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Phase amplitude coupling

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https://www.readbyqxmd.com/read/28816086/inducible-knockout-of-mouse-zfhx3-emphasizes-its-key-role-in-setting-the-pace-and-amplitude-of-the-adult-circadian-clock
#1
Ashleigh G Wilcox, Lucie Vizor, Michael J Parsons, Gareth Banks, Patrick M Nolan
The transcription factor zinc finger homeobox 3 (ZFHX3) plays a key role in coupling intracellular transcriptional-translational oscillations with intercellular synchrony in mouse suprachiasmatic nucleus (SCN). However, like many key players in central nervous system function, ZFHX3 serves an important role in neurulation and neuronal terminal differentiation while retaining discrete additional functions in the adult SCN. Recently, using a dominant missense mutation in mouse Zfhx3, we established that this gene can modify circadian period and sleep in adult animals...
August 1, 2017: Journal of Biological Rhythms
https://www.readbyqxmd.com/read/28801622/decoupling-frequencies-amplitudes-and-phases-in-nonlinear-optics
#2
Bruno E Schmidt, Philippe Lassonde, Guilmot Ernotte, Matteo Clerici, Roberto Morandotti, Heide Ibrahim, François Légaré
In linear optics, light fields do not mutually interact in a medium. However, they do mix when their field strength becomes comparable to electron binding energies in the so-called nonlinear optical regime. Such high fields are typically achieved with ultra-short laser pulses containing very broad frequency spectra where their amplitudes and phases are mutually coupled in a convolution process. Here, we describe a regime of nonlinear interactions without mixing of different frequencies. We demonstrate both in theory and experiment how frequency domain nonlinear optics overcomes the shortcomings arising from the convolution in conventional time domain interactions...
August 11, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28801562/explosive-death-induced-by-mean-field-diffusion-in-identical-oscillators
#3
Umesh Kumar Verma, Amit Sharma, Neeraj Kumar Kamal, Jürgen Kurths, Manish Dev Shrimali
We report the occurrence of an explosive death transition for the first time in an ensemble of identical limit cycle and chaotic oscillators coupled via mean-field diffusion. In both systems, the variation of the normalized amplitude with the coupling strength exhibits an abrupt and irreversible transition to death state from an oscillatory state and this first order phase transition to death state is independent of the size of the system. This transition is quite general and has been found in all the coupled systems where in-phase oscillations co-exist with a coupling dependent homogeneous steady state...
August 11, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28794978/localization-of-beta-and-high-frequency-oscillations-within-the-subthalamic-nucleus-region
#4
B C M van Wijk, A Pogosyan, M I Hariz, H Akram, T Foltynie, P Limousin, A Horn, S Ewert, P Brown, V Litvak
Parkinsonian bradykinesia and rigidity are typically associated with excessive beta band oscillations in the subthalamic nucleus. Recently another spectral peak has been identified that might be implicated in the pathophysiology of the disease: high-frequency oscillations (HFO) within the 150-400 Hz range. Beta-HFO phase-amplitude coupling (PAC) has been found to correlate with severity of motor impairment. However, the neuronal origin of HFO and its usefulness as a potential target for deep brain stimulation remain to be established...
2017: NeuroImage: Clinical
https://www.readbyqxmd.com/read/28777881/early-stage-attenuation-of-phase-amplitude-coupling-in-the-hippocampus-and-medial-prefrontal-cortex-in-a-transgenic-rat-model-of-ad
#5
Paolo Bazzigaluppi, Tina L Beckett, Margaret M Koletar, Aaron Y Lai, Illsung L Joo, Mary E Brown, Peter L Carlen, JoAnne McLaurin, Bojana Stefanovic
Alzheimer's disease (AD) is pathologically characterized by amyloid-β peptide (Aβ) accumulation, neurofibrillary tangle formation, and neurodegeneration. Preclinical studies on neuronal impairments associated with progressive amyloidosis have demonstrated some Aβ-dependent neuronal dysfunction including modulation of GABAergic signalling. The present work focuses on the early stage of disease progression and uses TgF344-AD rats that recapitulate a broad repertoire of AD-like pathologies to investigate the neuronal network functioning using simultaneous intracranial recordings from the hippocampus (HPC) and the medial prefrontal cortex (mPFC), followed by pathological analyses of gamma-aminobutyric acid (GABAA ) receptors subunits α1, α5 and δ, and glutamic acid decarboxylases (GAD65 and GAD67)...
August 4, 2017: Journal of Neurochemistry
https://www.readbyqxmd.com/read/28757194/time-resolved-phase-amplitude-coupling-in-neural-oscillations
#6
Soheila Samiee, Sylvain Baillet
Cross-frequency coupling between neural oscillations is a phenomenon observed across spatial scales in a wide range of preparations, including human non-invasive electrophysiology. Although the functional role and mechanisms involved are not entirely understood, the concept of interdependent neural oscillations drives an active field of research to comprehend the ubiquitous polyrhythmic activity of the brain, beyond empirical observations. Phase-amplitude coupling, a particular form of cross-frequency coupling between bursts of high-frequency oscillations and the phase of lower frequency rhythms, has recently received considerable attention...
July 27, 2017: NeuroImage
https://www.readbyqxmd.com/read/28755546/temporal-spatial-characteristics-of-phase-amplitude-coupling-in-electrocorticogram-for-human-temporal-lobe-epilepsy
#7
Ruihua Zhang, Ye Ren, Chunyan Liu, Na Xu, Xiaoli Li, Fengyu Cong, Tapani Ristaniemi, YuPing Wang
OBJECTIVE: Neural activity of the epileptic human brain contains low- and high-frequency oscillations in different frequency bands, some of which have been used as reliable biomarkers of the epileptogenic brain areas. However, the relationship between the low- and high-frequency oscillations in different cortical areas during the period from pre-seizure to post-seizure has not been completely clarified. METHODS: We recorded electrocorticogram data from the temporal lobe and hippocampus of seven patients with temporal lobe epilepsy...
June 28, 2017: Clinical Neurophysiology: Official Journal of the International Federation of Clinical Neurophysiology
https://www.readbyqxmd.com/read/28737272/dynamic-coupling-between-fmri-local-connectivity-and-interictal-eeg-in-focal-epilepsy-a-wavelet-analysis-approach
#8
Amir Omidvarnia, Mangor Pedersen, David N Vaughan, Jennifer M Walz, David F Abbott, Andrew Zalesky, Graeme D Jackson
Simultaneous scalp EEG-fMRI recording is a noninvasive neuroimaging technique for combining electrophysiological and hemodynamic aspects of brain function. Despite the time-varying nature of both measurements, their relationship is usually considered as time-invariant. The aim of this study was to detect direct associations between scalp-recorded EEG and regional changes of hemodynamic brain connectivity in focal epilepsy through a time-frequency paradigm. To do so, we developed a voxel-wise framework that analyses wavelet coherence between dynamic regional phase synchrony (DRePS, calculated from fMRI) and band amplitude fluctuation (BAF) of a target EEG electrode with dominant interictal epileptiform discharges (IEDs)...
July 24, 2017: Human Brain Mapping
https://www.readbyqxmd.com/read/28735144/entorhinal-tau-pathology-disrupts-hippocampal-prefrontal-oscillatory-coupling-during-associative-learning
#9
Stephanie E Tanninen, Bardia Nouriziabari, Mark D Morrissey, Rami Bakir, Robert D Dayton, Ronald L Klein, Kaori Takehara-Nishiuchi
A neural signature of asymptomatic preclinical Alzheimer's disease (AD) is disrupted connectivity between brain regions; however, its underlying mechanisms remain unknown. Here, we tested whether a preclinical pathologic feature, tau aggregation in the entorhinal cortex (EC) is sufficient to disrupt the coordination of local field potentials (LFPs) between its efferent regions. P301L-mutant human tau or green fluorescent protein (GFP) was virally overexpressed in the EC of adult rats. LFPs were recorded from the dorsal hippocampus and prelimbic medial prefrontal cortex while the rats underwent trace eyeblink conditioning where they learned to associate 2 stimuli separated by a short time interval...
July 6, 2017: Neurobiology of Aging
https://www.readbyqxmd.com/read/28734290/effect-of-interlamellar-interactions-on-shear-induced-multilamellar-vesicle-formation
#10
Y Kawabata, R Bradbury, S Kugizaki, K Weigandt, Y B Melnichenko, K Sadakane, N L Yamada, H Endo, M Nagao, H Seto
Shear-induced multilamellar vesicle (MLV) formation has been studied by coupling the small-angle neutron scattering (SANS) technique with neutron spin echo (NSE) spectroscopy. A 10% mass fraction of the nonionic surfactant pentaethylene glycol dodecyl ether (C12E5) in water was selected as a model system for studying weak inter-lamellar interactions. These interactions are controlled either by adding an anionic surfactant, sodium dodecyl sulfate, or an antagonistic salt, rubidium tetraphenylborate. Increasing the charge density in the bilayer induces an enhanced ordering of the lamellar structure...
July 21, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28729438/electrophysiological-evidence-that-the-retrosplenial-cortex-displays-a-strong-and-specific-activation-phased-with-hippocampal-theta-during-paradoxical-rem-sleep
#11
Koike Bruna Del Vechio, Farias Kelly Soares, Billwiller Francesca, Almeida-Filho Daniel, Libourel Paul-Antoine, Tiran-Cappello Alix, Parmentier Régis, Blanco Wilfredo, Ribeiro Sidarta, Luppi Pierre-Herve, Queiroz Claudio Marcos
It is widely accepted that cortical neurons are similarly more activated during waking and paradoxical sleep (PS, aka REM) than during slow wave sleep (SWS). However, we recently reported using Fos labeling that only a few limbic cortical structures including the retrosplenial (RSC) and anterior cingulate (ACA) cortices contain a large number of neurons activated during PS hypersomnia. Our aim in the present study was to record local field potentials (LFPs) and unit activity from these two structures across all vigilance states in freely moving male rats to determine whether the RSC and the ACA are electrophysiologically specifically active during basal PS episodes...
July 20, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/28726858/pumping-and-probing-vibrational-modulated-coupled-electronic-coherence-in-hcn-using-short-uv-fs-laser-pulses-a-2d-quantum-nuclear-dynamical-study
#12
S van den Wildenberg, B Mignolet, R D Levine, F Remacle
The coupled electronic-nuclear coherent dynamics induced by a short strong VUV fs pulse in the low excited electronic states of HCN is probed by transient absorption spectroscopy with a second weaker fs UV pulse. The nuclear time-dependent Schrodinger equation is solved on a 2D nuclear grid with several electronic states with a Hamiltonian including the dipole coupling to the pump and the probe electric fields. The two internal nuclear coordinates describe the motion of the light H atom. There is a band of several excited electronic states at about 8 eV above the ground state (GS) that is transiently accessed by the pump pulse...
July 20, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28709240/extreme-events-in-fitzhugh-nagumo-oscillators-coupled-with-two-time-delays
#13
Arindam Saha, Ulrike Feudel
We study two identical FitzHugh-Nagumo oscillators which are coupled with one or two different time delays. If only a single-delay coupling is used, the length of the delay determines whether the synchronization manifold is transversally stable or unstable, exhibiting mixed-mode or chaotic oscillations in which the small amplitude oscillations are always in phase but the large amplitude oscillations are in phase or out of phase, respectively. For two delays we find an intricate dynamics which comprises an irregular alteration of small amplitude oscillations, in-phase and out-of-phase large amplitude oscillations, also called extreme events...
June 2017: Physical Review. E
https://www.readbyqxmd.com/read/28708551/indoor-airborne-ultrasonic-wireless-communication-using-ofdm-methods
#14
Wentao Jiang, William M D Wright
Concerns still exist over the safety of prolonged exposure to radio frequency (RF) wireless transmissions and there are also potential data security issues due to remote signal interception techniques such as Bluesniping. Airborne ultrasound may be used as an alternative to RF for indoor wireless communication systems for securely transmitting data over short ranges, as signals are difficult to intercept from outside the room. Two types of air-coupled capacitive ultrasonic transducer were used in the implementation of an indoor airborne wireless communication system...
July 11, 2017: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
https://www.readbyqxmd.com/read/28679224/temporal-intermittency-and-the-lifetime-of-chimera-states-in-ensembles-of-nonlocally-coupled-chaotic-oscillators
#15
N I Semenova, G I Strelkova, V S Anishchenko, A Zakharova
We describe numerical results for the dynamics of networks of nonlocally coupled chaotic maps. Switchings in time between amplitude and phase chimera states have been first established and studied. It has been shown that in autonomous ensembles, a nonstationary regime of switchings has a finite lifetime and represents a transient process towards a stationary regime of phase chimera. The lifetime of the nonstationary switching regime can be increased to infinity by applying short-term noise perturbations.
June 2017: Chaos
https://www.readbyqxmd.com/read/28673716/contribution-of-the-supplementary-motor-area-and-the-cerebellum-to-the-anticipatory-postural-adjustments-and-execution-phases-of-human-gait-initiation
#16
Aliénor Richard, Angèle Van Hamme, Xavier Drevelle, Jean-Louis Golmard, Sabine Meunier, Marie-Laure Welter
Several brain structures including the brainstem, the cerebellum and the frontal cortico-basal ganglia network, with the primary and premotor areas have been shown to participate in the functional organization of gait initiation and postural control in humans, but their respective roles remain poorly understood. The aim of this study was to better understand the role of the supplementary motor area (SMA) and posterior cerebellum in the gait initiation process. Gait initiation parameters were recorded in 22 controls both before and after continuous theta burst transcranial stimulation (cTBS) of the SMA and cerebellum, and were compared to sham stimulation, using a randomized double-blind design study...
July 1, 2017: Neuroscience
https://www.readbyqxmd.com/read/28668004/a-compact-two-way-power-divider-based-on-five-port-structure
#17
Letian Guo, Jiawei Li, Wenhua Huang, Hao Shao, Tao Ba, Shaoyi Xie
A novel compact five-port waveguide power divider based on the single-ridge waveguide and three-ridge waveguide structure is proposed. It is realized by the coupling of the TE10 and TE30 modes. At the central coupling section, the single-ridge and three-ridge waveguides are used to constitute the conventional rectangular waveguide to reduce the sectional sizes. It consists of one input port, two output ports, and two isolated ports. For validation, a compact five-port power divider is designed, fabricated, and measured...
June 2017: Review of Scientific Instruments
https://www.readbyqxmd.com/read/28667703/hippocampal-gamma-slow-oscillation-coupling-in-macaques-during-sedation-and-sleep
#18
Andrew G Richardson, Xilin Liu, Pauline K Weigand, Eric D Hudgins, Joel M Stein, Sandhitsu R Das, Alexander Proekt, Max B Kelz, Milin Zhang, Jan Van der Spiegel, Timothy H Lucas
Behavioral and neurophysiological evidence suggests that the slow (≤ 1 Hz) oscillation (SO) during sleep plays a role in consolidating hippocampal (HIPP)-dependent memories. The effects of the SO on HIPP activity have been studied in rodents and cats both during natural sleep and during anesthetic administration titrated to mimic sleep-like slow rhythms. In this study, we sought to document these effects in primates. First, HIPP field potentials were recorded during ketamine-dexmedetomidine sedation and during natural sleep in three rhesus macaques...
July 1, 2017: Hippocampus
https://www.readbyqxmd.com/read/28659769/propofol-sevoflurane-and-ketamine-induce-a-reversible-increase-in-delta-gamma-and-theta-gamma-phase-amplitude-coupling-in-frontal-cortex-of-rat
#19
Dinesh Pal, Brian H Silverstein, Lana Sharba, Duan Li, Viviane S Hambrecht-Wiedbusch, Anthony G Hudetz, George A Mashour
Studies from human and non-human species have demonstrated a breakdown of functional corticocortical connectivity during general anesthesia induced by anesthetics with diverse molecular, neurophysiological, and pharmacological profiles. Recent studies have demonstrated that changes in long-range neural communication, and by corollary, functional connectivity, might be influenced by cross-frequency coupling (CFC) between the phase of slow oscillations and the amplitude of local fast oscillations. Phase-amplitude coupling (PAC) between slow oscillations and alpha rhythm during general anesthesia reveal distinct patterns depending on the anesthetic...
2017: Frontiers in Systems Neuroscience
https://www.readbyqxmd.com/read/28632051/quantifying-coordination-among-the-rearfoot-midfoot-and-forefoot-segments-during-running
#20
Tomoya Takabayashi, Mutsuaki Edama, Erika Yokoyama, Chiaki Kanaya, Masayoshi Kubo
Because previous studies have suggested that there is a relationship between injury risk and inter-segment coordination, quantifying coordination between the segments is essential. Even though the midfoot and forefoot segments play important roles in dynamic tasks, previous studies have mostly focused on coordination between the shank and rearfoot segments. This study aimed to quantify coordination among rearfoot, midfoot, and forefoot segments during running. Eleven healthy young men ran on a treadmill. The coupling angle, representing inter-segment coordination, was calculated using a modified vector coding technique...
February 28, 2017: Sports Biomechanics
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