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https://www.readbyqxmd.com/read/28102460/neural-mass-models-as-a-tool-to-investigate-neural-dynamics-during-seizures
#1
Tatiana Kameneva, Tianlin Ying, Ben Guo, Dean R Freestone
Epilepsy is one of the most common neurological disorders and is characterized by recurrent seizures. We use theoretical neuroscience tools to study brain dynamics during seizures. We derive and simulate a computational model of a network of hippocampal neuronal populations. Each population within the network is based on a model that has been shown to replicate the electrophysiological dynamics observed during seizures. The results provide insights into possible mechanisms for seizure spread. We observe that epileptiform activity remains localized to a pathological region when a global connectivity parameter is less than a critical value...
January 19, 2017: Journal of Computational Neuroscience
https://www.readbyqxmd.com/read/28102300/neural-correlates-of-speech-segregation-based-on-formant-frequencies-of-adjacent-vowels
#2
Claude Alain, Jessica S Arsenault, Linda Garami, Gavin M Bidelman, Joel S Snyder
The neural substrates by which speech sounds are perceptually segregated into distinct streams are poorly understood. Here, we recorded high-density scalp event-related potentials (ERPs) while participants were presented with a cyclic pattern of three vowel sounds (/ee/-/ae/-/ee/). Each trial consisted of an adaptation sequence, which could have either a small, intermediate, or large difference in first formant (Δf1) as well as a test sequence, in which Δf1 was always intermediate. For the adaptation sequence, participants tended to hear two streams ("streaming") when Δf1 was intermediate or large compared to when it was small...
January 19, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28102082/characterization-of-the-molecular-mechanisms-underlying-the-chronic-phase-of-stroke-in-a-cynomolgus-monkey-model-of-induced-cerebral-ischemia
#3
Henry C H Law, Samuel S W Szeto, Quan Quan, Yun Zhao, Zaijun Zhang, Olga Krakovska, Leong Ting Lui, Chengyou Zheng, Simon Ming Yuen Lee, K W Michael Siu, Yuqiang Wang, Ivan K Chu
Stroke is one of the main causes of mortality and long-term disability worldwide. The pathophysiological mechanisms underlying this disease are not well understood, particularly in the chronic phase after the initial ischemic episode. In this study, a Macaca fascicularis stroke model consisting of two sample groups, as determined by MRI-quantified infarct volumes as a measure of the stroke severity 28 days after the ischemic episode, was evaluated using qualitative and quantitative proteomics analyses. By using multiple online multidimensional liquid chromatography platforms, 8790 non-redundant proteins that condensed to 5223 protein groups at 1% global false discovery rate (FDR)...
January 19, 2017: Journal of Proteome Research
https://www.readbyqxmd.com/read/28101525/untangling-basal-ganglia-network-dynamics-and-function-role-of-dopamine-depletion-and-inhibition-investigated-in-a-spiking-network-model
#4
Mikael Lindahl, Jeanette Hellgren Kotaleski
The basal ganglia are a crucial brain system for behavioral selection, and their function is disturbed in Parkinson's disease (PD), where neurons exhibit inappropriate synchronization and oscillations. We present a spiking neural model of basal ganglia including plausible details on synaptic dynamics, connectivity patterns, neuron behavior, and dopamine effects. Recordings of neuronal activity in the subthalamic nucleus and Type A (TA; arkypallidal) and Type I (TI; prototypical) neurons in globus pallidus externa were used to validate the model...
November 2016: ENeuro
https://www.readbyqxmd.com/read/28101428/wide-field-and-highly-sensitive-angiography-based-on-optical-coherence-tomography-with-akinetic-swept-source
#5
Jingjiang Xu, Shaozhen Song, Wei Wei, Ruikang K Wang
Wide-field vascular visualization in bulk tissue that is of uneven surface is challenging due to the relatively short ranging distance and significant sensitivity fall-off for most current optical coherence tomography angiography (OCTA) systems. We report a long ranging and ultra-wide-field OCTA (UW-OCTA) system based on an akinetic swept laser. The narrow instantaneous linewidth of the swept source with its high phase stability, combined with high-speed detection in the system enable us to achieve long ranging (up to 46 mm) and almost negligible system sensitivity fall-off...
January 1, 2017: Biomedical Optics Express
https://www.readbyqxmd.com/read/28100830/neural-bases-of-recommendations-differ-according-to-social-network-structure
#6
Matthew Brook O'Donnell, Joseph B Bayer, Christopher N Cascio, Emily B Falk
Ideas spread across social networks, but not everyone is equally positioned to be a successful recommender. Do individuals with more opportunities to connect otherwise unconnected others-high information brokers-use their brains differently than low information brokers when making recommendations? We test the hypothesis that those with more opportunities for information brokerage may use brain systems implicated in considering the thoughts, perspectives, and mental states of others (i.e. 'mentalizing') more when spreading ideas...
January 18, 2017: Social Cognitive and Affective Neuroscience
https://www.readbyqxmd.com/read/28100828/an-integrated-modelling-framework-for-neural-circuits-with-multiple-neuromodulators
#7
Alok Joshi, Vahab Youssofzadeh, Vinith Vemana, T M McGinnity, Girijesh Prasad, KongFatt Wong-Lin
Neuromodulators are endogenous neurochemicals that regulate biophysical and biochemical processes, which control brain function and behaviour, and are often the targets of neuropharmacological drugs. Neuromodulator effects are generally complex partly owing to the involvement of broad innervation, co-release of neuromodulators, complex intra- and extrasynaptic mechanism, existence of multiple receptor subtypes and high interconnectivity within the brain. In this work, we propose an efficient yet sufficiently realistic computational neural modelling framework to study some of these complex behaviours...
January 2017: Journal of the Royal Society, Interface
https://www.readbyqxmd.com/read/28100742/visual-sampling-predicts-hippocampal-activity
#8
Zhong-Xu Liu, Kelly Shen, Rosanna K Olsen, Jennifer D Ryan
: Eye movements serve to accumulate information from the visual world, contributing to the formation of coherent memory representations that support cognition and behavior. The hippocampus and the oculomotor network are well connected anatomically through an extensive set of polysynaptic pathways. However, the extent to which visual sampling behavior is related to functional responses in the hippocampus during encoding has not been studied directly in human neuroimaging. In the current study, participants engaged in a face processing task while brain responses were recorded with fMRI and eye movements were monitored simultaneously...
January 18, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/28100734/does-the-superior-colliculus-control-perceptual-sensitivity-or-choice-bias-during-attention-evidence-from-a-multialternative-decision-framework
#9
Devarajan Sridharan, Nicholas A Steinmetz, Tirin Moore, Eric I Knudsen
: Distinct networks in the forebrain and the midbrain coordinate to control spatial attention. The critical involvement of the superior colliculus (SC)-the central structure in the midbrain network-in visuospatial attention has been shown by four seminal, published studies in monkeys (Macaca mulatta) performing multialternative tasks. However, due to the lack of a mechanistic framework for interpreting behavioral data in such tasks, the nature of the SC's contribution to attention remains unclear...
January 18, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/28100728/direct-cortical-stimulation-of-human-posteromedial-cortex
#10
Brett L Foster, Josef Parvizi
BACKGROUND: The posteromedial cortex (PMC) is a collective term for an anatomically heterogeneous area of the brain constituting a core node of the human default mode network (DMN), which is engaged during internally focused subjective cognition such as autobiographical memory. METHODS: We explored the effects of causal perturbations of PMC with direct electric brain stimulation (EBS) during presurgical epilepsy monitoring with intracranial EEG electrodes. RESULTS: Data were collected from 885 stimulations in 25 patients implanted with intracranial electrodes across the PMC...
January 18, 2017: Neurology
https://www.readbyqxmd.com/read/28100688/the-use-of-oxytocin-to-improve-feeding-and-social-skills-in-infants-with-prader-willi-syndrome
#11
Maïthé Tauber, Kader Boulanouar, Gwenaelle Diene, Sophie Çabal-Berthoumieu, Virginie Ehlinger, Pascale Fichaux-Bourin, Catherine Molinas, Sandy Faye, Marion Valette, Jeanne Pourrinet, Catie Cessans, Sylvie Viaux-Sauvelon, Céline Bascoul, Antoine Guedeney, Patric Delhanty, Vincent Geenen, Henri Martens, Françoise Muscatelli, David Cohen, Angèle Consoli, Pierre Payoux, Catherine Arnaud, Jean-Pierre Salles
BACKGROUND AND OBJECTIVES: Patients with Prader-Willi syndrome (PWS) display poor feeding and social skills as infants and fewer hypothalamic oxytocin (OXT)-producing neurons were documented in adults. Animal data demonstrated that early treatment with OXT restores sucking after birth. Our aim is to reproduce these data in infants with PWS. METHODS: We conducted a phase 2 escalating dose study of a short course (7 days) of intranasal OXT administration. We enrolled 18 infants with PWS under 6 months old (6 infants in each step) who received 4 IU of OXT either every other day, daily, or twice daily...
January 18, 2017: Pediatrics
https://www.readbyqxmd.com/read/28100246/genetic-effect-of-interleukin-1-beta-c-511t-polymorphism-on-the-structural-covariance-network-and-white-matter-integrity-in-alzheimer-s-disease
#12
Chi-Wei Huang, Shih-Wei Hsu, Shih-Jen Tsai, Nai-Ching Chen, Mu-En Liu, Chen-Chang Lee, Shu-Hua Huang, Weng-Neng Chang, Ya-Ting Chang, Wan-Chen Tsai, Chiung-Chih Chang
BACKGROUND: Inflammatory processes play a pivotal role in the degenerative process of Alzheimer's disease. In humans, a biallelic (C/T) polymorphism in the promoter region (position-511) (rs16944) of the interleukin-1 beta gene has been significantly associated with differences in the secretory capacity of interleukin-1 beta. In this study, we investigated whether this functional polymorphism mediates the brain networks in patients with Alzheimer's disease. METHODS: We enrolled a total of 135 patients with Alzheimer's disease (65 males, 70 females), and investigated their gray matter structural covariance networks using 3D T1 magnetic resonance imaging and their white matter macro-structural integrities using fractional anisotropy...
January 18, 2017: Journal of Neuroinflammation
https://www.readbyqxmd.com/read/28100076/precuneus-structure-changes-in-amnestic-mild-cognitive-impairment
#13
Robert Haussmann, Annett Werner, Antonia Gruschwitz, Antje Osterrath, Jan Lange, Katharina L Donix, Jennifer Linn, Markus Donix
Patients with amnestic mild cognitive impairment (aMCI) are at risk for developing Alzheimer's disease. Due to their prominent memory impairment, structural magnetic resonance imaging (MRI) often focuses on the hippocampal region. However, recent positron-emission tomography data suggest that within a network of frontal and temporal changes, patients with aMCI show metabolic alterations in the precuneus, a key region for higher cognitive functions. Using high-resolution MRI and whole-brain cortical thickness analyses in 28 patients with aMCI and 25 healthy individuals, we wanted to investigate whether structural changes in the precuneus would be associated with cortical thickness reductions in frontal and temporal brain regions in patients with aMCI...
February 2017: American Journal of Alzheimer's Disease and Other Dementias
https://www.readbyqxmd.com/read/28100032/sequential-learning-during-contextual-fear-conditioning-guides-the-rate-of-systems-consolidation-implications-for-consolidation-of-multiple-memory-traces
#14
Lizeth K Pedraza, Rodrigo O Sierra, Ana P Crestani, Jorge A Quillfeldt, Lucas de Oliveira Alvares
Systems consolidation has been described as a time-dependent reorganization process involving the neocortical and hippocampal networks underlying memory storage and retrieval. Previous studies of our lab were able to demonstrate that systems consolidation is a dynamic process, rather than a merely passive, time-dependent phenomenon. Here, we studied the influence of sequential learning in contextual fear conditioning (CFC) with different training intensities in the time-course of hippocampal dependency and contextual specificity...
January 18, 2017: Hippocampus
https://www.readbyqxmd.com/read/28099997/on-joint-estimation-of-gaussian-graphical-models-for-spatial-and-temporal-data
#15
Zhixiang Lin, Tao Wang, Can Yang, Hongyu Zhao
In this article, we first propose a Bayesian neighborhood selection method to estimate Gaussian Graphical Models (GGMs). We show the graph selection consistency of this method in the sense that the posterior probability of the true model converges to one. When there are multiple groups of data available, instead of estimating the networks independently for each group, joint estimation of the networks may utilize the shared information among groups and lead to improved estimation for each individual network...
January 18, 2017: Biometrics
https://www.readbyqxmd.com/read/28099209/functional-neuroimaging-in-obesity
#16
Laura Patriarca, Greta Magerowski, Miguel Alonso-Alonso
PURPOSE OF REVIEW: The review examines recent advances in the use of functional neuroimaging to study human obesity, a field that is rapidly expanding and continues to be of paramount importance for a better understanding of the pathogenesis of this condition. With rising levels of obesity worldwide and limited therapeutic options, there is a great need for the development of new solutions that can benefit patients. RECENT FINDINGS: Studies that utilize functional neuroimaging are beginning to shed light on the nature of behavioral and neurocognitive dysfunctions previously identified in individuals with obesity...
January 17, 2017: Current Opinion in Endocrinology, Diabetes, and Obesity
https://www.readbyqxmd.com/read/28099068/same-story-different-story
#17
Yaara Yeshurun, Stephen Swanson, Erez Simony, Janice Chen, Christina Lazaridi, Christopher J Honey, Uri Hasson
Differences in people's beliefs can substantially impact their interpretation of a series of events. In this functional MRI study, we manipulated subjects' beliefs, leading two groups of subjects to interpret the same narrative in different ways. We found that responses in higher-order brain areas-including the default-mode network, language areas, and subsets of the mirror neuron system-tended to be similar among people who shared the same interpretation, but different from those of people with an opposing interpretation...
January 1, 2017: Psychological Science
https://www.readbyqxmd.com/read/28098893/systematic-analysis-of-microarray-datasets-to-identify-parkinson-s-disease%C3%A2-associated-pathways-and-genes
#18
Yinling Feng, Xuefeng Wang
In order to investigate commonly disturbed genes and pathways in various brain regions of patients with Parkinson's disease (PD), microarray datasets from previous studies were collected and systematically analyzed. Different normalization methods were applied to microarray datasets from different platforms. A strategy combining gene co‑expression networks and clinical information was adopted, using weighted gene co‑expression network analysis (WGCNA) to screen for commonly disturbed genes in different brain regions of patients with PD...
January 16, 2017: Molecular Medicine Reports
https://www.readbyqxmd.com/read/28097803/regulation-of-mrna-following-brain-ischemia-and-reperfusion
#19
REVIEW
Donald J DeGracia
There is growing appreciation that mRNA regulation plays important roles in disease and injury. mRNA regulation and ribonomics occur in brain ischemia and reperfusion (I/R) following stroke and cardiac arrest and resuscitation. It was recognized over 40 years ago that translation arrest (TA) accompanies brain I/R and is now recognized as part of the intrinsic stress responses triggered in neurons. However, neuron death correlates to a prolonged TA in cells fated to undergo delayed neuronal death (DND). Dysfunction of mRNA regulatory processes in cells fated to DND prevents them from translating stress-induced mRNAs such as heat shock proteins...
January 17, 2017: Wiley Interdisciplinary Reviews. RNA
https://www.readbyqxmd.com/read/28097513/stable-control-of-firing-rate-mean-and-variance-by-dual-homeostatic-mechanisms
#20
Jonathan Cannon, Paul Miller
Homeostatic processes that provide negative feedback to regulate neuronal firing rates are essential for normal brain function. Indeed, multiple parameters of individual neurons, including the scale of afferent synapse strengths and the densities of specific ion channels, have been observed to change on homeostatic time scales to oppose the effects of chronic changes in synaptic input. This raises the question of whether these processes are controlled by a single slow feedback variable or multiple slow variables...
December 2017: Journal of Mathematical Neuroscience
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