keyword
MENU ▼
Read by QxMD icon Read
search

Circadian activity

keyword
https://www.readbyqxmd.com/read/29450111/the-binding-structure-and-affinity-of-photodamaged-duplex-dna-with-members-of-the-photolyase-cryptochrome-family-a-computational-study
#1
Ryuma Sato, Ryuhei Harada, Yasuteru Shigeta
Photolyases (PHRs) and cryptochromes (CRYs) belong to the same family known as blue-light photoreceptors. Although their amino acid sequences and corresponding structures are similar to each other, they exert different functions. PHRs function as an enzyme to repair UV-induced deoxyribonucleic acid (DNA) lesions such as a cyclobutane pyrimidine dimer (CPD) and a (6-4) photoproduct ((6-4)pp), whereas CRYs are a circadian photoreceptor in plants and animals and at the same time they control the photoperiodic induction of flowering in plants...
2018: Biophysics and Physicobiology
https://www.readbyqxmd.com/read/29448041/vip-changes-during-daytime-in-chicken-intrinsic-choroidal-neurons
#2
Bettina Hohberger, Carmen Jessberger, Matthias Zenkel, Alexandra Kaser-Eichberger, Antonio Bergua, Falk Schrödl, Winfried Neuhuber
PURPOSE: Ocular autonomic control is mediated by sympathetic and parasympathetic nerve fibres. Their interactions are complemented by primary afferent nerve fibers of and intrinsic choroidal neurons (ICN). As the vasodilatative neuropeptide, vasoactive intestinal peptide (VIP), is expressed in extrinsic and intrinsic ocular neurons, it is of special interest in ophthalmic research. Since circadian changes of ocular blood flow are known in humans and birds, this study aimed at investigating VIP expression at different daytimes in chicken choroid, the preferred model species in ICN research...
February 12, 2018: Experimental Eye Research
https://www.readbyqxmd.com/read/29447387/ezh2-promotes-clock-function-and-hematopoiesis-independent-of-histone-methyltransferase-activity-in-zebrafish
#3
Yingbin Zhong, Qiang Ye, Chengyan Chen, Mingyong Wang, Han Wang
EZH2 is a subunit of polycomb repressive complex 2 (PRC2) that silences gene transcription via H3K27me3 and was shown to be essential for mammalian liver circadian regulation and hematopoiesis through gene silencing. Much less, however, is known about how Ezh2 acts in live zebrafish. Here, we show that zebrafish ezh2 is regulated directly by the circadian clock via both E-box and RORE motif, while core circadian clock genes per1a, per1b, cry1aa and cry1ab are down-regulated in ezh2 null mutant and ezh2 morphant zebrafish, and either knockdown or overexpression of ezh2 alters locomotor rhythms, indicating that Ezh2 is required for zebrafish circadian regulation...
February 13, 2018: Nucleic Acids Research
https://www.readbyqxmd.com/read/29444258/modeling-the-influence-of-seasonal-differences-in-the-hpa-axis-on-synchronization-of-the-circadian-clock-and-cell-cycle
#4
Kamau Pierre, Rohit T Rao, Clara Hartmanshenn, Ioannis P Androulakis
Synchronization of biological functions to environmental signals enables organisms to anticipate and appropriately respond to daily external fluctuations and is critical to the maintenance of homeostasis. Misalignment of circadian rhythms with environmental cues is associated with adverse health outcomes. Cortisol, the downstream effector of hypothalamic-pituitary-adrenal (HPA) activity, facilitates synchronization of peripheral biological processes to the environment. Cortisol levels exhibit substantial seasonal rhythmicity, with peak levels occurring during the short-photoperiod winter months and reduced levels occurring in the long-photoperiod summer season...
February 12, 2018: Endocrinology
https://www.readbyqxmd.com/read/29442316/odd-paired-the-drosophila-zic-gene
#5
Deborah A Hursh, Brian G Stultz
Zinc finger in the cerebellum (Zic) proteins are a family of transcription factors with multiple roles during development, particularly in neural tissues. The founding member of the Zic family is the Drosophila odd-paired (opa) gene. The Opa protein has a DNA binding domain containing five Cys2His2-type zinc fingers and has been shown to act as a sequence-specific DNA binding protein. Opa has significant homology to mammalian Zic1, Zic2, and Zic3 within the zinc finger domain and in two other conserved regions outside that domain...
2018: Advances in Experimental Medicine and Biology
https://www.readbyqxmd.com/read/29441579/brain-anatomy-of-the-4-day-old-european-rabbit
#6
Nanette Y Schneider, Frédérique Datiche, Gérard Coureaud
The European rabbit (Oryctolagus cuniculus) is a widely used model in fundamental, medical and veterinary neurosciences. Besides investigations in adults, rabbit pups are relevant to study perinatal neurodevelopment and early behaviour. To date, the rabbit is also the only species in which a pheromone - the mammary pheromone (MP) - emitted by lactating females and active on neonatal adaptation has been described. The MP is crucial since it contributes directly to nipple localisation and oral seizing in neonates, i...
February 14, 2018: Journal of Anatomy
https://www.readbyqxmd.com/read/29440637/cytosine-modifications-exhibit-circadian-oscillations-that-are-involved-in-epigenetic-diversity-and-aging
#7
Gabriel Oh, Sasha Ebrahimi, Matthew Carlucci, Aiping Zhang, Akhil Nair, Daniel E Groot, Viviane Labrie, Peixin Jia, Edward S Oh, Richie H Jeremian, Miki Susic, Tenjin C Shrestha, Martin R Ralph, Juozas Gordevičius, Karolis Koncevičius, Art Petronis
Circadian rhythmicity governs a remarkable array of fundamental biological functions and is mediated by cyclical transcriptomic and proteomic activities. Epigenetic factors are also involved in this circadian machinery; however, despite extensive efforts, detection and characterization of circadian cytosine modifications at the nucleotide level have remained elusive. In this study, we report that a large proportion of epigenetically variable cytosines show a circadian pattern in their modification status in mice...
February 13, 2018: Nature Communications
https://www.readbyqxmd.com/read/29436510/hidden-markov-models-for-monitoring-circadian-rhythmicity-in-telemetric-activity-data
#8
Qi Huang, Dwayne Cohen, Sandra Komarzynski, Xiao-Mei Li, Pasquale Innominato, Francis Lévi, Bärbel Finkenstädt
Wearable computing devices allow collection of densely sampled real-time information on movement enabling researchers and medical experts to obtain objective and non-obtrusive records of actual activity of a subject in the real world over many days. Our interest here is motivated by the use of activity data for evaluating and monitoring the circadian rhythmicity of subjects for research in chronobiology and chronotherapeutic healthcare. In order to translate the information from such high-volume data arising we propose the use of a Markov modelling approach which (i) naturally captures the notable square wave form observed in activity data along with heterogeneous ultradian variances over the circadian cycle of human activity, (ii) thresholds activity into different states in a probabilistic way while respecting time dependence and (iii) gives rise to circadian rhythm parameter estimates, based on probabilities of transitions between rest and activity, that are interpretable and of interest to circadian research...
February 2018: Journal of the Royal Society, Interface
https://www.readbyqxmd.com/read/29434312/circadian-clocks-of-both-plants-and-pollinators-influence-flower-seeking-behavior-of-the-pollinator-hawkmoth-manduca-sexta
#9
Myles P Fenske, LeAnn P Nguyen, Erin K Horn, Jeffrey A Riffell, Takato Imaizumi
Most plant-pollinator interactions occur during specific periods during the day. To facilitate these interactions, many flowers are known to display their attractive qualities, such as scent emission and petal opening, in a daily rhythmic fashion. However, less is known about how the internal timing mechanisms (the circadian clocks) of plants and animals influence their daily interactions. We examine the role of the circadian clock in modulating the interaction between Petunia and one of its pollinators, the hawkmoth Manduca sexta...
February 12, 2018: Scientific Reports
https://www.readbyqxmd.com/read/29433969/shift-work-is-associated-with-reduced-heart-rate-variability-among-men-but-not-women
#10
Gerben Hulsegge, Nidhi Gupta, Karin I Proper, Natasja van Lobenstein, Wilhelmina IJzelenberg, David M Hallman, Andreas Holtermann, Allard J van der Beek
BACKGROUND: Imbalance in the autonomic nervous system due to a disrupted circadian rhythm may be a cause of shift work-related cardiovascular diseases. OBJECTIVE: We aimed to determine the association between shift work and cardiac autonomic activity in blue-collar workers. METHODS: The study included 665 blue-collar workers aged 18-68 years in different occupations from two Danish cohort studies. Time and frequency domain parameters of heart rate variability (HRV) were measured during sleep using the Actiheart monitor, and used as markers of cardiac autonomic function...
February 9, 2018: International Journal of Cardiology
https://www.readbyqxmd.com/read/29432701/plasticity-of-light-induced-concurrent-glutamatergic-and-gabaergic-quantal-events-in-the-suprachiasmatic-nucleus
#11
Juan Cheng, Xu Huang, Yue Liang, Tian Xue, Liecheng Wang, Jin Bao
Neurons in the suprachiasmatic nucleus (SCN) exhibit circadian variation in their neuronal activities. Here, we show that their input synapses undergo daily regulation. We discovered daily variation in the frequencies, but not the peak amplitudes, of miniature postsynaptic currents (mPSCs) for both glutamatergic and GABAergic synapses. In addition, the changes in the frequencies of mPSCs from glutamatergic and GABAergic synapses were antiphasic: An increase in the glutamatergic mPSC frequency and a decrease in the GABAergic mPSC frequency co-occurred during the dark phase of the light-dark cycle...
February 2018: Journal of Biological Rhythms
https://www.readbyqxmd.com/read/29432155/circadian-clock-dependent-and-independent-posttranscriptional-regulation-underlies-temporal-mrna-accumulation-in-mouse-liver
#12
Jingkui Wang, Laura Symul, Jake Yeung, Cédric Gobet, Jonathan Sobel, Sarah Lück, Pål O Westermark, Nacho Molina, Felix Naef
The mammalian circadian clock coordinates physiology with environmental cycles through the regulation of daily oscillations of gene expression. Thousands of transcripts exhibit rhythmic accumulations across mouse tissues, as determined by the balance of their synthesis and degradation. While diurnally rhythmic transcription regulation is well studied and often thought to be the main factor generating rhythmic mRNA accumulation, the extent of rhythmic posttranscriptional regulation is debated, and the kinetic parameters (e...
February 5, 2018: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/29430734/gaba-and-serotonin-expressing-neurons-take-part-in-inhibitory-as-well-as-excitatory-input-pathways-to-the-circadian-clock-of-the-madeira-cockroach-rhyparobia-maderae
#13
Maria Giese, Julia Gestrich, Azar Massah, Jonas Peterle, HongYing Wei, Monika Stengl
In the Madeira cockroach pigment-dispersing factor-immunoreactive (PDF-ir) neurons innervating the circadian clock, the accessory medulla (AME) in the brain's optic lobes, control circadian behavior. Circadian activity rhythms are entrained to daily light-dark cycles only by compound eye photoreceptors terminating in the lamina and medulla. Still, it is unknown which neurons connect the photoreceptors to the clock to allow for light-entrainment. Here, we characterized by multiple-label immunocytochemistry the serotonin (5-HT)-ir anterior fiber fan and GABA-ir pathways connecting the AME- and optic lobe neuropils...
February 11, 2018: European Journal of Neuroscience
https://www.readbyqxmd.com/read/29430586/the-antidepressant-effect-of-light-therapy-from-retinal-projections
#14
REVIEW
Xiaotao Li, Xiang Li
Observations from clinical trials have frequently demonstrated that light therapy can be an effective therapy for seasonal and non-seasonal major depression. Despite the fact that light therapy is known to have several advantages over antidepressant drugs like a low cost, minimal side-effects, and fast onset of therapeutic effect, the mechanism underlying light therapy remains unclear. So far, it is known that light therapy modulates mood states and cognitive functions, involving circadian and non-circadian pathways from retinas into brain...
February 12, 2018: Neuroscience Bulletin
https://www.readbyqxmd.com/read/29428440/melatonin-a-cutaneous-perspective-on-its-production-metabolism-and-functions
#15
REVIEW
Andrzej T Slominski, Ruediger Hardeland, Michal A Zmijewski, Radomir M Slominski, Russel J Reiter, Ralf Paus
Melatonin, an evolutionarily ancient derivative of serotonin with hormonal properties, is the main neuroendocrine secretory product of the pineal gland. Although melatonin is best known to regulate circadian rhythmicity and lower vertebrate skin pigmentation, the full spectrum of functional activities of this free radical-scavenging molecule, which also induces/promotes complex antioxidative and DNA repair systems, includes immunomodulatory, thermoregulatory, and antitumor properties. Because this plethora of functional melatonin properties still awaits to be fully appreciated by dermatologists, the current review synthesizes the main features that render melatonin a promising candidate for the management of several dermatoses associated with substantial oxidative damage...
February 7, 2018: Journal of Investigative Dermatology
https://www.readbyqxmd.com/read/29425573/diurnal-variation-of-default-mode-network-in-patients-with-restless-legs-syndrome
#16
Jeonghun Ku, Yeong Seon Lee, Hyuk Won Chang, Christopher J Earley, Richard P Allen, Yong Won Cho
OBJECTIVE: Restless legs syndrome (RLS) patients compared to controls have been found to have abnormal patterns in the default mode network (DMN) in the morning when symptom threshold is the highest and symptoms are least likely to occur. If these morning abnormalities in DMN are pertinent to disease expression, then similar or further detectable differences may be expected on a nighttime assessment when RLS symptom threshold is at its lowest. The purpose of this study was to elucidate the potential neural mechanisms underlying the circadian aspect of RLS symptom expression by assessing diurnal changes in DMN...
January 2018: Sleep Medicine
https://www.readbyqxmd.com/read/29422633/long-term-study-of-heart-rate-variability-responses-to-changes-in-the-solar-and-geomagnetic-environment
#17
Abdullah Alabdulgader, Rollin McCraty, Michael Atkinson, York Dobyns, Alfonsas Vainoras, Minvydas Ragulskis, Viktor Stolc
This long-term study examined relationships between solar and magnetic factors and the time course and lags of autonomic nervous system (ANS) responses to changes in solar and geomagnetic activity. Heart rate variability (HRV) was recorded for 72 consecutive hours each week over a five-month period in 16 participants in order to examine ANS responses during normal background environmental periods. HRV measures were correlated with solar and geomagnetic variables using multivariate linear regression analysis with Bonferroni corrections for multiple comparisons after removing circadian influences from both datasets...
February 8, 2018: Scientific Reports
https://www.readbyqxmd.com/read/29420838/study-design-parameters-affecting-exposure-response-analysis-of-qt-data-results-from-simulation-studies
#18
Georg Ferber, Yaning Sun, Borje Darpo, Christine Garnett, Jiang Liu
The operating characteristics of dose-escalating studies in terms of false-negative predictions of the QT effect and the power to exclude clinically relevant QT effects are not quantitatively established. One thousand single-ascending-dose (SAD) studies with 7 dose groups with 6/2 subjects on active drug/placebo were generated through simulation for each of 32 scenarios with (1) 8 different QT effects of the study drug and (2) achieved plasma concentration 2- or 4-fold above therapeutic levels. For each subject, drug-free QT data from a thorough QT study were subsampled to capture the circadian profile, on which a drug effect was added...
February 8, 2018: Journal of Clinical Pharmacology
https://www.readbyqxmd.com/read/29415552/eveningness-is-associated-with-poor-sleep-quality-and-negative-affect-in-obsessive-compulsive-disorder
#19
Péter Simor, András Harsányi, Kata Csigó, Gergely Miklós, Alpár Sándor Lázár, Gyula Demeter
Background Obsessive-compulsive disorder (OCD) is characterized by intrusive thoughts and repetitive behaviors that severely encumber daily functioning. OCD patients seem to exhibit sleep disturbances, especially delayed bedtimes that reflect disrupted circadian rhythmicity. Morningness-eveningness is a fundamental factor reflecting individual variations in diurnal preferences related to sleep and waking activities. Eveningness reflecting a delayed sleep-wake timing has repeatedly been associated with sleep problems and negative affect (NA)...
February 8, 2018: Journal of Behavioral Addictions
https://www.readbyqxmd.com/read/29410618/biological-clocks-and-rhythms-of-anger-and-aggression
#20
REVIEW
Suzanne Hood, Shimon Amir
The body's internal timekeeping system is an under-recognized but highly influential force in behaviors and emotions including anger and reactive aggression. Predictable cycles or rhythms in behavior are expressed on several different time scales such as circadian (circa diem, or approximately 24-h rhythms) and infradian (exceeding 24 h, such as monthly or seasonal cycles). The circadian timekeeping system underlying rhythmic behaviors in mammals is constituted by a network of clocks distributed throughout the brain and body, the activity of which synchronizes to a central pacemaker, or master clock...
2018: Frontiers in Behavioral Neuroscience
keyword
keyword
44164
1
2
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"