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theta rhythm

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
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
Robert M G Reinhart
Rescuing executive functions in people with neurological and neuropsychiatric disorders has been a major goal of psychology and neuroscience for decades. Innovative computer-training regimes for executive functions have made tremendous inroads, yet the positive effects of training have not always translated into improved cognitive functioning and often take many days to emerge. In the present study, we asked whether it was possible to immediately change components of executive function by directly manipulating neural activity using a stimulation technology called high-definition transcranial alternating current stimulation (HD-tACS)...
October 24, 2017: Proceedings of the National Academy of Sciences of the United States of America
Brian J Gereke, Alexandra J Mably, Laura Lee Colgin
CA1 place cells become more anticipatory with experience, an effect thought to be caused by NMDA receptor-dependent plasticity in the CA3-CA1 network. Theta (~5-12 Hz), slow gamma (~25-50 Hz), and fast gamma (~50-100 Hz) rhythms are thought to route spatial information in the hippocampal formation and to coordinate place cell ensembles. Yet, it is unknown whether these rhythms exhibit experience-dependent changes concurrent with those observed in place cells. Slow gamma rhythms are thought to indicate inputs from CA3 to CA1, and such inputs are thought to be strengthened with experience...
October 25, 2017: Journal of Neurophysiology
Sam C Berens, Aidan J Horner
The low frequency theta rhythm is thought to promote the formation of long-term multimodal memories in the hippocampus by orchestrating input from multiple cortical sources. New research has demonstrated a causal association between the timing of experimentally induced theta rhythms and episodic memory formation in humans.
October 23, 2017: Current Biology: CB
Manling Ge, Jundan Guo, Yangyang Xing, Zhiguo Feng, Weide Lu, Xinxin Ma, Yuehua Geng, Xin Zhang
The inhibitory impacts of spikes on LFP theta rhythms(4-8Hz) are investigated around sporadic spikes(SSs) based on intracerebral EEG of 4 REM sleep patients with temporal lobe epilepsy(TLE) under the pre-surgical monitoring. Sequential interictal spikes in both genesis area and extended propagation pathway are collected, that, SSs genesis only in anterior hippocampus(aH)(possible propagation pathway in Entorhinal cortex(EC)), only in EC(possible propagation pathway in aH), and in both aH and EC synchronously...
July 2017: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
S Schulz, B Legorburu Cladera, B Giraldo, M Bolz, K J Bar, A Voss
Synchronization is a central key feature of neural information processing and communication between different brain areas. Disturbance of oscillatory brain rhythms and decreased synchronization have been associated with different disorders including schizophrenia. The aim of this study was to investigate whether synchronization (in relaxed conditions with no stimuli) between different brain areas within the delta, theta, alpha (alpha1, alpha2), beta (beta1, beta2), and gamma bands is altered in patients with a neurological disorder in order to generate significant cortical enhancements...
July 2017: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
Y Shoji, C R Patti, D Cvetkovic
Retrieval of positive Autobiographical Memory (AM) has been reported to increase positive emotions in healthy population. Evidence suggests that positive AM retrieval tasks are correlated with synchronisation of frontal Theta rhythms (4-8Hz). The present study has developed the Electroencephalography (EEG) based Neurofeedback (NF) protocols to promote voluntary elevation or up-regulation of positive AM retrieval related Theta rhythms over F3, Fz, F4 electrode sites (10-20 System). The protocols were evaluated with a human participant in 10-day NF training...
July 2017: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
Antonio Diaz-Parra, Santiago Canals, David Moratal
Identification of brain states measured with electrophysiological methods such as electroencephalography and local field potential (LFP) recordings is of great importance in numerous neuroscientific applications. For instance, in Brain Computer Interface, in the diagnosis of neurological disorders as well as to investigate how brain rhythms stem from synchronized physiological mechanisms (e.g., memory and learning). In this work, we propose a fully automated method with the aim of partitioning LFP signals into stationary segments as well as classifying each detected segment into three different classes (delta, regular theta or irregular theta rhythms)...
July 2017: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
José R Castro Conde, Desiré González Barrios, Candelaria González Campo, Nieves L González González, Beatriz Reyes Millán, Alejandro Jiménez Sosa
BACKGROUND: What constitutes a "normal" background electroencephalography (EEG) rhythm immediately after birth is not well understood. We performed video-electroencephalography recordings in the first six hours (first measure) and the third day of life (second measure) for evidence of transient changes in brain function. METHODS: We performed a cohort study of an incidental sample of healthy term neonates in a single-center nursery. Main outcome measures were as follows: (1) EEG visual analysis, which included sleep-wake cycles, proportions of discontinuity and bursts with delta brushes, and number per hour of alpha/theta rolandic activity, encoches frontales, and transients; and (2) the electroencephalographic spectral analysis, which included power spectrum in the following frequency bands: delta, 0...
May 4, 2017: Pediatric Neurology
Marian Tsanov
Anatomical differences between the medial and lateral septum have associated these nuclei with dissimilar functional roles and behaviors. While the medial septum has been implicated, predominantly, in theta rhythm generation along the septo-hippocampal axis, the lateral septum has mainly been investigated in the context of septo-hypothalamic dialogue. Recent advances suggest that medial and lateral septum are more closely functionally-related than previously appreciated. Here, we explore the hypothesis that the medial septum mediates ascending septo-hippocampal theta propagation, while the lateral septum processes a descending hippocampo-septal and septo-hypothalamic reinforcement signal that mediates navigation during motivated behavior...
October 17, 2017: European Journal of Neuroscience
Yongzhi Huang, Alexander L Green, Jonathan Hyam, James Fitzgerald, Tipu Z Aziz, Shouyan Wang
OBJECTIVE: Understanding the function of sensory thalamic neural activity is essential for developing and improving interventions for neuropathic pain. However, there is a lack of investigation of the relationship between sensory thalamic oscillations and pain relief in patients with neuropathic pain. This study aims to identify the oscillatory neural characteristics correlated with pain relief induced by deep brain stimulation (DBS), and develop a quantitative model to predict pain relief by integrating characteristic measures of the neural oscillations...
October 13, 2017: Neurobiology of Disease
Airui Chen, Aijun Wang, Tianqi Wang, Xiaoyu Tang, Ming Zhang
The spotlight of attention is full of discrete moments and operates periodically. Recently, it has been well-documented there were behavioral oscillations in visual attention, however, different periodicities were demonstrated. Task difficulty may be an important factor causing disagreement in attentional periodic patterns. The present study examined behavioral oscillations in visual attention during difficult and easy tasks. A modified high temporal resolution cue-target paradigm in which the cue-target stimulus onset asynchrony (SOAs) varied from 0...
2017: Frontiers in Psychology
Miles Wischnewski, Dennis J L G Schutter
OBJECTIVE: Phase synchronization is suggested to be among the mechanisms that can explain the effects of transcranial alternating current stimulation (tACS). However, little is known about the effects of tACS on event-related oscillatory activity. Therefore the objective was to investigate frequency-related effects of frontal tACS on event-related oscillatory power. METHODS: In a double blind randomized controlled cross-over design, twenty-four participants received 12min of delta (2...
September 21, 2017: Clinical Neurophysiology: Official Journal of the International Federation of Clinical Neurophysiology
Kensuke Arai, Robert E Kass
Oscillations are observed at various frequency bands in continuous-valued neural recordings like the electroencephalogram (EEG) and local field potential (LFP) in bulk brain matter, and analysis of spike-field coherence reveals that spiking of single neurons often occurs at certain phases of the global oscillation. Oscillatory modulation has been examined in relation to continuous-valued oscillatory signals, and independently from the spike train alone, but behavior or stimulus triggered firing-rate modulation, spiking sparseness, presence of slow modulation not locked to stimuli and irregular oscillations with large variability in oscillatory periods, present challenges to searching for temporal structures present in the spike train...
October 2017: PLoS Computational Biology
Marian Tsanov
Several cortical and diencephalic limbic brain regions incorporate neurons that fire in correlation with the speed of whole-body motion, also known as linear velocity. Besides the field mapping and head-directional information, the linear velocity is among the major signals that guide animal's spatial navigation. Large neuronal populations in the same limbic regions oscillate with theta rhythm during spatial navigation or attention episodes; and the frequency of theta also correlates with linear velocity. A functional similarity between these brain areas is that their inactivation impairs the ability to form new spatial memories; whereas an anatomical similarity is that they all receive projections from medial septum-diagonal band of Broca complex...
2017: Frontiers in Systems Neuroscience
Linda M Amarante, Marcelo S Caetano, Mark Laubach
Rodents lick to consume fluids. The reward value of ingested fluids is likely to be encoded by neuronal activity entrained to the lick cycle. Here, we investigated relationships between licking and reward signaling by the medial frontal cortex (MFC), a key cortical region for reward-guided learning and decision-making. Multielectrode recordings of spike activity and field potentials were made in male rats as they performed an incentive contrast licking task. Rats received access to higher- and lower-value sucrose rewards over alternating 30 s periods...
November 1, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Laetitia Lalla, Pavel E Rueda Orozco, Maria-Teresa Jurado-Parras, Andrea Brovelli, David Robbe
In the cortex and hippocampus, neuronal oscillations of different frequencies can be observed in local field potentials (LFPs). LFPs oscillations in the theta band (6-10 Hz) have also been observed in the dorsolateral striatum (DLS) of rodents, mostly during locomotion, and have been proposed to mediate behaviorally-relevant interactions between striatum and cortex (or between striatum and hippocampus). However, it is unclear if these theta oscillations are generated in the striatum. To address this issue, we recorded LFPs and spiking activity in the DLS of rats performing a running sequence on a motorized treadmill...
September 2017: ENeuro
Mohammed Z Ariffin, Chian-Ming Low, Sanjay Khanna
Cholinergic mechanisms in supramammillary nucleus (SuM), especially the lateral SuM (lSuM) modulates septo-hippocampal neural activity. The lSuM, as compared to the contiguous medial SuM (mSuM) has relatively dense projections to hippocampus and cingulate cortex (Cg). In the present study, we have investigated whether the effects of cholinergic activation of SuM on hippocampal and cortical neural activities involve a cooperative interaction with the medial septum (MS). Microinjection of the broad-spectrum cholinergic agonist, carbachol, or the cholinergic-nicotinic receptor agonist, nicotine, into the lSuM and the mSuM in urethane anesthetized rat evoked a similar pattern of hippocampal theta rhythm...
2017: Frontiers in Neuroanatomy
Vasily Grigorovsky, Berj L Bardakjian
OBJECTIVE: One of the features used in the study of hyperexcitablility are high frequency oscillations (HFOs, >80Hz). HFOs have been reported in the electrical rhythms of the brain's neuro-glial networks under physiological and pathological conditions. Cross-frequency coupling (CFC) of HFOs with low frequency rhythms was used to identify pathologic HFOs (pHFOs) (i) in the epileptogenic zones of epileptic patients, and (ii) as a biomarker for the severity of seizure-like events in genetically modified rodent models...
September 28, 2017: IEEE Transactions on Bio-medical Engineering
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