• Title, Summary, Keyword: Circadian rhythm

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Circadian rhythms in subjective activation, mood, and performance efficiency (주관적 각성정도, 기분, 수행능력의 일중변화)

  • Yoon, In-Young
    • Sleep Medicine and Psychophysiology
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    • v.5 no.1
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    • pp.12-17
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    • 1998
  • Circadian rhythms in subjective alertness, mood, and performance can be classified as psychological rhythm, compared with physiological rhythm such as body temperature and hormonal change. While in normal condition entrained by 24hr zeitgeber, subjective alertness would reach its maximum value around midday, subjective alertness would parallel body temperature rhythm with its peak at evening in non-entrained, free-running state. With desynchronization technique, subjective alertness rhythm is thought to be controlled by both temperature and sleep-wake rhythm oscillator. Circadian performance rhythms depend on the kind of task tested. It shows parallelism with body temperature rhythm when subjects are tested with simple, repetitive task. But when tested with tasks requiring complex verbal reasoning or immediate memory, subjects would perform them best at early morning, with performance decreasing as time of day advances. The desynchronization technique shows that circadian performance rhythm of simple, repetitive task is dependent on temperature oscillator but circadian performance rhythm of complex verbal reasoning is influenced by both temperature and sleep-wake rhythm oscillator or another independent oscillator. It would be worthwhile to compare psychological rhythm with hormonal change such as cortisol and melatonin. And more simple and time-saving method than desynchronization technique may facilitate the study of the mechanism underlying psychological rhythm.

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Implications of Circadian Rhythm in Dopamine and Mood Regulation

  • Kim, Jeongah;Jang, Sangwon;Choe, Han Kyoung;Chung, Sooyoung;Son, Gi Hoon;Kim, Kyungjin
    • Molecules and Cells
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    • v.40 no.7
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    • pp.450-456
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    • 2017
  • Mammalian physiology and behavior are regulated by an internal time-keeping system, referred to as circadian rhythm. The circadian timing system has a hierarchical organization composed of the master clock in the suprachiasmatic nucleus (SCN) and local clocks in extra-SCN brain regions and peripheral organs. The circadian clock molecular mechanism involves a network of transcription-translation feedback loops. In addition to the clinical association between circadian rhythm disruption and mood disorders, recent studies have suggested a molecular link between mood regulation and circadian rhythm. Specifically, genetic deletion of the circadian nuclear receptor Rev-$erb{\alpha}$ induces mania-like behavior caused by increased midbrain dopaminergic (DAergic) tone at dusk. The association between circadian rhythm and emotion-related behaviors can be applied to pathological conditions, including neurodegenerative diseases. In Parkinson's disease (PD), DAergic neurons in the substantia nigra pars compacta progressively degenerate leading to motor dysfunction. Patients with PD also exhibit non-motor symptoms, including sleep disorder and neuropsychiatric disorders. Thus, it is important to understand the mechanisms that link the molecular circadian clock and brain machinery in the regulation of emotional behaviors and related midbrain DAergic neuronal circuits in healthy and pathological states. This review summarizes the current literature regarding the association between circadian rhythm and mood regulation from a chronobiological perspective, and may provide insight into therapeutic approaches to target psychiatric symptoms in neurodegenerative diseases involving circadian rhythm dysfunction.

Pigment-dispersing factor induces phase shifts of circadian locomotor rhythm in the cricket Gryllus bimaculatus

  • Singaravel, Muniyandi;Tomioka, Kenji
    • Journal of Photoscience
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    • v.9 no.2
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    • pp.243-245
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    • 2002
  • Pigment-dispersing factor (PDF) is an octadecapeptide distributed in the optic lobe and the brain in a variety of insect species. There are lines of evidence suggesting possible involvement of PDF in the insect circadian system. However, its physiological roles in the circadian time keeping mechanism have not been clearly defined. In this study, we have examined the phase shifting effects of Gryllus-PDF on the circadian locomotor rhythm in the cricket Gryllus bimaculatus of which circadian clock is located in the optic lobe. Phase shifts in the circadian activity rhythm were measured following microinjection of 22nl of vehicle (Ringer's solution) or O.lmM PDF into the optic lobe through the compound eye at various circadian times. The results showed that PDF induced phase shifts of the circadian clock in a phase-dependent manner, suggesting that it may play a role as an input signal for the circadian clock.

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Human Circadian Rhythms (인체의 일주기리듬)

  • Lee, Hyunah;Cho, Chul-Hyun;Kim, Leen
    • Sleep Medicine and Psychophysiology
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    • v.21 no.2
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    • pp.51-60
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    • 2014
  • A 'circadian rhythm' is a self-sustained biological rhythm (cycle) that repeats itself approximately every 24 hours. Circadian rhythms are generated by an internal clock, or pacemaker, and persist even in the absence of environmental time cues, collectively termed 'zeitgebers.' Although organisms generate circadian rhythms internally, they are entrained by environmental stimuli, particularly the light-dark cycle. Measurement of the endogenous melatonin rhythm provides relatively reliable surrogate way of assessing the timing of the internal circadian clock. Also, core body temperature and cortisol can be used as markers of circadian rhythms. The sleep-wake cycle, body temperature, and melatonin rhythm have a stable internal phase relationship in humans and other diurnal species. They play an important role in controlling daily behavioral rhythms including task performance, blood pressure, and synthesis and secretion of several hormones. In this review, we address not only the properties, methods of measurement, and markers of circadian rhythms, but also the physiological and psychological importance of human circadian rhythms.

Neurobiological Functions of the Period Circadian Clock 2 Gene, Per2

  • Kim, Mikyung;Pena, June Bryan de la;Cheong, Jae Hoon;Kim, Hee Jin
    • Biomolecules & Therapeutics
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    • v.26 no.4
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    • pp.358-367
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    • 2018
  • Most organisms have adapted to a circadian rhythm that follows a roughly 24-hour cycle, which is modulated by both internal (clock-related genes) and external (environment) factors. In such organisms, the central nervous system (CNS) is influenced by the circadian rhythm of individual cells. Furthermore, the period circadian clock 2 (Per2) gene is an important component of the circadian clock, which modulates the circadian rhythm. Per2 is mainly expressed in the suprachiasmatic nucleus (SCN) of the hypothalamus as well as other brain areas, including the midbrain and forebrain. This indicates that Per2 may affect various neurobiological activities such as sleeping, depression, and addiction. In this review, we focus on the neurobiological functions of Per2, which could help to better understand its roles in the CNS.

Clinical Applications of Light Therapy for Sleep Disorders (수면장애에서 광치료의 이용)

  • Sohn, Chang-Ho
    • Sleep Medicine and Psychophysiology
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    • v.15 no.1
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    • pp.12-16
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    • 2008
  • Light therapy (also called light treatment or phototherapy) involves scheduled exposure to bright artificial light. Evidence-based treatments for sleep disorders especially for circadian rhythm sleep disorders include light therapy and pharmacotherapy. In clinical practice, many of patients with sleep problems tend to impair circadian rhythmicity. Considering that light is the most potent entraining agent of circadian rhythm, careful use of light therapy can be recommended for patients with several kinds of sleep disorders. I briefly review the possible therapeutic mechanisms and clinical applications of light therapy, focusing on circadian sleep disorders.

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A Study on Serum Ferrum, TIBC, and Ferritin's Circadian Rhythm in Normal Adults (정상 성인의 혈청 철과 TIBC 및 Ferritin의 Circadian Rhythm에 대한 연구)

  • Jeong Suk-Heui;Kim Myung-Ae
    • Journal of Korean Academy of Fundamentals of Nursing
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    • v.9 no.1
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    • pp.113-122
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    • 2002
  • Purpose: The purpose of this study was to identify characteristics of serum ferrum, TIBC and ferritin's circadian rhythm in normal adults and to prepare a standard to determine the examination material extraction time. Method: Nine women and ten men made up the convenience sample for this study they were from the staff of D university hospital and students in D medical School located in K city who met the qualifications for inclusion in the sample. The value of serum ferrum, TIBC and circadian rhythm were calculated as follows : First. each variable's amplitude. the acrophase and average were measured for a 24 hour cycle using the cosinor method, and then each person's rhythm was analyzed. Results: There were significant serum iron circadian rhythm for both men and women (p<.05). For the men, mesor was $105.91{\mu}g/dl$. amplitude was $29.52{\mu}g/dl$, and the acrophase was 9.76 hour. For the women, mesor was $108.17{\mu}g/dl$, amplitude was $28.09{\mu}g/dl$, and the acrophase was 11.42 hour The rhythm change of TIBC was only significant for the women (p<.05), mesor was 383.39mg/dl, amplitude was 60.29mg/dl. and the acrophase was 14.93hour. As for the circadian rhythm of the ferritin, there are no diurnal variation in either sex, men were between 134.0ng/ml and 137.4ng/ml, and women, between 29.1ng/ml and 30.1ng/ml. Conclusion: To help diagnose the boundary line between normal or deficiency in iron, measurement should be carried out at a fixed time in the morning and evening, or a more proper time would be in the afternoon at the time when the width of amplitude is the least.

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Effect of the Circadian Rhythm on Social Network Service Addiction

  • Hong, Sunyeun;Park, Gangwoo;Kim, Teasun
    • International Journal of Advanced Culture Technology
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    • v.6 no.2
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    • pp.16-22
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    • 2018
  • This study is a descriptive survey research to investigate the effect of the circadian rhythm of the college students in different departments on the addiction to SNS. The subjects of this study were 150 freshman students in the Department of Nursing in K university, a four-year university located in Gumi, Gyeongbuk, and 130 freshmen students in the Department of Mechanical Engineering in K Engineering university located in the same city. In this study, the difference of circadian rhythm and SNS addiction was analyzed among the subjects in different departments. The result showed that the circadian rhythm was not significantly different between the departments, but SNS addiction showed significant difference between the departments.

The Effect of Circadian Rhythm on the Pharmacokinetics of Acebutolol after Intravenous Administration to Rabbits (가토에서 정맥투여시 생체리듬이 아세부토롤의 약물동태에 미친영향)

  • Choi, Jun Shik
    • Korean Journal of Clinical Pharmacy
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    • v.11 no.2
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    • pp.57-61
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    • 2001
  • The effect of circadian rhythm on the pharmacokinetics of acebutolol was studied in rabbits administered intravenous 5 mg/kg dose of acebutolol at 09:00 in the morning (a.m) and 22:00 in the evening (p.m). A significant effect of circadian rhythm of pbarmacokinetic parameters as a function of time of day was noted in rabbits, showing lower total body clearance (CLt), higher plasma concentration and the area under the plasma concentration time curve (AUC) when acebutolol was given in the evening. The plasma concentration of acebutolol was increased significantly (p<0.05) at 12-24 hr after dosing in the evening. The AUC was greater in the evening $(111\%)$ than that in the morning and $CL_t$, was higher when acebutolol was given in the morning ($1.12\pm0.24$ ml/hr) versus in the evening ($1.01\pm0.22$ ml/hr), but those were not significant. Therefore, It is reasonable to consider individual circadian rhythm for effective dosage regimen of acebutolol in clinical chronotherapeutics.

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The Circadian Rhythm Variation of Pain in the Orofacial Region

  • Kim, Moon Jong;Chung, Jin Woo;Kho, Hong-Seop;Park, Ji Woon
    • Journal of Oral Medicine and Pain
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    • v.40 no.3
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    • pp.89-95
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    • 2015
  • All living organisms have a biological clock that orchestrates every biological process and function, and this internal clock operates following a circadian rhythm. This biological clock is known to influence various clinical indicators such as blood pressure and body temperature. Also, the fluctuation of signs and symptoms of diseases including pain disorders are affected by circadian rhythm. It has been reported that the pain intensity of various somatic and neuropathic pain disorders show unique pain patterns that depend on the passage of time. The generation of pain patterns could be explained by extrinsic (e.g., physical activity, tactile stimulation, ambient temperature) and also intrinsic factors (neural and neuroendocrine modulation) that are related to the circadian rhythm. It is important to recognize and identify the individual pain pattern in pain therapy to approve treatment outcome. Moreover, chronotherapeutics which considers pain patterns and pharmacokinetics in context of the circadian rhythm could produce greater analgesia in response to medication. However, only a limited number of studies handle the issue of pain patterns according to circadian rhythm and chronotherapeutics in the orofacial region. The present review intends to reflect on the most recent and relevant data concerning the bidirectional relation between pain disorders of the orofacial region and circadian patterns.