scholarly journals Disruption of Circadian Rhythms: A Crucial Factor in the Etiology of Depression

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Roberto Salgado-Delgado ◽  
Araceli Tapia Osorio ◽  
Nadia Saderi ◽  
Carolina Escobar
Keyword(s):  
Circadian Rhythms ◽  
Biological Clock ◽  
Therapeutic Strategies ◽  
Circadian System ◽  
Metabolic Functions ◽  
Lighting Conditions ◽  
Wide Range ◽  
Close Relationship ◽  
And Behavior ◽  
Depressive States

Circadian factors might play a crucial role in the etiology of depression. It has been demonstrated that the disruption of circadian rhythms by lighting conditions and lifestyle predisposes individuals to a wide range of mood disorders, including impulsivity, mania and depression. Also, associated with depression, there is the impairment of circadian rhythmicity of behavioral, endocrine, and metabolic functions. Inspite of this close relationship between both processes, the complex relationship between the biological clock and the incidence of depressive symptoms is far from being understood. The efficiency and the timing of treatments based on chronotherapy (e.g., light treatment, sleep deprivation, and scheduled medication) indicate that the circadian system is an essential target in the therapy of depression. The aim of the present review is to analyze the biological and clinical data that link depression with the disruption of circadian rhythms, emphasizing the contribution of circadian desynchrony. Therefore, we examine the conditions that may lead to circadian disruption of physiology and behavior as described in depressive states, and, according to this approach, we discuss therapeutic strategies aimed at treating the circadian system and depression.

scholarly journals Timing metabolism in cartilage and bone: links between circadian clocks and tissue homeostasis

2019 ◽  
Vol 243 (3) ◽  
pp. R29-R46 ◽  
Author(s):  
Cátia F Gonçalves ◽  
Qing-Jun Meng
Keyword(s):  
Rheumatoid Arthritis ◽  
Circadian Rhythms ◽  
Circadian System ◽  
Tissue Homeostasis ◽  
Circadian Clocks ◽  
Clock System ◽  
Metabolic Functions ◽  
Biochemical Mechanisms ◽  
Skeletal Disorders ◽  
Bone Physiology

The circadian system in mammals is responsible for the temporal coordination of multiple physiological and behavioural processes that are necessary for homeostasis. In the skeleton, it has long been known that metabolic functions of chondrocytes, osteoblasts and osteoclasts exhibit intrinsic circadian rhythms. In addition, results from animal models reveal a close connection between the disruption of circadian rhythms and skeletal disorders such as rheumatoid arthritis, osteoarthritis and osteoporosis. In this review, we summarise the latest insights into the genetic and biochemical mechanisms linking cartilage and bone physiology to the circadian clock system. We also discuss how this knowledge can be utilised to improve human health.

scholarly journals Does a Red House Affect Rhythms in Mice with a Corrupted Circadian System?

2021 ◽  
Vol 22 (5) ◽  
pp. 2288
Author(s):  
Menekse Öztürk ◽  
Marc Ingenwerth ◽  
Martin Sager ◽  
Charlotte von Gall ◽  
Amira A. H. Ali
Keyword(s):  
Circadian Rhythms ◽  
Neuronal Activity ◽  
Clock Genes ◽  
Plasma Corticosterone ◽  
Cellular Level ◽  
Circadian System ◽  
Targeted Deletion ◽  
Long Wavelength ◽  
And Behavior ◽  
Time Information

The circadian rhythms of body functions in mammals are controlled by the circadian system. The suprachiasmatic nucleus (SCN) in the hypothalamus orchestrates subordinate oscillators. Time information is conveyed from the retina to the SCN to coordinate an organism’s physiology and behavior with the light/dark cycle. At the cellular level, molecular clockwork composed of interlocked transcriptional/translational feedback loops of clock genes drives rhythmic gene expression. Mice with targeted deletion of the essential clock gene Bmal1 (Bmal1−/−) have an impaired light input pathway into the circadian system and show a loss of circadian rhythms. The red house (RH) is an animal welfare measure widely used for rodents as a hiding place. Red plastic provides light at a low irradiance and long wavelength—conditions which affect the circadian system. It is not known yet whether the RH affects rhythmic behavior in mice with a corrupted circadian system. Here, we analyzed whether the RH affects spontaneous locomotor activity in Bmal1−/− mice under standard laboratory light conditions. In addition, mPER1- and p-ERK-immunoreactions, as markers for rhythmic SCN neuronal activity, and day/night plasma corticosterone levels were evaluated. Our findings indicate that application of the RH to Bmal1−/− abolishes rhythmic locomotor behavior and dampens rhythmic SCN neuronal activity. However, RH had no effect on the day/night difference in corticosterone levels.

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.

scholarly journals Post-Translational Mechanisms of Plant Circadian Regulation

Genes ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 325
Author(s):  
Jiapei Yan ◽  
Yeon Jeong Kim ◽  
David E. Somers
Keyword(s):  
Circadian Rhythms ◽  
Recent Work ◽  
Transcriptional Control ◽  
Circadian System ◽  
Circadian Oscillator ◽  
Circadian Regulation ◽  
Circadian Control ◽  
Wide Range ◽  
Molecular Components ◽  
Translational Mechanisms

The molecular components of the circadian system possess the interesting feature of acting together to create a self-sustaining oscillator, while at the same time acting individually, and in complexes, to confer phase-specific circadian control over a wide range of physiological and developmental outputs. This means that many circadian oscillator proteins are simultaneously also part of the circadian output pathway. Most studies have focused on transcriptional control of circadian rhythms, but work in plants and metazoans has shown the importance of post-transcriptional and post-translational processes within the circadian system. Here we highlight recent work describing post-translational mechanisms that impact both the function of the oscillator and the clock-controlled outputs.

Molecular Biology and Physiology of Circadian Clocks

2019 ◽  
Author(s):  
Ruifeng Cao
Keyword(s):  
Circadian Rhythms ◽  
Circadian System ◽  
Feedback Loops ◽  
The Body ◽  
Endogenous Rhythms ◽  
Peripheral Oscillators ◽  
Physiological Processes ◽  
And Behavior ◽  
Photic Input ◽  
Master Clock

Circadian rhythm is the approximately 24-hour rhythmicity that regulates physiology and behavior in a variety of organisms. The mammalian circadian system is organized in a hierarchical manner. Molecular circadian oscillations driven by genetic feedback loops are found in individual cells, whereas circadian rhythms in different systems of the body are orchestrated by the master clock in the suprachiasmatic nucleus (SCN) of the anterior hypothalamus. SCN receives photic input from retina and synchronizes endogenous rhythms with the external light/dark cycles. SCN regulates circadian rhythms in the peripheral oscillators via neural and humoral signals, which account for daily fluctuations of the physiological processes in these organs. Disruption of circadian rhythms can cause health problems and circadian dysfunction has been linked to many human diseases.

scholarly journals Circadian rhythms identified inCaenorhabditis elegansby in vivo long-term monitoring of a bioluminescent reporter

2016 ◽  
Vol 113 (48) ◽  
pp. E7837-E7845 ◽  
Author(s):  
María Eugenia Goya ◽  
Andrés Romanowski ◽  
Carlos S. Caldart ◽  
Claire Y. Bénard ◽  
Diego A. Golombek
Keyword(s):  
Circadian Rhythms ◽  
Circadian System ◽  
Phase Changes ◽  
Model Systems ◽  
Biological Variables ◽  
Evolutionarily Conserved ◽  
Gated Channel ◽  
Bioluminescence Assay ◽  
And Behavior

Circadian rhythms are based on endogenous clocks that allow organisms to adjust their physiology and behavior by entrainment to the solar day and, in turn, to select the optimal times for most biological variables. Diverse model systems—including mice, flies, fungi, plants, and bacteria—have provided important insights into the mechanisms of circadian rhythmicity. However, the general principles that govern the circadian clock ofCaenorhabditis eleganshave remained largely elusive. Here we report robust molecular circadian rhythms inC.elegansrecorded with a bioluminescence assay in vivo and demonstrate the main features of the circadian system of the nematode. By constructing a luciferase-based reporter coupled to the promoter of the suppressor of activatedlet-60Ras (sur-5) gene, we show in both population and single-nematode assays thatC.elegansexpresses ∼24-h rhythms that can be entrained by light/dark and temperature cycles. We provide evidence that these rhythms are temperature-compensated and can be re-entrained after phase changes of the synchronizing agents. In addition, we demonstrate that light and temperature sensing requires the photoreceptors LITE and GUR-3, and the cyclic nucleotide-gated channel subunit TAX-2. Our results shed light onC.eleganscircadian biology and demonstrate evolutionarily conserved features in the circadian system of the nematode.

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.

Tickets for the Inclusive Museum

2020 ◽  
pp. 390-406
Author(s):  
Magda Nikolaraizi ◽  
Charikleia Kanari ◽  
Marc Marschark
Keyword(s):  
Hard Of Hearing ◽  
Learning Experiences ◽  
Learning Needs ◽  
Participatory Learning ◽  
Maximum Benefit ◽  
Wide Range ◽  
The Right ◽  
Physical Features ◽  
And Behavior

In recent years, museums of various kinds have broadened their mission and made systematic efforts to develop a dynamic role in learning by offering a wide range of less formal experiences for individuals with diverse characteristics, including individuals who are deaf or hard-of-hearing (DHH). Despite the worthwhile efforts, in the case of DHH individuals, museums frequently neglect to consider their unique communication, cognitive, cultural, and learning characteristics, thus limiting their access and opportunities for fully experiencing what museums have to offer. This chapter examines the potential for creating accessible museum environments and methods that reflect an understanding of the diverse communication, cognitive, cultural, and learning needs of DHH visitors, all of which enhance their access and participation in the museum activities. The role of the physical features of museum spaces for the access and behavior of DHH visitors is emphasized, together with attention to exhibition methods and the communication and cognitive challenges that need to be considered so DHH visitors can get the maximum benefit. The chapter emphasizes the right of individuals who are DHH to nonformal learning and analyzes how museums could become more accessible to DHH individuals by designing, from the beginning, participatory learning experiences that address their diverse needs.

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.

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