Hippocampal Oscillations
Mostrando 1-12 de 21 artigos, teses e dissertações.
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1. Caracterização dos acoplamentos fase-amplitude na região CA1 do hopocampo
As oscilações cerebrais não são completamente independentes, mas capazes de interagir umas com as outras através de acoplamentos entre frequências (cross-frequency coupling, doravante CFC) em pelo menos quatro diferentes modalidades: amplitudeamplitude, fase-fase (coerência), fase-frequência e fase-amplitude. Evidências recentes sugerem que não som
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 02/12/2011
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2. Desenvolvimento de uma tecnica multimodal associando eletroencefalografia e imagens funcionais po ressonancia magnetica para o estudo de memoria operacional : aplicação em individuos com epilepsia de lobo temporal mesial associada a atrofia hipocampal
In this work, a multimodal approach involving electroencefalography (EEG) and functional Magnetic Resonance Imaging (fMRI) was implemented in order to perform studies on working memory in a group of subjects including controls and patients with mesial temporal lobe epilepsy (MTLE) associated with left hippocampal atrophy. In order to do that, a series of mem
Publicado em: 2008
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3. Communication between neocortex and hippocampus during sleep in rodents
Both neocortical and hippocampal networks organize the firing patterns of their neurons by prominent oscillations during sleep, but the functional role of these rhythms is not well understood. Here, we show a robust correlation of neuronal discharges between the somatosensory cortex and hippocampus on both slow and fine time scales in the mouse and rat. Neur
The National Academy of Sciences.
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4. Oscillatory brain states and learning: Impact of hippocampal theta-contingent training
Eyeblink classical conditioning is a relatively simple form of associative learning that has become an invaluable tool in our understanding of the neural mechanisms of learning. When studying rabbits in this paradigm, we observed a dramatic modification of learning rate by conducting training during episodes of either hippocampal theta or hippocampal non-the
The National Academy of Sciences.
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5. Spatiotemporal patterns of gamma frequency oscillations tetanically induced in the rat hippocampal slice.
1. We used transverse and longitudinal rat hippocampal slices to study the synchronization of gamma frequency (> 20 Hz) oscillations, across distances of up to 4.5 mm. gamma oscillations were evoked in the CA1 region by tetanic stimulation at one or two sites simultaneously, and were associated with population spikes. Tetanic stimuli that were strong enough
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6. Morphine disrupts long-range synchrony of gamma oscillations in hippocampal slices
Oscillations in neuronal population activity within the gamma frequency band (>25 Hz) have been correlated with cognition: Gamma oscillations could bind together features of a sensory stimulus by generating synchrony between discrete cortical areas [Eckhorn, R., Bauer, R., Jordan, W., Brosch, M., Kruse, W., Munk, M. & Reitboeck, H. J. (1989) Biol. Cybern. 60
The National Academy of Sciences.
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7. Gamma and beta frequency oscillations in response to novel auditory stimuli: A comparison of human electroencephalogram (EEG) data with in vitro models
Investigations using hippocampal slices maintained in vitro have demonstrated that bursts of oscillatory field potentials in the gamma frequency range (30–80 Hz) are followed by a slower oscillation in the beta 1 range (12–20 Hz). In this study, we demonstrate that a comparable gamma-to-beta transition is seen in the human electroencephalogram (EEG) in r
The National Academy of Sciences.
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8. Reset of human neocortical oscillations during a working memory task
Both amplitude and phase of rhythmic slow-wave electroencephalographic activity are physiological correlates of learning and memory in rodents. In humans, oscillatory amplitude has been shown to correlate with memory; however, the role of oscillatory phase in human memory is unknown. We recorded intracranial electroencephalogram from human cortical and h
National Academy of Sciences.
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9. Synaptic Noise and Physiological Coupling Generate High-Frequency Oscillations in a Hippocampal Computational Model
There is great interest in the role of coherent oscillations in the brain. In some cases, high-frequency oscillations (HFOs) are integral to normal brain function, whereas at other times they are implicated as markers of epileptic tissue. Mechanisms underlying HFO generation, especially in abnormal tissue, are not well understood. Using a physiological compu
American Physiological Society.
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10. Alternative splicing modulates the frequency-dependent response of CaMKII to Ca2+ oscillations
Ca2+ oscillations are required in various signal trans duction pathways, and contain information both in their amplitude and frequency. Remarkably, the Ca2+/calmodulin(CaM)-dependent protein kinase II (CaMKII) can decode such frequencies. A Ca2+/CaM-stimulated autophosphorylation leads to Ca2+/CaM-independent (autonomous) activity of the kinase that outlast
Oxford University Press.
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11. Recurrent excitatory postsynaptic potentials induced by synchronized fast cortical oscillations
Gamma frequency (about 20–70 Hz) oscillations occur during novel sensory stimulation, with tight synchrony over distances of at least 7 mm. Synchronization in the visual system has been proposed to reflect coactivation of different parts of the visual field by a single spatially extended object. We have shown that intracortical mechanisms, including spike
The National Academy of Sciences of the USA.
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12. Theta oscillations and sensorimotor performance
Performance and cognitive effort in humans have recently been related to amplitude and multisite coherence of alpha (7-12 Hz) and theta (4-7 Hz) band electroencephalogram oscillations. I examined this phenomenon in rats by using theta band oscillations of the local field potential to signify sniffing as a sensorimotor process. Olfactory bulb (OB) theta oscil
National Academy of Sciences.