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Journal of Circadian Rhythms

Tatiana D Viena, Christina M Gobin, Ana I Fins, Travis J A Craddock, Aurélien Tartar, Jaime L Tartar
BACKGROUND: Expression of the clock family of genes in the suprachiasmatic nuclei (SCN) regulates the molecular control of circadian timing. Increasing evidence also implicates clock gene activity in the development of mood disorders. In particular, variation in the PER3 clock gene has been shown to influence diurnal preference and sleep homeostasis. However, there is not currently a clear association between PER3 polymorphisms and mood. This is possibly because the PER3 gene has been shown to influence homeostatic sleep drive, rather than circadian timing, and the PER3 gene may be behaviorally relevant only under chronic sleep loss conditions...
March 10, 2016: Journal of Circadian Rhythms
Shawn D Youngstedt, Christopher E Kline, Jeffrey A Elliott, Mark R Zielinski, Tina M Devlin, Teresa A Moore
Limited research has compared the circadian phase-shifting effects of bright light and exercise and additive effects of these stimuli. The aim of this study was to compare the phase-delaying effects of late night bright light, late night exercise, and late evening bright light followed by early morning exercise. In a within-subjects, counterbalanced design, 6 young adults completed each of three 2.5-day protocols. Participants followed a 3-h ultra-short sleep-wake cycle, involving wakefulness in dim light for 2h, followed by attempted sleep in darkness for 1 h, repeated throughout each protocol...
February 26, 2016: Journal of Circadian Rhythms
Reza Kazemi, Rashid Haidarimoghadam, Majid Motamedzadeh, Rostam Golmohamadi, Alireza Soltanian, Mohamad Reza Zoghipaydar
Shift work is associated with both sleepiness and reduced performance. The aim of this study was to examine cognitive performance, sleepiness, and sleep quality among petrochemical control room shift workers. Sixty shift workers participated in this study. Cognitive performance was evaluated using a number of objective tests, including continuous performance test, n-back test, and simple reaction time test; sleepiness was measured using the subjective Karolinska Sleepiness Scale (KSS); and sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI) questionnaire...
February 3, 2016: Journal of Circadian Rhythms
Julia M Selfridge, Kurtis Moyer, Daniel G S Capelluto, Carla V Finkielstein
BACKGROUND: Circadian rhythms are daily changes in our physiology and behavior that are manifested as patterns of brain wave activity, periodic hormone production, recurring cell regeneration, and other oscillatory biological activities. Their importance to human health is becoming apparent; they are deranged by shift work and jet-lag and in disparate conditions such as insomnia, sleep syndromes, coronary heart attacks, and depression, and are endogenous factors that contribute to cancer development and progression...
November 5, 2015: Journal of Circadian Rhythms
Cathalijn H C Leenaars, Inge P M Klinkenberg, Audrey Aussems, Nedim Borger, Vivian Faatz, Anneloes Hak, Ellen Houben, Joyce Ramackers, Daphne Snackers, Andries Kalsbeek
BACKGROUND: The increased risk of obesity among short sleepers is most likely explained by increased energy intake. However, food intake could not only be altered quantitavely but also qualitatively. Therefore, we performed a correlational analysis on self-reported food intake and sleep in 51 students from Maastricht and surroundings. RESULTS: Students that slept longer had a lower caloric intake: ρ = -0.378, p = 0.006, the amount of calories consumed per minute awake remaining relatively stable...
July 13, 2015: Journal of Circadian Rhythms
Andrew Ferrante, David Gellerman, Ahmet Ay, Kerri Pruitt Woods, Allan Michael Filipowicz, Kriti Jain, Neil Bearden, Krista Kenyon Ingram
BACKGROUND: Circadian rhythms play an integral role in human behavior, physiology and health. Individual differences in daily rhythms (chronotypes) can affect individual sleep-wake cycles, activity patterns and behavioral choices. Diurnal preference, the tendency towards morningness or eveningness among individuals, has been associated with interpersonal variation in circadian clock-related output measures, including body temperature, melatonin levels and clock gene mRNA in blood, oral mucosa, and dermal fibroblast cell cultures...
June 5, 2015: Journal of Circadian Rhythms
Ruzong Fan, Victoria Chen, Yunlong Xie, Lanlan Yin, Sungduk Kim, Paul S Albert, Bruce Simons-Morton
BACKGROUND: Longitudinal or time-dependent activity data are useful to characterize the circadian activity patterns and to identify physical activity differences among multiple samples. Statistical methods designed to analyze multiple activity sample data are desired, and related software is needed to perform data analysis. METHODS: This paper introduces a functional data analysis (fda) approach to perform a functional analysis of variance (fANOVA) for longitudinal circadian activity count data and to investigate the association of covariates such as weight or body mass index (BMI) on physical activity...
April 8, 2015: Journal of Circadian Rhythms
Amrita Srivastava, Shalie Malik, Garima Yadav, Sangeeta Rani
BACKGROUND: Daily feeding and locomotion are interrelated behaviours. The time spent in feeding and rate of food intake depends on food availability. In low food condition, the birds would show intense movement (locomotion) for a longer time throughout the day however during abundant food supply they may chose higher activity and food intake in the morning and evening only. In the present study we hypothesized that in Spotted Munia (Lonchura punctulata), intermittent food availability during day would reallocate their interrelated behaviors, the feeding (food intake) and locomotor activity patterns...
2015: Journal of Circadian Rhythms
Katherine J Burton, Xiaohan Li, Jia-Da Li, Wang-Ping Hu, Qun-Yong Zhou
The mammalian circadian clock is composed of single-cell oscillators. Neurochemical and electrical signaling among these oscillators is important for the normal expression of circadian rhythms. Prokineticin 2 (PK2), encoding a cysteine-rich secreted protein, has been shown to be a critical signaling molecule for the regulation of circadian rhythms. PK2 expression in the suprachiasmatic nucleus (SCN) is highly rhythmic, peaking during the day and being essentially absent during the night. Mice with disrupted PK2 gene or its receptor PKR2 display greatly reduced rhythmicity of broad circadian parameters such as locomotor activity, body temperature and sleep/wake patterns...
2015: Journal of Circadian Rhythms
Nermien E Waly, Richard Hallworth
The suprachiasmatic nucleus (SCN) is the master circadian pacemaker. The pineal hormone melatonin is involved in the regulation of circadian phase. As a part of the circadian system, its synthesis and secretion is under SCN control. On the other hand, melatonin feeds back on the SCN to regulate its function. Melatonin has two specific windows of time at which it regulates SCN function, namely dusk and dawn. It has been suggested that melatonin exerts its effect on the SCN during that specific window of time via one or both of its specific receptors, MT1 or MT2...
2015: Journal of Circadian Rhythms
Megan L Fritz, Edward D Walker, Aaron J Yunker, Ian Dworkin
BACKGROUND: Blood feeding by free-living insect vectors of disease is rhythmic and can be used to predict when infectious bites will occur. These daily rhythms can also be targeted by control measures, as in insecticide-treated nets. Culex pipiens form pipiens and C.p. f. molestus are two members of the Culex pipiens assemblage and vectors of West Nile Virus throughout North America. Although Culex species vector human pathogens and parasites, the daily blood feeding rhythms of C.p. f...
2014: Journal of Circadian Rhythms
Akihiko Okamoto, Takuro Yamamoto, Ritsuko Matsumura, Koichi Node, Makoto Akashi
BACKGROUND: Although out-of-lab investigation of the human circadian clock at the clock gene expression level remains difficult, a recent method using hair follicle cells might be useful. While exercise may function as an entrainment cue for circadian rhythms, it remains unclear whether exercise affects human circadian clock gene expression. METHODS: Efforts to observe apparent effects of exercise on clock gene expression require that several specific conditions be met: intense exercise should be habitually performed at a relatively uncommon time of day over an extended period; and any relative phase shift thereby observed should be validated by comparison of exercise and no-exercise periods...
September 3, 2013: Journal of Circadian Rhythms
Aline V Machado-Nils, Larissa Om de Faria, André S Vieira, Simone A Teixeira, Marcelo N Muscará, Elenice Am Ferrari
BACKGROUND: Nitric oxide synthase (NOS) is essential for the synthesis of nitric oxide (NO), a non-conventional neurotransmitter with an important role in synaptic plasticity underlying processes of hippocampus-dependent memory and in the regulation of biological clocks and circadian rhythms. Many studies have shown that both the NOS cytosolic protein content and its enzymatic activity present a circadian variation in different regions of the rodent brain, including the hippocampus. The present study investigated the daily variation of NOS enzymatic activity and the cytosolic content of nNOS in the hippocampus of pigeons...
2013: Journal of Circadian Rhythms
Marie Aramendy, Sascha Seibert, Philipp Treppmann, Karin Richter, Gudrun Ahnert-Hilger, Urs Albrecht
BACKGROUND: Mammals can adapt to changing light/dark conditions by advancing or delaying their circadian clock phase. Light pulses evoke changes in gene expression and neuronal activity in the suprachiasmatic nuclei (SCN), the central pacemaker of the circadian system. Alterations in neuronal activity are partially mediated by changes in synaptic vesicle (SV) fusion at the presynaptic membrane, which modulates release of neurotransmitters. METHODS: Male synaptophysin (Syp) knock-out and littermate control wild type mice were tested in an Aschoff type I resetting paradigm...
2013: Journal of Circadian Rhythms
Takao Miki, Misty Chen-Goodspeed, Zhaoyang Zhao, Cheng Chi Lee
BACKGROUND: Our recent studies demonstrate that the murine homolog of the human tumor suppressor promyelocytic leukemia (PML) regulates circadian behavior of mice. To further gather insight into PML's contribution to circadian behavior, we generated two strains of mice deficient in one of the two period (Per) genes and the PML gene, with Per1-/-/Pml-/- and Per2-/-/Pml-/- genotypes. RESULTS: Here we report the circadian behavior of these mice based on wheel-running behavioral analysis...
2013: Journal of Circadian Rhythms
Adrián Báez-Ruiz, Karina Cázares-Gómez, Olivia Vázquez-Martínez, Raúl Aguilar-Roblero, Mauricio Díaz-Muñoz
BACKGROUND: Intracellular calcium is a biochemical messenger that regulates part of the metabolic adaptations in the daily fed-fast cycle. The aim of this study was to characterize the 24-h variations of the liver ryanodine and IP3 receptors (RyR and IP3R) as well as of the endoplasmic-reticulum and plasma-membrane Ca2+-ATPases (SERCA and PMCA) in daytime restricted feeding protocol. METHODS: A biochemical and immunohistochemical approach was implemented in this study: specific ligand-binding for RyR and IP3R, enzymatic activity (SERCA and PMCA), and protein levels and zonational hepatic-distribution were determined by immunoblot and immunohistochemistry respectively under conditions of fasting, feeding, and temporal food-restriction...
2013: Journal of Circadian Rhythms
Antoni Díez-Noguera
When one is faced with the analysis of long time series, one often finds that the characteristics of circadian rhythms vary with time throughout the series. To cope with this situation, the whole series can be fragmented into successive sections which are analyzed one after the other, which constitutes a serial analysis. This article discusses serial analysis techniques, beginning with the characteristics that the sections must have and how they can affect the results. After consideration of the effects of some simple filters, different types of serial analysis are discussed systematically according to the variable analyzed or the estimated parameters: scalar magnitudes, angular magnitudes (time or phase), magnitudes related to frequencies (or periods), periodograms, and derived and / or special magnitudes and variables...
2013: Journal of Circadian Rhythms
Harold B Dowse
There is an array of numerical techniques available to estimate the period of circadian and other biological rhythms. Criteria for choosing a method include accuracy of period measurement, resolution of signal embedded in noise or of multiple periodicities, and sensitivity to the presence of weak rhythms and robustness in the presence of stochastic noise. Maximum Entropy Spectral Analysis (MESA) has proven itself excellent in all regards. The MESA algorithm fits an autoregressive model to the data and extracts the spectrum from its coefficients...
2013: Journal of Circadian Rhythms
Tanya L Leise
: We review time-frequency methods that can be useful in quantifying circadian and ultradian patterns in behavioral records. These records typically exhibit details that may not be captured through commonly used measures such as activity onset and so may require alternative approaches. For instance, activity may involve multiple bouts that vary in duration and magnitude within a day, or may exhibit day-to-day changes in period and in ultradian activity patterns. The discrete Fourier transform and other types of periodograms can estimate the period of a circadian rhythm, but we show that they can fail to correctly assess ultradian periods...
2013: Journal of Circadian Rhythms
Kai Wada, Shota Yata, Osami Akimitsu, Milada Krejci, Teruki Noji, Miyo Nakade, Hitomi Takeuchi, Tetsuo Harada
BACKGROUND: Epidemiological studies in Japan have documented an association between morning type and a tryptophan-rich breakfast followed by exposure to sunlight in children. The association may be mediated by enhanced melatonin synthesis, which facilitates sleep at night. However, melatonin is inhibited by artificial light levels with high color-temperature common in Japanese homes at night. In this study, we investigated whether a combination of tryptophan-rich breakfast and light with low color-temperature at night could enhance melatonin secretion and encourage earlier sleep times...
2013: Journal of Circadian Rhythms
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