scholarly journals High-Amplitude Circadian Rhythms inDrosophilaDriven by Calcineurin-Mediated Post-translational Control ofsarah

Genetics ◽  
2018 ◽  
pp. genetics.300808.2018 ◽  
Author(s):  
Sin Ho Kweon ◽  
Jongbin Lee ◽  
Chunghun Lim ◽  
Joonho Choe
Keyword(s):  
Circadian Rhythms ◽  
Translational Control ◽  
High Amplitude

Circadian clock precision, health, and longevity

2021 ◽  
Vol 23 (1) ◽  
pp. 3-15
Author(s):  
D. G. Gubin ◽  
◽  
S. N. Kolomeichuk ◽  
D. Weinert ◽  
◽  
...  
Keyword(s):  
Health Status ◽  
Circadian Rhythms ◽  
Life Expectancy ◽  
Circadian Clock ◽  
Animal Species ◽  
Genetic Factors ◽  
High Amplitude ◽  
Phenotypic Trait ◽  
Precision Health ◽  
Lower Morbidity

An accurate circadian clock, associated with the precise intrinsic period, tau, can be linked with a definite chronotype and health status. Exemplified by different animal species, and, as we argue herein, may as well be in humans, endogenous tau close enough to 24 hours is associated with higher life expectancy, lower morbidity, and is possibly adhered to moderate morning chronotype. Accurate circadian tau facilitates maintaining a high amplitude of circadian rhythms, a phenotypic trait that is related to health and longevity. Some genetic factors that coordinate tau and ensure circadian clock precision is considered.

scholarly journals Disruption of Circadian Rhythms by Ambient Light during Neurodevelopment Leads to Autistic-like Molecular and Behavioral Alterations in Adult Mice

Cells ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 3314
Author(s):  
Kun Fang ◽  
Dong Liu ◽  
Salil S. Pathak ◽  
Bowen Yang ◽  
Jin Li ◽  
...  
Keyword(s):  
Circadian Rhythms ◽  
Translational Control ◽  
Pyramidal Neurons ◽  
Critical Role ◽  
Mapk Signaling ◽  
Repetitive Behaviors ◽  
Behavioral Changes ◽  
Circadian Disruption ◽  
Electrophysiological Recording ◽  
Functional Changes

Although circadian rhythms are thought to be essential for maintaining body health, the effects of chronic circadian disruption during neurodevelopment remain elusive. Here, using the “Short Day” (SD) mouse model, in which an 8 h/8 h light/dark (LD) cycle was applied from embryonic day 1 to postnatal day 42, we investigated the molecular and behavioral changes after circadian disruption in mice. Adult SD mice fully entrained to the 8 h/8 h LD cycle, and the circadian oscillations of the clock proteins, PERIOD1 and PERIOD2, were disrupted in the suprachiasmatic nucleus and the hippocampus of these mice. By RNA-seq widespread changes were identified in the hippocampal transcriptome, which are functionally associated with neurodevelopment, translational control, and autism. By western blotting and immunostaining hyperactivation of the mTOR and MAPK signaling pathways and enhanced global protein synthesis were found in the hippocampi of SD mice. Electrophysiological recording uncovered enhanced excitatory, but attenuated inhibitory, synaptic transmission in the hippocampal CA1 pyramidal neurons. These functional changes at synapses were corroborated by the immature morphology of the dendritic spines in these neurons. Lastly, autistic-like animal behavioral changes, including impaired social interaction and communication, increased repetitive behaviors, and impaired novel object recognition and location memory, were found in SD mice. Together, these results demonstrate molecular, cellular, and behavioral changes in SD mice, all of which resemble autistic-like phenotypes caused by circadian rhythm disruption. The findings highlight a critical role for circadian rhythms in neurodevelopment.

646 Translational Control of the Circadian Rhythms by MicroRNA-34a in Human Cholangiocarcinoma

2014 ◽  
Vol 146 (5) ◽  
pp. S-920
Author(s):  
Yuyan Han ◽  
Fanyin Meng ◽  
Shannon Glaser ◽  
Julie Venter ◽  
Kelly McDaniel ◽  
...  
Keyword(s):  
Circadian Rhythms ◽  
Translational Control

scholarly journals Wild-Type Circadian Rhythmicity Is Dependent on Closely Spaced E Boxes in the Drosophila timelessPromoter

2001 ◽  
Vol 21 (4) ◽  
pp. 1207-1217 ◽  
Author(s):  
Michael J. McDonald ◽  
Michael Rosbash ◽  
Patrick Emery
Keyword(s):  
Transcription Factor ◽  
Transcriptional Regulation ◽  
Locomotor Activity ◽  
Circadian Rhythms ◽  
High Amplitude ◽  
Wild Type ◽  
Activity Rhythms ◽  
E Box ◽  
E Boxes ◽  
Circadian Transcription

ABSTRACT Transcriptional regulation plays an important role inDrosophila melanogaster circadian rhythms. The period promoter has been well studied, but the timeless promoter has not been analyzed in detail. Mutagenesis of the canonical E box in the timelesspromoter reduces but does not eliminate timeless mRNA cycling or locomotor activity rhythms. This is because there are at least two other cis-acting elements close to the canonical E box, which can also be transactivated by the circadian transcription factor dCLOCK. These E-box-like sequences cooperate with the canonical E-box element to promote high-amplitude transcription, which is necessary for wild-type rhythmicity.

Vibrational Control of a 2-Link Mechanism

2020 ◽  
Author(s):  
Zakia Ahmed ◽  
Sevak Tahmasian ◽  
Craig A. Woolsey
Keyword(s):  
Translational Control ◽  
High Frequency ◽  
Horizontal Plane ◽  
High Amplitude ◽  
Torsional Stiffness ◽  
Physical Parameters ◽  
Vibrational Control ◽  
Link Mechanism ◽  
Torsional Damping ◽  
Fixed Input

Abstract This paper describes vibrational control and stability of a planar, horizontal 2-link mechanism using translational control of the base pivot. The system is a 3-DOF two-link mechanism that is subject to torsional damping, torsional stiffness, and is moving on a horizontal plane. The goal is to drive the averaged dynamics of the system to a desired configuration using a high-frequency, high-amplitude force applied at the base pivot. The desired configuration is achieved by applying an amplitude and angle of the input determined using the averaged dynamics of the system. We find the range of stable configurations that can be achieved by the system by changing the amplitude of the oscillations for a fixed input angle and oscillation frequency. The effects of varying the physical parameters on the achievable stable configurations are studied. Stability analysis of the system is performed using two methods: the averaged dynamics and averaged potential.

scholarly journals Spatiotemporal Patterns of High-Frequency Activity (80-170 Hz) in Long-term Intracranial EEG

Neurology ◽  
2020 ◽  
pp. 10.1212/WNL.0000000000011408
Author(s):  
Zhuying Chen ◽  
David B. Grayden ◽  
Anthony N. Burkitt ◽  
Udaya Seneviratne ◽  
Wendyl J. D'Souza ◽  
...  
Keyword(s):  
Circadian Rhythms ◽  
High Frequency ◽  
Focal Epilepsy ◽  
High Amplitude ◽  
Oscillatory Behavior ◽  
Patient Specific ◽  
Intracranial Eeg ◽  
Large Variability ◽  
High Frequency Activity

Objective:To determine the utility of high-frequency activity (HFA) and epileptiform spikes as biomarkers for epilepsy, we examined the variability in their rates and locations using long-term ambulatory intracranial EEG (iEEG) recordings.Methods:This study used continuous iEEG recordings obtained over an average of 1.4 years from 15 patients with drug-resistant focal epilepsy. HFA was defined as 80-170 Hz events with amplitudes clearly larger than the background, which was automatically detected using a custom algorithm. The automatically detected HFA was compared with visually annotated high-frequency oscillations (HFOs). The variations of HFA rates were compared with spikes and seizures on patient-specific and electrode-specific bases.Results:HFA included manually annotated HFOs and high-amplitude events occurring in the 80-170 Hz range without observable oscillatory behavior. HFA and spike rates had high amounts of intra- and inter-patient variability. Rates of HFA and spikes had large variability after electrode implantation in most of the patients. Locations of HFA and/or spikes varied up to weeks in more than one-third of the patients. Both HFA and spike rates showed strong circadian rhythms in all patients and some also showed multiday cycles. Furthermore, the circadian patterns of HFA and spike rates had patient-specific correlations with seizures, which tended to vary across electrodes.Conclusions:Analysis of HFA and epileptiform spikes should consider post-implantation variability. HFA and epileptiform spikes, like seizures, show circadian rhythms. However, the circadian profiles can vary spatially within patients and their correlations to seizures are patient-specific.

Postnatal ontogenesis of the circadian clock within the rat liver

2007 ◽  
Vol 292 (3) ◽  
pp. R1224-R1229 ◽  
Author(s):  
Martin Sládek ◽  
Zuzana Jindráková ◽  
Zdenka Bendová ◽  
Alena Sumová
Keyword(s):  
Circadian Rhythms ◽  
Rat Liver ◽  
Clock Genes ◽  
High Amplitude ◽  
Postnatal Ontogenesis ◽  
Amplitude Variation ◽  
Peripheral Tissues ◽  
Molecular Core ◽  
Peripheral Clocks ◽  
Low Amplitude

In mammals, the circadian oscillator within the suprachiasmatic nuclei (SCN) entrains circadian clocks in numerous peripheral tissues. Central and peripheral clocks share a molecular core clock mechanism governing daily time measurement. In the rat SCN, the molecular clockwork develops gradually during postnatal ontogenesis. The aim of the present work was to elucidate when during ontogenesis the expression of clock genes in the rat liver starts to be rhythmic. Daily profiles of mRNA expression of clock genes Per1, Per2, Cry1, Clock, Rev-Erbα, and Bmal1 were analyzed in the liver of fetuses at embryonic day 20 (E20) or pups at postnatal age 2 (P2), P10, P20, P30, and in adults by real-time RT-PCR. At E20, only a high-amplitude rhythm in Rev-Erbα and a low-amplitude variation in Cry1 but no clear circadian rhythms in expression of other clock genes were detectable. At P2, a high-amplitude rhythm in Rev-Erbα and a low-amplitude variation in Bmal1 but no rhythms in expression of other genes were detected. At P10, significant rhythms only in Per1 and Rev-Erbα expression were present. At P20, clear circadian rhythms in the expression of Per1, Per2, Rev-Erbα, and Bmal1, but not yet of Cry1 and Clock, were detected. At P30, all clock genes were expressed rhythmically. The phase of the rhythms shifted between all studied developmental periods until the adult stage was achieved. The data indicate that the development of the molecular clockwork in the rat liver proceeds gradually and is roughly completed by 30 days after birth.

On Vibrational Stabilization of a Horizontal Pendulum

2016 ◽  
Author(s):  
Sevak Tahmasian ◽  
Farid Jafari ◽  
Craig A. Woolsey
Keyword(s):  
Translational Control ◽  
High Frequency ◽  
Small Neighborhood ◽  
Constraint Equation ◽  
High Amplitude ◽  
Geometric Interpretation ◽  
Vibrational Stabilization ◽  
Linear Damping ◽  
And Control ◽  
Horizontal Pendulum

This paper describes control design and stability analysis for a horizontal pendulum using translational control of the pivot. The system is a one-link mechanism subject to linear damping and moving in the horizontal plane. The goal is to drive the system to a desired configuration such that the system oscillates in an arbitrarily small neighborhood of that desired configuration. We consider two cases: prescribed displacement inputs and prescribed force inputs. The proposed control law has two parts, a proportional-derivative part for control of actuated coordinates, and a high-frequency, high-amplitude oscillatory forcing to control the motion of unactuated coordinate. The control system is a high-frequency, time-periodic system. Therefore we use averaging techniques to determine the necessary input amplitudes and control gains. We show that using a certain oscillatory input, the amplitudes of that input must follow a constraint equation. We discuss the geometric interpretation of constraint equation and stability conditions of the system. We also discuss the effects of damping and relative phase of the oscillatory inputs on the system and their physical and geometric interpretation.

scholarly journals Casein kinase 1 dynamics underlie substrate selectivity and the PER2 circadian phosphoswitch

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Jonathan M Philpott ◽  
Rajesh Narasimamurthy ◽  
Clarisse G Ricci ◽  
Alfred M Freeberg ◽  
Sabrina R Hunt ◽  
...  
Keyword(s):  
Circadian Rhythms ◽  
Translational Control ◽  
Binding Sites ◽  
Casein Kinase ◽  
Anion Binding ◽  
Activation Loop ◽  
Substrate Selectivity ◽  
Casein Kinase 1 ◽  
Kinase Activation ◽  
Shed Light

Post-translational control of PERIOD stability by Casein Kinase 1δ and ε (CK1) plays a key regulatory role in metazoan circadian rhythms. Despite the deep evolutionary conservation of CK1 in eukaryotes, little is known about its regulation and the factors that influence substrate selectivity on functionally antagonistic sites in PERIOD that directly control circadian period. Here we describe a molecular switch involving a highly conserved anion binding site in CK1. This switch controls conformation of the kinase activation loop and determines which sites on mammalian PER2 are preferentially phosphorylated, thereby directly regulating PER2 stability. Integrated experimental and computational studies shed light on the allosteric linkage between two anion binding sites that dynamically regulate kinase activity. We show that period-altering kinase mutations from humans to Drosophila differentially modulate this activation loop switch to elicit predictable changes in PER2 stability, providing a foundation to understand and further manipulate CK1 regulation of circadian rhythms.

Sign in / Sign up

Export Citation Format

Share Document