Rhythmic Constraints on Hippocampal Processing: State and Phase-Related Fluctuations of Synaptic Excitability During Theta and the Slow Oscillation

2008 ◽  
Vol 99 (2) ◽  
pp. 888-899 ◽  
Author(s):  
Kurt P. Schall ◽  
Jon Kerber ◽  
Clayton T. Dickson
Keyword(s):  
Medial Temporal Lobe ◽  
Evoked Potential ◽  
Rhythmic Activity ◽  
Slow Oscillation ◽  
Perforant Path ◽  
Oscillatory Activity ◽  
Deep Sleep ◽  
Differential Effects ◽  
Input Processing ◽  
State Dependent

Coordinated patterns of state-dependent synchronized oscillatory activity have been suggested to play differential roles in both the encoding and consolidation phases of hippocampal-dependent memories. Previous studies have concentrated on the mutually exclusive patterns of theta and sharp-wave/ripple activity because these were thought to be the only collective oscillatory patterns expressed in the hippocampus. Recently we (and others) have described a novel rhythmic activity expressed during anesthesia and deep sleep, the hippocampal slow oscillation (SO). In an attempt to describe the differential effects of theta and the SO on processing in the hippocampal circuit, we performed evoked potential analysis of two major pathways (the commissural and perforant) in urethan-anesthetized rats across spontaneously expressed theta and SO states. We show that synaptic excitability was significantly enhanced in all pathways during the SO as compared with theta with the exception of the medial perforant path to the dentate gyrus, which showed greater excitability during theta. Furthermore, within each ongoing rhythm, there was a phase-dependent modulation of synaptic excitability. This occurred across all sites and similarly favored the falling phase (positive to negative) of both theta and the SO. Differential effects on the input, processing, and output circuitries of the hippocampus across mutually exclusive coordinated oscillatory patterns expressed during different states may be relevant for the staging of memory processes in the medial temporal lobe.

scholarly journals Stochastic Resonance Mediates the State-Dependent Effect of Periodic Stimulation on Cortical Alpha Oscillations

2017 ◽  
Author(s):  
Jérémie Lefebvre ◽  
Flavio Frohlich ◽  
Axel Hutt
Keyword(s):  
Stochastic Resonance ◽  
Rhythmic Activity ◽  
Oscillatory Activity ◽  
Alpha Oscillations ◽  
State Dependent ◽  
Periodic Stimulation ◽  
Brain States ◽  
Behavioral States ◽  
Thalamocortical System ◽  
And Task

ABSTRACTBrain stimulation can be used to engage and modulate rhythmic activity in cortical networks. However, the outcomes have been shown to be impacted by behavioral states and endogenous brain fluctuations. To better understand how this intrinsic oscillatory activity controls the brain’s susceptibility to stimulation, we analyzed a computational model of the thalamocortical system in both the rest and task states, to identify the mechanisms by which endogenous alpha oscillations (8Hz-12Hz) are impacted by periodic stimulation. Our analysis shows that the differences between different brain states can be explained by a passage through a bifurcation combined to stochastic resonance - a mechanism whereby irregular fluctuations amplify the response of a nonlinear system to weak signals. Indeed, our findings suggest that modulating brain oscillations is best achieved in states of low endogenous rhythmic activity, and that irregular state-dependent fluctuations in thalamic inputs shape the susceptibility of cortical population to periodic stimulation.

scholarly journals Stochastic resonance mediates the state-dependent effect of periodic stimulation on cortical alpha oscillations

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Jérémie Lefebvre ◽  
Axel Hutt ◽  
Flavio Frohlich
Keyword(s):  
Stochastic Resonance ◽  
Brain Stimulation ◽  
Brain Activity ◽  
Rhythmic Activity ◽  
Oscillatory Activity ◽  
Alpha Oscillations ◽  
State Dependent ◽  
Periodic Stimulation ◽  
Brain States ◽  
Cortical System

Brain stimulation can be used to engage and modulate rhythmic activity in brain networks. However, the outcomes of brain stimulation are shaped by behavioral states and endogenous fluctuations in brain activity. To better understand how this intrinsic oscillatory activity controls the susceptibility of the brain to stimulation, we analyzed a computational model of the thalamo-cortical system in two distinct states (rest and task-engaged) to identify the mechanisms by which endogenous alpha oscillations (8Hz–12Hz) are modulated by periodic stimulation. Our analysis shows that the different responses to stimulation observed experimentally in these brain states can be explained by a passage through a bifurcation combined with stochastic resonance — a mechanism by which irregular fluctuations amplify the response of a nonlinear system to weak periodic signals. Indeed, our findings suggest that modulation of brain oscillations is best achieved in states of low endogenous rhythmic activity, and that irregular state-dependent fluctuations in thalamic inputs shape the susceptibility of cortical population to periodic stimulation.

scholarly journals Desynchronization of slow oscillations in the basal ganglia during natural sleep

2018 ◽  
Vol 115 (18) ◽  
pp. E4274-E4283 ◽  
Author(s):  
Aviv D. Mizrahi-Kliger ◽  
Alexander Kaplan ◽  
Zvi Israel ◽  
Hagai Bergman
Keyword(s):  
Basal Ganglia ◽  
Field Potential ◽  
Slow Oscillation ◽  
Oscillatory Activity ◽  
Neuronal Cultures ◽  
Vervet Monkeys ◽  
Slow Oscillations ◽  
Natural Sleep ◽  
Sleep Physiology ◽  
Local Circuits

Slow oscillations of neuronal activity alternating between firing and silence are a hallmark of slow-wave sleep (SWS). These oscillations reflect the default activity present in all mammalian species, and are ubiquitous to anesthesia, brain slice preparations, and neuronal cultures. In all these cases, neuronal firing is highly synchronous within local circuits, suggesting that oscillation–synchronization coupling may be a governing principle of sleep physiology regardless of anatomical connectivity. To investigate whether this principle applies to overall brain organization, we recorded the activity of individual neurons from basal ganglia (BG) structures and the thalamocortical (TC) network over 70 full nights of natural sleep in two vervet monkeys. During SWS, BG neurons manifested slow oscillations (∼0.5 Hz) in firing rate that were as prominent as in the TC network. However, in sharp contrast to any neural substrate explored thus far, the slow oscillations in all BG structures were completely desynchronized between individual neurons. Furthermore, whereas in the TC network single-cell spiking was locked to slow oscillations in the local field potential (LFP), the BG LFP exhibited only weak slow oscillatory activity and failed to entrain nearby cells. We thus show that synchrony is not inherent to slow oscillations, and propose that the BG desynchronization of slow oscillations could stem from its unique anatomy and functional connectivity. Finally, we posit that BG slow-oscillation desynchronization may further the reemergence of slow-oscillation traveling waves from multiple independent origins in the frontal cortex, thus significantly contributing to normal SWS.

EEG Event-Related Desynchronization and Event-Related Synchronization

2017 ◽  
Author(s):  
Gert Pfurtscheller ◽  
Fernando Lopes da Silva
Keyword(s):  
Resting State ◽  
Rhythmic Activity ◽  
Oscillatory Activity ◽  
Motor Tasks ◽  
Stroke Patients ◽  
Phase Coupling ◽  
Pressure Oscillations ◽  
Frequency Bands ◽  
Event Related Desynchronization ◽  
Evoked Response Potentials

Event-related desynchronization (ERD) reflects a decrease of oscillatory activity related to internally or externally paced events. The increase of rhythmic activity is called event-related synchronization (ERS). They represent dynamical states of thalamocortical networks associated with cortical information-processing changes. This chapter discusses differences between ERD/ERS and evoked response potentials and methodologies for quantifying ERD/ERS and selecting frequency bands. It covers the interpretation of ERD/ERS in the alpha and beta bands and theta ERS and alpha ERD in behavioral tasks. ERD/ERS in scalp and subdural recordings, in various frequency bands, is discussed. Also presented is the modulation of alpha and beta rhythms by 0.1-Hz oscillations in the resting state and phase-coupling of the latter with slow changes of prefrontal hemodynamic signals (HbO2), blood pressure oscillations, and heart rate interval variations in the resting state and in relation to behavioral motor tasks. Potential uses of ERD-based strategies in stroke patients are discussed.

TMS entrainment of pre-stimulus oscillatory activity in tactile perception

2012 ◽  
Vol 25 (0) ◽  
pp. 152
Author(s):  
Manuela Ruzzoli ◽  
Salvador Soto-Faraco
Keyword(s):  
Parietal Cortex ◽  
Target Location ◽  
Repetitive Transcranial Magnetic Stimulation ◽  
Rhythmic Activity ◽  
Tactile Perception ◽  
Oscillatory Activity ◽  
Alpha Frequency ◽  
Specific Frequency ◽  
The Right ◽  
Beta Frequency

It is widely recognized that oscillatory activity plays an important functional role in neural systems. Decreases in alpha (∼10 Hz) EEG/MEG activity in the parietal cortex correlate with the deployment of spatial attention controlateral to target location in visual, auditory and tactile domains. Recently, repetitive Transcranial Magnetic Stimulation (rTMS) has been successfully applied to entrain a specific frequency at the parietal cortex (IPS) and the visual cortex. A short burst of 10 Hz rTMS impaired contralateral visual target detection and improved it ipsilaterally, compared to other control frequencies. This finding suggests a causal role of rhythmic activity in the alfa range in perception. The aim of the present study is to address whether entraining alpha frequency in the IPS plays a role in tactile orienting, indicating similarities between senses (vision and touch) in the communication between top-down (parietal) and primary sensory areas (V1 or S1). We applied rhythmic TMS at 10 and 20 Hz to the (right or left) IPS and S1, immediately before a masked vibrotactile target stimulus (present in 50% of the trials) to the left or right hand. Preliminary results lean towards the consequential effects of entraining alpha frequency into IPS for tactile detection such that it decreases tactile perception contralaterally and increases it ipsilaterally, compared to Beta frequency.

Modulation of the Sleep State–Dependent P50 Midlatency Auditory-Evoked Potential by Electric Stimulation of Acupuncture Points

2005 ◽  
Vol 86 (10) ◽  
pp. 2018-2026 ◽  
Author(s):  
Patricia A. Bray ◽  
Noriaki Mamiya ◽  
Alice V. Fann ◽  
Harris Gellman ◽  
Robert D. Skinner ◽  
...  
Keyword(s):  
Electric Stimulation ◽  
Evoked Potential ◽  
Auditory Evoked Potential ◽  
Acupuncture Points ◽  
Sleep State ◽  
State Dependent ◽  
Stimulation Of

scholarly journals Gamma activity accelerates during prefrontal development

2020 ◽  
Author(s):  
Sebastian H. Bitzenhofer ◽  
Jastyn A. Pöpplau ◽  
Ileana L. Hanganu-Opatz
Keyword(s):  
Prefrontal Cortex ◽  
Pyramidal Neurons ◽  
Temporal Dynamics ◽  
Rhythmic Activity ◽  
Gamma Oscillations ◽  
Gamma Activity ◽  
Oscillatory Activity ◽  
Gamma Frequency ◽  
Gamma Rhythms ◽  
Fast Oscillations

AbstractGamma oscillations are a prominent activity pattern in the cerebral cortex. While gamma rhythms have been extensively studied in the adult prefrontal cortex in the context of cognitive (dys)functions, little is known about their development. We addressed this issue by using extracellular recordings and optogenetic stimulations in mice across postnatal development. We show that fast rhythmic activity in the prefrontal cortex becomes prominent during the second postnatal week. While initially at about 15 Hz, fast oscillatory activity progressively accelerates with age and stabilizes within gamma frequency range (30-80 Hz) during the fourth postnatal week. Activation of layer 2/3 pyramidal neurons drives fast oscillations throughout development, yet the acceleration of their frequency follows similar temporal dynamics as the maturation of fast-spiking interneurons. These findings uncover the development of prefrontal gamma activity and provide a framework to examine the origin of abnormal gamma activity in neurodevelopmental disorders.

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