scholarly journals Minutes, days and years: molecular interactions among different scales of biological timing

2014 ◽  
Vol 369 (1637) ◽  
pp. 20120465 ◽  
Author(s):  
Diego A. Golombek ◽  
Ivana L. Bussi ◽  
Patricia V. Agostino

Biological clocks are genetically encoded oscillators that allow organisms to keep track of their environment. Among them, the circadian system is a highly conserved timing structure that regulates several physiological, metabolic and behavioural functions with periods close to 24 h. Time is also crucial for everyday activities that involve conscious time estimation. Timing behaviour in the second-to-minutes range, known as interval timing, involves the interaction of cortico-striatal circuits. In this review, we summarize current findings on the neurobiological basis of the circadian system, both at the genetic and behavioural level, and also focus on its interactions with interval timing and seasonal rhythms, in order to construct a multi-level biological clock.

Elements ◽  
2009 ◽  
Vol 5 (1) ◽  
Author(s):  
Michael Minkoff

This paper is a phenomenological exploration into the true nature of musical time. Drawing on the thought of Henri Bergson, Vladimir Jankelevitch, and contemporary philosophers of music, I propose that the nature of musical time lies within the performer and that its existence is parallel to that of the ordinary lived time of the empirical universe. We experience musical time as "mobile" (Bergson's terminology) and as a phenomenon of passing. A musician's ability to play music "in time" is governed by what I refer to as his "internal musical biological clock." However, as music is an art form that is typically performed in a group, a musician's relationship must be an intersubjective relationship where the performers' experience of time is forced by a synchronization of their internal musical biological clocks.


2021 ◽  
Author(s):  
Przemysław GILUN ◽  
Barbara Wąsowska ◽  
Magdalena Sowa-Kućma ◽  
Katarzyna Kozioł ◽  
Maria Romerowicz-Misielak ◽  
...  

Abstract Mature males of a wild boar-pig crossbreed during long- and short-day seasons were used for the study, which demonstrated that the chemical light carrier CO regulates the expression of biological clock genes in the hypothalamus (preoptic area - POA and dorsal part of hypothalamus - DH) via humoral pathways. Autologous blood with experimentally elevated concentrations of endogenous CO (using lamps with white light-emitting diodes) was infused into the ophthalmic venous sinus via the right dorsal nasal vein.The results showed that elevated endogenous CO levels through blood irradiation induced changes in gene expression involved in the functioning of the main biological clock. Changes in the expression of the transcription factors Bmal1, Clock and Npas2 had a similar pattern in both structures, where a very large decrease in gene expression was shown after exposure to elevated endogenous CO levels. The changes in the gene expression of PER 1-2, CRY 1-2, REV-ERB α-β and ROR β are not the same for both POA and DH hypothalamic structures, indicating that both structures respond differently to the received humoral signal.The obtained results indicate that CO is a chemical light molecule whose production in organisms depends on the amount of light. An adequate amount of light is an essential factor for the proper functioning of the main biological clock.


2001 ◽  
Vol 280 (4) ◽  
pp. R1023-R1030 ◽  
Author(s):  
M. M. Canal-Corretger ◽  
J. Vilaplana ◽  
T. Cambras ◽  
A. Díez-Noguera

Lighting conditions influence biological clocks. The present experiment was designed to test the presence of a critical window of days during the lactation stage of the rat in which light has a decisive role on the development of the circadian system. Rats were exposed to 4, 8, or 12 days of constant light (LL) during the first days of life. Their circadian rhythm was later studied under LL and constant darkness. The response to a light pulse was also examined. Results show that the greater the number of LL days during lactation, the stronger the rhythm under LL and the smaller the phase shift due to the light pulse. These responses are enhanced when rats are exposed to LL days around postnatal day 12. A mathematical model was built to explain the responses of the circadian system with respect to the timing of LL during lactation, and we deduced that between postnatal days 10 to 20there is a critical period of sensitivity to light; consequently, exposure to LL during this time modifies the circadian organization of the motor activity.


2021 ◽  
Vol 42 (1) ◽  
pp. 97-111
Author(s):  
Paro Mishra ◽  
Ravinder Kaur

This paper maps the impact of gender imbalance on intergenerational relations in north India. It uses the idea of multiple biological clocks to understand the impact that gender imbalance and male marriage squeeze have on two categories of persons: “overage” unmarried sons and their aging parents, and the inter-generational contract between them within the family-household. De-linking the idea of the biological clock from the female body, this paper demonstrates that social understandings of bodily progression are equally significant for men, who, in the Indian context, need to marry by a certain age, and their elderly parents who need to be cared for. In north India, where family-household unit is the most important welfare and security institution for the elderly, disruptions to household formation due to bride shortage caused by sex ratio imbalance, is subjecting families to severe stress. Families with unmarried sons struggle with anxieties centred on the inability to arrange marriages for aging sons, questions of allocation of household labor, the continuation of family line, and lack of care for the elderly. Based on ethnographic fieldwork in north India, this paper explores the tensions and negotiations between elderly parents and unmarried sons concerning the fulfillment (or lack of it) of the intergenerational contract against the backdrop of gender imbalance. It concludes by discussing the various strategies available to families in crisis that involve shame-faced adoption of domestic and care tasks by unmarried sons or bringing cross-region brides who then provide productive, reproductive, and care labour.


The structure of the human biological rhythm is most sensitive to changes that occur when you alter usual living conditions. That is why the authors of the work devoted their attention to the study of its basic parameters such as the analysis of the daily regimen, taking into account the “wakefulness and rest” cycles, the sleep quality index, the severity of insomnia. These parameters directly affect the person’s efficiency and results of sports activities. The authors have developed a system for the electronic diagnosis of human biorhythms. You can get acquainted with it at the open educational resources of V.N.Karazin Kharkiv National University. In the work, for the first time, the basic cycles of “wakefulness and sleep”, “activity and rest” were evaluated as basic cycles of the day regimen of students professionally involved in sports using electronic diagnostics. Insomnia severity index was evaluated, which directly affects the psychosomatic state and can be a cause of violation of the dynamic stereotype of a person, deterioration of health. These factors contribute to the development of desynchronosis. The data obtained indicate that the surveyed group of individuals can quite easily adapt to work both in the morning and in the evening, but it is likely that these individuals have unnatural types of daily working capacity, which are manifestations of adaptation to new living conditions. Also, this group of people is characterized by medium and high levels of sleep quality and body recovery. It is easier for people of this group to fall asleep in non-standard conditions than to stay awake at unusual time. Modern youth, despite an active (sporty) lifestyle, has certain violations in the duration and nature of sleep. The data obtained indicate that reducing the duration of sleep by 1.3–1.5 hours directly affects the state of wakefulness and sleep during the day. Despite the fact that chronic sleep deprivation in this group of students professionally involved in sports has not been identified, some individual variations in the need for quality of sleep are revealed, after a long sleep, there is minimal improvement in daytime wakefulness, reduction of fatigue, improvement in the processes of memory, perception and concentration. All these indicators directly affect the sports result. Compensation of lack of nocturnal sleep is mainly possible only due to longer breaks for rest during the day. Thus, the need for sleep is determined on the one hand by the processes of relaxation and fatigue, which increase during wakefulness, and the circadian process – the cycle of “activity and rest”. The level of need for sleep increases during wakefulness and decreases during sleep, while the circadian rhythm is an independent component under the control of the internal biological clock. Thus, the need for sleep at any given moment is a summation of the processes of “activity and rest”, “wakefulness and sleep” and internal biological clocks, and disturbances in the interaction of these processes explain subjective experiences associated with disruption of the daily rhythm at abrupt changes in the daily pattern and changes of length of daylight. Therefore, when the time of falling asleep falls on the period of activity and the person cannot fall asleep, and feels constant drowsiness during the day due to the growing need for sleep, this is a violation of the “wakefulness and sleep” cycle associated with new living conditions and stress loads on the body.


1996 ◽  
Vol 199 (1) ◽  
pp. 39-48 ◽  
Author(s):  
E Gwinner

In migratory birds, endogenous daily (circadian) and annual (circannual) rhythms serve as biological clocks that provide the major basis for their temporal orientation. Circannual rhythms are responsible for the initiation of migration both in autumn and spring. This function of timing migrations is particularly important for birds that spend the winter close to the equator where the environment is too constant or irregular to provide accurate timing cues. In addition, circannual rhythms produce programmes that determine both the temporal and the spatial course of migration. In Sylvia warblers, the time programmes controlling autumn migration are organized in a species- or population-specific manner. It has been proposed that, in first-year migrants, the time programme for autumn migration plays a major role in determining migratory distance, thus providing the vector component in a mechanism of vector navigation. It is not yet clear, however, whether this programme does indeed determine migratory distance or whether it only provides the temporal framework within which other factors determine how far a bird flies. Evidence against the first alternative comes from findings indicating that migratory activity can be drastically modified by a constellation of rather specific, but highly relevant, factors and that the resulting changes in migratory activity are not compensated by subsequent increases or decreases of migratory activity. In normally day-active but nocturnally migrating birds, circannual signals cause alterations in the circadian system leading to the development of nocturnal activity. Although the nature of these signals is unknown, there is evidence that changes in the diurnal pattern of melatonin secretion by the pineal gland are associated with, and possibly causally involved in, the waxing and waning of nocturnal activity. These changes in the melatonin pattern presumably also affect general synchronization properties of the circadian system to Zeitgebers in such a way that circadian rhythms adjust faster to new conditions after long transmeridian flights.


Motor Control ◽  
2015 ◽  
Vol 19 (1) ◽  
pp. 90-101 ◽  
Author(s):  
Yin-Hua Chen ◽  
Paola Cesari

Evaluating time properly is crucial for everyday activities from fundamental behaviors to refined coordinative movements such as in sport playing. Lately the concept of the existence of a unique internal clock for evaluating time in different scales has been challenged by recent neurophysiology studies. Here we provide evidence that individuals evaluate time durations below and above a second based on two different internal clocks for sub- and suprasecond time ranges: a faster clock for the subsecond range and a slower one for suprasecond time. Interestingly, the level of precision presented by these two clocks can be finely tuned through long-term sport training: Elite athletes, independently from their sport domains, generate better time estimates than nonathletes by showing higher accuracy and lower variability, particularly for subsecond time. We interpret this better time estimation in the short durations as being due to their extraordinary perceptual and motor ability in fast actions.


2002 ◽  
Vol 71 (4) ◽  
pp. 773-785 ◽  
Author(s):  
M.-Y Ho ◽  
D.N Velázquez-Martı́nez ◽  
C.M Bradshaw ◽  
E Szabadi

2015 ◽  
Vol 3 (3-4) ◽  
pp. 307-316
Author(s):  
Neşe Alkan

This commentary is designed to provide an analysis of issues pertinent to the investigation of the effects of the temporary cessation of breathing (apnea), particularly during water immersion or diving, and its effects on time estimation in general and the timing of motor representation in particular. In addition, this analysis provides alternative explanations of certain unexpected findings reported by Di Rienzo et al. (2014) pertaining to apnea and interval timing. The perspective and guidance that this commentary provides on the relationship between apnea and time estimation is especially relevant considering the scarcity of experimental and clinical studies examining these variables.


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