Read by QxMD icon Read

dynamic neural field

Claudia Compagnucci, Emanuela Piermarini, Antonella Sferra, Rossella Borghi, Alessia Niceforo, Stefania Petrini, Fiorella Piemonte, Enrico Bertini
Patient-derived induced pluripotent stem cells (iPSCs) provide a novel tool to investigate the pathophysiology of poorly known diseases, in particular those affecting the nervous system, which has been difficult to study for its lack of accessibility. In this emerging and promising field, recent iPSCs studies are mostly used as "proof-of-principle" experiments that are confirmatory of previous findings obtained from animal models and postmortem human studies; its promise as a discovery tool is just beginning to be realized...
October 15, 2016: Molecular and Cellular Neurosciences
Samuel A Neymotin, Zoe N Talbot, Jeeyune Q Jung, André A Fenton, William W Lytton
BACKGROUND: Correlated neuronal activity in the brain is hypothesized to contribute to information representation, and is important for gauging brain dynamics in health and disease. Due to high dimensional neural datasets, it is difficult to study temporal variations in correlation structure. NEW METHOD: We developed a multiscale method, Population Coordination (PCo), to assess neural population structure in multiunit single neuron ensemble and multi-site local field potential (LFP) recordings...
October 13, 2016: Journal of Neuroscience Methods
Hannah Bos, Markus Diesmann, Moritz Helias
Oscillations are omnipresent in neural population signals, like multi-unit recordings, EEG/MEG, and the local field potential. They have been linked to the population firing rate of neurons, with individual neurons firing in a close-to-irregular fashion at low rates. Using a combination of mean-field and linear response theory we predict the spectra generated in a layered microcircuit model of V1, composed of leaky integrate-and-fire neurons and based on connectivity compiled from anatomical and electrophysiological studies...
October 2016: PLoS Computational Biology
Laura D Lewis, Kawin Setsompop, Bruce R Rosen, Jonathan R Polimeni
Oscillatory neural dynamics play an important role in the coordination of large-scale brain networks. High-level cognitive processes depend on dynamics evolving over hundreds of milliseconds, so measuring neural activity in this frequency range is important for cognitive neuroscience. However, current noninvasive neuroimaging methods are not able to precisely localize oscillatory neural activity above 0.2 Hz. Electroencephalography and magnetoencephalography have limited spatial resolution, whereas fMRI has limited temporal resolution because it measures vascular responses rather than directly recording neural activity...
October 11, 2016: Proceedings of the National Academy of Sciences of the United States of America
Joel Pearson, Rocco Chiou, Sebastian Rogers, Marcus Wicken, Stewart Heitmann, Bard Ermentrout
Hallucinations occur in both normal and clinical populations. Due to their unpredictability and complexity, the mechanisms underlying hallucinations remain largely untested. Here we show that visual hallucinations can be induced in the normal population by visual flicker, limited to an annulus that constricts content complexity to simple moving grey blobs, allowing objective mechanistic investigation. Hallucination strength peaked at ~11 Hz flicker and was dependent on cortical processing. Hallucinated motion speed increased with flicker rate, when mapped onto visual cortex it was independent of eccentricity, underwent local sensory adaptation and showed the same bistable and mnemonic dynamics as sensory perception...
October 11, 2016: ELife
Suresh Kondati Natarajan, Jörg Behler
Solid-liquid interfaces have received considerable attention in recent years due to their central role in many technologically relevant fields like electrochemistry, heterogeneous catalysis and corrosion. As the chemical processes in these examples take place primarily at the interface, understanding the structural and dynamical properties of the interfacial water molecules is of vital importance. Here, we use a first-principles quality high-dimensional neural network potential built from dispersion-corrected density functional theory data in molecular dynamics simulations to investigate water-copper interfaces as a prototypical case...
October 7, 2016: Physical Chemistry Chemical Physics: PCCP
Dimitris A Pinotsis, Roman Loonis, Andre M Bastos, Earl K Miller, Karl J Friston
Neural rhythms or oscillations are ubiquitous in neuroimaging data. These spectral responses have been linked to several cognitive processes; including working memory, attention, perceptual binding and neuronal coordination. In this paper, we show how Bayesian methods can be used to finesse the ill-posed problem of reconstructing-and explaining-oscillatory responses. We offer an overview of recent developments in this field, focusing on (i) the use of MEG data and Empirical Bayes to build hierarchical models for group analyses-and the identification of important sources of inter-subject variability and (ii) the construction of novel dynamic causal models of intralaminar recordings to explain layer-specific activity...
October 7, 2016: Brain Topography
Sean E Cavanagh, Joni D Wallis, Steven W Kennerley, Laurence T Hunt
Correlates of value are routinely observed in the prefrontal cortex (PFC) during reward-guided decision making. In previous work (Hunt et al., 2015), we argued that PFC correlates of chosen value are a consequence of varying rates of a dynamical evidence accumulation process. Yet within PFC, there is substantial variability in chosen value correlates across individual neurons. Here we show that this variability is explained by neurons having different temporal receptive fields of integration, indexed by examining neuronal spike rate autocorrelation structure whilst at rest...
October 5, 2016: ELife
Edith Lesburguères, Fraser T Sparks, Kally C O'Reilly, André A Fenton
Training in the active place avoidance task changes hippocampus synaptic function, the dynamics of hippocampus local field potentials, place cell discharge, and active place avoidance memory is maintained by persistent PKMζ activity. The extent to which these changes reflect memory processes and/or stress responses is unknown. We designed a study to assess stress within the active place avoidance task by measuring serum corticosterone (CORT) at different stages of training. CORT levels did not differ between trained mice that learned to avoid the location of the mild foot shock, and untrained no-shock controls exposed to the same environment for the same amount of time...
October 4, 2016: Hippocampus
Morris H Baslow, Christopher K Cain, Robert Sears, Donald A Wilson, Alvin Bachman, Scott Gerum, David N Guilfoyle
Brain activation studies in humans have shown the dynamic nature of neuronal N-acetylaspartate (NAA) and N-acetylaspartylglutamate (NAAG) based on changes in their MRS signals in response to stimulation. These studies demonstrated that upon visual stimulation there was a focal increase in cerebral blood flow (CBF) and a decrease in NAA or in the total of NAA and NAAG signals in the visual cortex, and that these changes were reversed upon cessation of stimulation. In the present study we have developed an animal model in order to explore the relationships between brain stimulation, neuronal activity, CBF and NAA...
October 3, 2016: NMR in Biomedicine
Helen H Yang, François St-Pierre
UNLABELLED: A longstanding goal in neuroscience is to understand how spatiotemporal patterns of neuronal electrical activity underlie brain function, from sensory representations to decision making. An emerging technology for monitoring electrical dynamics, voltage imaging using genetically encoded voltage indicators (GEVIs), couples the power of genetics with the advantages of light. Here, we review the properties that determine indicator performance and applicability, discussing both recent progress and technical limitations...
September 28, 2016: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Clara Bourrelly, Julie Quinet, Patrick Cavanagh, Laurent Goffart
An object moving in the visual field triggers a saccade that brings its image onto the fovea. It is followed by a combination of slow eye movements and catch-up saccades that try to keep the target image on the fovea as long as possible. The accuracy of this ability to track the "here-and-now" location of a visual target contrasts with the spatiotemporally distributed nature of its encoding in the brain. We show in six experimentally naive monkeys how this performance is acquired and gradually evolves during successive daily sessions...
September 28, 2016: Journal of Neurophysiology
Axel Hutt, Andreas Mierau, Jérémie Lefebvre
Oscillatory brain activity is believed to play a central role in neural coding. Accumulating evidence shows that features of these oscillations are highly dynamic: power, frequency and phase fluctuate alongside changes in behavior and task demands. The role and mechanism supporting this variability is however poorly understood. We here analyze a network of recurrently connected spiking neurons with time delay displaying stable synchronous dynamics. Using mean-field and stability analyses, we investigate the influence of dynamic inputs on the frequency of firing rate oscillations...
2016: PloS One
Gennady Erlikhman, Gideon P Caplovitz
During dynamic occlusion, an object passes behind an occluding surface and then later reappears. Even when completely occluded from view, such objects are experienced as continuing to exist or persist behind the occluder, even though they are no longer visible. The contents and neural basis of this persistent representation remain poorly understood. Questions remain as to whether there is information maintained about the object itself (i.e. its shape or identity) or, non-object-specific information such as its position or velocity as it is tracked behind an occluder as well as which areas of visual cortex represent such information...
September 20, 2016: NeuroImage
Aaron Kucyi, Karen D Davis
Pain occurs in time. In naturalistic settings, pain perception is sometimes stable but often varies in intensity and quality over the course of seconds, minutes, and days. A principal aim in classic electrophysiology studies of pain was to uncover a neural code based on the temporal patterns of single neuron firing. In contrast, modern neuroimaging studies have placed emphasis on uncovering the spatial pattern of brain activity (or "map") that may reflect the pain experience. However, in the emerging field of connectomics, communication within and among brain networks is characterized as intrinsically dynamic on multiple time scales...
September 22, 2016: Neuroscientist: a Review Journal Bringing Neurobiology, Neurology and Psychiatry
Scott L Brincat, Earl K Miller
UNLABELLED: As we learn about items in our environment, their neural representations become increasingly enriched with our acquired knowledge. But there is little understanding of how network dynamics and neural processing related to external information changes as it becomes laden with "internal" memories. We sampled spiking and local field potential activity simultaneously from multiple sites in the lateral prefrontal cortex (PFC) and the hippocampus (HPC)-regions critical for sensory associations-of monkeys performing an object paired-associate learning task...
September 14, 2016: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Philip A Kragel, Annchen R Knodt, Ahmad R Hariri, Kevin S LaBar
Pattern classification of human brain activity provides unique insight into the neural underpinnings of diverse mental states. These multivariate tools have recently been used within the field of affective neuroscience to classify distributed patterns of brain activation evoked during emotion induction procedures. Here we assess whether neural models developed to discriminate among distinct emotion categories exhibit predictive validity in the absence of exteroceptive emotional stimulation. In two experiments, we show that spontaneous fluctuations in human resting-state brain activity can be decoded into categories of experience delineating unique emotional states that exhibit spatiotemporal coherence, covary with individual differences in mood and personality traits, and predict on-line, self-reported feelings...
September 2016: PLoS Biology
Kristin K Sellers, Chunxiu Yu, Zhe Charles Zhou, Iain Stitt, Yuhui Li, Susanne Radtke-Schuller, Sankaraleengam Alagapan, Flavio Fröhlich
Sustained attention requires the coordination of neural activity across multiple cortical areas in the frontoparietal network, in particular the prefrontal cortex (PFC) and posterior parietal cortex (PPC). Previous work has demonstrated that activity in these brain regions is coordinated by neuronal oscillations of the local field potential (LFP). However, the underlying coordination of activity in terms of organization of single unit (SU) spiking activity has remained poorly understood, particularly in the freely moving animal...
September 13, 2016: Cell Reports
Caroline E Robertson, Katherine L Hermann, Anna Mynick, Dwight J Kravitz, Nancy Kanwisher
We experience our visual environment as a seamless, immersive panorama. Yet, each view is discrete and fleeting, separated by expansive eye movements and discontinuous views of our spatial surroundings. How are discrete views of a panoramic environment knit together into a broad, unified memory representation? Regions of the brain's "scene network" are well poised to integrate retinal input and memory [1]: they are visually driven [2, 3] but also densely interconnected with memory structures in the medial temporal lobe [4]...
September 26, 2016: Current Biology: CB
C Joseph Burnett, Michael J Krashes
Designer receptors exclusively activated by designer drugs (DREADDs) have proven to be highly effective neuromodulatory tools for the investigation of neural circuits underlying behavioral outputs. They exhibit a number of advantages: they rely on cell-specific manipulations through canonical intracellular signaling pathways, they are easy and cost-effective to implement in a laboratory setting, and they are easily scalable for single-region or full-brain manipulations. On the other hand, DREADDs rely on ligand-G-protein-coupled receptor interactions, leading to coarse temporal dynamics...
September 7, 2016: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
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"