Read by QxMD icon Read

Journal of Biological Rhythms

Jan L Souman, Tobias Borra, Iris de Goijer, Luc J M Schlangen, Björn N S Vlaskamp, Marcel P Lucassen
Studies with monochromatic light stimuli have shown that the action spectrum for melatonin suppression exhibits its highest sensitivity at short wavelengths, around 460 to 480 nm. Other studies have demonstrated that filtering out the short wavelengths from white light reduces melatonin suppression. However, this filtering of short wavelengths was generally confounded with reduced light intensity and/or changes in color temperature. Moreover, it changed the appearance from white light to yellow/orange, rendering it unusable for many practical applications...
July 1, 2018: Journal of Biological Rhythms
John K McNeill, James C Walton, H Elliott Albers
Over 90% of neurons within the suprachiasmatic nucleus (SCN) express γ-aminobutyric acid (GABA). Although GABA is primarily an inhibitory neurotransmitter, in vitro studies suggest that the activation of GABAA receptors (GABAA R) elicits excitation in the adult SCN. The ratio of excitatory to inhibitory responses to GABA depends on the balance of chloride influx by Na+ -K+ -Cl- cotransporter 1 (NKCC1) and chloride efflux by K+ -Cl- cotransporters (KCCs). Excitatory responses to GABA can be blocked by inhibition of the inward chloride cotransporter, NKCC1, with the loop diuretic bumetanide...
July 1, 2018: Journal of Biological Rhythms
Anna Zamm, Youyi Wang, Caroline Palmer
Many human action sequences, such as speaking and performing music, are inherently rhythmic: Sequence events are produced at quasi-regular temporal intervals. A wide range of interindividual variation has been noted in spontaneous production rates of these rhythmic action sequences. Dynamical theories of motor coordination suggest that individuals spontaneously produce rhythmic sequences at a natural frequency characterized by minimal energy expenditure and maximal temporal stability, relative to other frequencies...
June 1, 2018: Journal of Biological Rhythms
Kenkichi Baba, Gianluca Tosini
The eye contains a circadian system that acts independently from the master circadian clock located in the brain. This circadian system regulates important physiological functions within the eye. Emerging experimental evidence also indicates that disruption of the ocular circadian clock, or its outputs, negatively affects the overall health of the eye. Although previous studies have investigated the effect of aging on the regulation of circadian rhythms, no study has investigated the effects of aging on the circadian rhythm in the ocular system...
June 1, 2018: Journal of Biological Rhythms
Dmytro Grygoryev, Michael R Rountree, Furaha Rwatambuga, Anna Ohlrich, Ayaka Kukino, Matthew P Butler, Charles N Allen, Mitchell S Turker
Mammalian tissues display circadian rhythms in transcription, translation, and histone modifications. Here we asked how an advance of the light-dark cycle alters daily rhythms in the liver epigenome at the H3K4me3 (trimethylation of lysine 4 on histone 3) modification, which is found at active and poised gene promoters. H3K4me3 levels were first measured at 4 time points (zeitgeber time [ZT] 3, 8, 15, and 20) during a normal 12L:12D light-dark cycle. Peak levels were observed during the early dark phase at ZT15 and dropped to low levels around lights-on (ZT0) between ZT20 and ZT3...
June 1, 2018: Journal of Biological Rhythms
Emily A Mulawa, Jay S Kirkwood, Lisa M Wolfe, Samantha J Wojda, Jessica E Prenni, Gregory L Florant, Seth W Donahue
Hibernation is a naturally occurring model for studying diseases such as obesity and osteoporosis. Hibernators, marmots (Marmota flaviventris) among them, are able to nearly double their body mass by increasing fat stores prior to hibernation without the negative consequences of obesity. They are also physically inactive for extended periods of time without experiencing negative effects on the skeleton. The endocannabinoid system is involved in modulating neural signaling, circannual rhythms, behavior, appetite, thermogenesis, and bone and energy metabolism...
June 1, 2018: Journal of Biological Rhythms
Jialou Zhu, Chengwei Li, Changxia Gong, Xiaodong Li
The circadian clock orchestrates gene expression rhythms. Regulation at the level of gene transcription is essential for molecular and cellular rhythms. Pol II pause release is a critical step of transcription regulation. However, whether and how Pol II pause release is regulated during daily transcription have not been characterized. In this study, we performed Pol II ChIP-seq across the day in the mouse liver and quantitatively analyzed binding signals within the transcription start site (TSS) region and the gene body...
May 1, 2018: Journal of Biological Rhythms
Sandra A Heldstab, Dennis W H Müller, Sereina M Graber, Laurie Bingaman Lackey, Eberhard Rensch, Jean-Michel Hatt, Philipp Zerbe, Marcus Clauss
Patterns of reproductive seasonality in the Carnivora are difficult to study comparatively, due to limited numbers of species for which information is available. Long-term databases of captive populations could overcome this difficulty. We apply a categorical description and a quantitative high-resolution measure (birth peak breadth, the number of days in which 80% of all births occur) based on daily observations in captivity to characterize the degree of reproductive seasonality in the Carnivora for 114 species with on average 1357 births per species...
May 1, 2018: Journal of Biological Rhythms
Rachael C Crew, Peter J Mark, Brendan J Waddell
Obesity during pregnancy causes numerous maternal and fetal health complications, but the underlying mechanisms remain unclear. Adipose tissue dysfunction in obesity has previously been linked to disruption of the intrinsic adipose clock gene network that is crucial for normal metabolic function. This adipose clock also undergoes major change as part of the maternal metabolic adaptation to pregnancy, but whether this is affected by maternal obesity is unknown. Consequently, in this study we tested the hypothesis that obesity disturbs rhythmic gene expression in maternal adipose tissue across pregnancy...
June 2018: Journal of Biological Rhythms
Gustavo B S Rivas, Rayane Teles-de-Freitas, Márcio G Pavan, José B P Lima, Alexandre A Peixoto, Rafaela Vieira Bruno
Most organisms feature an endogenous circadian clock capable of synchronization with their environment. The most well-known synchronizing agents are light and temperature. The circadian clock of mosquitoes, vectors of many pathogens, drives important behaviors related to vectoral capacity, including oviposition, host seeking, and hematophagy. Main clock gene expression, as well as locomotor activity patterns, has been identified in Aedes aegypti and Culex quinquefasciatus under artificial light-dark cycles...
June 2018: Journal of Biological Rhythms
Omer Benjakob, Rona Aviram
While research has shown that scientists use Wikipedia and that scientific content on Wikipedia ramifies back into scientific literature, many questions remain on how the two sides interact and through what paradigm this dynamic may be best understood. Using the circadian clock field as a case study, we discuss this scientific field's representation on Wikipedia. We traced the changes made to the articles for "Circadian clock" and "Circadian rhythm" and reviewed the debates that informed them over a span of a decade, using Wikipedia's native and third-party tools...
June 2018: Journal of Biological Rhythms
Michael C Tackenberg, Jeff R Jones, Terry L Page, Jacob J Hughey
Estimations of period and phase are essential in circadian biology. While many techniques exist for estimating period, comparatively few methods are available for estimating phase. Current approaches to analyzing phase often vary between studies and are sensitive to coincident changes in period and the stage of the circadian cycle at which the stimulus occurs. Here we propose a new technique, tau-independent phase analysis (TIPA), for quantifying phase shifts in multiple types of circadian time-course data...
June 2018: Journal of Biological Rhythms
Cristina Sáenz de Miera, Dominique Sage-Ciocca, Valérie Simonneaux, Paul Pévet, Stefanie Monecke
Adaptation of biological rhythms to a seasonal environment in circannual mammals is achieved via the synchronization of intrinsic circannual rhythms to the external year by photoperiod. In mammals, the photoperiodic information is integrated to seasonal physiology via the pineal hormone melatonin regulation of pars tuberalis (PT) TSHβ expression and its downstream control of hypothalamic dio2 gene expression. In the circannual European hamster, however, photoperiodic entrainment of the circannual clock is possible in pinealectomized animals...
June 2018: Journal of Biological Rhythms
Amanda R Liberman, Lumbardh Halitjaha, Ahmet Ay, Krista K Ingram
Anxiety and other mood disorders, such as major depressive disorder (MDD) and seasonal affective disorder (SAD), affect nearly one-fifth of the global population and disproportionately affect young adults. Individuals affected by mood disorders are frequently plagued by sleep and circadian problems, and recent genetic studies provide ample support for the association of circadian and sleep syndromes with depression and anxiety. Mathematical modeling has been crucial in understanding some of the essential features of the mammalian circadian clock and is now a vital tool for dissecting how circadian genes regulate the molecular mechanisms that influence mood...
June 2018: Journal of Biological Rhythms
Janina Kay, Pamela Menegazzi, Stephanie Mildner, Flavio Roces, Charlotte Helfrich-Förster
The circadian clock of social insects has become a focal point of interest for research, as social insects show complex forms of timed behavior and organization within their colonies. These behaviors include brood care, nest maintenance, foraging, swarming, defense, and many other tasks, of which several require social synchronization and accurate timing. Ants of the genus Camponotus have been shown to display a variety of daily timed behaviors such as the emergence of males from the nest, foraging, and relocation of brood...
June 2018: Journal of Biological Rhythms
Matti J Salmela, Robby L McMinn, Carmela R Guadagno, Brent E Ewers, Cynthia Weinig
The circadian clock is a molecular timekeeper that matches endogenous rhythms in diverse traits with 24-h cycles in the external environment. Although a lack of clock resonance to the environment is detrimental to performance, clock phenotypes in wild populations nevertheless deviate substantially from the predicted optimal cycle length of 24 h, and significant genetic variation exists for circadian parameters. Here, we describe covariation between 2 traits considered to reflect adaptation to different aspects of temporal environmental heterogeneity, circadian rhythms (adaptation to daily environmental cycles) and flowering time (adaptation to seasonal cycles), in a Rocky Mountain population of the mustard Boechera stricta, a North American relative of Arabidopsis thaliana...
June 2018: Journal of Biological Rhythms
David R Weaver, Vincent van der Vinne, E Lela Giannaris, Thomas J Vajtay, Kristopher L Holloway, Christelle Anaclet
Mice with targeted gene disruption have provided important information about the molecular mechanisms of circadian clock function. A full understanding of the roles of circadian-relevant genes requires manipulation of their expression in a tissue-specific manner, ideally including manipulation with high efficiency within the suprachiasmatic nuclei (SCN). To date, conditional manipulation of genes within the SCN has been difficult. In a previously developed mouse line, Cre recombinase was inserted into the vesicular GABA transporter (Vgat) locus...
April 2018: Journal of Biological Rhythms
Lydia Hannou, Erika Bélanger-Nelson, Emma K O'Callaghan, Julien Dufort-Gervais, Maria Neus Ballester Roig, Pierre-Gabriel Roy, Jean-Martin Beaulieu, Nicolas Cermakian, Valérie Mongrain
NEUROLIGIN-1 (NLGN1) is a postsynaptic adhesion molecule involved in the regulation of glutamatergic transmission. It has been associated with several features of sleep and psychiatric disorders. Our previous work suggested that transcription of the Nlgn1 gene could be regulated by the transcription factors CLOCK and BMAL1 because they bind to the Nlgn1 gene promoter in vivo. However, whether CLOCK/BMAL1 can directly activate Nlgn1 transcription is not yet known. We thus aimed to verify whether CLOCK/BMAL1, as well as their homologs NPAS2 and BMAL2, can activate transcription via the Nlgn1 promoter by using luciferase assays in COS-7 cells...
April 2018: Journal of Biological Rhythms
Roelof A Hut, Menno P Gerkema, Domien G M Beersma, Joost M Tinbergen
No abstract text is available yet for this article.
April 2018: Journal of Biological Rhythms
Svetlana Postnova, Steven W Lockley, Peter A Robinson
A model of arousal dynamics is applied to predict objective performance and subjective sleepiness measures, including lapses and reaction time on a visual Performance Vigilance Test (vPVT), performance on a mathematical addition task (ADD), and the Karolinska Sleepiness Scale (KSS). The arousal dynamics model is comprised of a physiologically based flip-flop switch between the wake- and sleep-active neuronal populations and a dynamic circadian oscillator, thus allowing prediction of sleep propensity. Published group-level experimental constant routine (CR) and forced desynchrony (FD) data are used to calibrate the model to predict performance and sleepiness...
April 2018: Journal of Biological Rhythms
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"