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Deep oscillation

Wolf-Julian Neumann, Julius Huebl, Christof Brücke, Roxanne Lofredi, Andreas Horn, Assel Saryyeva, Kirsten Müller-Vahl, Joachim K Krauss, Andrea A Kühn
OBJECTIVE: Aberrant oscillatory activity has been hypothesized to play a role in the pathophysiology of Tourette syndrome (TS). Deep brain stimulation (DBS) has recently been established as an effective treatment for severe TS. Modulation of symptom specific oscillations may underlie the mechanism of action of DBS and could be used for adaptive neuromodulation to improve therapeutic efficacy. The objective of this study was to demonstrate a pathophysiological association of pallidal and thalamic local field potentials (LFP) with TS...
August 15, 2018: Annals of Neurology
Kyle R Clem, Andrew Orr, James O Pope
Observational records starting in the 1950s show West Antarctica is amongst the most rapidly warming regions on the planet. Together with increased intrusions of warm circumpolar deep water (CDW) onto the continental shelf due to local wind forcing (the primary mechanism in recent decades), this has resulted in enhanced surface and basal melting of floating ice shelves and an associated acceleration and thinning of West Antarctic outlet glaciers, increasing the rate of global sea level rise. In this study, it is shown that during the austral spring season, significant surface warming across West Antarctica has shifted westward to the Ross Ice Shelf in recent decades in response to enhanced cyclonic circulation over the Ross Sea...
August 10, 2018: Scientific Reports
Michael Ip, Anthony Ransford, Andrew M Jayich, Xueping Long, Conrad Roman, Wesley C Campbell
We demonstrate the use of a frequency-doubled optical frequency comb to load, cool, and crystallize trapped atomic ions as an alternative to ultraviolet (UV) or even deep UV continuous-wave lasers. We find that the Doppler shift from the atom's oscillation in the trap, driven by the blue-detuned comb teeth, introduces additional cooling and amplification which gives rise to steady-state phonon lasing of the ion's harmonic motion in the trap. The phonon laser's gain saturation keeps the optical frequency comb from continually adding energy without bound...
July 27, 2018: Physical Review Letters
Chintan S Oza, David T Brocker, Christina E Behrend, Warren M Grill
Deep brain stimulation (DBS) is an effective therapy for movement disorders including Parkinson's disease (PD), although the mechanisms of action remain unclear. Abnormal oscillatory neural activity is correlated with motor symptoms and pharmacological or DBS treatment that alleviates motor symptoms appears to suppress abnormal oscillations. However, whether such oscillatory activity is causal of motor deficits such as tremor remains unclear. Our goal was to generate abnormal oscillatory activity in the cortex-basal ganglia loop using patterned subthalamic nucleus DBS and quantify motor behavior in awake healthy rats...
August 8, 2018: Journal of Neurophysiology
Dan Piña-Fuentes, Martijn Beudel, Simon Little, Jonathan van Zijl, Jan Willem Elting, D L Marinus Oterdoom, Martje E van Egmond, J Marc C van Dijk, Marina A J Tijssen
The presence of abnormal neural oscillations within the cortico-basal ganglia-thalamo-cortical (CBGTC) network has emerged as one of the current principal theories to explain the pathophysiology of movement disorders. In theory, these oscillations can be used as biomarkers and thereby serve as a feedback signal to control the delivery of deep brain stimulation (DBS). This new form of DBS, dependent on different characteristics of pathological oscillations, is called adaptive DBS (aDBS), and it has already been applied in patients with Parkinson's disease...
August 2018: Neurosurgical Focus
Weihua Zhang, Kenneth Lam, Kurt Ungar
Using a previously developed digital gamma-gamma coincidence/anticoincidence spectrometer, daily aerosol samples collected at Resolute Bay, Canada (74.71°N, 94.97°W) from May 2016 to April 2017 were analysed for activity concentrations of 22 Na and 7 Be. The spectrometer design allows a more selective measurement of 22 Na with a significant background reduction by gamma-gamma coincidence events processing. It has been demonstrated that the improved spectrometer provides a more sensitive and effective way to quantify trace amounts of 22 Na and 7 Be with a critical limit of 3 mBq and 5 Bq respectively for a 20 h counting...
July 28, 2018: Journal of Environmental Radioactivity
Karthik Soman, Vignesh Muralidharan, V Srinivasa Chakravarthy
Oscillatory phenomena are ubiquitous in the brain. Although there are oscillator-based models of brain dynamics, their universal computational properties have not been explored much unlike in the case of rate-coded and spiking neuron network models. Use of oscillator-based models is often limited to special phenomena like locomotor rhythms and oscillatory attractor-based memories. If neuronal ensembles are taken to be the basic functional units of brain dynamics, it is desirable to develop oscillator-based models that can explain a wide variety of neural phenomena...
2018: Frontiers in Computational Neuroscience
Edoardo Baldini, Tania Palmieri, Adriel Dominguez, Pascal Ruello, Angel Rubio, Majed Chergui
The way nuclear motion affects electronic responses has become a very hot topic in materials science. Coherent acoustic phonons can dynamically modify optical, magnetic, and mechanical properties at ultrasonic frequencies, with promising applications as sensors and transducers. Here, by means of ultrafast broadband deep-ultraviolet spectroscopy, we demonstrate that coherent acoustic phonons confined in anatase TiO2 nanoparticles can selectively modulate the oscillator strength of the two-dimensional bound excitons supported by the material...
August 8, 2018: Nano Letters
Nicholas AuYong, Mahsa Malekmohammadi, Joni Ricks-Oddie, Nader Pouratian
There is converging evidence that bilateral basal ganglia motor networks jointly support normal movement behaviors including unilateral movements. The extent and manner in which these networks interact during lateralized movement remains unclear. In this study, simultaneously recorded bilateral Globus Pallidus interna (GPi) local field potentials (LFP) were examined from 19 subjects with idiopathic Parkinson disease (PD), while undergoing awake deep brain stimulation (DBS) implantation. Recordings were carried out during two behavioral states; rest and cued left hand movement (finger tapping)...
2018: Frontiers in Human Neuroscience
Alexander V Maltsev
True hibernators are remarkable group of mammals whose hearts are resistant to such stressors as deep hypothermia, ischemia, arrhythmia. Capability of cardiac cells from hibernating species to effectively rule Ca2+ homeostasis during torpor is poorly studied. Better understanding of these mechanisms could allow to introduce new strategies for improvement the cardiac performance and may be useful for cardiovascular medicine. Here for the first time we have shown that the regulation of Ca2+ handling and thereby cardiomyocyte contractility by endogenous neurotransmitter agmatine occurs through the modulation of calcium-sensing receptor (CaSR)...
July 17, 2018: Cellular Signalling
Richard Rammo, Rushna Ali, Aqueel Pabaney, Michael Seidman, Jason Schwalb
INTRODUCTION: Tinnitus is the conscious perception of an auditory sensation in the absence of external stimulus. Proposed theories are based on neuroplastic changes that occur due to sensory deprivation. The authors review the relevant literature on functional imaging and neuromodulation of tinnitus and describe potential targets for deep brain stimulation (DBS). MATERIALS AND METHODS: A MEDLINE keyword and Medical Subject Heading term literature search was performed using PubMed for tinnitus, neuromodulation, DBS, transcranial magnetic stimulation, epidural electrode stimulation, intradural electrode stimulation, functional imaging, and connectivity...
July 17, 2018: Neuromodulation: Journal of the International Neuromodulation Society
B A Mitchell, L R Petzold
Recent improvements in hardware and data collection have lowered the barrier to practical neural control. Most of the current contributions to the field have focus on model-based control, however, models of neural systems are quite complex and difficult to design. To circumvent these issues, we adapt a model-free method from the reinforcement learning literature, Deep Deterministic Policy Gradients (DDPG). Model-free reinforcement learning presents an attractive framework because of the flexibility it offers, allowing the user to avoid modeling system dynamics...
July 16, 2018: Scientific Reports
Gonzalo Martín-Vázquez, Toshitake Asabuki, Yoshikazu Isomura, Tomoki Fukai
Motor cortical microcircuits receive inputs from dispersed cortical and subcortical regions in behaving animals. However, how these inputs contribute to learning and execution of voluntary sequential motor behaviors remains elusive. Here, we analyzed the independent components extracted from the local field potential (LFP) activity recorded at multiple depths of rat motor cortex during reward-motivated movement to study their roles in motor learning. Because slow gamma (30-50 Hz), fast gamma (60-120 Hz), and theta (4-10 Hz) oscillations temporally coordinate task-relevant motor cortical activities, we first explored the behavioral state- and layer-dependent coordination of motor behavior in these frequency ranges...
2018: Frontiers in Neuroscience
Jiayang Guo, Kun Yang, Hongyi Liu, Chunli Yin, Jing Xiang, Hailong Li, Rongrong Ji, Yue Gao
High-frequency oscillations (HFOs) are spontaneous magnetoencephalography (MEG) patterns that have been acknowledged as a putative biomarker to identify epileptic foci. Correct detection of HFOs in the MEG signals is crucial for accurate and timely clinical evaluation. Since the visual examination of HFOs is time-consuming, error-prone and with poor inter-reviewer reliability, an automatic HFOs detector is highly desirable in clinical practice. However, existing approaches for HFOs detection may not be applicable for MEG signals with noisy background activity...
May 15, 2018: IEEE Transactions on Medical Imaging
Chen Liu, Changsong Zhou, Jiang Wang, Kenneth A Loparo
A mathematical modeling for description of oscillation suppression by deep brain stimulation (DBS) is explored in this work. High frequency DBS introduced to the basal ganglia network can suppress pathological neural oscillations that occur in the Parkinsonian state. However, selecting appropriate stimulation parameters remains a challenging issue due to the limited understanding of the underlying mechanisms of the Parkinsonian state and its control. In this work, we use describing function analysis to provide an intuitive way to select the optimal stimulation parameters based on a biologically plausible computational model of the Parkinsonian neural network...
July 5, 2018: IEEE Transactions on Neural Systems and Rehabilitation Engineering
Ronald Marquez, Ana M Forgiarini, Dominique Langevin, Jean-Louis Salager
We have studied emulsions made with two- and three-phase oil-water-surfactant systems in which one of the phases is a microemulsion, the other phases being water or/and oil excess phases. Such systems have been extensively studied in the 1970-1980s for applications in enhanced oil recovery. It was found at that time that the emulsions became very unstable in the three-phase systems, but so far few explanations have been proposed. In the most complete one, Kabalnov and colleagues related the emulsion stability to the probability of hole nucleation in the liquid film separating two nearby emulsion drops and associated this probability to the curvature elastic energy of the surfactant layer covering drop surfaces...
August 7, 2018: Langmuir: the ACS Journal of Surfaces and Colloids
Tao Yu, Xueyuan Wang, Yongjie Li, Guojun Zhang, Gregory Worrell, Patrick Chauvel, Duanyu Ni, Liang Qiao, Chang Liu, Liping Li, Liankun Ren, Yuping Wang
Epilepsy has been classically seen as a brain disorder resulting from abnormally enhanced neuronal excitability and synchronization. Although it has been described since antiquity, there are still significant challenges achieving the therapeutic goal of seizure freedom. Deep brain stimulation of the anterior nucleus of the thalamus has emerged as a promising therapy for focal drug-resistant epilepsy; the basic mechanism of action, however, remains unclear. Here, we show that desynchronization is a potential mechanism of deep brain stimulation of the anterior nucleus of the thalamus by studying local field potentials recordings from the cortex during high-frequency stimulation (130 Hz) of the anterior nucleus of the thalamus in nine patients with drug-resistant focal epilepsy...
July 6, 2018: Brain: a Journal of Neurology
Fengchao Yao, Ibrahim Hoteit
The Red Sea hosts a deep marine environment unique among the world's oceans. It is occupied, almost homogeneously from the subsurface (~137 to 300 m) to depths over 2000 m, by a warm (~21.5°C) and highly saline (~40.5) water mass, referred to as the Red Sea Deep Water (RSDW). Previous studies suggested that the RSDW is mainly ventilated, continuously or intermittently, by dense outflows from the northern Gulfs of Suez and Aqaba with a resulting sluggish renewal time on the order of 36 to 90 years. We use six repeated hydrographic observations spanning the period 1982-2011 and simulations of an ocean general circulation model with realistic atmospheric forcing to show that large portions of the RSDW were episodically replaced during 1982-2001 by new dense waters mainly formed by open-ocean deep convections in the northern Red Sea during anomalously cold winters, pointing to a much shorter renewal time for the RSDW on the order of a decade...
June 2018: Science Advances
Gary A Glatzmaier
We describe computer simulations of thermal convection and magnetic field generation in Jupiter's deep interior: that is, its convective dynamo. Results from three different simulations highlight the importance of including the dynamics in the very deep interior, although much of the convection and field generation seems to be confined to the upper part of the interior. A long-debated question is to what depth do Jupiter's zonal winds extend below its surface. Our simulations suggest that, if global latitudinally banded patterns in Jupiter's near-surface magnetic and gravity fields were detected by Juno, NASA's orbiting spacecraft at Jupiter [Bolton S, et al...
July 3, 2018: Proceedings of the National Academy of Sciences of the United States of America
Jarkko Luoma, Eero Pekkonen, Katja Airaksinen, Liisa Helle, Jussi Nurminen, Samu Taulu, Jyrki P Mäkelä
Advanced Parkinson's disease (PD) is characterized by an excessive oscillatory beta band activity in the subthalamic nucleus (STN). Deep brain stimulation (DBS) of STN alleviates motor symptoms in PD and suppresses the STN beta band activity. The effect of DBS on cortical sensorimotor activity is more ambiguous; both increases and decreases of beta band activity have been reported. Non-invasive studies with simultaneous DBS are problematic due to DBS-induced artifacts. We recorded magnetoencephalography (MEG) from 16 advanced PD patients with and without STN DBS during rest and wrist extension...
June 22, 2018: Neuroscience Letters
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