scholarly journals Adaptive Spike-Artifact Removal from Local Field Potentials Uncovers Prominent Beta and Gamma Band Neuronal Synchronization

2019 ◽  
Author(s):  
Kianoush Banaie Boroujeni ◽  
Paul Tiesinga ◽  
Thilo Womelsdorf

AbstractBackgroundMany neurons synchronize their action potentials to the phase of local field potential (LFP) fluctuations in one or more frequency bands. Analyzing this spike-to-LFP synchronization is challenging, however, when neural spikes and LFP are generated in the same local circuit, because the spike’s action potential waveform leak into the LFP and distort phase synchrony estimates. Existing approaches to address this spike bleed-through artifact relied on removing the average action potential waveforms of neurons, but this leaves artifacts in the LFP and distorts synchrony estimates.New MethodWe describe a spike-removal method that surpasses these limitations by decomposing individual action potentials into their frequency components before their removal from the LFP. The adaptively estimated frequency components allow for variable spread, strength and temporal variation of the spike artifact.ResultsThis adaptive approach effectively removes spike bleed-through artifacts in synthetic data with known ground truth, and in single neuron and LFP recordings in nonhuman primate striatum. For a large population of neurons with both narrow and broad action potential waveforms, the use of adaptive artifact removal uncovered 20-35 Hz beta and 35-45 Hz gamma band spike-LFP synchronization that would have remained contaminated otherwise.Comparison with Existing MethodsWe demonstrate that adaptive spike-artifact removal cleans LFP data that remained contaminated when applying existing Bayesian and non-Bayesian methods of average spike-artifact removal.ConclusionsApplying adaptive spike-removal from field potentials allows to estimate the phase at which neurons synchronize and the consistency of their phase-locked firing for both beta and low gamma frequencies. These metrics may prove essential to understand cell-to-circuit neuronal interactions in multiple brain systems.

1993 ◽  
Vol 69 (6) ◽  
pp. 1940-1947 ◽  
Author(s):  
L. D. Rhines ◽  
P. G. Sokolove ◽  
J. Flores ◽  
D. W. Tank ◽  
A. Gelperin

1. The olfactory processing network in the procerebral (PC) lobe of the terrestrial mollusk Limax maximus exhibits a coherent oscillation of local field potential that is modulated by odor input. To understand the cellular basis of this oscillation, we developed a cell culture preparation of isolated PC neurons and studied the responses of isolated cells to stimulation with neurotransmitters known to be present in the PC lobe. 2. The distribution of PC soma diameters suggests at least two different populations of neurons. Approximately 95% of isolated cells had soma diameters of 7-8 microns, with the remaining cells having larger diameters (10-15 microns). 3. Extracellular measurements of action potentials and optical measurements of intracellular calcium concentrations in fura-2-loaded cells were made. Serotonin and dopamine excited PC neurons and promoted transitions from steady to bursty activity. Both amines elicited increases in intracellular calcium, presumably concomitant with the increase in action-potential frequency. 4. Glutamate suppressed action-potential firing and reduced intracellular calcium. This effect was seen most clearly when glutamate was applied to cells excited by high potassium medium. Quisqualate is an effective glutamate agonist in this system, whereas kainate is not. 5. Combined with anatomic and biochemical data and with studies of the effects of these neurotransmitters on the oscillating local field potential of the intact PC network, the data from isolated PC neurons are consistent with the hypothesis that dopamine and serotonin modulate network dynamics, whereas glutamate is involved in generating the basic oscillation of local field potential in the PC. 6. The optical studies of fura-2-loaded cells showed that several treatments that increase the rate of action-potential production lead to elevations in intracellular calcium. Optical studies of intracellular calcium may be useful for multisite measurements of activity in the intact, oscillating PC lobe network.


1990 ◽  
Vol 64 (6) ◽  
pp. 1747-1757 ◽  
Author(s):  
M. Avoli ◽  
C. Drapeau ◽  
P. Perreault ◽  
J. Louvel ◽  
R. Pumain

1. Extracellular and intracellular recordings and measurements of the extracellular concentration of free K+ ([K+]o) were performed in the CA1 subfield of the rat hippocampal slice during perfusion with artificial cerebrospinal fluid (ACSF) in which NaCl had been replaced with equimolar Na-isethionate or Na-methylsulfate (hereafter called low Cl- ACSF). 2. CAl pyramidal cells perfused with low Cl- ACSF generated intracellular epileptiform potentials in response to orthodromic, single-shock stimuli delivered in stratum (S.) radiatum. Low-intensity stimuli evoked a short-lasting epileptiform burst (SB) of action potentials that lasted 40–150 ms and was followed by a prolonged hyperpolarization. When the stimulus strength was increased, a long-lasting epileptiform burst (LB) appeared; it had a duration of 4–15 s and consisted of an early discharge of action potentials similar to the SB, followed by a prolonged, large-amplitude depolarizing plateau. The refractory period of the LB was longer than 20 s. SB and LB were also seen after stimulation of the alveus. 3. Variations of the membrane potential with injection of steady. DC current modified the shape of SB and LB. When microelectrodes filled with the lidocaine derivative QX-314 were used, the amplitudes of both SB and LB increased in a linear fashion during changes of the baseline membrane potential in the hyperpolarizing direction. The membrane input resistance, as measured by injecting brief square pulses of hyperpolarizing current, decreased by 65-80% during the long-lasting depolarizing plateau of LB. 4. A synchronous field potential and a transient increase in [K+]o accompanied the epileptiform responses. The extracellular counterpart of the SB was a burst of three to six population spikes and a small increase in [K+]o (less than or equal to 2 mM from a resting value of approximately 2.5 mM). The LB was associated with a large-amplitude, biphasic, negative field potential and a large increase in [K+]o (up to 12.4 mM above the resting value). Changes in [K+]o during the LB were largest at the border between S. oriens and S. pyramidale. This was also the site where the field potentials measured 2–5 s after the stimulus attained their maximal amplitude. Conversely, field potentials associated with the early component of the LB or with the SB displayed a maximal amplitude in the S. radiatum. 5. Spontaneous SBs and LBs were at times recorded in the CA1 and in the CA3 subfield.(ABSTRACT TRUNCATED AT 400 WORDS)


2016 ◽  
Vol 28 (8) ◽  
pp. 1498-1502 ◽  
Author(s):  
Henning U. Voss

The leaky integrator, the basis for many neuronal models, possesses a negative group delay when a time-delayed recurrent inhibition is added to it. By means of this delay, the leaky integrator becomes a predictor for some frequency components of the input signal. The prediction properties are derived analytically, and an application to a local field potential is provided.


2017 ◽  
Author(s):  
James E. Carmichael ◽  
Jimmie M. Gmaz ◽  
Matthijs A. A. van der Meer

AbstractLocal field potentials (LFP) recorded from the human and rodent ventral striatum (vStr) exhibit prominent, behaviorally relevant gamma-band oscillations. These oscillations are related to local spiking activity and transiently synchronize with anatomically related areas, suggesting a possible role in organizing vStr activity. However, the origin of vStr gamma is unknown. We recorded vStr gamma oscillations across a 1.4mm2 grid spanned by 64 recording electrodes as rats rested and foraged for rewards, revealing a highly consistent power gradient originating in the adjacent piriform cortex. Phase differences across the vStr were consistently small (<10°) and current source density analysis further confirmed the absence of local sink-source pairs in the vStr. Reversible occlusions of the ipsilateral (but not contralateral) nostril, known to abolish gamma oscillations in the piriform cortex, strongly reduced vStr gamma power and the occurrence of transient gamma-band events. These results imply that local circuitry is not a major contributor to gamma oscillations in the vStr LFP, and that piriform cortex is an important driver of gamma-band oscillations in the vStr and associated limbic areas.Significance StatementThe ventral striatum is an area of anatomical convergence in circuits underlying motivated behavior, but it remains unclear how its inputs from different sources interact. One of the major proposals of how neural circuits may dynamically switch between convergent inputs is through temporal organization reflected in local field potential (LFP) oscillations. Our results show that in the rat, the mechanisms controlling vStr gamma oscillations are primarily located in the in the adjacent piriform cortex, rather than vStr itself. This provides a novel interpretation of previous rodent work on gamma oscillations in the vStr and related circuits, and an important consideration for future work seeking to use oscillations in these areas as biomarkers in rodent models of human behavioral and neurological disorders.


2017 ◽  
Author(s):  
Brendon O. Watson ◽  
Mingxin Ding ◽  
György Buzsáki

AbstractThe local field potential (LFP) is an aggregate measure of group neuronal activity and is often correlated with the action potentials of single neurons. In recent years investigators have found that action potential firing rates increase during elevations in power high-frequency band oscillations (50-200 Hz range). However action potentials also contribute to the LFP signal itself, making the spike–LFP relationship complex. Here we examine the relationship between spike rates and LFPs in varying frequency bands in rat neocortical recordings. We find that 50-180Hz oscillations correlate most consistently with high firing rates, but that other LFPs bands also carry information relating to spiking, including in some cases anti-correlations. Relatedly, we find that spiking itself and electromyographic activity contribute to LFP power in these bands. The relationship between spike rates and LFP power varies between brain states and between individual cells. Finally, we create an improved oscillation-based predictor of action potential activity by specifically utilizing information from across the entire recorded frequency spectrum of LFP. The findings illustrate both caveats and improvements to be taken into account in attempts to infer spiking activity from LFP.


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