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https://www.readbyqxmd.com/read/28931610/the-coupling-of-synaptic-inputs-to-local-cortical-activity-differs-among-neurons-and-adapts-following-stimulus-onset
#1
Nathaniel Caleb Wright, Mahmood Sayed Hoseini, Tansel Baran Yasar, Ralf Wessel
Cortical activity contributes significantly to the high variability of sensory responses of interconnected pyramidal neurons, which has crucial implications for sensory coding. Yet, largely because of technical limitations of in vivo intracellular recordings, the coupling of a pyramidal neuron's synaptic inputs to the local cortical activity has evaded full understanding. Here, we obtained excitatory synaptic conductance (g) measurements from putative pyramidal neurons and local field potential (LFP) recordings from adjacent cortical circuits during visual processing in the turtle whole-brain ex vivo preparation...
September 20, 2017: Journal of Neurophysiology
https://www.readbyqxmd.com/read/28929474/-new-thalamic-potential-associated-with-somatosensory-evoked-potentials
#2
L Vega-Zelaya, C V Torres, M Navas-Garcia, R G Sola, J Pastor
INTRODUCTION: The response of the thalamus during the study with somatosensory evoked potentials (SSEP) is not sufficiently understood. CASE REPORT: A 17-year-old man undergoing surgery for deep brain stimulation in the centromedian nucleus for drug-resistant epilepsy under complete sedation. During the intervention, the responses to SSEPs of the thalamic nuclei were recorded by means of four microelectrodes. These responses can be decomposed into three types: local field potentials (LFP), low amplitude fast oscillations (LFO), and high amplitude slow oscillations (HSO)...
October 1, 2017: Revista de Neurologia
https://www.readbyqxmd.com/read/28927833/modulation-of-hippocampal-activity-with-fornix-deep-brain-stimulation
#3
Paul H Stypulkowski, Scott R Stanslaski, Jonathon E Giftakis
BACKGROUND: Deep Brain Stimulation (DBS) within the Papez circuit is under investigation as a treatment for epilepsy and Alzheimer's disease. We previously reported the effects of stimulation at nodes within this network (anterior thalamic nucleus and hippocampus) on hippocampal activity in a large animal model, using a chronic implantable, clinical-grade system that permits concurrent stimulation and recording. OBJECTIVE: In this study we extended earlier work to compare the effects of fornix DBS on evoked potentials (EPs) and local field potential (LFP) activity within the hippocampus, and to assess closed-loop stimulation...
September 6, 2017: Brain Stimulation
https://www.readbyqxmd.com/read/28924008/primary-generators-of-visually-evoked-field-potentials-recorded-in-the-macaque-auditory-cortex
#4
Yoshinao Kajikawa, John F Smiley, Charles E Schroeder
Prior studies have reported "local" field potential (LFP) responses to faces in the macaque auditory cortex and have suggested that such face-LFPs may be substrates of audiovisual integration. However, while field potentials (FPs) may reflect the synaptic currents of neurons near the recording electrode, due to the use of a distant reference electrode, they often reflect those of synaptic activity occurring in distant sites as well. Thus, FP recordings within a given brain region (e.g., auditory cortex) may be "contaminated" by activity generated elsewhere in the brain...
September 18, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/28920903/brain-control-of-an-external-device-by-extracting-the-highest-force-related-contents-of-local-field-potentials-in-freely-moving-rats
#5
Abed Khorasani, Reza Foodeh, Vahid Shalchyan, Mohammad Reza Daliri
A local field potential (LFP) signal is an alternative source to neural action potentials for decoding kinematic and kinetic information from the brain. Here we demonstrate that better extraction of force-related features from multichannel LFPs improves the accuracy of force decoding. We propose that applying canonical correlation analysis (CCA) filter on the envelopes of separate frequency bands (band-specific CCA) seperates non- task related information from the LFPs. The decoding accuracy of the continuous force signal based on the proposed method were compared with three feature reduction methods: 1) Band-specific principal component analysis (bandspecific PCA) method that extract the components which leads to maximum variance from envelopes of different frequency bands, 2) Correlation coefficient-based (CC-based) feature reduction that selects the best features from the envelopes sorted based on the absolute correlation coefficient between each envelope and the target force signal and 3) Mutual information -based (MI-based) feature reduction that selects the best features from the envelopes sorted based on the mutual information between each envelope and output force signal...
September 12, 2017: IEEE Transactions on Neural Systems and Rehabilitation Engineering
https://www.readbyqxmd.com/read/28918300/dynamical-properties-of-lfps-from-mice-with-unilateral-injection-of-tent
#6
Eleonora Vannini, Matteo Caleo, Santi Chillemi, Angelo Di Garbo
Local field potential (LFP) recordings were performed from the visual cortex (V1) of a focal epilepsy mouse model. Epilepsy was induced by a unilateral injection of the synaptic blocker tetanus neurotoxin (TeNT). LFP signals were simultaneously recorded from V1 of both hemispheres of each animal under acute and chronic conditions (i.e. during and after the period of TeNT action). All data were analysed by using nonlinear time series methods. Suitable values of the lag time and embedding dimension for phase space reconstruction were estimated by employing well-known methods...
September 13, 2017: Bio Systems
https://www.readbyqxmd.com/read/28912155/visual-motion-discrimination-by-propagating-patterns-in-primate-cerebral-cortex
#7
Rory Townsend, Selina S Solomon, Paul R Martin, Samuel G Solomon, Pulin Gong
Visual stimuli can evoke waves of neural activity that propagate across the surface of visual cortical areas. The relevance of these waves for visual processing is unknown. Here we measured the phase and amplitude of local field potentials (LFPs) in electrode array recordings from motion-processing medial temporal area (MT) of anesthetized male marmosets. Animals viewed grating or dot-field stimuli drifting in different directions. We found that on individual trials, the direction of LFP wave propagation is sensitive to the direction of stimulus motion...
September 14, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/28910623/laminar-organization-of-encoding-and-memory-reactivation-in-the-parietal-cortex
#8
Aaron A Wilber, Ivan Skelin, Wei Wu, Bruce L McNaughton
Egocentric neural coding has been observed in parietal cortex (PC), but its topographical and laminar organization is not well characterized. We used multi-site recording to look for evidence of local clustering and laminar consistency of linear and angular velocity encoding in multi-neuronal spiking activity (MUA) and in the high-frequency (300-900 Hz) component of the local field potential (HF-LFP), believed to reflect local spiking activity. Rats were trained to run many trials on a large circular platform, either to LED-cued goal locations or as a spatial sequence from memory...
September 13, 2017: Neuron
https://www.readbyqxmd.com/read/28900900/mapping-the-information-trace-in-local-field-potentials-by-a-computational-method-of-two-dimensional-time-shifting-synchronization-likelihood-based-on-graphic-processing-unit-acceleration
#9
Zi-Fang Zhao, Xue-Zhu Li, You Wan
The local field potential (LFP) is a signal reflecting the electrical activity of neurons surrounding the electrode tip. Synchronization between LFP signals provides important details about how neural networks are organized. Synchronization between two distant brain regions is hard to detect using linear synchronization algorithms like correlation and coherence. Synchronization likelihood (SL) is a non-linear synchronization-detecting algorithm widely used in studies of neural signals from two distant brain areas...
September 12, 2017: Neuroscience Bulletin
https://www.readbyqxmd.com/read/28891502/extrapolating-meaning-from-local-field-potential-recordings
#10
Amber L Harris Bozer, Megan L Uhelski, Ai-Ling Li
Local field potentials (LFP) reflect the spatially weighted low-frequency activity nearest to a recording electrode. LFP recording is a window to a wide range of cellular activities and has gained increasing attention over recent years. We here review major conceptual issues related to LFP with the goal of creating a resource for non-experts considering implementing LFP into their research. We discuss the cellular activity that constitutes the local field potential; recording techniques, including recommendations and limitations; approaches to analysis of LFP data (with focus on power-banded analyses); and finally we discuss reports of the successful use of LFP in clinical applications...
2017: Journal of Integrative Neuroscience
https://www.readbyqxmd.com/read/28891497/a-framework-to-reconcile-frequency-scaling-measurements-from-intracellular-recordings-local-field-potentials-up-to-eeg-and-meg%C3%A2-signals
#11
Claude Bedard, Jean-Marie Gomes, Thierry Bal, Alain Destexhe
In this viewpoint article, we discuss the electric properties of the medium around neurons, which are important to correctly interpret extracellular potentials or electric field effects in neural tissue. We focus on how these electric properties shape the frequency scaling of brain signals at different scales, such as intracellular recordings, the local field potential (LFP), the electroencephalogram (EEG) or the magnetoencephalogram (MEG). These signals display frequency-scaling properties which are not consistent with resistive media...
2017: Journal of Integrative Neuroscience
https://www.readbyqxmd.com/read/28890315/subthalamic-neural-entropy-is-a-feature-of-freezing-of-gait-in-freely-moving-people-with-parkinson-s-disease
#12
Judy Syrkin-Nikolau, Mandy Miller Koop, Thomas Prieto, Chioma Anidi, Muhammad Furqan Afzal, Anca Velisar, Zack Blumenfeld, Talora Martin, Megan Trager, Helen Bronte-Stewart
The goal of this study was to investigate subthalamic (STN) neural features of Freezers and Non-Freezers with Parkinson's disease (PD), while freely walking without freezing of gait (FOG) and during periods of FOG, which were better elicited during a novel turning and barrier gait task than during forward walking. METHODS: Synchronous STN local field potentials (LFPs), shank angular velocities, and ground reaction forces were measured in fourteen PD subjects (eight Freezers) off medication, OFF deep brain stimulation (DBS), using an investigative, implanted, sensing neurostimulator (Activa® PC+S, Medtronic, Inc...
September 7, 2017: Neurobiology of Disease
https://www.readbyqxmd.com/read/28890054/home-cage-odors-spatial-cues-elicit-theta-phase-gamma-amplitude-coupling-between-olfactory-bulb-and-dorsal-hippocampus
#13
Roberta Ribas Pena, Daniel de Castro Medeiros, Leonardo de Oliveira Guarnieri, Julio Boriollo Guerra, Vinícius Rezende Carvalho, Eduardo Mazoni Andrade Marçal Mendes, Grace Schenatto Pereira, Márcio Flávio Dutra Moraes
The brain oscillations may play a critical role in synchronizing neuronal assemblies in order to establish appropriate sensory-motor integration. In fact, studies have demonstrated phase-amplitude coupling of distinct oscillatory rhythms during cognitive processes. Here we investigated whether olfacto-hippocampal coupling occurs when mice are detecting familiar odors located in a spatially restricted area of a new context. The spatial olfactory task (SOT) was designed to expose mice to a new environment in which only one quadrant (target) contains odors provided by its own home-cage bedding...
September 7, 2017: Neuroscience
https://www.readbyqxmd.com/read/28890051/systemic-administration-of-two-different-anxiolytic-drugs-decreases-local-field-potential-theta-frequency-in-the-medial-entorhinal-cortex-without-affecting-grid-cell-firing-fields
#14
Caitlin K Monaghan, G William Chapman, Michael E Hasselmo
Neurons coding spatial location (grid cells) are found in medial entorhinal cortex (MEC) and demonstrate increasing size of firing fields and spacing between fields (grid scale) along the dorsoventral axis. This change in grid scale correlates with differences in theta frequency, a 6-10Hz rhythm in the local field potential (LFP) and rhythmic firing of cells. A relationship between theta frequency and grid scale can be found when examining grid cells recorded in different locations along the dorsoventral axis of MEC...
September 8, 2017: Neuroscience
https://www.readbyqxmd.com/read/28885487/luminance-information-decoding-on-the-basis-of-local-field-potential-signals-of-pigeon-optic-tectum-neurons
#15
Songwei Wang, Lijun Liu, Zhizhong Wang, Xiaoke Niu, Yuxia Hu, Li Shi
Important aspects of brain information processing can be understood by examining decoding of visual stimuli from neuronal response signals. In this research, the luminance information is decoded from the local field potential signal in the optic tectum region of the pigeon. We designed a luminance visual stimulus model with transient flicker characteristics, recorded multichannel local field potential (LFP) signals using a microelectrode array, extracted LFP Fourier transform energy and phase features, constructed a multivariate linear inverse filter luminance information decoding algorithm, and evaluated decoding effects using a cross-correlation method...
September 6, 2017: Neuroreport
https://www.readbyqxmd.com/read/28872359/ambulatory-blood-pressure-results-and-heart-rate-variability-in-patients-with-premature-ventricular-contractions
#16
Lutfu Askin, Mustafa Cetin, Serdar Turkmen
BACKGROUND: The presence of premature ventricular contractions (PVCs) is a sign of arrhythmia and typically trigerred by over stimulation of the sympathetic nervous system. This study examined the relationships among PVCs, heart rate variability (HRV), and 24-hour ambulatory blood pressure (ABP) results. METHODS: This observational clinical study evaluated a cohort of 100 consecutive patients (58 women and 42 men) with PVCs. The individuals were split into occasional (n = 50) and frequent (n = 50) PVCs groups...
September 5, 2017: Clinical and Experimental Hypertension: CHE
https://www.readbyqxmd.com/read/28866626/sleep-patterns-in-parkinson-s-disease-direct-recordings-from-the-subthalamic-nucleus
#17
John A Thompson, Anand Tekriwal, Gidon Felsen, Musa Ozturk, Ilknur Telkes, Jiangping Wu, Nuri Firat Ince, Aviva Abosch
Sleep is a fundamental homeostatic process, and disorders of sleep can greatly affect quality of life. Parkinson's disease (PD) is highly comorbid for a spectrum of sleep disorders and deep brain stimulation (DBS) of the subthalamic nucleus (STN) has been reported to improve sleep architecture in PD. We studied local field potential (LFP) recordings in PD subjects undergoing STN-DBS over the course of a full-night's sleep. We examined the changes in oscillatory activity recorded from STN between ultradian sleep states to determine whether sleep-stage dependent spectral patterns might reflect underlying dysfunction...
September 2, 2017: Journal of Neurology, Neurosurgery, and Psychiatry
https://www.readbyqxmd.com/read/28861464/organic-electronics-for-high-resolution-electrocorticography-of-the-human-brain
#18
Dion Khodagholy, Jennifer N Gelinas, Zifang Zhao, Malcolm Yeh, Michael Long, Jeremy D Greenlee, Werner Doyle, Orrin Devinsky, György Buzsáki
Localizing neuronal patterns that generate pathological brain signals may assist with tissue resection and intervention strategies in patients with neurological diseases. Precise localization requires high spatiotemporal recording from populations of neurons while minimizing invasiveness and adverse events. We describe a large-scale, high-density, organic material-based, conformable neural interface device ("NeuroGrid") capable of simultaneously recording local field potentials (LFPs) and action potentials from the cortical surface...
November 2016: Science Advances
https://www.readbyqxmd.com/read/28853123/resistance-to-abrasion-of-extrinsic-porcelain-esthetic-characterization-techniques
#19
Woo J Chi, William Browning, Stephen Looney, J Rodway Mackert, Richard J Windhorn, Frederick Rueggeberg
STATEMENT OF PROBLEM: A novel esthetic porcelain characterization technique involves mixing an appropriate amount of ceramic colorants with clear, low-fusing porcelain (LFP), applying the mixture on the external surfaces, and firing the combined components onto the surface of restorations in a porcelain oven. This method may provide better esthetic qualities and toothbrush abrasion resistance compared to the conventional techniques of applying color-corrective porcelain colorants alone, or applying a clear glaze layer over the colorants...
July 2017: U.S. Army Medical Department Journal
https://www.readbyqxmd.com/read/28845452/visualizing-redox-orbitals-and-their-potentials-in-advanced-lithium-ion-battery-materials-using-high-resolution-x-ray-compton-scattering
#20
Hasnain Hafiz, Kosuke Suzuki, Bernardo Barbiellini, Yuki Orikasa, Vincent Callewaert, Staszek Kaprzyk, Masayoshi Itou, Kentaro Yamamoto, Ryota Yamada, Yoshiharu Uchimoto, Yoshiharu Sakurai, Hiroshi Sakurai, Arun Bansil
Reduction-oxidation (redox) reactions are the key processes that underlie the batteries powering smartphones, laptops, and electric cars. A redox process involves transfer of electrons between two species. For example, in a lithium-ion battery, current is generated when conduction electrons from the lithium anode are transferred to the redox orbitals of the cathode material. The ability to visualize or image the redox orbitals and how these orbitals evolve under lithiation and delithiation processes is thus of great fundamental and practical interest for understanding the workings of battery materials...
August 2017: Science Advances
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