Sleep and its Interaction with Endocrine Rhythms

1983 ◽  
Vol 142 (3) ◽  
pp. 215-219 ◽  
Author(s):  
Paul E. Mullen
Keyword(s):  
Biological Rhythms ◽  
Biological Processes ◽  
Close Approximation ◽  
Important Group ◽  
Internal Oscillator ◽  
Free Running ◽  
The Individual

Rhythmic variations with frequences from fractions of seconds to years characterise a wide variety of biological processes (Aschoff, 1979). Biological rhythms can be observed, not only in the individual of the species, but also in the cells which comprise the organism and the populations of which it is a member. These regular fluctuations can be endogenously generated by some form of internal oscillator, or alternatively may passively reflect exogenous environmental alterations. An important group of rhythms combines both endogenous and exogenous inputs with an internal oscillator or oscillators which are capable of being influenced by some external change. In this situation, the internal rhythm is kept in harmony with an environmental cycle by a change in the outside world acting as a synchroniser or zeitgeber. In this type if the animal is artificially isolated from its normal external synchroniser, the rhythm will continue, but free running, with a periodicity which is a close approximation to the duration of the environmental cycle to which it is normally tied. These rhythms normally synchronised to an environmental cycle but capable of being self-sustaining at approximately the same rate, are termed circa rhythms: thus circadian, circannual and circalunar rhythms, according to the geophysical cycle by which they are normally entrained.

Internal synchronization among several circadian rhythms in rats under constant light

1978 ◽  
Vol 235 (5) ◽  
pp. R243-R249 ◽  
Author(s):  
K. I. Honma ◽  
T. Hiroshige
Keyword(s):  
Locomotor Activity ◽  
Body Temperature ◽  
Circadian Rhythms ◽  
Continuous Light ◽  
Biological Rhythms ◽  
Plasma Corticosterone ◽  
Dark Cycle ◽  
Internal Oscillator ◽  
Free Running ◽  
Phase Angles

Three biological rhythms (locomotor activity, body temperature, and plasma corticosterone) were measured simultaneously in individual rats under light-dark cycles and continuous light. Spontaneous locomotor activity was recorded on an Animex and body temperature was telemetrically monitored throughout the experiments. Blood samples were obtained serially at 2-h intervals on the experimental days. Phase angles of these rhythms were calculated by a least-squares spectrum analysis. Under light-dark cycles, the acrophases of locomotor activity, body temperature, and plasma corticosterone were found at 0029, 0106, and 1940 h, respectively. When rats were exposed to 200 lx continuous light, locomotor activity and body temperature showed free-running rhythms with a period of 25.2 h on the average. Plasma corticosterone levels determined at 12 days after exposure to continuous light exhibited a circadian rhythm with the acrophase shifted to 0720. The acrophases of locomotor activity and body temperature, determined simultaneously on the same day, were found to be located at 1303 and 1358 h, respectively. Phase-angle differences among the three rhythms on the 12th day of continuous light were essentially the same with those under the light-dark cycle. These results suggest that circadian rhythms of locomotor activity, body temperature, and plasma corticosterone are most probably coupled to a common internal oscillator in the rat.

Studies on the Physiology of Awareness: The Effect of Rhythmic Sensory Bombardment on Emotions, Blood Oxygen Saturation and the Levels of Consciousness

1952 ◽  
Vol 98 (413) ◽  
pp. 640-653 ◽  
Author(s):  
John W. Lovett Doust ◽  
Robert A. Schneider
Keyword(s):  
Biological Rhythms ◽  
Breath Holding ◽  
Biological Processes ◽  
Urinary Function ◽  
Blood Oxygen Saturation ◽  
Chemical Systems ◽  
Physiological Variables ◽  
Blood Ph ◽  
Spot Activity ◽  
The Individual

Biological rhythms exist in a rich variety and almost bewildering profusion to attend and equilibrate the physiology of man. Such dynamic phasic activity appears not only to be intimately concerned with the phenomenology of life and biological processes in general, but is also to be found in purely chemical systems (Hedges and Meyers, 1926). Modalities of the periodicities associated with life can be divided into those external to the organism—including diurnal and climatic variation, sun-spot activity, etc., and into those inherent within the individual such as the respiratory and cardiac rhythms, the menstrual cycle, sleep and awakening. Only less well marked are certain psychological periodicities such as “cyclothymic “variations in mood and personality. In the course of the present century much painstaking research has attempted to link external with internal rhythmic activities, significant correlations being adduced between seasonal variation and, for example, the incidence of psychiatric disorder (Huntington, 1915), immunity from disease (Spencer and Melroy, 1943, Webster, 1944), temperament and behaviour (Petersen, 1934-36; Mills, 1942), and an impressive array of biochemical and physiological variables ranging from blood pH, lactic acid and protein to breath-holding time, plethysmography, tests of hand strength and fatigability, dark adaptation time and various tests of urinary function (Petersen, 1947).

scholarly journals Association of the Chronotype Score with Circulating Trimethylamine N-Oxide (TMAO) Concentrations

Nutrients ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 1671
Author(s):  
Luigi Barrea ◽  
Giovanna Muscogiuri ◽  
Gabriella Pugliese ◽  
Chiara Graziadio ◽  
Maria Maisto ◽  
...  
Keyword(s):  
Mediterranean Diet ◽  
Metabolic Profile ◽  
Cardiometabolic Risk ◽  
Linear Regression Analysis ◽  
Biological Rhythms ◽  
Unhealthy Lifestyle ◽  
Gut Dysbiosis ◽  
Study Population ◽  
The Mediterranean ◽  
The Individual

Individual differences in the chronotype, an attitude that best expresses the individual circadian preference in behavioral and biological rhythms, have been associated with cardiometabolic risk and gut dysbiosis. Up to now, there are no studies evaluating the association between chronotypes and circulating TMAO concentrations, a predictor of cardiometabolic risk and a useful marker of gut dysbiosis. In this study population (147 females and 100 males), subjects with the morning chronotype had the lowest BMI and waist circumference (p < 0.001), and a better metabolic profile compared to the other chronotypes. In addition, the morning chronotype had the highest adherence to the Mediterranean diet (p < 0.001) and the lowest circulating TMAO concentrations (p < 0.001). After adjusting for BMI and adherence to the Mediterranean diet, the correlation between circulating TMAO concentrations and chronotype score was still kept (r = −0.627, p < 0.001). Using a linear regression analysis, higher chronotype scores were mostly associated with lower circulating TMAO concentrations (β = −0.479, t = −12.08, and p < 0.001). Using a restricted cubic spline analysis, we found that a chronotype score ≥59 (p < 0.001, R2 = −0.824) demonstrated a more significant inverse linear relationship with circulating TMAO concentrations compared with knots <59 (neither chronotype) and <41 (evening chronotype). The current study reported the first evidence that higher circulating TMAO concentrations were associated with the evening chronotype that, in turn, is usually linked to an unhealthy lifestyle mostly characterized by low adherence to the MD.

Zur Beziehung zwischen Phasenlage und Spontanfrequenz bei der endogenen Tagesperiodik

1963 ◽  
Vol 18 (2) ◽  
pp. 154-157 ◽  
Author(s):  
Klaus Hoffmann
Keyword(s):  
Phase Angle ◽  
Diurnal Rhythm ◽  
Activity Rhythm ◽  
Sustained Oscillation ◽  
Temperature Cycle ◽  
Biological Processes ◽  
Experimental Demonstration ◽  
Free Running ◽  
Spontaneous Frequency ◽  
Free Running Period

The mechanism underlying the endogenous diurnal periodicity of biological processes can be considered a self-sustained oscillation, which can be entrained to an external cycle. In such oscillations the phase-angle of the entrained cycle depends upon the spontaneous frequency (free-running period) of the oscillator.The activity rhythm of lizards kept in constant light, and in a sinusoidal 24-hour temperature cycle, showed entrainment to this cycle. The phase of the entrained rhythm depended on the spontaneous frequency which was expressed in constant conditions occurring immediately before or after the exposure to the extraneous cycle. This is the first experimental demonstration showing the dependence of phase on the free-running period in an endogenous diurnal rhythm.

scholarly journals Genetic variation and phenotypic plasticity in circadian rhythms in an armed beetle, Gnatocerus cornutus (Tenebrionidae)

2020 ◽  
Vol 130 (1) ◽  
pp. 34-40 ◽  
Author(s):  
Kentarou Matsumura ◽  
Masato S Abe ◽  
Manmohan D Sharma ◽  
David J Hosken ◽  
Taishi Yoshii ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Phenotypic Plasticity ◽  
Circadian Rhythms ◽  
Temperature Effects ◽  
Temperature Compensation ◽  
Biological Rhythms ◽  
Total Activity ◽  
Biological Clocks ◽  
Isofemale Lines ◽  
Free Running

Abstract Circadian rhythms, their free-running periods and the power of the rhythms are often used as indicators of biological clocks, and there is evidence that the free-running periods of circadian rhythms are not affected by environmental factors, such as temperature. However, there are few studies of environmental effects on the power of the rhythms, and it is not clear whether temperature compensation is universal. Additionally, genetic variation and phenotypic plasticity in biological clocks are important for understanding the evolution of biological rhythms, but genetic and plastic effects are rarely investigated. Here, we used 18 isofemale lines (genotypes) of Gnatocerus cornutus to assess rhythms of locomotor activity, while also testing for temperature effects. We found that total activity and the power of the circadian rhythm were affected by interactions between sex and genotype or between sex, genotype and temperature. The males tended to be more active and showed greater increases in activity, but this effect varied across both genotypes and temperatures. The period of activity varied only by genotype and was thus independent of temperature. The complicated genotype–sex–environment interactions we recorded stress the importance of investigating circadian activity in more integrated ways.

scholarly journals Metabolism and Functions of Inositol Pyrophosphates: Insights Gained from the Application of Synthetic Analogues

Molecules ◽  
2020 ◽  
Vol 25 (19) ◽  
pp. 4515
Author(s):  
Stephen B. Shears ◽  
Huanchen Wang
Keyword(s):  
Chemical Synthesis ◽  
Molecular Level ◽  
Biological Information ◽  
Biological Processes ◽  
Synthetic Analogues ◽  
Metabolic Turnover ◽  
Important Group ◽  
Wide Range ◽  
Inositol Pyrophosphates ◽  
Low Levels

Inositol pyrophosphates (PP-InsPs) comprise an important group of intracellular, diffusible cellular signals that a wide range of biological processes throughout the yeast, plant, and animal kingdoms. It has been difficult to gain a molecular-level mechanistic understanding of the actions of these molecules, due to their highly phosphorylated nature, their low levels, and their rapid metabolic turnover. More recently, these obstacles to success are being surmounted by the chemical synthesis of a number of insightful PP-InsP analogs. This review will describe these analogs and will indicate the important chemical and biological information gained by using them.

Biological alarm clock arouses hibernating big brown bats, Eptesicus fuscus

1987 ◽  
Vol 65 (7) ◽  
pp. 1668-1674 ◽  
Author(s):  
John W. Twente ◽  
Janet Twente
Keyword(s):  
Laboratory Study ◽  
Eptesicus Fuscus ◽  
Continuous Darkness ◽  
Exogenous Variables ◽  
Alarm Clock ◽  
Big Brown Bats ◽  
Free Running ◽  
The Times ◽  
The Individual

This laboratory study showed that the individual averages of the times of day of arousal from hibernation of 55 big brown bats, Eptesicus fuscus, maintained in darkness, ranged from 14:05 to 20:50 (2:05 p.m. to 8:50 p.m.). The data were interpreted as representing a persistent but inexact 24-h rhythm that functioned as a biological alarm clock. This rhythm was, according to the parameters measured, apparent only on the day of arousal. The rhythm was determined to be independent of the length of time the bat had hibernated; independent of temperature; persistent and did not drift and become free-running in continuous darkness; unapparent in daily cardiac patterns or themogenic activity; and independent of obvious exogenous variables.

Pawilony bioniczne

BUILDER ◽  
2019 ◽  
Vol 258 (1) ◽  
pp. 26-28
Author(s):  
Anna Nowak ◽  
Wiesław Rokicki
Keyword(s):  
Fibonacci Sequence ◽  
Natural World ◽  
Digital Tools ◽  
Biological Processes ◽  
Structural Elements ◽  
Biological Models ◽  
Natural Processes ◽  
Advanced Knowledge ◽  
The Individual ◽  
Advanced Computer

INSPIRATIONS OF NATURE IN ARCHITECTURE. BIONIC PAVILIONS. The search for bionics is an interesting design notion, where the form of architectural objects is not only inspired by the aesthetics or patterns found in nature, but how its shape is reproduced by the natural processes of morphogenesis. Depending on how various patters in nature are replicated, a number of bionic modeling can be observed. The design based on the principles of forming natural structures requires some understanding of the ongoing processes and their changes. Thanks to the improvement of generative design methods allowing for the advanced knowledge in the field of technology to build the individual structural elements, a structural replication and analysis of biological processes is possible. The creation of mathematical models is an attempt to describe the forms found in the natural world, in particular the aspects of the morphogenesis. The Voronoi diagrams, or the Fibonacci sequence, which are increasingly used as a method of the discretization of the surface, deserve special consideration among the mentioned patterns found in nature. Digital tools play an important role in this process through the application of appropriate algorithms and advanced computer programs, but also experimental activities geared to building prototype solutions. The design of complicated spatial forms under different aspects is also aimed at searching for optimized technical and material solutions, in which unnecessary geometry is being eliminated. The transfer of biological models into architecture also applies to functional processes and systems found in nature in terms of shaping the coating elements. This paper is dedicated to the presentation of the completed experimental pavilions, which were created based on the bionic ideas, where the search for the multifunctional materials seems to be particularly important and could in turn revolutionize the building industry.

scholarly journals Association between mammalian lifespan and circadian free-running period: the circadian resonance hypothesis revisited

2010 ◽  
Vol 6 (5) ◽  
pp. 696-698 ◽  
Author(s):  
C. A. Wyse ◽  
A. N. Coogan ◽  
C. Selman ◽  
D. G. Hazlerigg ◽  
J. R. Speakman
Keyword(s):  
Laboratory Mouse ◽  
Biological Rhythms ◽  
Primate Species ◽  
Mouse Strains ◽  
Endogenous Rhythms ◽  
Physiological Cost ◽  
The Earth ◽  
Free Running ◽  
Rotation Of The Earth ◽  
Free Running Period

Biological rhythms that oscillate with periods close to 24 h (circadian cycles) are pervasive features of mammalian physiology, facilitating entrainment to the 24 h cycle generated by the rotation of the Earth. In the absence of environmental time cues, circadian rhythms default to their endogenous period called tau , or the free-running period. This sustained circadian rhythmicity in constant conditions has been reported across the animal kingdom, a ubiquity that could imply that innate rhythmicity confers an adaptive advantage. In this study, we found that the deviation of tau from 24 h was inversely related to the lifespan in laboratory mouse strains, and in other rodent and primate species. These findings support the hypothesis that misalignment of endogenous rhythms and 24 h environmental cycles may be associated with a physiological cost that has an effect on longevity.

scholarly journals Desynchronization of biological rhythms in response to environmental factors

2017 ◽  
Vol 95 (6) ◽  
pp. 502-512
Author(s):  
F. I. Komarov ◽  
S. I. Rapoport ◽  
Tamara K. Breus ◽  
S. M. Chibisov
Keyword(s):  
Circadian Rhythm ◽  
Environmental Factors ◽  
Temporal Structure ◽  
Biological Rhythms ◽  
Biological Processes ◽  
Structure And Dynamics ◽  
Causative Factors ◽  
Temperature Rhythms ◽  
Rotation Of The Earth ◽  
Circadian Rhythm Disorders

The temporal structure and dynamics of biological rhythms were formed in the course of evolution under the influence of environmental factors. Circadian rhythm as a central one in biological objects developed in response to daily luminosity and temperature rhythms related to rotation of the Earth. New causative factors that could be involved in this process and affect the entire spectrum of biological rhythms emerged with the advent of space research. The discovery of solar wind, interplanetary magnetic field, and Earth’s magnetosphere revealed similar periodicity of biological rhythms and magnetic factors which suggests possible participation of the latter in the formation of the former. Disturbances in magnetic rhythms may lead to desynchronization of biological processes by the adaptive stress mechanism as exemplified by circadian rhythm disorders in response to jetlag. This hypothesis forwarded by the authors in the 1990s was confirmed by further investigations including those reported by foreign researchers.

Sign in / Sign up

Export Citation Format

Share Document