scholarly journals Low activity microstates during sleep

2016 ◽  
Author(s):  
Hiroyuki Miyawaki ◽  
Yazan N. Billeh ◽  
Kamran Diba
Keyword(s):  
Rem Sleep ◽  
Activity Patterns ◽  
Field Potential ◽  
Ca1 Neurons ◽  
Anterior Thalamus ◽  
Large Populations ◽  
Electroencephalogram Eeg ◽  
The Brain ◽  
Local Field Potential Lfp ◽  
Low Activity

AbstractA better understanding of sleep requires evaluating the distinct activity patterns of the brain during sleep. We performed extracellular recordings of large populations of hippocampal region CA1 neurons in freely moving rats across sleep and waking states. Throughout non-REM (non-rapid eye movement) sleep, we observed periods of diminished oscillatory and population spiking activity lasting on the order of seconds, which we refer to as “LOW” activity sleep states. LOW states featured enhanced firing in a subset of “LOW-active” cells, and greater firing in putative interneurons compared to DOWN/OFF states. LOW activity sleep was preceded and followed by increased sharp-wave ripple (SWR) activity. We also observed decreased slow-wave activity (SWA) and sleep spindles in the hippocampus local-field potential (LFP) and neocortical electroencephalogram (EEG) upon LOW onset, but only a partial rebound immediately after LOW. LOW states demonstrated LFP, EEG, and EMG patterns consistent with sleep, but frequently transitioned into microarousals (MAs) and showed EMG and LFP spectral differences from previously described small-amplitude irregular activity (SIA) during quiet waking. Their likelihood increased over the course of sleep, particularly following REM sleep. To confirm that LOW is a brain-wide phenomenon, we analyzed data from the entorhinal cortex of rats, medial prefrontal cortex, and anterior thalamus of mice, obtained from crcns.org and found that LOW states corresponded to markedly diminished activity simultaneously in all of these regions. We propose that LOW states are an important microstate within non-REM sleep that provide respite from high-activity sleep, and may serve a restorative function.

Coherent Electrical Activity Between Vibrissa Sensory Areas of Cerebellum and Neocortex Is Enhanced During Free Whisking

2002 ◽  
Vol 87 (4) ◽  
pp. 2137-2148 ◽  
Author(s):  
Sean M. O'Connor ◽  
Rune W. Berg ◽  
David Kleinfeld
Keyword(s):  
Electrical Activity ◽  
Sensory Input ◽  
Field Potential ◽  
Sensory Cortex ◽  
Brain Areas ◽  
Low Coherence ◽  
Primary Sensory Cortex ◽  
High Level ◽  
The Brain ◽  
Local Field Potential Lfp

We tested if coherent signaling between the sensory vibrissa areas of cerebellum and neocortex in rats was enhanced as they whisked in air. Whisking was accompanied by 5- to 15-Hz oscillations in the mystatial electromyogram, a measure of vibrissa position, and by 5- to 20-Hz oscillations in the differentially recorded local field potential (∇LFP) within the vibrissa area of cerebellum and within the ∇LFP of primary sensory cortex. We observed that only 10% of the activity in either cerebellum or sensory neocortex was significantly phase-locked to rhythmic motion of the vibrissae; the extent of this modulation is in agreement with the results from previous single-unit measurements in sensory neocortex. In addition, we found that 40% of the activity in the vibrissa areas of cerebellum and neocortex was significantly coherent during periods of whisking. The relatively high level of coherence between these two brain areas, in comparison with their relatively low coherence with whisking per se, implies that the vibrissa areas of cerebellum and neocortex communicate in a manner that is incommensurate with whisking. To the extent that the vibrissa areas of cerebellum and neocortex communicate over the same frequency band as that used by whisking, these areas must multiplex electrical activity that is internal to the brain with activity that is that phase-locked to vibrissa sensory input.

Analysis of LFP Phase Predicts Sensory Response of Barrel Cortex

2006 ◽  
Vol 96 (3) ◽  
pp. 1658-1663 ◽  
Author(s):  
R. Haslinger ◽  
I. Ulbert ◽  
C. I. Moore ◽  
E. N. Brown ◽  
A. Devor
Keyword(s):  
Barrel Cortex ◽  
Temporal Dynamics ◽  
Field Potential ◽  
Electrode Array ◽  
Sensory Response ◽  
Strong Function ◽  
Large Populations ◽  
Up And Down States ◽  
Sensory Evoked ◽  
Local Field Potential Lfp

Several previous studies have shown the existence of Up and Down states and have linked their magnitude (e.g., depolarization level) to the size of sensory-evoked responses. Here, we studied how the temporal dynamics of such states influence the sensory-evoked response to vibrissa deflection. Under α-chloralose anesthesia, barrel cortex exhibits strong quasi-periodic ∼1-Hz local field potential (LFP) oscillations generated by the synchronized fluctuation of large populations of neurons between depolarized (Up) and hyperpolarized (Down) states. Using a linear depth electrode array, we recorded the LFP and multiunit activity (MUA) simultaneously across multiple layers of the barrel column and used the LFP to approximate the subthreshold Up–Down fluctuations. Our central finding is that the MUA response is a strong function of the LFP oscillation’s phase. When only ongoing LFP magnitude was considered, the response was largest in the Down state, in agreement with previous studies. However, consideration of the LFP phase revealed that the MUA response varied smoothly as a function of LFP phase in a manner that was not monotonically dependent on LFP magnitude. The LFP phase is therefore a better predictor of the MUA response than the LFP magnitude is. Our results suggest that, in the presence of ongoing oscillations, there can be a continuum of response properties and that each phase may, at times, need to be considered a distinct cortical state.

scholarly journals Effect of amplitude correlations on coherence in the local field potential

2014 ◽  
Vol 112 (4) ◽  
pp. 741-751 ◽  
Author(s):  
Ramanujan Srinath ◽  
Supratim Ray
Keyword(s):  
Local Field ◽  
Local Field Potential ◽  
Multiple Scales ◽  
Field Potential ◽  
Interelectrode Distance ◽  
Study Phase ◽  
Temporal Correlations ◽  
Two Factors ◽  
The Brain ◽  
Local Field Potential Lfp

Neural activity across the brain shows both spatial and temporal correlations at multiple scales, and understanding these correlations is a key step toward understanding cortical processing. Correlation in the local field potential (LFP) recorded from two brain areas is often characterized by computing the coherence, which is generally taken to reflect the degree of phase consistency across trials between two sites. Coherence, however, depends on two factors—phase consistency as well as amplitude covariation across trials—but the spatial structure of amplitude correlations across sites and its contribution to coherence are not well characterized. We recorded LFP from an array of microelectrodes chronically implanted in the primary visual cortex of monkeys and studied correlations in amplitude across electrodes as a function of interelectrode distance. We found that amplitude correlations showed a similar trend as coherence as a function of frequency and interelectrode distance. Importantly, even when phases were completely randomized between two electrodes, amplitude correlations introduced significant coherence. To quantify the contributions of phase consistency and amplitude correlations to coherence, we simulated pairs of sinusoids with varying phase consistency and amplitude correlations. These simulations confirmed that amplitude correlations can significantly bias coherence measurements, resulting in either over- or underestimation of true phase coherence. Our results highlight the importance of accounting for the correlations in amplitude while using coherence to study phase relationships across sites and frequencies.

scholarly journals Visual cortex neurons phase-lock selectively to subsets of LFP oscillations

2019 ◽  
Vol 121 (6) ◽  
pp. 2364-2378 ◽  
Author(s):  
N. V. Swindale ◽  
M. A. Spacek
Keyword(s):  
Visual Cortex ◽  
Receptive Field ◽  
Local Field ◽  
Rem Sleep ◽  
Local Field Potential ◽  
Cortical Neurons ◽  
Field Potential ◽  
Frequency Selective ◽  
Visual Cortex Neurons ◽  
Local Field Potential Lfp

It is generally thought that apart from receptive field differences, such as preferred orientation and spatial frequency selectivity, primary visual cortex neurons are functionally similar to each other. However, the genetic diversity of cortical neurons plus the existence of inputs additional to those required to explain known receptive field properties might suggest otherwise. Here we report the existence of desynchronized states in anesthetized cat area 17 lasting up to 45 min, characterized by variable narrow-band local field potential (LFP) oscillations in the range 2–100 Hz and the absence of a synchronized 1/ f frequency spectrum. During these periods, spontaneously active neurons phase-locked to variable subsets of LFP oscillations. Individual neurons often ignored frequencies that others phase-locked to. We suggest that these desynchronized periods may correspond to REM sleep-like episodes occurring under anesthesia. Frequency-selective codes may be used for signaling during these periods. Hence frequency-selective combination and frequency-labeled pathways may represent a previously unsuspected dimension of cortical organization. NEW & NOTEWORTHY We investigated spontaneous neuronal firing during periods of desynchronized local field potential (LFP) activity, resembling REM sleep, in anesthetized cats. During these periods, neurons synchronized their spikes to specific phases of multiple LFP frequency components, with some neurons ignoring frequencies that others were synchronized to. Some neurons fired at phase alignments of frequency pairs, thereby acting as phase coincidence detectors. These results suggest that internal brain signaling may use frequency combination codes to generate temporally structured spike trains.

Electroencephalography and Local Field Potentials in Animals

2015 ◽  
Author(s):  
Sean Reed ◽  
Sonia Jego ◽  
Antoine Adamantidis
Keyword(s):  
Animal Models ◽  
Local Field ◽  
Field Potential ◽  
Electrical Current ◽  
Ionic Currents ◽  
Synaptic Activity ◽  
Field Potentials ◽  
Motivational States ◽  
The Brain ◽  
Local Field Potential Lfp

This chapter discusses the history, practice, and application of electroencephalography (EEG) and local field potential (LFP) recordings, with a particular focus on animal models. EEG measures the fluctuations of electrical activity resulting from ionic currents in the brain. These measurements are often taken from electrodes placed on the surface of the scalp, or in animal models, directly on the skull. LFP recordings are more invasive, measuring electrical current from all nearby dendritic synaptic activity within a volume of tissue. These two techniques are useful in determining how neural activity can synchronize during different behavioral or motivational states.

scholarly journals Altered Postnatal Development of Cortico—Hippocampal Neuronal Electric Activity in Mice Deficient for the Mitochondrial Aspartate—Glutamate Transporter

2011 ◽  
Vol 32 (2) ◽  
pp. 306-317 ◽  
Author(s):  
Marta Gómez-Galán ◽  
Julia Makarova ◽  
Irene Llorente-Folch ◽  
Takeyori Saheki ◽  
Beatriz Pardo ◽  
...  
Keyword(s):  
Evoked Potentials ◽  
Brain Metabolism ◽  
Glutamate Transporter ◽  
Field Potential ◽  
Electric Activity ◽  
Postnatal Growth ◽  
Epileptic Activity ◽  
And Control ◽  
The Brain ◽  
Local Field Potential Lfp

The deficiency in the mitochondrial aspartate/glutamate transporter Aralar/AGC1 results in a loss of the malate-aspartate NADH shuttle in the brain neurons, hypomyelination, and additional defects in the brain metabolism. We studied the development of cortico/hippocampal local field potential (LFP) in Aralar/AGC1 knockout (KO) mice. Laminar profiles of LFP, evoked potentials, and unit activity were recorded under anesthesia in young (P15 to P22) Aralar-KO and control mice as well as control adults. While LFP power increased 3 to 7 times in both cortex and hippocampus of control animals during P15 to P22, the Aralar-KO specimens hardly progressed. The divergence was more pronounced in the CA3/hilus region. In parallel, spontaneous multiunit activity declined severely in KO mice. Postnatal growth of hippocampal-evoked potentials was delayed in KO mice, and indicated abnormal synaptic and spike electrogenesis and reduced output at P20 to P22. The lack of LFP development in KO mice was accompanied by the gradual appearance of epileptic activity in the CA3/hilus region that evolved to status epilepticus. Strikingly, CA3 bursts were poorly conducted to the CA1 field. We conclude that disturbed substrate supply to neuronal mitochondria impairs development of cortico—hippocampal LFPs. Aberrant neuronal electrogenesis and reduced neuron output may explain circuit dysfunction and phenotype deficiencies.

scholarly journals Effects of Propofol and Ketamine on The Neural Oscillations in CA1 of Rat Intact Hippocampus

2020 ◽  
Author(s):  
Zhang Yu ◽  
Ping Chen ◽  
Zhi-yi Tu ◽  
Yi-heng Liu ◽  
Zhi-ru Wang ◽  
...  
Keyword(s):  
Field Potential ◽  
Inhibitory Effect ◽  
Neural Oscillations ◽  
General Anesthetics ◽  
Bath Application ◽  
Spectrum Intensity ◽  
Underlying Mechanisms ◽  
The Brain ◽  
Local Field Potential Lfp

Abstract In this study, in vitro intact hippocampal preparation model was utilized to observe the effects of propofol and ketamine on the neural oscillations in CA1 of rat hippocampus. The intact hippocampi were dissected from the brain tissues of rats aged 14-16 days postnatal. Local field potential (LFP) recordings were performed with propofol and ketamine bath application at different concentrations. The power spectrum intensity of LFP in all the frequency bands, including delta (1-4 Hz), theta (4-8 Hz), alpha (8-13 Hz), beta (13-30 Hz) and gamma (30-80 Hz), were inhibited in a concentrationdependent manner by both general anesthetics. In order to further investigate the underlying mechanisms, the major binding site of propofol and ketamine were blocked respectively by picrotoxin and (2R)-amino-5-phosphonopentanoate when bath applying the general anesthetics. It revealed that the inhibitory effect of propofol on hippocampal oscillations might be via γ-aminobutyric acid A receptor, while the inhibitory effect of ketamine might be unconcerned with N-methyl-D-aspartic acid receptor.

scholarly journals Collective Dynamics of Neural Networks With Sleep-Related Biological Drives in Drosophila

2021 ◽  
Vol 15 ◽  
Author(s):  
Shuihan Qiu ◽  
Kaijia Sun ◽  
Zengru Di
Keyword(s):  
Neural Network ◽  
Field Potential ◽  
Mean Value ◽  
Network Structures ◽  
Regular Spike ◽  
Wake Time ◽  
The Neural Network ◽  
The Mean ◽  
The Brain ◽  
Local Field Potential Lfp

The collective electrophysiological dynamics of the brain as a result of sleep-related biological drives in Drosophila are investigated in this paper. Based on the Huber-Braun thermoreceptor model, the conductance-based neurons model is extended to a coupled neural network to analyze the local field potential (LFP). The LFP is calculated by using two different metrics: the mean value and the distance-dependent LFP. The distribution of neurons around the electrodes is assumed to have a circular or grid distribution on a two-dimensional plane. Regardless of which method is used, qualitatively similar results are obtained that are roughly consistent with the experimental data. During wake, the LFP has an irregular or a regular spike. However, the LFP becomes regular bursting during sleep. To further analyze the results, wavelet analysis and raster plots are used to examine how the LFP frequencies changed. The synchronization of neurons under different network structures is also studied. The results demonstrate that there are obvious oscillations at approximately 8 Hz during sleep that are absent during wake. Different time series of the LFP can be obtained under different network structures and the density of the network will also affect the magnitude of the potential. As the number of coupled neurons increases, the neural network becomes easier to synchronize, but the sleep and wake time described by the LFP spectrogram do not change. Moreover, the parameters that affect the durations of sleep and wake are analyzed.

scholarly journals Single neuron firing cascades underlie global spontaneous brain events

2021 ◽  
Author(s):  
Xiao Liu ◽  
David A. Leopold ◽  
Yifan Yang
Keyword(s):  
Spontaneous Activity ◽  
Large Scale ◽  
Significant Proportion ◽  
Field Potential ◽  
Low Frequency ◽  
Isolated Cells ◽  
Physiological Indicators ◽  
Subcortical Regions ◽  
The Brain ◽  
Local Field Potential Lfp

AbstractThe resting brain consumes enormous energy and shows highly organized spontaneous activity. To investigate how this activity is manifest among single neurons, we analyzed spiking discharges of ∼10,000 isolated cells recorded from multiple cortical and subcortical regions of the mouse brain during immobile rest. We found that firing of a significant proportion (∼70%) of neurons conformed to a ubiquitous, temporally sequenced cascade of spiking that was synchronized with global events and elapsed over timescales of 5-10 seconds. Across the brain, two intermixed populations of neurons supported orthogonal cascades. The relative phases of these cascades determined, at each moment, the response magnitude evoked by an external visual stimulus. Furthermore, the spiking of individual neurons embedded in these cascades was time locked to physiological indicators of arousal, including local field potential (LFP) power, pupil diameter, and hippocampal ripples. These findings demonstrate that the large-scale coordination of low-frequency spontaneous activity, which is commonly observed in brain imaging and linked to arousal, sensory processing, and memory, is underpinned by sequential, large-scale temporal cascades of neuronal spiking across the brain.

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