scholarly journals Neuronal rhythms orchestrate cell assembles to distinguish perceptual categories

2017 ◽  
Author(s):  
Morteza Moazami Goudarzi ◽  
Jason Cromer ◽  
Jefferson Roy ◽  
Earl K. Miller
Keyword(s):  
Prefrontal Cortex ◽  
Local Field ◽  
Local Field Potential ◽  
Field Potential ◽  
Beta Band ◽  
Lateral Prefrontal Cortex ◽  
Category Information ◽  
Oscillatory Rhythms ◽  
Field Coherence ◽  
Local Field Potential Lfp

AbstractCategories are reflected in the spiking activity of neurons. However, how neurons form ensembles for categories is unclear. To address this, we simultaneously recorded spiking and local field potential (LFP) activity in the lateral prefrontal cortex (lPFC) of monkeys performing a delayed match to category task with two independent category sets (Animals: Cats vs Dogs; Cars: Sports Cars vs Sedans). We found stimulus and category information in alpha and beta band oscillations. Different category distinctions engaged different frequencies. There was greater spike field coherence (SFC) in alpha (∼8-14 Hz) for Cats and in beta (∼16-22 Hz) for Dogs. Cars showed similar differences, albeit less pronounced: greater alpha SFC for Sedans and greater beta SFC for Sports Cars. Thus, oscillatory rhythms can help coordinate neurons into different ensembles. Engagement of different frequencies may help differentiate the categories.

scholarly journals Aberrant Auditory Steady-State Response of Awake Mice After Single Application of the NMDA Receptor Antagonist MK-801 Into the Medial Geniculate Body

2020 ◽  
Vol 23 (7) ◽  
pp. 459-468 ◽  
Author(s):  
Xuejiao Wang ◽  
Yingzhuo Li ◽  
Jingyu Chen ◽  
Zijie Li ◽  
Jinhong Li ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Steady State ◽  
Local Field ◽  
Local Field Potential ◽  
Phase Locking ◽  
Field Potential ◽  
Medial Geniculate Body ◽  
Systemic Administration ◽  
Mk 801 ◽  
Medial Geniculate

Abstract Background Systemic administration of noncompetitive N-methyl-D-aspartate receptor (NMDAR) antagonists such as MK-801 is widely used to model psychosis of schizophrenia (SZ). Acute systemic MK-801 in rodents caused an increase of the auditory steady-state responses (ASSRs), the oscillatory neural responses to periodic auditory stimulation, while most studies in patients with SZ reported a decrease of ASSRs. This inconsistency may be attributable to the comprehensive effects of systemic administration of MK-801. Here, we examined how the ASSR is affected by selectively blocking NMDAR in the thalamus. Methods We implanted multiple electrodes in the auditory cortex (AC) and prefrontal cortex to simultaneously record the local field potential and spike activity (SA) of multiple sites from awake mice. Click-trains at a 40-Hz repetition rate were used to evoke the ASSR. We compared the mean trial power and phase-locking factor and the firing rate of SA before and after microinjection of MK-801 (1.5 µg) into the medial geniculate body (MGB). Results We found that both the AC and prefrontal cortex showed a transient local field potential response at the onset of click-train stimulus, which was less affected by the application of MK-801 in the MGB. Following the onset response, the AC also showed a response continuing throughout the stimulus period, corresponding to the ASSR, which was suppressed by the application of MK-801. Conclusion Our data suggest that the MGB is one of the generators of ASSR, and NMDAR hypofunction in the thalamocortical projection may account for the ASSR deficits in SZ.

scholarly journals Comparison of tuning properties of gamma and high-gamma power in local field potential (LFP) versus electrocorticogram (ECoG) in visual cortex

2019 ◽  
Author(s):  
Agrita Dubey ◽  
Supratim Ray
Keyword(s):  
Visual Cortex ◽  
Local Field ◽  
Local Field Potential ◽  
Field Potential ◽  
Gamma Oscillations ◽  
Orientation Contrast ◽  
High Gamma ◽  
Gamma Power ◽  
Electrocorticogram Ecog ◽  
Local Field Potential Lfp

AbstractElectrocorticogram (ECoG), obtained from macroelectrodes placed on the cortex, is typically used in drug-resistant epilepsy patients, and is increasingly being used to study cognition in humans. These studies often use power in gamma (30-70 Hz) or high-gamma (>80 Hz) ranges to make inferences about neural processing. However, while the stimulus tuning properties of gamma/high-gamma power have been well characterized in local field potential (LFP; obtained from microelectrodes), analogous characterization has not been done for ECoG. Using a hybrid array containing both micro and ECoG electrodes implanted in the primary visual cortex of two female macaques, we compared the stimulus tuning preferences of gamma/high-gamma power in LFP versus ECoG and found them to be surprisingly similar. High-gamma power, thought to index the average firing rate around the electrode, was highest for the smallest stimulus (0.3° radius), and decreased with increasing size in both LFP and ECoG, suggesting local origins of both signals. Further, gamma oscillations were similarly tuned in LFP and ECoG to stimulus orientation, contrast and spatial frequency. This tuning was significantly weaker in electroencephalogram (EEG), suggesting that ECoG is more like LFP than EEG. Overall, our results validate the use of ECoG in clinical and basic cognitive research.

scholarly journals Novel Porous Brain Electrodes for Augmented Local Field Potential Signal Detection

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 542 ◽  
Author(s):  
Sung Lee ◽  
Kyeong-Seok Lee ◽  
Saurav Sorcar ◽  
Abdul Razzaq ◽  
Maan-Gee Lee ◽  
...  
Keyword(s):  
Local Field ◽  
Local Field Potential ◽  
Brain Activity ◽  
Field Potential ◽  
Porous Electrodes ◽  
Surface Topology ◽  
Neural Electrode ◽  
Flow Of Information ◽  
Potential Signal ◽  
Local Field Potential Lfp

Intracerebral local field potential (LFP) measurements are commonly used to monitor brain activity, providing insight into the flow of information across neural networks. Herein we describe synthesis and application of a neural electrode possessing a nano/micro-scale porous surface topology for improved LFP measurement. Compared with conventional brain electrodes, the porous electrodes demonstrate higher measured amplitudes with lower noise levels.

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 How Global Are Olfactory Bulb Oscillations?

2010 ◽  
Vol 104 (3) ◽  
pp. 1768-1773 ◽  
Author(s):  
Leslie M. Kay ◽  
Philip Lazzara
Keyword(s):  
Olfactory Bulb ◽  
Local Field ◽  
Local Field Potential ◽  
Field Potential ◽  
Beta Band ◽  
Recording Site ◽  
Potential Oscillations ◽  
Frequency Bands ◽  
Surface Electrodes ◽  
Analysis Window

Previous studies in waking animals have shown that the frequency structure of olfactory bulb (OB) local field potential oscillations is very similar across the OB, but large low-impedance surface electrodes may have favored highly coherent events, averaging out local inhomogeneities. We tested the hypothesis that OB oscillations represent spatially homogeneous phenomena at all scales. We used pairs of concentric electrodes (200 μm outer shaft surrounding an inner 2–3 μm recording site) beginning on the dorsal OB at anterior and medial locations in urethane-anesthetized rats and measured local field potential responses at successive 200 μm depths before and during odor stimulation. Within locations (outer vs. inner lead on a single probe), on the time scale of 0.5 s, coherence in all frequency bands was significant, but on larger time scales (10 s), only respiratory (1–4 Hz) and beta (15–30 Hz) oscillations showed prominent peaks. Across locations, coherence in all frequency bands was significantly lower for both sizes of electrodes at all depths but the most superficial 600 μm. Near the pial surface, coherence across outer (larger) electrodes at different sites was equal to coherence across outer and inner (small) electrodes within a single site and larger than coherence across inner electrodes at different sites. Overall, the beta band showed the largest coherence across bulbar sites and electrodes. Therefore larger electrodes at the surface of the OB favor globally coherent events, and at all depths, coherence depends on the type of oscillation (beta or gamma) and duration of the analysis window.

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.

scholarly journals Effect of propofol on local field potential in rat prefrontal cortex during working memory task

2012 ◽  
Vol 02 (03) ◽  
pp. 166-171
Author(s):  
Xinyu Xu ◽  
Guolin Wang ◽  
Wenqian Zhai ◽  
Wenwen Bai ◽  
Tiaotiao Liu ◽  
...  
Keyword(s):  
Working Memory ◽  
Prefrontal Cortex ◽  
Local Field ◽  
Local Field Potential ◽  
Memory Task ◽  
Field Potential
Sign in / Sign up

Export Citation Format

Share Document