Dumerilii ◽  
Strong Control

AbstractBackgroundThe marine bristle wormPlatynereis dumeriliiis a useful functional model system for the study of the circadian clock and its interplay with others, e.g. circalunar clocks. The focus has so far been on the worm’s head. However, behavioral and physiological cycles in other animals typically arise from the coordination of circadian clocks located in the brain and in peripheral tissues. Here we focus on peripheral circadian rhythms and clocks, revisit and expand classical circadian work on the worm’s chromatophores, investigate locomotion as read-out and include molecular analyses.ResultsWe establish that different pieces of the trunk exhibit synchronized, robust oscillations of core circadian clock genes. These circadian core clock transcripts are under strong control of the light-dark cycle, quickly losing synchronized oscillation under constant darkness, irrespective of the absence or presence of heads. Different wavelengths are differently effective in controlling the peripheral molecular synchronization. We have previously shown that locomotor activity is under circadian clock control. Here we show that upon decapitation it still follows the light-dark cycle, but does not free-run under constant darkness. We also observe the rhythmicity of pigments in the worm’s individual chromatophores, confirming that chromatophore size changes follow a circadian pattern. These size changes continue under constant darkness, but cannot be re-entrained by light upon decapitation.ConclusionsHere we provide the first basic characterization of the peripheral circadian clock ofPlatynereis dumerilii. In the absence of the head, light is essential as a major synchronization cue for peripheral molecular and locomotor circadian rhythms. Circadian changes in chromatophore size can however continue for several days in the absence of light/dark changes and the head. Thus, the dependence on the head depends on the type of peripheral rhythm studied. These data show that peripheral circadian rhythms and clocks should be considered when investigating the interactions of clocks with different period lengths, a notion likely also true for other organisms with circadian and non-circadian clocks.

Masking of the Circadian Rhythms of Heart Rate and Core Temperature by the Rest-Activity Cycle in Man

1986 ◽  
Vol 1 (2) ◽  
pp. 119-135 ◽  
Author(s):  
Philippa H. Gander ◽  
Linda J. Connell ◽  
R. Curtis Graeber
Keyword(s):  
Heart Rate ◽  
Circadian Rhythms ◽  
Core Temperature ◽  
Activity Cycle ◽  
Rest Activity

scholarly journals Tissue physiology revolving around the clock: circadian rhythms as exemplified by the intervertebral disc

2021 ◽  
pp. annrheumdis-2020-219515
Author(s):  
Honor Morris ◽  
Cátia F Gonçalves ◽  
Michal Dudek ◽  
Judith Hoyland ◽  
Qing-Jun Meng
Keyword(s):  
Back Pain ◽  
Circadian Rhythms ◽  
Intervertebral Disc ◽  
Lower Back Pain ◽  
Circadian Clocks ◽  
Ageing Population ◽  
Diurnal Changes ◽  
Lower Back ◽  
Ivd Degeneration ◽  
Rest Activity

Circadian clocks in the brain and peripheral tissues temporally coordinate local physiology to align with the 24 hours rhythmic environment through light/darkness, rest/activity and feeding/fasting cycles. Circadian disruptions (during ageing, shift work and jet-lag) have been proposed as a risk factor for degeneration and disease of tissues, including the musculoskeletal system. The intervertebral disc (IVD) in the spine separates the bony vertebrae and permits movement of the spinal column. IVD degeneration is highly prevalent among the ageing population and is a leading cause of lower back pain. The IVD is known to experience diurnal changes in loading patterns driven by the circadian rhythm in rest/activity cycles. In recent years, emerging evidence indicates the existence of molecular circadian clocks within the IVD, disruption to which accelerates tissue ageing and predispose animals to IVD degeneration. The cell-intrinsic circadian clocks in the IVD control key aspects of physiology and pathophysiology by rhythmically regulating the expression of ~3.5% of the IVD transcriptome, allowing cells to cope with the drastic biomechanical and chemical changes that occur throughout the day. Indeed, epidemiological studies on long-term shift workers have shown an increased incidence of lower back pain. In this review, we summarise recent findings of circadian rhythms in health and disease, with the IVD as an exemplar tissue system. We focus on rhythmic IVD functions and discuss implications of utilising biological timing mechanisms to improve tissue health and mitigate degeneration. These findings may have broader implications in chronic rheumatic conditions, given the recent findings of musculoskeletal circadian clocks.

ACCELERATION OF ANNUAL HIBERNATING CYCLE TO 6 WEEKS IN CAPTIVE DORMICE

1966 ◽  
Vol 44 (5) ◽  
pp. 903-910 ◽  
Author(s):  
N. Mrosovsky
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Sunflower Seed ◽  
Body Temperatures ◽  
Glis Glis ◽  
Ad Libitum

Cycles of food intake and body weight lasting a few weeks occurred in dormice, Glis glis, kept in the laboratory in relatively constant conditions of temperature (about 25 °C) and photoperiod (about 12 hours light–dark schedule). These fluctuations appeared to be more marked in the winter months. Periods of reduced eating were associated with low body temperatures and lethargy. The frequent disturbance and arousal of the animals was probably an important factor in these short hibernating cycles. The influence of variation of the diet on body weight of dormice is described. Animals kept on ad libitum supplies of sunflower seed became obese and remained so for many months.

scholarly journals Neuropeptide Y1 and Y5 Receptors Mediate the Effects of Neuropeptide Y on the Hypothalamic-Pituitary-Thyroid Axis

Endocrinology ◽  
2002 ◽  
Vol 143 (12) ◽  
pp. 4513-4519 ◽  
Author(s):  
Csaba Fekete ◽  
Sumit Sarkar ◽  
William M. Rand ◽  
John W. Harney ◽  
Charles H. Emerson ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Food Intake ◽  
Neuropeptide Y ◽  
Paraventricular Nucleus ◽  
Receptor Agonist ◽  
Pituitary Thyroid Axis ◽  
Thyroid Axis ◽  
Ad Libitum ◽  
Thyroid Hormone Levels ◽  
Hpt Axis

Abstract Neuropeptide Y (NPY) is one of the most important hypothalamic-derived neuropeptides mediating the effects of leptin on energy homeostasis. Central administration of NPY not only markedly stimulates food intake, but simultaneously inhibits the hypothalamic-pituitary-thyroid axis (HPT axis), replicating the central hypothyroid state associated with fasting. To identify the specific NPY receptor subtypes involved in the action of NPY on the HPT axis, we studied the effects of the highly selective Y1 ([Phe7,Pro34]pNPY) and Y5 ([chicken pancreatic polypeptide1–7, NPY19–23, Ala31, Aib32 (aminoisobutyric acid), Q34]human pancreatic polypeptide) receptor agonists on circulating thyroid hormone levels and proTRH mRNA in hypophysiotropic neurons of the hypothalamic paraventricular nucleus. The peptides were administered continuously by osmotic minipump into the cerebrospinal fluid (CSF) over 3 d in ad libitum-fed animals and animals pair-fed to artificial CSF (aCSF)-infused controls. Both Y1 and Y5 receptor agonists nearly doubled food intake compared with that of control animals receiving aCSF, similar to the effect observed for NPY. NPY, Y1, and Y5 receptor agonist administration suppressed circulating levels of thyroid hormones (T3 and T4) and resulted in inappropriately normal or low TSH levels. These alterations were also associated with significant suppression of proTRH mRNA in the paraventricular nucleus, particularly in the Y1 receptor agonist-infused group [aCSF, NPY, Y1, and Y5 (density units ± sem), 97.2 ± 8.6, 39.6 ± 8.4, 19.9 ± 1.9, and 44.6 ± 8.4]. No significant differences in thyroid hormone levels, TSH, or proTRH mRNA were observed between the agonist-infused FSanimals eating ad libitum and the agonist-infused animals pair-fed with vehicle-treated controls. These data confirm the importance of both Y1 and Y5 receptors in the NPY-mediated increase in food consumption and demonstrate that both Y1 and Y5 receptors can mediate the inhibitory effects of NPY on the HPT axis.

scholarly journals Drugs of Abuse Can Entrain Circadian Rhythms

2007 ◽  
Vol 7 ◽  
pp. 203-212 ◽  
Author(s):  
Ann E. K. Kosobud ◽  
Andrea G. Gillman ◽  
Joseph K. Leffel ◽  
Norman C. Pecoraro ◽  
G. V. Rebec ◽  
...  
Keyword(s):  
Locomotor Activity ◽  
Circadian Rhythms ◽  
Drug Metabolism ◽  
Suprachiasmatic Nucleus ◽  
Drugs Of Abuse ◽  
Social Cues ◽  
Dark Cycle ◽  
Drug Reward ◽  
Locomotor Stimulation ◽  
Almost All

Circadian rhythms prepare organisms for predictable events during the Earth's 24-h day. These rhythms are entrained by a variety of stimuli. Light is the most ubiquitous and best known zeitgeber, but a number of others have been identified, including food, social cues, locomotor activity, and, most recently drugs of abuse. Given the diversity of zeitgebers, it is probably not surprising that genes capable of clock functions are located throughout almost all organs and tissues. Recent evidence suggests that drugs of abuse can directly entrain some circadian rhythms. We have report here that entrainment by drugs of abuse is independent of the suprachiasmatic nucleus and the light/dark cycle, is not dependent on direct locomotor stimulation, and is shared by a variety of classes of drugs of abuse. We suggest that drug-entrained rhythms reflect variations in underlying neurophysiological states. This could be the basis for known daily variations in drug metabolism, tolerance, and sensitivity to drug reward. These rhythms could also take the form of daily periods of increased motivation to seek and take drugs, and thus contribute to abuse, addiction and relapse.

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