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gamma oscillations

Rachael L Sumner, Rebecca L McMilllan, Alexander D Shaw, Krish D Singh, Fred Sundram, Suresh D Muthukumaraswamy
Fluctuations in gonadal hormones over the course of the menstrual cycle are known to cause functional brain changes and are thought to modulate changes in the balance of cortical excitation and inhibition. Animal research has shown this occurs primarily via the major metabolite of progesterone, allopregnanolone, and its action as a positive allosteric modulator of the GABAA receptor. Our study used EEG to record gamma oscillations induced in the visual cortex using stationary and moving gratings. Recordings took place during twenty females' mid-luteal phase when progesterone and estradiol are highest, and early follicular phase when progesterone and estradiol are lowest...
April 17, 2018: Human Brain Mapping
Adam T Brockett, Gary A Kane, Patrick K Monari, Brandy A Briones, Pierre-Antoine Vigneron, Gabriela A Barber, Andres Bermudez, Uma Dieffenbach, Alexander D Kloth, Timothy J Buschman, Elizabeth Gould
The medial prefrontal cortex (mPFC) is important for cognitive flexibility, the ability to switch between two task-relevant dimensions. Changes in neuronal oscillations and alterations in the coupling across frequency ranges have been correlated with attention and cognitive flexibility. Here we show that astrocytes in the mPFC of adult male Sprague Dawley rats, participate in cognitive flexibility through the astrocyte-specific Ca2+ binding protein S100β, which improves cognitive flexibility and increases phase amplitude coupling between theta and gamma oscillations...
2018: PloS One
Darrin J Lee, Edwin Kulubya, Philippe Goldin, Amir Goodarzi, Fady Girgis
Objective: Meditation is one type of mental training that has been shown to produce many cognitive benefits. Meditation practice is associated with improvement in concentration and reduction of stress, depression, and anxiety symptoms. Furthermore, different forms of meditation training are now being used as interventions for a variety of psychological and somatic illnesses. These benefits are thought to occur as a result of neurophysiologic changes. The most commonly studied specific meditation practices are focused attention (FA), open-monitoring (OM), as well as transcendental meditation (TM), and loving-kindness (LK) meditation...
2018: Frontiers in Neuroscience
Malte Wöstmann, Johannes Vosskuhl, Jonas Obleser, Christoph S Herrmann
BACKGROUND: Spatial attention relatively increases the power of neural 10-Hz alpha oscillations in the hemisphere ipsilateral to attention, and decreases alpha power in the contralateral hemisphere. For gamma oscillations (>40 Hz), the opposite effect has been observed. The functional roles of lateralised oscillations for attention are currently unclear. HYPOTHESIS: If lateralised oscillations are functionally relevant for attention, transcranial stimulation of alpha versus gamma oscillations in one hemisphere should differentially modulate the accuracy of spatial attention to the ipsi-versus contralateral side...
April 6, 2018: Brain Stimulation
Thomas J Reilly, Judith F Nottage, Erich Studerus, Grazia Rutigliano, Andrea I De Micheli, Paolo Fusar-Poli, Philip McGuire
Abnormal gamma oscillations, measured by electroencephalography (EEG), have been associated with chronic psychotic disorders, but their prevalence in the early phase of psychosis is less clear. We sought to address this issues by systematically reviewing the relevant literature. We searched for EEG studies of gamma band oscillations in subjects at high risk for psychosis and in patients with first episode psychosis. The following measures of gamma oscillations were extracted: resting power, evoked power, induced power, connectivity and peak frequency...
April 12, 2018: Neuroscience and Biobehavioral Reviews
Yixuan Ku
Selective attention and working memory are inter-dependent core cognitive functions. It is critical to allocate attention on selected targets during the capacity-limited working memory processes to fulfill the goal-directed behavior. The trends of research on both topics are increasing exponentially in recent years, and it is considered that selective attention and working memory share similar underlying neural mechanisms. Different types of attention orientation in working memory are introduced by distinctive cues, and the means using retrospective cues are strengthened currently as it is manipulating the representation in memory, instead of the perceptual representation...
2018: PeerJ
Petia Popova, Brigitte Rockstroh, Gregory A Miller, Christian Wienbruch, Almut M Carolus, Tzvetan Popov
Schizophrenia patients exhibit less gamma-frequency EEG/MEG activity (>30 Hz), a finding interpreted as evidence of poor temporal neural organization and functional network communication. Research has shown that neuroplasticity-oriented training can improve task-related oscillatory dynamics, indicating some reorganization capacity in schizophrenia. Demonstrating a generalization of such task training effects to spontaneous oscillations at rest would not only enrich understanding of this neuroplastic potential but inform the interpretation of spontaneous gamma oscillations in the service of normal cognitive function...
April 6, 2018: Psychophysiology
Tim James Viney, Minas Salib, Abhilasha Joshi, Gunes Unal, Naomi Berry, Peter Somogyi
Rhythmic theta frequency (~5-12 Hz) oscillations coordinate neuronal synchrony and higher frequency oscillations across the cortex. Spatial navigation and context-dependent episodic memories are represented in several interconnected regions including the hippocampal and entorhinal cortices, but the cellular mechanisms for their dynamic coupling remain to be defined. Using monosynaptically-restricted retrograde viral tracing in mice, we identified a subcortical GABAergic input from the medial septum that terminated in the entorhinal cortex, with collaterals innervating the dorsal presubiculum...
April 5, 2018: ELife
Attila Korik, Ronen Sosnik, Nazmul Siddique, Damien Coyle
Objective: To date, motion trajectory prediction (MTP) of a limb from non-invasive electroencephalography (EEG) has relied, primarily, on band-pass filtered samples of EEG potentials i.e., the potential time-series model. Most MTP studies involve decoding 2D and 3D arm movements i.e., executed arm movements. Decoding of observed or imagined 3D movements has been demonstrated with limited success and only reported in a few studies. MTP studies normally use EEG potentials filtered in the low delta (~1 Hz) band for reconstructing the trajectory of an executed or an imagined/observed movement...
2018: Frontiers in Neuroscience
Giulia Borghini, Michela Candini, Cristina Filannino, Masud Hussain, Vincent Walsh, Vincenzo Romei, Nahid Zokaei, Marinella Cappelletti
Ageing adults typically show reduced ability to ignore task-irrelevant information, an essential skill for optimal performance in many cognitive operations, including those requiring working memory (WM) resources. In a first experiment, young and elderly human participants of both genders performed an established WM paradigm probing inhibitory abilities by means of valid, invalid and neutral retro-cues. Elderly participants showed an overall cost, especially in performing invalid trials while youngers' general performance was comparatively higher, as expected...
April 3, 2018: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Andrea Guerra, Antonio Suppa, Matteo Bologna, Valentina D'Onofrio, Edoardo Bianchini, Peter Brown, Vincenzo Di Lazzaro, Alfredo Berardelli
BACKGROUND: Transcranial Alternating Current Stimulation (tACS) consists in delivering electric current to the brain using an oscillatory pattern that may entrain the rhythmic activity of cortical neurons. When delivered at gamma frequency, tACS modulates motor performance and GABA-A-ergic interneuron activity. OBJECTIVE: Since interneuronal discharges play a crucial role in brain plasticity phenomena, here we co-stimulated the primary motor cortex (M1) in healthy subjects by means of tACS during intermittent theta-burst stimulation (iTBS), a transcranial magnetic stimulation paradigm known to induce long-term potentiation (LTP)-like plasticity...
March 24, 2018: Brain Stimulation
Jonathan W Lovelace, Iryna M Ethell, Devin K Binder, Khaleel A Razak
Identification of comparable biomarkers in humans and validated animal models will facilitate pre-clinical to clinical therapeutic pipelines to treat neurodevelopmental disorders. Fragile X Syndrome (FXS) is a leading known genetic cause of intellectual disability with symptoms that include increased anxiety, social and sensory processing deficits. Recent EEG studies in humans with FXS have identified neural oscillation deficits that include enhanced resting state gamma power and reduced inter-trial coherence of sound evoked gamma oscillations...
March 29, 2018: Neurobiology of Disease
Patrick D Skosnik, Mihály Hajós, Jose A Cortes-Briones, Chad R Edwards, Brian P Pittman, William E Hoffmann, Andrew R Sewell, Deepak C D'Souza, Mohini Ranganathan
Cannabis use has been associated with altered sensory gating and neural oscillations. However, it is unclear which constituent in cannabis is responsible for these effects, or whether these are cannabinoid receptor 1 (CB1R) mediated. Therefore, the present study in humans and rats examined whether cannabinoid administration would disrupt sensory gating and evoked oscillations utilizing electroencephalography (EEG) and local field potentials (LFPs), respectively. Human subjects (n = 15) completed four test days during which they received intravenous delta-9-tetrahydrocannabinol (Δ9 -THC), cannabidiol (CBD), Δ9 -THC + CBD, or placebo...
March 28, 2018: Neuropharmacology
Nicholas S Bland, Jason B Mattingley, Martin V Sale
Phase synchronization drives connectivity between neural oscillators, providing a flexible mechanism through which information can be effectively and selectively routed between task-relevant cortical areas. The ability to keep track of objects moving between the left and right visual hemifields, for example, requires the integration of information between the two cerebral hemispheres. Both animal and human studies have suggested that coherent (or phase-locked) gamma oscillations (30-80 Hz) might underlie this ability...
2018: Frontiers in Psychology
Lukasz Chrobok, Katarzyna Palus-Chramiec, Jagoda Stanislawa Jeczmien-Lazur, Tomasz Blasiak, Marian Henryk Lewandowski
Physiological function of rhythmic firing in the neuronal networks of sensory systems has been linked with information coding. Also, neuronal oscillations in different frequency bands often change as a signature of brain state or sensory processing. Infra-slow oscillation (ISO) in the neuronal firing dependent on the retinal network has been previously described in the structures of the subcortical visual system. In this paper, we show for the first time that firing of ISO neurons in the lateral geniculate nucleus is also characterised by a harmonic discharge pattern, i...
March 25, 2018: Journal of Physiology
Marco Bimbi, Fabrizia Festante, Gino Coudé, Ross E Vanderwert, Nathan A Fox, Pier Francesco Ferrari
The desynchronization of alpha and beta oscillations (mu rhythm) in the central scalp EEG during action observation and action execution is thought to reflect neural mirroring processes. However, the extent to which mirror neurons (MNs) or other populations of neurons contribute to such EEG desynchronization is still unknown. Here, we provide the first evidence that, in the monkey, the neuronal activity recorded from the ventral premotor cortex (PMv) strongly contributes to the EEG changes occurring in the beta band over central scalp electrodes, during executed and observed actions...
March 20, 2018: NeuroImage
Xinyi Geng, Xin Xu, Andreas Horn, Ningfei Li, Zhipei Ling, Peter Brown, Shouyan Wang
OBJECTIVE: This study aims to use the activities recorded directly from the deep brain stimulation (DBS) electrode to address the focality and distinct nature of the local field potential (LFP) activities of different frequency. METHODS: Pre-operative and intra-operative magnetic resonance imaging (MRI) were acquired from patients with Parkinson's disease (PD) who underwent DBS in the subthalamic nucleus and intra-operative LFP recording at rest and during cued movements...
May 2018: Clinical Neurophysiology: Official Journal of the International Federation of Clinical Neurophysiology
Wei Cao, Shen Lin, Qiang-Qiang Xia, Yong-Lan Du, Qian Yang, Meng-Ying Zhang, Yi-Qing Lu, Jing Xu, Shu-Min Duan, Jun Xia, Guoping Feng, Junyu Xu, Jian-Hong Luo
No abstract text is available yet for this article.
March 21, 2018: Neuron
Meng-Yi Xu, Albert H C Wong
Schizophrenia is considered primarily as a cognitive disorder. However, functional outcomes in schizophrenia are limited by the lack of effective pharmacological and psychosocial interventions for cognitive impairment. GABA (gamma-aminobutyric acid) interneurons are the main inhibitory neurons in the central nervous system (CNS), and they play a critical role in a variety of pathophysiological processes including modulation of cortical and hippocampal neural circuitry and activity, cognitive function-related neural oscillations (eg, gamma oscillations) and information integration and processing...
March 22, 2018: Acta Pharmacologica Sinica
Seiichiro Amemiya, A David Redish
During decision making, hippocampal activity encodes information sometimes about present and sometimes about potential future plans. The mechanisms underlying this transition remain unknown. Building on the evidence that gamma oscillations at different frequencies (low gamma [LG], 30-55 Hz; high gamma [HG], 60-90 Hz; and epsilon, 100-140 Hz) reflect inputs from different circuits, we identified how changes in those frequencies reflect different information-processing states. Using a unique noradrenergic manipulation by clonidine, which shifted both neural representations and gamma states, we found that future representations depended on gamma components...
March 20, 2018: Cell Reports
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