Why circadian rhythms are needed, or how to change the rate of the "biological clock"

2017 ◽  
Vol 12 ◽  
pp. 50-62
Author(s):  
S.I. Romanyuk ◽  
◽  
S.V. Komisarenko ◽  
Keyword(s):  
Circadian Rhythms ◽  
Biological Clock

The Biological Clock and Sleep in the Elderly

2006 ◽  
Vol 19 (1) ◽  
pp. 45-51 ◽  
Author(s):  
Myriam Juda ◽  
Mirjam Münch ◽  
Anna Wirz-Justice ◽  
Martha Merrow ◽  
Till Roenneberg
Keyword(s):  
Circadian Rhythms ◽  
Biological Clock ◽  
The Elderly ◽  
Early Morning ◽  
Behavioral Changes ◽  
Older Age ◽  
Age Related ◽  
Theoretical Considerations ◽  
Sleep Difficulties ◽  
Circadian Biology

Abstract: Among many other changes, older age is characterized by advanced sleep-wake cycles, changes in the amplitude of various circadian rhythms, as well as reduced entrainment to zeitgebers. These features reveal themselves through early morning awakenings, sleep difficulties at night, and a re-emergence of daytime napping. This review summarizes the observations concerning the biological clock and sleep in the elderly and discusses the documented and theoretical considerations behind these age-related behavioral changes, especially with respect to circadian biology.

Nonphotic entrainment of the human circadian pacemaker

1998 ◽  
Vol 274 (4) ◽  
pp. R991-R996 ◽  
Author(s):  
Elizabeth B. Klerman ◽  
David W. Rimmer ◽  
Derk-Jan Dijk ◽  
Richard E. Kronauer ◽  
Joseph F. Rizzo ◽  
...  
Keyword(s):  
Circadian Rhythms ◽  
Light Exposure ◽  
Core Body Temperature ◽  
Biological Clock ◽  
Bright Light ◽  
Circadian Pacemaker ◽  
Temperature Rhythms ◽  
Blind Individuals ◽  
Nonphotic Entrainment ◽  
Core Body

In organisms as diverse as single-celled algae and humans, light is the primary stimulus mediating entrainment of the circadian biological clock. Reports that some totally blind individuals appear entrained to the 24-h day have suggested that nonphotic stimuli may also be effective circadian synchronizers in humans, although the nonphotic stimuli are probably comparatively weak synchronizers, because the circadian rhythms of many totally blind individuals “free run” even when they maintain a 24-h activity-rest schedule. To investigate entrainment by nonphotic synchronizers, we studied the endogenous circadian melatonin and core body temperature rhythms of 15 totally blind subjects who lacked conscious light perception and exhibited no suppression of plasma melatonin in response to ocular bright-light exposure. Nine of these fifteen blind individuals were able to maintain synchronization to the 24-h day, albeit often at an atypical phase angle of entrainment. Nonphotic stimuli also synchronized the endogenous circadian rhythms of a totally blind individual to a non-24-h schedule while living in constant near darkness. We conclude that nonphotic stimuli can entrain the human circadian pacemaker in some individuals lacking ocular circadian photoreception.

Time-restricted eating and circadian rhythms: the biological clock is ticking

2020 ◽  
pp. 1-13 ◽  
Author(s):  
Jéssica do Nascimento Queiroz ◽  
Rodrigo Cauduro Oliveira Macedo ◽  
Grant M. Tinsley ◽  
Alvaro Reischak-Oliveira
Keyword(s):  
Circadian Rhythms ◽  
Biological Clock

scholarly journals Individual Ants Do Not Show Active-rest Rhythms in Natural Nest Conditions

2020 ◽  
Author(s):  
Haruna Fujioka ◽  
Masato S. Abe ◽  
Yasukazu Okada
Keyword(s):  
Circadian Rhythms ◽  
Social Interactions ◽  
Social Insects ◽  
Tracking System ◽  
Abiotic Factors ◽  
Small Body ◽  
Biological Clock ◽  
Diversity Pattern ◽  
Laboratory Colony ◽  
Abiotic And Biotic Factors

AbstractCircadian rhythms, which respond to the day/night cycle on the earth, arise from the endogenous timekeeping system within organisms, called the biological clock. For accurate circadian rhythms, endogenous oscillations are synchronized to light and temperature. In social insects, both abiotic and biotic factors (i.e., social interactions) play a significant role in active/rest rhythm regulation. However, it is challenging to monitor individual active-rest rhythms in a colony because of the large group size and small body size. Therefore, it is unclear how social interactions coordinate each individual’s active/rest rhythms. This study developed an image-based tracking system using 2D barcodes for <I>Diacamma</I> sp. (a monomorphic ant) and measured the locomotor activities of all colony members under laboratory colony conditions. We also investigated the effect of broods on active/rest rhythms by removing all broods under colony conditions. Active/rest rhythms appeared only in solitary ants, not under colony conditions. In addition, arrhythmic active-rest rhythms were retained after brood removal. Therefore, a mixture of social interactions, not abiotic factors, induces the loss of active/rest rhythms. These results contribute to the knowledge of the diversity pattern of circadian rhythms in social insects.

Roles of cell adhesion molecules in the function of biological clock of circadian rhythms

1998 ◽  
Vol 31 ◽  
pp. S217
Author(s):  
Shigeru Yamada ◽  
Yoshiharu Takayama ◽  
Tatsunori Seki ◽  
Masato Okada ◽  
Katsuya Nagai
Keyword(s):  
Cell Adhesion ◽  
Circadian Rhythms ◽  
Adhesion Molecules ◽  
Cell Adhesion Molecules ◽  
Biological Clock

scholarly journals Sleep and Depression: What We Know and What to Learn?

2020 ◽  
pp. 33-49
Author(s):  
Andrey Viktorovich Antsyborov ◽  
Anna Valerievna Kalinchuk ◽  
Irina Vladimirovna Dubatova
Keyword(s):  
Obstructive Sleep Apnea ◽  
Circadian Rhythms ◽  
Affective Disorders ◽  
Sleep Disturbances ◽  
Biological Clock ◽  
The Core ◽  
Obstructive Sleep ◽  
Function Of Sleep ◽  
Depressive Episodes

Presently, a lot of data indicate that the disturbance of mechanisms underlying the regulation of sleep-waking cycle coincides with the mechanisms underlying the development of depression. The disturbance of circadian rhythms is one of the core factors in the genesis of the most affective disorders including depression, which indicates the role of the internal biological clock in the pathophysiology of affective disorders. The episodes of depression, mania or hypomania may result from the disturbances in endogenous biological timing. In this review, we have summarized the literature data obtained in animal models or in the patients with affective pathology, in which the connection between the function of sleep and depression was demonstrated. Specifically, we highlight the mechanisms underlying sleep dysfunction during depression (imbalance of circadian rhythms, melatonin metabolism and mechanisms of neuroinflammatory dysregulation) and provide an evidence for the link between sleep function and depression (sleep disturbances during depressive episodes, the effects of pharmacotherapy, chronotherapy, the effect of sleep deprivation, comorbidity of obstructive sleep apnea and depression).

Chronobiological Treatments

Depression ◽  
2019 ◽  
pp. 390-396
Author(s):  
Raymond W. Lam
Keyword(s):  
Circadian Rhythms ◽  
Seasonal Affective Disorder ◽  
Low Cost ◽  
Biological Clock ◽  
Light Therapy ◽  
Rapid Onset ◽  
Circadian System ◽  
Environmental Light ◽  
Psychiatric Conditions ◽  
The Brain

Chronobiology is the study of circadian rhythms that are present in many aspects of our daily health, from molecular to behavioral levels. Bright environmental light is known to synchronize the biological clock in the brain that regulates circadian hormonal and sleep–wake cycles. There is increasing evidence for disruption of circadian rhythms in the pathophysiology of major depressive disorder (MDD), especially in seasonal affective disorder (SAD). Chronobiological treatments that target the circadian system, including wake therapy (total sleep deprivation) and light therapy, have been studied for over four decades, with evidence supporting their efficacy in SAD and non-seasonal MDD, as well as in other psychiatric conditions. Wake and light therapies are useful additions to the clinical armamentarium for patients with MDD because of their noninvasive nature, low propensity for adverse events, rapid onset of effect, low cost, and ease of combining with other treatments for depression.

Late-night presentation of an auditory stimulus phase delays human circadian rhythms

2005 ◽  
Vol 289 (1) ◽  
pp. R209-R216 ◽  
Author(s):  
Namni Goel
Keyword(s):  
Circadian Rhythms ◽  
Auditory Stimulus ◽  
Core Body Temperature ◽  
Biological Clock ◽  
Phase Changes ◽  
Circadian Phase ◽  
Late Night ◽  
Human Circadian Rhythms ◽  
Before And After ◽  
Dim Light

Although light is considered the primary entrainer of circadian rhythms in humans, nonphotic stimuli, including exercise and melatonin also phase shift the biological clock. Furthermore, in birds and nonhuman mammals, auditory stimuli are effective zeitgebers. This study investigated whether a nonphotic auditory stimulus phase shifts human circadian rhythms. Ten subjects (5 men and 5 women, ages 18–72, mean age ± SD, 44.7 ± 21.4 yr) completed two 4-day laboratory sessions in constant dim light (<20 lux). They received two consecutive presentations of either a 2-h auditory or control stimulus from 0100 to 0300 on the second and third nights (presentation order of the stimulus and control was counterbalanced). Core body temperature (CBT) was collected and stored in 2-min bins throughout the study and salivary melatonin was obtained every 30 min from 1900 to 2330 on the baseline and poststimulus/postcontrol nights. Circadian phase of dim light melatonin onset (DLMO) and of CBT minimum, before and after auditory or control presentation was assessed. The auditory stimulus produced significantly larger phase delays of the circadian melatonin (mean ± SD, −0.89 ± 0.40 h vs. −0.27 ± 0.16 h) and CBT (−1.16 ± 0.69 h vs. −0.44 ± 0.27 h) rhythms than the control. Phase changes for the two circadian rhythms also positively correlated, indicating direct effects on the biological clock. In addition, the auditory stimulus significantly decreased fatigue compared with the control. This study is the first demonstration of an auditory stimulus phase-shifting circadian rhythms in humans, with shifts similar in size and direction to those of other nonphotic stimuli presented during the early subjective night. This novel stimulus may be a useful countermeasure to facilitate circadian adaptation after transmeridian travel or shift work.

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