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https://www.readbyqxmd.com/read/29227992/thalamocortical-control-of-propofol-phase-amplitude-coupling
#1
Austin E Soplata, Michelle M McCarthy, Jason Sherfey, Shane Lee, Patrick L Purdon, Emery N Brown, Nancy Kopell
The anesthetic propofol elicits many different spectral properties on the EEG, including alpha oscillations (8-12 Hz), Slow Wave Oscillations (SWO, 0.1-1.5 Hz), and dose-dependent phase-amplitude coupling (PAC) between alpha and SWO. Propofol is known to increase GABAA inhibition and decrease H-current strength, but how it generates these rhythms and their interactions is still unknown. To investigate both generation of the alpha rhythm and its PAC to SWO, we simulate a Hodgkin-Huxley network model of a hyperpolarized thalamus and corticothalamic inputs...
December 11, 2017: PLoS Computational Biology
https://www.readbyqxmd.com/read/29226709/enhanced-brain-network-activity-in-complex-movement-rhythms-a-simultaneous-fmri-eeg-study
#2
Bhim Mani Adhikari, Charles M Epstein, Mukesh Dhamala
Generating movement rhythms is known to involve a network of distributed brain regions associated with motor planning, control, execution, and perception of timing for the repertoire of motor actions. What brain areas are bound in the network and how the network activity is modulated by rhythmic complexity have not been completely explored. To contribute to answering these questions, we designed a study in which nine healthy participants performed simple to complex rhythmic finger movement tasks while undergoing simultaneous functional magnetic resonance imaging and electroencephalography (fMRI-EEG) recordings of their brain activity during the tasks and rest...
December 10, 2017: Brain Connectivity
https://www.readbyqxmd.com/read/29213509/comparative-analysis-of-the-electroencephalogram-in-patients-with-alzheimer-s-disease-diffuse-axonal-injury-patients-and-healthy-controls-using-loreta-analysis
#3
Jéssica Natuline Ianof, Francisco José Fraga, Leonardo Alves Ferreira, Renato Teodoro Ramos, José Luiz Carlos Demario, Regina Baratho, Luís Fernando Hindi Basile, Ricardo Nitrini, Renato Anghinah
Alzheimer's disease (AD) is a dementia that affects a large contingent of the elderly population characterized by the presence of neurofibrillary tangles and senile plaques. Traumatic brain injury (TBI) is a non-degenerative injury caused by an external mechanical force. One of the main causes of TBI is diffuse axonal injury (DAI), promoted by acceleration-deceleration mechanisms. Objective: To understand the electroencephalographic differences in functional mechanisms between AD and DAI groups...
April 2017: Dementia & Neuropsychologia
https://www.readbyqxmd.com/read/29203678/multiple-oscillatory-rhythms-determine-the-temporal-organization-of-perception
#4
Luca Ronconi, Nikolaas N Oosterhof, Claudia Bonmassar, David Melcher
Incoming sensory input is condensed by our perceptual system to optimally represent and store information. In the temporal domain, this process has been described in terms of temporal windows (TWs) of integration/segregation, in which the phase of ongoing neural oscillations determines whether two stimuli are integrated into a single percept or segregated into separate events. However, TWs can vary substantially, raising the question of whether different TWs map onto unique oscillations or, rather, reflect a single, general fluctuation in cortical excitability (e...
December 4, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/29181883/real-time-fmri-neurofeedback-of-the-mediodorsal-and-anterior-thalamus-enhances-correlation-between-thalamic-bold-activity-and-alpha-eeg-rhythm
#5
Vadim Zotev, Masaya Misaki, Raquel Phillips, Chung Ki Wong, Jerzy Bodurka
Real-time fMRI neurofeedback (rtfMRI-nf) with simultaneous EEG allows volitional modulation of BOLD activity of target brain regions and investigation of related electrophysiological activity. We applied this approach to study correlations between thalamic BOLD activity and alpha EEG rhythm. Healthy volunteers in the experimental group (EG, n = 15) learned to upregulate BOLD activity of the target region consisting of the mediodorsal (MD) and anterior (AN) thalamic nuclei using rtfMRI-nf during retrieval of happy autobiographical memories...
November 27, 2017: Human Brain Mapping
https://www.readbyqxmd.com/read/29181439/rest-activity-circadian-rhythms-and-bone-mineral-density-in-elderly-men
#6
Tara S Rogers, Stephanie Harrison, Christine Swanson, Jane A Cauley, Elizabeth Barrett-Connor, Eric Orwoll, Katie L Stone, Nancy E Lane
Background: Disrupted rest-activity circadian rhythm (RAR) patterns have been associated with poor health outcomes (i.e. diminished cognitive function, increased risk of dementia and falls). Circadian time cues in bone influence the differentiation of osteoblasts and osteoclasts, and bone turnover markers exhibit circadian variation; relationships between bone outcomes and RAR are emerging areas of research. We evaluated associations between RAR and areal bone mineral density (aBMD) at the total hip and femoral neck in older men from the Osteoporotic Fractures in Men (MrOS) cohort...
December 2017: Bone Reports
https://www.readbyqxmd.com/read/29172186/-neural-basis-for-producing-temporal-order
#7
Shigeru Kitazawa
It has been proposed that a position in time can be discriminated in two ways. First, each position is either past, present, or future (A series). Second, each position is either before or after another (B series). In this review, we aim to infer how the two series are represented in the brain on the basis of findings from clinical, neurophysiological, and neuroimaging studies. We suggest that the precuneus and posterior cingulate cortex are critically involved in the A series. In the B series, we suggest that a group of events are represented in space around the intraparietal cortex and are combined with the temporal directional cue provided by the motion signals in the left temporo-parietal junction...
November 2017: Brain and Nerve, Shinkei Kenkyū No Shinpo
https://www.readbyqxmd.com/read/29157006/chronotype-description-in-search-of-a-solid-subjective-amplitude-scale
#8
Halszka Oginska, Justyna Mojsa-Kaja, Olivier Mairesse
The term "subjective circadian amplitude" refers to the range or the distinctness of diurnal variations of arousal, that is, the awareness (or lack thereof) of difference between hyper- and hypo-activation phases, the ability to volitionally modulate one's own psychophysiological state, the strength of morning-evening preferences and flexibility of the rhythm or perceived stability of the circadian phase. The complexity of this construct is the source of difficulties in research and measurement. The psychometric features of distinctness subscales of the Chronotype Questionnaire and the Caen Chronotype Questionnaire are not satisfactory...
November 20, 2017: Chronobiology International
https://www.readbyqxmd.com/read/29153327/auditory-sensitivity-and-decision-criteria-oscillate-at-different-frequencies-separately-for-the-two-ears
#9
Hao Tam Ho, Johahn Leung, David C Burr, David Alais, Maria Concetta Morrone
Many behavioral measures of visual perception fluctuate continually in a rhythmic manner, reflecting the influence of endogenous brain oscillations, particularly theta (∼4-7 Hz) and alpha (∼8-12 Hz) rhythms [1-3]. However, it is unclear whether these oscillations are unique to vision or whether auditory performance also oscillates [4, 5]. Several studies report no oscillatory modulation in audition [6, 7], while those with positive findings suffer from confounds relating to neural entrainment [8-10]. Here, we used a bilateral pitch-identification task to investigate rhythmic fluctuations in auditory performance separately for the two ears and applied signal detection theory (SDT) to test for oscillations of both sensitivity and criterion (changes in decision boundary) [11, 12]...
November 10, 2017: Current Biology: CB
https://www.readbyqxmd.com/read/29142322/bilateral-5%C3%A2-hz-transcranial-alternating-current-stimulation-on-fronto-temporal-areas-modulates-resting-state-eeg
#10
Aurora D'Atri, Claudia Romano, Maurizio Gorgoni, Serena Scarpelli, Valentina Alfonsi, Michele Ferrara, Fabio Ferlazzo, Paolo Maria Rossini, Luigi De Gennaro
Rhythmic non-invasive brain stimulations are promising tools to modulate brain activity by entraining neural oscillations in specific cortical networks. The aim of the study was to assess the possibility to influence the neural circuits of the wake-sleep transition in awake subjects via a bilateral transcranial alternating current stimulation at 5 Hz (θ-tACS) on fronto-temporal areas. 25 healthy volunteers participated in two within-subject sessions (θ-tACS and sham), one week apart and in counterbalanced order...
November 15, 2017: Scientific Reports
https://www.readbyqxmd.com/read/29139226/cortical-nociceptive-processes-are-reduced-by-visual-alpha-band-entrainment-in-the-human-brain
#11
K Ecsy, C A Brown, A K P Jones
BACKGROUND: Acute noxious stimuli induce a suppression of cortical alpha activity, yet little is known about whether increasing alpha activity affects the processing of noxious stimuli. We have previously shown that visual alpha stimulation reduces experimental pain. Here, we demonstrate that increasing alpha power causes a reciprocal suppression of acute nociceptive processing. METHODS: We attempted to increase cortical alpha activity through visual entrainment at 8 Hz, 10 Hz and 12 Hz to investigate the influence on the electrophysiological pain response...
November 14, 2017: European Journal of Pain: EJP
https://www.readbyqxmd.com/read/29133861/coupling-of-oxy-and-deoxyhemoglobin-concentrations-with-eeg-rhythms-during-motor-task
#12
Piotr Lachert, Dariusz Janusek, Przemyslaw Pulawski, Adam Liebert, Daniel Milej, Katarzyna J Blinowska
A relationship between the brain rhythmic activity and the hemodynamic response was studied using the simultaneous measurement of electroencephalogram (EEG) and the functional near-infrared spectroscopy (fNIRS) during a motor task (self-paced right finger movements) for 10 subjects. An EEG recording with a 32-electrode (10-10) system was made and the hemodynamic response was obtained using 8 optodes placed over the sensorimotor cortex on both hemispheres. During the task an increase in oxyhemoglobine (HbO) was accompanied by a decrease in deoxyhemoglobine (HbR) concentration and a decrease in amplitudes (desynchronisation) of alpha (8-13 Hz) and beta (13-30 Hz) EEG rhythms...
November 13, 2017: Scientific Reports
https://www.readbyqxmd.com/read/29133062/anatomical-and-physiological-basis-of-continuous-spike-wave-of-sleep-syndrome-after-early-thalamic-lesions
#13
Alberto Leal, Eulália Calado, José P Vieira, Carla Mendonça, José C Ferreira, Hugo Ferreira, Daniel Carvalho, Fátima Furtado, Roseli Gomes, José P Monteiro
OBJECTIVE: Early neonatal thalamic lesions account for about 14% of continuous spike-wave of sleep (CSWS) syndrome, representing the most common etiology in this epileptic encephalopathy in children, and promise useful insights into the pathophysiology of the disease. METHODS: We describe nine patients with unilateral neonatal thalamic lesions which progressed to CSWS. Longitudinal whole-night and high-density electroencephalograms (EEGs) were performed, as well as detailed imaging and clinical evaluation...
November 10, 2017: Epilepsy & Behavior: E&B
https://www.readbyqxmd.com/read/29132359/portable-wireless-neurofeedback-system-of-eeg-alpha-rhythm-enhances-memory
#14
Ting-Ying Wei, Da-Wei Chang, You-De Liu, Chen-Wei Liu, Chung-Ping Young, Sheng-Fu Liang, Fu-Zen Shaw
BACKGROUND: Effect of neurofeedback training (NFT) on enhancement of cognitive function or amelioration of clinical symptoms is inconclusive. The trainability of brain rhythm using a neurofeedback system is uncertainty because various experimental designs are used in previous studies. The current study aimed to develop a portable wireless NFT system for alpha rhythm and to validate effect of the NFT system on memory with a sham-controlled group. METHODS: The proposed system contained an EEG signal analysis device and a smartphone with wireless Bluetooth low-energy technology...
November 13, 2017: Biomedical Engineering Online
https://www.readbyqxmd.com/read/29128425/using-sweat-to-measure-cytokines-in-older-adults-compared-to-younger-adults-a-pilot-study
#15
Melissa Hladek, Sarah L Szanton, Young-Eun Cho, Chen Lai, Caroline Sacko, Laken Roberts, Jessica Gill
BACKGROUND/OBJECTIVES: Current measures of cytokines involve urine, blood or saliva which have drawbacks including circadian rhythm variations and complicated collection methods. Sweat has been used to measure cytokines in young and middle-aged adults, but not older adults. We sought to determine the feasibility of using sweat to measure cytokines in older adults compared to younger adults. DESIGN: Two visit cross-sectional pilot study stratified by age group. SETTING: Independent living facility and Johns Hopkins University both in Maryland...
November 8, 2017: Journal of Immunological Methods
https://www.readbyqxmd.com/read/29127449/determining-a-threshold-sub-acute-dose-leading-to-minimal-physiological-alterations-following-prolonged-exposure-to-the-nerve-agent-vx-in-rats
#16
E Bloch-Shilderman, I Rabinovitz, I Egoz, G Yacov, N Allon, U Nili
VX, a potent inhibitor of cholinesterase (ChE), is considered as one of the most toxic, persistent and least volatile nerve agents. VX is absorbed in various environmental surfaces and is gradually released long after its initial dispersal. Its toxicity is mainly caused by disrupting central and peripheral cholinergic nervous system activity, leading to potential long-term detrimental effects on health. The primary objective of the present study was to assess the threshold VX dose leading to minimal physiological alterations following prolonged VX exposure...
November 10, 2017: Archives of Toxicology
https://www.readbyqxmd.com/read/29124547/online-reduction-of-artifacts-in-eeg-of-simultaneous-eeg-fmri-using-reference-layer-adaptive-filtering-rlaf
#17
David Steyrl, Gunther Krausz, Karl Koschutnig, Günter Edlinger, Gernot R Müller-Putz
Simultaneous electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) allow us to study the active human brain from two perspectives concurrently. Signal processing based artifact reduction techniques are mandatory for this, however, to obtain reasonable EEG quality in simultaneous EEG-fMRI. Current artifact reduction techniques like average artifact subtraction (AAS), typically become less effective when artifact reduction has to be performed on-the-fly. We thus present and evaluate a new technique to improve EEG quality online...
November 9, 2017: Brain Topography
https://www.readbyqxmd.com/read/29121108/spatio-temporal-dynamics-of-multimodal-eeg-fnirs-signals-in-the-loss-and-recovery-of-consciousness-under-sedation-using-midazolam-and-propofol
#18
Seul-Ki Yeom, Dong-Ok Won, Seong In Chi, Kwang-Suk Seo, Hyun Jeong Kim, Klaus-Robert Müller, Seong-Whan Lee
On sedation motivated by the clinical needs for safety and reliability, recent studies have attempted to identify brain-specific signatures for tracking patient transition into and out of consciousness, but the differences in neurophysiological effects between 1) the sedative types and 2) the presence/absence of surgical stimulations still remain unclear. Here we used multimodal electroencephalography-functional near-infrared spectroscopy (EEG-fNIRS) measurements to observe electrical and hemodynamic responses during sedation simultaneously...
2017: PloS One
https://www.readbyqxmd.com/read/29108940/cortical-layers-rhythms-and-bold-signals
#19
REVIEW
René Scheeringa, Pascal Fries
This review investigates how laminar fMRI can complement insights into brain function derived from the study of rhythmic neuronal synchronization. Neuronal synchronization in various frequency bands plays an important role in neuronal communication between brain areas, and it does so on the backbone of layer-specific interareal anatomical projections. Feedforward projections originate predominantly in supragranular cortical layers and terminate in layer 4, and this pattern is reflected in inter-laminar and interareal directed gamma-band influences...
November 3, 2017: NeuroImage
https://www.readbyqxmd.com/read/29073146/unified-thalamic-model-generates-multiple-distinct-oscillations-with-state-dependent-entrainment-by-stimulation
#20
Guoshi Li, Craig S Henriquez, Flavio Fröhlich
The thalamus plays a critical role in the genesis of thalamocortical oscillations, yet the underlying mechanisms remain elusive. To understand whether the isolated thalamus can generate multiple distinct oscillations, we developed a biophysical thalamic model to test the hypothesis that generation of and transition between distinct thalamic oscillations can be explained as a function of neuromodulation by acetylcholine (ACh) and norepinephrine (NE) and afferent synaptic excitation. Indeed, the model exhibited four distinct thalamic rhythms (delta, sleep spindle, alpha and gamma oscillations) that span the physiological states corresponding to different arousal levels from deep sleep to focused attention...
October 2017: PLoS Computational Biology
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