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Gamma rhythm

Magdalena Martinez-Losa, Tara E Tracy, Keran Ma, Laure Verret, Alexandra Clemente-Perez, Abdullah S Khan, Inma Cobos, Kaitlyn Ho, Li Gan, Lennart Mucke, Manuel Alvarez-Dolado, Jorge J Palop
Inhibitory interneurons regulate the oscillatory rhythms and network synchrony that are required for cognitive functions and disrupted in Alzheimer's disease (AD). Network dysrhythmias in AD and multiple neuropsychiatric disorders are associated with hypofunction of Nav1.1, a voltage-gated sodium channel subunit predominantly expressed in interneurons. We show that Nav1.1-overexpressing, but not wild-type, interneuron transplants derived from the embryonic medial ganglionic eminence (MGE) enhance behavior-dependent gamma oscillatory activity, reduce network hypersynchrony, and improve cognitive functions in human amyloid precursor protein (hAPP)-transgenic mice, which simulate key aspects of AD...
March 15, 2018: Neuron
Kilmer S McCully
The indoleamine hormone melatonin is synthesized by the pineal gland, controls circadian rhythm, and is dependent upon adenosyl methionine for enzymatic synthesis of melatonin from N-acetyl serotonin. Pineal melatonin secretion declines dramatically with aging and dementia. Elevated plasma homocysteine is a risk factor for atherosclerosis and Alzheimer's disease, and the marked decline in adenosyl methionine with aging leads to dysregulation of methionine metabolism and hyperhomocysteinemia. Thioretinaco ozonide is a disulfonium complex formed from thioretinamide, cobalamin, and ozone, which binds the alpha and gamma-phosphate groups of adenosine triphosphate (ATP) and oxygen in the process of oxidative phosphorylation within mitochondria...
January 2018: Annals of Clinical and Laboratory Science
Ravi V Chacko, Byungchan Kim, Suh Woo Jung, Amy L Daitch, Jarod L Roland, Nicholas V Metcalf, Maurizio Corbetta, Gordon L Shulman, Eric C Leuthardt
Spatial attention is the cognitive function that coordinates the selection of visual stimuli with appropriate behavioral responses. Recent studies have reported that phase-amplitude coupling (PAC) of low and high frequencies covaries with spatial attention, but differ on the direction of covariation and the frequency ranges involved. We hypothesized that distinct phase-amplitude frequency pairs have differentiable contributions during tasks that manipulate spatial attention. We investigated this hypothesis with electrocorticography (ECoG) recordings from participants who engaged in a cued spatial attention task...
March 5, 2018: NeuroImage
S Khan, J A Hashmi, F Mamashli, K Michmizos, M G Kitzbichler, H Bharadwaj, Y Bekhti, S Ganesan, K A Garel, S Whitfield-Gabrieli, R L Gollub, J Kong, L M Vaina, K D Rana, S S Stufflebeam, M S Hämäläinen, T Kenet
The functional significance of resting state networks and their abnormal manifestations in psychiatric disorders are firmly established, as is the importance of the cortical rhythms in mediating these networks. Resting state networks are known to undergo substantial reorganization from childhood to adulthood, but whether distinct cortical rhythms, which are generated by separable neural mechanisms and are often manifested abnormally in psychiatric conditions, mediate maturation differentially, remains unknown...
February 17, 2018: NeuroImage
José R Donoso, Dietmar Schmitz, Nikolaus Maier, Richard Kempter
Hippocampal ripples are involved in memory consolidation, but the mechanisms underlying their generation remain unclear. Models relying on interneuron networks in the CA1 region disagree on the predominant source of excitation to interneurons: either 'direct', via the Schaffer collaterals that provide feedforward input from CA3 to CA1, or 'indirect', via the local pyramidal cells in CA1, which are embedded in a recurrent excitatory-inhibitory network. Here, we used physiologically constrained computational models of basket-cell networks to investigate how they respond to different conditions of transient, noisy excitation...
February 16, 2018: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Akihiko Akao, Yutaro Ogawa, Yasuhiko Jimbo, G Bard Ermentrout, Kiyoshi Kotani
Gamma oscillations are thought to play an important role in brain function. Interneuron gamma (ING) and pyramidal interneuron gamma (PING) mechanisms have been proposed as generation mechanisms for these oscillations. However, the relation between the generation mechanisms and the dynamical properties of the gamma oscillation are still unclear. Among the dynamical properties of the gamma oscillation, the phase response function (PRF) is important because it encodes the response of the oscillation to inputs...
January 2018: Physical Review. E
Claudio Babiloni, Claudio Del Percio, Roberta Lizio, Giuseppe Noce, Susanna Lopez, Andrea Soricelli, Raffaele Ferri, Maria Teresa Pascarelli, Valentina Catania, Flavio Nobili, Dario Arnaldi, Francesco Famà, Dag Aarsland, Francesco Orzi, Carla Buttinelli, Franco Giubilei, Marco Onofrj, Fabrizio Stocchi, Laura Vacca, Paola Stirpe, Peter Fuhr, Ute Gschwandtner, Gerhard Ransmayr, Heinrich Garn, Lucia Fraioli, Michela Pievani, Giovanni B Frisoni, Fabrizia D'Antonio, Carlo De Lena, Bahar Güntekin, Lutfu Hanoğlu, Erol Başar, Görsev Yener, Derya Durusu Emek-Savaş, Antonio Ivano Triggiani, Raffaella Franciotti, John Paul Taylor, Maria Francesca De Pandis, Laura Bonanni
The present study tested the hypothesis that cortical sources of resting state eyes-closed electroencephalographic (rsEEG) rhythms reveal different abnormalities in cortical neural synchronization in groups of patients with mild cognitive impairment due to Alzheimer's disease (ADMCI) and dementia with Lewy bodies (DLBMCI) as compared to cognitively normal elderly (Nold) subjects. Clinical and rsEEG data in 30 ADMCI, 23 DLBMCI, and 30 Nold subjects were available in an international archive. Age, gender, and education were carefully matched in the three groups...
2018: Journal of Alzheimer's Disease: JAD
Adriano B L Tort, Jurij Brankačk, Andreas Draguhn
We revisit recent evidence showing that nasal respiration entrains oscillations at the same frequency as breathing in several regions of the rodent brain. Moreover, respiration modulates the amplitude of a specific gamma sub-band (70-120Hz), most prominently in frontal regions. Since rodents often breathe at delta and theta frequencies, we caution that previous studies on delta and theta power and their cross-regional synchrony, as well as on delta-gamma and theta-gamma coupling, may have detected the respiration-entrained rhythm and respiration-gamma coupling...
February 8, 2018: Trends in Neurosciences
Carlos Perez, Ghanim Ullah
Beta amyloid (A[Formula: see text] ) associated with Alzheimer's disease (AD) leads to abnormal behavior in inhibitory neurons, resulting in hyperactive neuronal networks, epileptiform behavior, disrupted gamma rhythms, and aberrant synaptic plasticity. Previously, we used a dual modeling-experimental approach to explain several observations, including failure to reliably produce action potentials (APs), smaller AP amplitudes, higher resting membrane potential, and higher membrane depolarization in response to a range of stimuli in hippocampal inhibitory neurons from 12- to 16-month-old female AP Pswe/PSEN1DeltaE9 (APdE9) AD mice as compared to age-matched non-transgenic (NTG) mice...
February 9, 2018: European Biophysics Journal: EBJ
Alon Amir, Drew B Headley, Seung-Chan Lee, Darrell Haufler, Denis Paré
Principal basolateral amygdala (BL) neurons profoundly influence motivated behaviors, yet few of them are activated by emotionally valenced stimuli. Here, we show that a likely explanation for this paradox is the synchronizing influence of the high-gamma rhythm. High-gamma (75-95 Hz) entrained BL firing more strongly than all other rhythms. It was most pronounced during states of increased vigilance, when rats were apprehensive. Relative to behavioral states, high-gamma produced minor changes in firing rates yet dramatic increases in synchrony...
February 7, 2018: Neuron
Claudio Babiloni, Claudio Del Percio, Roberta Lizio, Giuseppe Noce, Susanna Lopez, Andrea Soricelli, Raffaele Ferri, Flavio Nobili, Dario Arnaldi, Francesco Famà, Dag Aarsland, Francesco Orzi, Carla Buttinelli, Franco Giubilei, Marco Onofrj, Fabrizio Stocchi, Paola Stirpe, Peter Fuhr, Ute Gschwandtner, Gerhard Ransmayr, Heinrich Garn, Lucia Fraioli, Michela Pievani, Giovanni B Frisoni, Fabrizia D'Antonio, Carlo De Lena, Bahar Güntekin, Lutfu Hanoğlu, Erol Başar, Görsev Yener, Derya Durusu Emek-Savaş, Antonio Ivano Triggiani, Raffaella Franciotti, John Paul Taylor, Laura Vacca, Maria Francesca De Pandis, Laura Bonanni
Previous evidence showed abnormal posterior sources of resting-state delta (<4 Hz) and alpha (8-12 Hz) rhythms in patients with Alzheimer's disease with dementia (ADD), Parkinson's disease with dementia (PDD), and Lewy body dementia (DLB), as cortical neural synchronization markers in quiet wakefulness. Here, we tested the hypothesis of additional abnormalities in functional cortical connectivity computed in those sources, in ADD, considered as a "disconnection cortical syndrome", in comparison with PDD and DLB...
December 30, 2017: Neurobiology of Aging
Andreas Wutz, Roman Loonis, Jefferson E Roy, Jacob A Donoghue, Earl K Miller
Categories can be grouped by shared sensory attributes (i.e., cats) or a more abstract rule (i.e., animals). We explored the neural basis of abstraction by recording from multi-electrode arrays in prefrontal cortex (PFC) while monkeys performed a dot-pattern categorization task. Category abstraction was varied by the degree of exemplar distortion from the prototype pattern. Different dynamics in different PFC regions processed different levels of category abstraction. Bottom-up dynamics (stimulus-locked gamma power and spiking) in the ventral PFC processed more low-level abstractions, whereas top-down dynamics (beta power and beta spike-LFP coherence) in the dorsal PFC processed more high-level abstractions...
January 26, 2018: Neuron
Jonathan Levy, Abraham Goldstein, Maayan Pratt, Ruth Feldman
While empathy to the pain of conspecific is evolutionary-ancient and is observed in rodents and in primates, it also integrates higher-order affective representations. Yet, it is unclear whether human empathy for pain is inborn or matures during development and what neural processes underpin its maturation. Using magnetoencephalography, we monitored the brain response of children, adolescents, and adults (n = 209) to others' pain, testing the shift from childhood to adult functioning. Results indicate that children's vicarious empathy for pain operates via rudimentary sensory predictions involving alpha oscillations in somatosensory cortex, while adults' response recruits advanced mechanisms of updating sensory predictions and activating affective empathy in viceromotor cortex via higher-level representations involving beta- and gamma-band activity...
January 29, 2018: Scientific Reports
Timothy Owen West, Luc Berthouze, David M Halliday, Vladimir Litvak, Andrew Sharott, Peter J Magill, Simon F Farmer
Much of the motor impairment associated with Parkinson's disease is thought to arise from pathological activity in the networks formed by the basal ganglia (BG) and motor cortex. To evaluate several hypotheses proposed to explain the emergence of pathological oscillations in Parkinsonism, we investigated changes to the directed connectivity in BG networks following dopamine depletion. We recorded local field potentials (LFPs) in the cortex and basal ganglia of rats rendered Parkinsonian by injection of 6-hydroxydopamine (6-OHDA) and in dopamine-intact controls...
January 10, 2018: Journal of Neurophysiology
André M Bastos, Roman Loonis, Simon Kornblith, Mikael Lundqvist, Earl K Miller
All of the cerebral cortex has some degree of laminar organization. These different layers are composed of neurons with distinct connectivity patterns, embryonic origins, and molecular profiles. There are little data on the laminar specificity of cognitive functions in the frontal cortex, however. We recorded neuronal spiking/local field potentials (LFPs) using laminar probes in the frontal cortex (PMd, 8A, 8B, SMA/ACC, DLPFC, and VLPFC) of monkeys performing working memory (WM) tasks. LFP power in the gamma band (50-250 Hz) was strongest in superficial layers, and LFP power in the alpha/beta band (4-22 Hz) was strongest in deep layers...
January 16, 2018: Proceedings of the National Academy of Sciences of the United States of America
Pejman Memar, Farhad Faradji
Sleep stage classification is one of the most critical steps in effective diagnosis and the treatment of sleep-related disorders. Visual inspection undertaken by sleep experts is a time-consuming and burdensome task. A computer-assisted sleep stage classification system is thus essential for both sleep-related disorders diagnosis and sleep monitoring. In this paper, we propose a system to classify the wake and sleep stages with high rates of sensitivity and specificity. The EEG signals of 25 subjects with suspected sleep-disordered breathing, and the EEG signals of 20 healthy subjects from three data sets are used...
January 2018: IEEE Transactions on Neural Systems and Rehabilitation Engineering
Gabriel Amador de Lara, Ivan Alekseichuk, Zsolt Turi, Albert Lehr, Andrea Antal, Walter Paulus
BACKGROUND: Phase-amplitude cross-frequency coupling (PAC) is characterized by the modulation of the power of a fast brain oscillation (e.g., gamma) by the phase of a slow rhythm (e.g., theta). PAC in different sub- and neocortical regions is known to underlie effective neural communication and correlates with successful long-term memory formation. OBJECTIVE/HYPOTHESIS: The present work aims to extend earlier observational data, by probing the functional role of theta-gamma PAC in the left temporal cortex in humans during verbal long-term memory encoding...
December 25, 2017: Brain Stimulation
Hillel Adesnik
Rhythmic activity can synchronize neural ensembles within and across cortical layers. While gamma band rhythmicity has been observed in all layers, the laminar sources and functional impacts of neuronal synchronization in the cortex remain incompletely understood. Here, layer-specific optogenetic stimulation demonstrates that populations of excitatory neurons in any cortical layer of the mouse's primary visual cortex are sufficient to powerfully entrain neuronal oscillations in the gamma band. Within each layer, inhibition balances excitation and keeps activity in check...
January 5, 2018: Journal of Physiology
Leonel Perez-Atencio, Nicolas Garcia-Aracil, Eduardo Fernandez, Luis C Barrio, Juan A Barios
Behavioral states alternate between wakefulness (wk), rapid eye movement (rem) and non-rem (nrem) sleep at time scale of hours i.e., light and dark cycle rhythms and from several tens of minutes to seconds (i.e., brief awakenings during sleep). Using statistical analysis of bout duration, Markov chains of sleep-wk dynamics and quantitative EEG analysis, we evaluated the influence of light/dark (ld) changes on brain function along the sleep-wk cycle. Bout duration (bd) histograms and Kaplan-Meier (km) survival curves of wk showed a bimodal statistical distribution, suggesting that two types of wk do exist: brief-wk (wkb) and long-wk (wkl)...
2018: PloS One
Omid Talakoub, Raquel R Paiva, Matija Milosevic, Marcelo Q Hoexter, Ruth Franco, Eduardo Alho, Jessie Navarro, José F Pereira, Milos R Popovic, Cary Savage, Antonio C Lopes, Pedro Alvarenga, Durval Damiani, Manoel J Teixeira, Euripides C Miguel, Erich T Fonoff, Marcelo C Batistuzzo, Clement Hamani
Lateral hypothalamic area (LHA) local field potentials (LFPs) were recorded in a Prader-Willi patient undergoing deep brain stimulation (DBS) for obesity. During hunger, exposure to food-related cues induced an increase in beta/low-gamma activity. In contrast, recordings during satiety were marked by prominent alpha rhythms. Based on these findings, we have delivered alpha-frequency DBS prior to and during food intake. Despite reporting an early sensation of fullness, the patient continued to crave food. This suggests that the pattern of activity in LHA may indicate hunger/satiety states in humans but attest to the complexity of conducting neuromodulation studies in obesity...
December 2017: Annals of Clinical and Translational Neurology
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