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Cortical connectivity

Viktor Müller, Johanna Sänger, Ulman Lindenberger
When playing music in an ensemble, musicians need to precisely coordinate their actions with one another. As shown in our previous studies on guitar duets, interbrain synchronization plays an essential role during such interactions. In this study, we simultaneously recorded electroencephalograms from four guitarists during quartet playing, to explore the extent and the functional significance of synchronized cortical activity across four brains. We found that hyperbrain networks based on intra- and interbrain connectivity across four brains dwell on higher frequencies for intrabrain communication and on lower frequencies for interbrain connections...
March 15, 2018: Annals of the New York Academy of Sciences
Christopher Ebsch, Robert Rosenbaum
Understanding the relationship between external stimuli and the spiking activity of cortical populations is a central problem in neuroscience. Dense recurrent connectivity in local cortical circuits can lead to counterintuitive response properties, raising the question of whether there are simple arithmetical rules for relating circuits' connectivity structure to their response properties. One such arithmetic is provided by the mean field theory of balanced networks, which is derived in a limit where excitatory and inhibitory synaptic currents precisely balance on average...
March 15, 2018: PLoS Computational Biology
A V Dolzhich, S E Avetisov
PURPOSE: to assess the neurophysiological effect and clinical effectiveness of transcranial direct current stimulation in combination with drug therapy in amblyopic children. MATERIAL AND METHODS: The study involved 32 healthy children in the age of 5-12 years and 97 patients of the same age with refractive strabismic amblyopia. All study subjects underwent standard examination including ophthalmological (visometry, refractometry in normal conditions and in cycloplegia, biomicroscopy, ophthalmoscopy, type of vision), neurophysiological methods (determination of retinal electric sensitivity threshold, electric lability of optic nerve, amplitude and latency period of visual evoked potentials, electroencephalogram wave amplitudes, localization of peak electrical activity area of the cerebral cortex), assessment of neuropsychic development and estimation of mental development coefficient with age tests...
2018: Vestnik Oftalmologii
Kathleen S Rockland
Recent commentaries on the role of the thalamus consider a wide sphere of influence beyond sensory-motor transformation, to include task-relevant cognitive processes. In this short review, I reconsider known anatomic features of corticothalamic connectivity, primarily for macaque monkey, and discuss these as part of an intricate network architecture consistent with multiple connectional re-combinations and a diversity of functional tasks. Drawing mainly on results from single axon analysis for the two broad classes of corticothalamic (CT) connections, I review the strikingly complementary spatial parameters of their extrinsic CT arbors in relation to intrinsic cortical collaterals...
March 14, 2018: European Journal of Neuroscience
Andrew J Lawrence, Daniel J Tozer, Emmanuel A Stamatakis, Hugh S Markus
Objective: MRI measures of network integrity may be useful disease markers in cerebral small vessel disease (SVD). We compared the sensitivity and reproducibility of MRI derived structural and functional network measures in healthy controls and SVD subjects. Methods: Diffusion tractography and resting state fMRI were used to create connectivity matrices from 26 subjects with symptomatic MRI confirmed lacunar stroke and 19 controls. Matrices were constructed at multiple scales based on a multi-resolution cortical atlas and at multiple thresholds for the matrix density...
2018: NeuroImage: Clinical
Alireza Shahbabaie, Mitra Ebrahimpoor, Ali Hariri, Michael A Nitsche, Javad Hatami, Emad Fatemizadeh, Mohammad Ali Oghabian, Hamed Ekhtiari
Background: Transcranial direct current stimulation (tDCS) is a noninvasive brain stimulation tool suited to alter cortical excitability and activity via the application of weak direct electrical currents. An increasing number of studies in the addiction literature suggests that tDCS modulates subjective self-reported craving through stimulation of dorsolateral prefrontal cortex (DLPFC). The major goal of this study was to explore effects of bilateral DLPFC stimulation on resting state networks (RSNs) in association with drug craving modulation...
March 2018: Brain and Behavior
Jiayue Cai, Soojin Lee, Fang Ba, Saurabh Garg, Laura J Kim, Aiping Liu, Diana Kim, Z Jane Wang, Martin J McKeown
Falls and balance difficulties remain a major source of morbidity in Parkinson's Disease (PD) and are stubbornly resistant to therapeutic interventions. The mechanisms of gait impairment in PD are incompletely understood but may involve changes in the Pedunculopontine Nucleus (PPN) and its associated connections. We utilized fMRI to explore the modulation of PPN connectivity by Galvanic Vestibular Stimulation (GVS) in healthy controls ( n = 12) and PD subjects even without overt evidence of Freezing of Gait (FOG) while on medication ( n = 23)...
2018: Frontiers in Neuroscience
Vipan K Parihar, Mattia Maroso, Amber Syage, Barrett D Allen, Maria C Angulo, Ivan Soltesz, Charles L Limoli
Of the many perils associated with deep space travel to Mars, neurocognitive complications associated with cosmic radiation exposure are of particular concern. Despite these realizations, whether and how realistic doses of cosmic radiation cause cognitive deficits and neuronal circuitry alterations several months after exposure remains unclear. In addition, even less is known about the temporal progression of cosmic radiation-induced changes transpiring over the duration of a time period commensurate with a flight to Mars...
March 11, 2018: Experimental Neurology
G Oriolo, E Egmond, Z Mariño, M Cavero, R Navines, L Zamarrenho, R Solà, J Pujol, N Bargallo, X Forns, R Martin-Santos
BACKGROUND: Chronic hepatitis C is considered a systemic disease because of extra-hepatic manifestations. Neuroimaging has been employed in hepatitis C virus-infected patients to find in vivo evidence of central nervous system alterations. AIMS: Systematic review and meta-analysis of neuroimaging research in chronic hepatitis C treatment naive patients, or patients previously treated without sustained viral response, to study structural and functional brain impact of hepatitis C...
March 14, 2018: Alimentary Pharmacology & Therapeutics
M Sehmbi, C D Rowley, L Minuzzi, F Kapczinski, M Steiner, R B Sassi, N A Bock, B N Frey
OBJECTIVE: Although cognitive dysfunction persists through affective and euthymic states in bipolar disorder (BD), its neurobiological correlates remain undetermined. We explore whole-cortex intracortical myelin (ICM) and cognition in BD-I and controls. METHODS: T1 -weighted images (3T) optimized for ICM measurement were analyzed using a surface-based approach. MRI signal was sampled at cortical mid-depth. Cognitive performance was measured via standardized computerized battery and paper-and-pencil Trails B...
March 13, 2018: Acta Psychiatrica Scandinavica
Federico Gennaro, Eling D de Bruin
Assessment of the cortical role during bipedalism has been a methodological challenge. While surface electroencephalography (EEG) is capable of non-invasively measuring cortical activity during human locomotion, it is associated with movement artifacts obscuring cerebral sources of activity. Recently, statistical methods based on blind source separation revealed potential for resolving this issue, by segregating non-cerebral/artifactual from cerebral sources of activity. This step marked a new opportunity for the investigation of the brains' role while moving and was tagged mobile brain/body imaging (MoBI)...
2018: Frontiers in Public Health
Linqiong Sang, Lin Chen, Li Wang, Jingna Zhang, Ye Zhang, Pengyue Li, Chuanming Li, Mingguo Qiu
Cognitive impairment caused by subcortical ischemic vascular disease (SIVD) has been elucidated by many neuroimaging studies. However, little is known regarding the changes in brain functional connectivity networks in relation to the severity of cognitive impairment in SIVD. In the present study, 20 subcortical ischemic vascular cognitive impairment no dementia patients (SIVCIND) and 20 dementia patients (SIVaD) were enrolled; additionally, 19 normal controls were recruited. Each participant underwent a resting-state functional MRI scan...
2018: Frontiers in Neurology
Gene-Jack Wang, Jizheng Zhao, Dardo Tomasi, Ehsan Shokri Kojori, Ruiliang Wang, Corinde E Wiers, Elisabeth C Caparelli, Nora D Volkow
BACKGROUND: The control of food intake in environments with easy access to highly rewarding foods is challenging to most modern societies. The combination of sustained release (SR) naltrexone and SR bupropion (NB32) has been used in weight-loss and obesity management. However, the effects of NB32 on the brain circuits implicated in the regulation of food intake are unknown. Here we used functional connectivity density (FCD) mapping to evaluate the effects of NB32 on resting brain FC. METHODS: Thirty-six healthy women underwent magnetic resonance imaging (MRI) before and after 4-week treatment with NB32 (n = 16) or with placebo (n = 20)...
February 23, 2018: International Journal of Obesity: Journal of the International Association for the Study of Obesity
Kenji Fugito Junior, Arthur Rodriguez Gonzalez Cortes, Ricardo de Carvalho Destro, Marcelo Yoshimoto
PURPOSE: The search for optimizing rehabilitation results with the use of osseointegrated implants has led oral surgeons to look for other technologies that can provide better predictability for treatments; however, effectiveness must be considered as well. This study aimed to compare temperature variation during preparation of implant surgical beds using conventional rotary implant burs versus ultrasonic tips and to study perforation effectiveness by analyzing the functional wear of both systems and the influence of such wear on the overheating of cortical bone...
March 2018: International Journal of Oral & Maxillofacial Implants
Jianwei Cao, Hanli Liu, George Alexandrakis
Cortical circuit reorganization induced by anodal transcranial direct current stimulation (tDCS) over the Broca's area of the dominant language hemisphere in 13 healthy adults was quantified by functional near-infrared spectroscopy (fNIRS). Transient cortical reorganization patterns in steady-state functional connectivity (seed-based and graph theory analysis) and temporal functional connectivity (sliding window correlation analysis) were recorded before, during, and after applying high current tDCS (1 mA, 8 min)...
April 2018: Neurophotonics
Nataliya Kraynyukova, Tatjana Tchumatchenko
A hallmark of cortical circuits is their versatility. They can perform multiple fundamental computations such as normalization, memory storage, and rhythm generation. Yet it is far from clear how such versatility can be achieved in a single circuit, given that specialized models are often needed to replicate each computation. Here, we show that the stabilized supralinear network (SSN) model, which was originally proposed for sensory integration phenomena such as contrast invariance, normalization, and surround suppression, can give rise to dynamic cortical features of working memory, persistent activity, and rhythm generation...
March 12, 2018: Proceedings of the National Academy of Sciences of the United States of America
Logan T Dowdle, Truman R Brown, Mark S George, Colleen A Hanlon
BACKGROUND: In the 20 years since our group established the feasibility of performing interleaved TMS/fMRI, no studies have reported direct comparisons of active prefrontal stimulation with a matched sham. Thus, for all studies there is concern about what is truly the TMS effect on cortical neurons. OBJECTIVE: After developing a sham control for use within the MRI scanner, we used fMRI to test the hypothesis of greater regional BOLD responses for active versus control stimulation...
February 24, 2018: Brain Stimulation
Edmund T Rolls, Wei Cheng, Matthieu Gilson, Jiang Qiu, Zicheng Hu, Hongtao Ruan, Yu Li, Chu-Chung Huang, Albert C Yang, Shih-Jen Tsai, Xiaodong Zhang, Kaixiang Zhuang, Ching-Po Lin, Gustavo Deco, Peng Xie, Jianfeng Feng
BACKGROUND: Resting-state functional connectivity reflects correlations in the activity between brain areas, whereas effective connectivity between different brain areas measures directed influences of brain regions on each other. Using the latter approach, we compare effective connectivity results in patients with major depressive disorder (MDD) and control subjects. METHODS: We used a new approach to the measurement of effective connectivity, in which each brain area has a simple dynamical model, and known anatomical connectivity is used to provide constraints...
February 2018: Biological Psychiatry: Cognitive Neuroscience and Neuroimaging
Nannan Guo, Marta E Soden, Charlotte Herber, Michael TaeWoo Kim, Antoine Besnard, Paoyan Lin, Xiang Ma, Constance L Cepko, Larry S Zweifel, Amar Sahay
Memories become less precise and generalized over time as memory traces reorganize in hippocampal-cortical networks. Increased time-dependent loss of memory precision is characterized by an overgeneralization of fear in individuals with post-traumatic stress disorder (PTSD) or age-related cognitive impairments. In the hippocampal dentate gyrus (DG), memories are thought to be encoded by so-called 'engram-bearing' dentate granule cells (eDGCs). Here we show, using rodents, that contextual fear conditioning increases connectivity between eDGCs and inhibitory interneurons (INs) in the downstream hippocampal CA3 region...
March 12, 2018: Nature Medicine
Christopher S Parker, Jonathan D Clayden, M Jorge Cardoso, Roman Rodionov, John S Duncan, Catherine Scott, Beate Diehl, Sebastien Ourselin
Patients with medically-refractory focal epilepsy may be candidates for neurosurgery and some may require placement of intracranial EEG electrodes to localise seizure onset. Assessing cerebral responses to single pulse electrical stimulation (SPES) may give diagnostically useful data. SPES produces cortico-cortical evoked potentials (CCEPs), which infer effective brain connectivity. Diffusion-weighted images and tractography may be used to estimate structural brain connectivity. This combination provides the opportunity to observe seizure onset and its propagation throughout the brain, spreading contiguously along the cortex explored with electrodes, or non-contiguously...
2018: NeuroImage: Clinical
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