scholarly journals A unifying principle underlying the extracellular field potential spectral responses in the human cortex

2015 ◽  
Vol 114 (1) ◽  
pp. 505-519 ◽  
Author(s):  
Ella Podvalny ◽  
Niv Noy ◽  
Michal Harel ◽  
Stephan Bickel ◽  
Gal Chechik ◽  
...  
Keyword(s):  
Field Potential ◽  
Neuronal Activation ◽  
Human Cortex ◽  
Neuronal Process ◽  
High Gamma ◽  
Neuronal Processes ◽  
Limited Power ◽  
Visuomotor Tasks ◽  
Band Limited ◽  
Spectrum Slope

Electrophysiological mass potentials show complex spectral changes upon neuronal activation. However, it is unknown to what extent these complex band-limited changes are interrelated or, alternatively, reflect separate neuronal processes. To address this question, intracranial electrocorticograms (ECoG) responses were recorded in patients engaged in visuomotor tasks. We found that in the 10- to 100-Hz frequency range there was a significant reduction in the exponent χ of the 1/ fχ component of the spectrum associated with neuronal activation. In a minority of electrodes showing particularly high activations the exponent reduction was associated with specific band-limited power modulations: emergence of a high gamma (80–100 Hz) and a decrease in the alpha (9–12 Hz) peaks. Importantly, the peaks' height was correlated with the 1/ fχ exponent on activation. Control simulation ruled out the possibility that the change in 1/ fχ exponent was a consequence of the analysis procedure. These results reveal a new global, cross-frequency (10–100 Hz) neuronal process reflected in a significant reduction of the power spectrum slope of the ECoG signal.

scholarly journals Origins of 1/f-like tissue oxygenation fluctuations in the murine cortex

2020 ◽  
Author(s):  
Qingguang Zhang ◽  
Kyle W. Gheres ◽  
Patrick J. Drew
Keyword(s):  
Neural Activity ◽  
Power Distribution ◽  
Tissue Oxygenation ◽  
Field Potential ◽  
Two Photon ◽  
Stochastic Fluctuations ◽  
Discrete Nature ◽  
Limited Power ◽  
Band Limited ◽  
The Brain

AbstractThe concentration of oxygen in the brain spontaneously fluctuates, and the power distribution in these fluctuations has 1/f-like dynamics. Though these oscillations have been interpreted as being driven by neural activity, the origins of these 1/f-like oscillations is not well understood. Here, to gain insight of the origin of the 1/f-like oxygen fluctuations, we investigated the dynamics of tissue oxygenation and neural activity in awake behaving mice. We found that oxygen signal recorded from the cortex of mice had 1/f-like spectra. However, band-limited power in the local field potential, did not show corresponding 1/f-like fluctuations. When local neural activity was suppressed, the 1/f-like fluctuations in oxygen concentration persisted. Two-photon measurements of erythrocyte spacing fluctuations (‘stalls’) and mathematical modelling show that stochastic fluctuations in erythrocyte flow and stalling could underlie 1/f-like dynamics in oxygenation. These results show discrete nature of erythrocytes and their irregular flow, rather than neural activity, could drive 1/f-like fluctuations in tissue oxygenation.

scholarly journals Origins of 1/f-like tissue oxygenation fluctuations in the murine cortex

PLoS Biology ◽  
2021 ◽  
Vol 19 (7) ◽  
pp. e3001298
Author(s):  
Qingguang Zhang ◽  
Kyle W. Gheres ◽  
Patrick J. Drew
Keyword(s):  
Neural Activity ◽  
Tissue Oxygenation ◽  
Field Potential ◽  
Low Frequencies ◽  
Two Photon ◽  
Stochastic Fluctuations ◽  
Discrete Nature ◽  
Limited Power ◽  
Band Limited ◽  
Distribution Of Power

The concentration of oxygen in the brain spontaneously fluctuates, and the distribution of power in these fluctuations has a 1/f-like spectra, where the power present at low frequencies of the power spectrum is orders of magnitude higher than at higher frequencies. Though these oscillations have been interpreted as being driven by neural activity, the origin of these 1/f-like oscillations is not well understood. Here, to gain insight of the origin of the 1/f-like oxygen fluctuations, we investigated the dynamics of tissue oxygenation and neural activity in awake behaving mice. We found that oxygen signal recorded from the cortex of mice had 1/f-like spectra. However, band-limited power in the local field potential did not show corresponding 1/f-like fluctuations. When local neural activity was suppressed, the 1/f-like fluctuations in oxygen concentration persisted. Two-photon measurements of erythrocyte spacing fluctuations and mathematical modeling show that stochastic fluctuations in erythrocyte flow could underlie 1/f-like dynamics in oxygenation. These results suggest that the discrete nature of erythrocytes and their irregular flow, rather than fluctuations in neural activity, could drive 1/f-like fluctuations in tissue oxygenation.

scholarly journals Superimposed gratings induce diverse response patterns of gamma oscillations in primary visual cortex

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bin Wang ◽  
Chuanliang Han ◽  
Tian Wang ◽  
Weifeng Dai ◽  
Yang Li ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Field Potential ◽  
Gamma Oscillations ◽  
Neural Mechanisms ◽  
Model Parameters ◽  
Response Patterns ◽  
Region Difference ◽  
High Gamma ◽  
Spiking Activity

AbstractStimulus-dependence of gamma oscillations (GAMMA, 30–90 Hz) has not been fully understood, but it is important for revealing neural mechanisms and functions of GAMMA. Here, we recorded spiking activity (MUA) and the local field potential (LFP), driven by a variety of plaids (generated by two superimposed gratings orthogonal to each other and with different contrast combinations), in the primary visual cortex of anesthetized cats. We found two distinct narrow-band GAMMAs in the LFPs and a variety of response patterns to plaids. Similar to MUA, most response patterns showed that the second grating suppressed GAMMAs driven by the first one. However, there is only a weak site-by-site correlation between cross-orientation interactions in GAMMAs and those in MUAs. We developed a normalization model that could unify the response patterns of both GAMMAs and MUAs. Interestingly, compared with MUAs, the GAMMAs demonstrated a wider range of model parameters and more diverse response patterns to plaids. Further analysis revealed that normalization parameters for high GAMMA, but not those for low GAMMA, were significantly correlated with the discrepancy of spatial frequency between stimulus and sites’ preferences. Consistent with these findings, normalization parameters and diversity of high GAMMA exhibited a clear transition trend and region difference between area 17 to 18. Our results show that GAMMAs are also regulated in the form of normalization, but that the neural mechanisms for these normalizations might differ from those of spiking activity. Normalizations in different brain signals could be due to interactions of excitation and inhibitions at multiple stages in the visual system.

scholarly journals Direct electrical stimulation of human cortex evokes high gamma activity that predicts conscious somatosensory perception

2018 ◽  
Vol 15 (2) ◽  
pp. 026015 ◽  
Author(s):  
Leah Muller ◽  
John D Rolston ◽  
Neal P Fox ◽  
Robert Knowlton ◽  
Vikram R Rao ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Gamma Activity ◽  
Direct Electrical Stimulation ◽  
Human Cortex ◽  
High Gamma ◽  
Stimulation Of

Band‐limited power flow into enclosures. II

1980 ◽  
Vol 67 (3) ◽  
pp. 823-826 ◽  
Author(s):  
L. D. Pope ◽  
J. F. Wilby
Keyword(s):  
Power Flow ◽  
Limited Power ◽  
Band Limited

Phasic basal ganglia activity associated with high-gamma oscillation during sleep in a songbird

2012 ◽  
Vol 107 (1) ◽  
pp. 424-432 ◽  
Author(s):  
Shin Yanagihara ◽  
Neal A. Hessler
Keyword(s):  
Basal Ganglia ◽  
Phase Locking ◽  
Critical Role ◽  
Field Potential ◽  
Vocal Plasticity ◽  
Song System ◽  
Gamma Frequency ◽  
High Gamma ◽  
Area X

The basal ganglia is thought to be critical for motor control and learning in mammals. In specific basal ganglia regions, gamma frequency oscillations occur during various behavioral states, including sleeping periods. Given the critical role of sleep in regulating vocal plasticity of songbirds, we examined the presence of such oscillations in the basal ganglia. In the song system nucleus Area X, epochs of high-gamma frequency (80–160 Hz) oscillation of local field potential during sleep were associated with phasic increases of neural activity. While birds were awake, activity of the same neurons increased specifically when birds were singing. Furthermore, during sleep there was a clear tendency for phase locking of spikes to these oscillations. Such patterned activity in the sleeping songbird basal ganglia could play a role in off-line processing of song system motor networks.

scholarly journals Nonuniform High-Gamma (60-500 Hz) Power Changes Dissociate Cognitive Task and Anatomy in Human Cortex

2011 ◽  
Vol 31 (6) ◽  
pp. 2091-2100 ◽  
Author(s):  
C. M. Gaona ◽  
M. Sharma ◽  
Z. V. Freudenburg ◽  
J. D. Breshears ◽  
D. T. Bundy ◽  
...  
Keyword(s):  
Cognitive Task ◽  
Human Cortex ◽  
High Gamma

scholarly journals Dynamics of the functional link between area MT LFPs and motion detection

2015 ◽  
Vol 114 (1) ◽  
pp. 80-98 ◽  
Author(s):  
Jackson E. T. Smith ◽  
Vincent Beliveau ◽  
Alan Schoen ◽  
Jordana Remz ◽  
Chang'an A. Zhan ◽  
...  
Keyword(s):  
Temporal Dynamics ◽  
Field Potential ◽  
Wide Band ◽  
Detection Performance ◽  
Common Input ◽  
Spike Response ◽  
Functional Link ◽  
Area Mt ◽  
Temporal Area ◽  
High Gamma

The evolution of a visually guided perceptual decision results from multiple neural processes, and recent work suggests that signals with different neural origins are reflected in separate frequency bands of the cortical local field potential (LFP). Spike activity and LFPs in the middle temporal area (MT) have a functional link with the perception of motion stimuli (referred to as neural-behavioral correlation). To cast light on the different neural origins that underlie this functional link, we compared the temporal dynamics of the neural-behavioral correlations of MT spikes and LFPs. Wide-band activity was simultaneously recorded from two locations of MT from monkeys performing a threshold, two-stimuli, motion pulse detection task. Shortly after the motion pulse occurred, we found that high-gamma (100–200 Hz) LFPs had a fast, positive correlation with detection performance that was similar to that of the spike response. Beta (10–30 Hz) LFPs were negatively correlated with detection performance, but their dynamics were much slower, peaked late, and did not depend on stimulus configuration or reaction time. A late change in the correlation of all LFPs across the two recording electrodes suggests that a common input arrived at both MT locations prior to the behavioral response. Our results support a framework in which early high-gamma LFPs likely reflected fast, bottom-up, sensory processing that was causally linked to perception of the motion pulse. In comparison, late-arriving beta and high-gamma LFPs likely reflected slower, top-down, sources of neural-behavioral correlation that originated after the perception of the motion pulse.

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