scholarly journals Theta-gamma cascades and running speed

2019 ◽  
Vol 121 (2) ◽  
pp. 444-458 ◽  
Author(s):  
A. Sheremet ◽  
J. P. Kennedy ◽  
Y. Qin ◽  
Y. Zhou ◽  
S. D. Lovett ◽  
...  
Keyword(s):  
Alternative Hypothesis ◽  
Field Potential ◽  
Gamma Oscillations ◽  
High Amplitude ◽  
Energy Cascade ◽  
Running Speed ◽  
Behavioral Correlates ◽  
Lower Amplitude ◽  
Phase Amplitude ◽  
The Brain

Oscillations in the hippocampal local field potential at theta and gamma frequencies are prominent during awake behavior and have demonstrated several behavioral correlates. Both oscillations have been observed to increase in amplitude and frequency as a function of running speed. Previous investigations, however, have examined the relationship between speed and each of these oscillation bands separately. Based on energy cascade models where “…perturbations of slow frequencies cause a cascade of energy dissipation at all frequency scales” (Buzsaki G. Rhythms of the Brain, 2006), we hypothesized that cross-frequency interactions between theta and gamma should increase as a function of speed. We examined these relationships across multiple layers of the CA1 subregion, which correspond to synaptic zones receiving different afferents. Across layers, we found a reliable correlation between the power of theta and the power of gamma, indicative of an amplitude-amplitude relationship. Moreover, there was an increase in the coherence between the power of gamma and the phase of theta, demonstrating increased phase-amplitude coupling with speed. Finally, at higher velocities, phase entrainment between theta and gamma increases. These results have important implications and provide new insights regarding how theta and gamma are integrated for neuronal circuit dynamics, with coupling strength determined by the excitatory drive within the hippocampus. Specifically, rather than arguing that different frequencies can be attributed to different psychological processes, we contend that cognitive processes occur across multiple frequency bands simultaneously with organization occurring as a function of the amount of energy iteratively propagated through the brain. NEW & NOTEWORTHY Often, the theta and gamma oscillations in the hippocampus have been believed to be a consequence of two marginally overlapping phenomena. This perspective, however, runs counter to an alternative hypothesis in which a slow-frequency, high-amplitude oscillation provides energy that cascades into higher frequency, lower amplitude oscillations. We found that as running speed increases, all measures of cross-frequency theta-gamma coupling intensify, providing evidence in favor of the energy cascade hypothesis.

Hippocampal-prefrontal theta coupling develops as mice become proficient in associative odorant discrimination learning

2021 ◽  
Author(s):  
Daniel Ramirez-Gordillo ◽  
Andrew A. Parra ◽  
K. Ulrich Bayer ◽  
Diego Restrepo
Keyword(s):  
Learning And Memory ◽  
Discrimination Learning ◽  
Gamma Oscillations ◽  
Oscillatory Activity ◽  
Dependent Protein Kinase ◽  
Dependent Protein ◽  
Theta Phase ◽  
Phase Amplitude ◽  
The Brain

Learning and memory requires coordinated activity between different regions of the brain. Here we studied the interaction between medial prefrontal cortex (mPFC) and hippocampal dorsal CA1 during associative odorant discrimination learning in the mouse. We found that as the animal learns to discriminate odorants in a go-no go task the coupling of high frequency neural oscillations to the phase of theta oscillations (phase-amplitude coupling or PAC) changes in a manner that results in divergence between rewarded and unrewarded odorant-elicited changes in the theta-phase referenced power (tPRP) for beta and gamma oscillations. In addition, in the proficient animal there was a decrease in the coordinated oscillatory activity between CA1 and mPFC in the presence of the unrewarded odorant. Furthermore, the changes in PAC resulted in a marked increase in the accuracy for decoding odorant identity from tPRP when the animal became proficient. Finally, we studied the role of Ca2+/calmodulin-dependent protein kinase II α (CaMKIIα), a protein involved in learning and memory, in oscillatory neural processing in this task. We find that the accuracy for decoding the odorant identity from tPRP decreases in CaMKIIα knockout mice and that this accuracy correlates with behavioral performance. These results implicate a role for PAC and CaMKIIα in olfactory go-no go associative learning in the hippocampal-prefrontal circuit.

scholarly journals The Generation and Modulation of Distinct Gamma Oscillations with Local, Horizontal, and Feedback Connections in the Primary Visual Cortex: A Model Study on Large-Scale Networks

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Chuanliang Han ◽  
Tian Wang ◽  
Yujie Wu ◽  
Yang Li ◽  
Yi Yang ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Information Integration ◽  
Large Scale ◽  
Spatial Scales ◽  
Field Potential ◽  
Gamma Oscillations ◽  
Gamma Oscillation ◽  
Response Property ◽  
The Brain

Gamma oscillation (GAMMA) in the local field potential (LFP) is a synchronized activity commonly found in many brain regions, and it has been thought as a functional signature of network connectivity in the brain, which plays important roles in information processing. Studies have shown that the response property of GAMMA is related to neural interaction through local recurrent connections (RC), feed-forward (FF), and feedback (FB) connections. However, the relationship between GAMMA and long-range horizontal connections (HC) in the brain remains unclear. Here, we aimed to understand this question in a large-scale network model for the primary visual cortex (V1). We created a computational model composed of multiple excitatory and inhibitory units with biologically plausible connectivity patterns for RC, FF, FB, and HC in V1; then, we quantitated GAMMA in network models at different strength levels of HC and other connection types. Surprisingly, we found that HC and FB, the two types of large-scale connections, play very different roles in generating and modulating GAMMA. While both FB and HC modulate a fast gamma oscillation (around 50-60 Hz) generated by FF and RC, HC generates a new GAMMA oscillating around 30 Hz, whose power and peak frequency can also be modulated by FB. Furthermore, response properties of the two GAMMAs in a network with both HC and FB are different in a way that is highly consistent with a recent experimental finding for distinct GAMMAs in macaque V1. The results suggest that distinct GAMMAs are signatures for neural connections in different spatial scales and they might be related to different functions for information integration. Our study, for the first time, pinpoints the underlying circuits for distinct GAMMAs in a mechanistic model for macaque V1, which might provide a new framework to study multiple gamma oscillations in other cortical regions.

scholarly journals Theta-Gamma Cascades and Running Speed

2018 ◽  
Author(s):  
A. Sheremet ◽  
J.P. Kennedy ◽  
Y. Qin ◽  
Y. Zhou ◽  
S.D. Lovett ◽  
...  
Keyword(s):  
Field Potentials ◽  
Running Speed ◽  
Behavioral Correlates ◽  
Electrical Currents ◽  
Cascade Models ◽  
Gamma Frequencies ◽  
Phase Amplitude ◽  
The Relationship ◽  
Reliable Correlation ◽  
Excitatory Drive

AbstractThe local field potentials (LFPs) of the hippocampus are primarily generated by the spatiotemporal accretion of electrical currents via activated synapses. Oscillations in the hippocampal LFP at theta and gamma frequencies are prominent during awake-behavior and have demonstrated several behavioral correlates. In particular, both oscillations have been observed to increase in amplitude and frequency as a function of running velocity. Previous investigations, however, have examined the relationship between velocity and each of these oscillation bands separately. Based on energy cascade models where “…perturbations of slow frequencies cause a cascade of energy dissipation at all frequency scales” (Buzsaki 2006), we hypothesized that the cross-frequency interactions between theta and gamma should increase as a function of velocity. We examined these relationships across multiple layers of the CA1 subregion and found a reliable correlation between the power of theta and the power of gamma, indicative of an amplitude-amplitude relationship. Moreover, there was an increase in the coherence between the power of gamma and the phase of theta, demonstrating increased phase-amplitude coupling with velocity. Finally, at higher velocities, phase entrainment between theta and gamma becomes stronger. These results have important implications and provide new insights regarding how theta and gamma are integrated for neuronal circuit dynamics, with coupling strength determined by the excitatory drive within the hippocampus.

Aluminum Suppresses Effect of Nicotine on Gamma Oscillations (20-40 Hz) in Mouse Hippocampal Slices

2018 ◽  
Vol 17 (6) ◽  
pp. 404-411 ◽  
Author(s):  
Syeda Mehpara Farhat ◽  
Touqeer Ahmed
Keyword(s):  
Nicotinic Acetylcholine Receptors ◽  
Cholinergic System ◽  
Acetylcholine Receptors ◽  
Peak Power ◽  
Hippocampal Slices ◽  
Field Potential ◽  
Gamma Oscillations ◽  
Gamma Oscillation ◽  
Facilitatory Effect

Background: Aluminum (Al) causes neurodegeneration and its toxic effects on cholinergic system in the brain is well documented. However, it is unknown whether and how Al changes oscillation patterns, driven by the cholinergic system, in the hippocampus. Objective: We studied acute effects of Al on nicotinic acetylcholine receptors (nAChRs)-mediated modulation of persistent gamma oscillations in the hippocampus. Method: The field potential recording was done in CA3 area of acute hippocampal slices. Results: Carbachol-induced gamma oscillation peak power increased (1.32±0.09mV2/Hz, P<0.01) in control conditions (without Al) by application of 10µM nicotine as compared to baseline value normalized to 1. This nicotine-induced facilitation of gamma oscillation peak power was found to depend on non-α7 nAChRs. In slices with Al pre-incubation for three to four hours, gamma oscillation peak power was reduced (5.4±1.8mV2/Hz, P<0.05) and facilitatory effect of nicotine on gamma oscillation peak power was blocked as compared to the control (18.06±2.1mV2/Hz) or one hour Al pre-incubated slices (11.3±2.5mV2/Hz). Intriguingly wash-out, after three to four hours of Al incubation, failed to restore baseline oscillation power and its facilitation by nicotine as no difference was observed in gamma oscillation peak power between Al wash-out slices (3.4±1.1mV2/Hz) and slices without washout (3.6±0.9mV2/Hz). Conclusion: This study shows that at cellular level, exposure of hippocampal tissue to Al compromised nAChR-mediated facilitation of cholinergic hippocampal gamma oscillations. Longer in vitro Al exposure caused permanent changes in hippocampal oscillogenic circuitry and changed its sensitivity to nAChR-modulation. This study will help to understand the possible mechanism of cognitive decline induced by Al.

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 Population dynamics of the modified theta model: macroscopic phase reduction and bifurcation analysis link microscopic neuronal interactions to macroscopic gamma oscillation

2014 ◽  
Vol 11 (95) ◽  
pp. 20140058 ◽  
Author(s):  
Kiyoshi Kotani ◽  
Ikuhiro Yamaguchi ◽  
Lui Yoshida ◽  
Yasuhiko Jimbo ◽  
G. Bard Ermentrout
Keyword(s):  
Bifurcation Analysis ◽  
Field Potential ◽  
Reversal Potential ◽  
Planck Equation ◽  
Gamma Oscillations ◽  
Gamma Oscillation ◽  
Synaptic Coupling ◽  
Time Constants ◽  
Shunting Inhibition ◽  
Synaptic Interactions

Gamma oscillations of the local field potential are organized by collective dynamics of numerous neurons and have many functional roles in cognition and/or attention. To mathematically and physiologically analyse relationships between individual inhibitory neurons and macroscopic oscillations, we derive a modification of the theta model, which possesses voltage-dependent dynamics with appropriate synaptic interactions. Bifurcation analysis of the corresponding Fokker–Planck equation (FPE) enables us to consider how synaptic interactions organize collective oscillations. We also develop the adjoint method (infinitesimal phase resetting curve) for simultaneous equations consisting of ordinary differential equations representing synaptic dynamics and a partial differential equation for determining the probability distribution of the membrane potential. This method provides a macroscopic phase response function (PRF), which gives insights into how it is modulated by external perturbation or internal changes of parameters. We investigate the effects of synaptic time constants and shunting inhibition on these gamma oscillations. The sensitivity of rising and decaying time constants is analysed in the oscillatory parameter regions; we find that these sensitivities are not largely dependent on rate of synaptic coupling but, rather, on current and noise intensity. Analyses of shunting inhibition reveal that it can affect both promotion and elimination of gamma oscillations. When the macroscopic oscillation is far from the bifurcation, shunting promotes the gamma oscillations and the PRF becomes flatter as the reversal potential of the synapse increases, indicating the insensitivity of gamma oscillations to perturbations. By contrast, when the macroscopic oscillation is near the bifurcation, shunting eliminates gamma oscillations and a stable firing state appears. More interestingly, under appropriate balance of parameters, two branches of bifurcation are found in our analysis of the FPE. In this case, shunting inhibition can effect both promotion and elimination of the gamma oscillation depending only on the reversal potential.

scholarly journals Frontal eye field microstimulation induces task-dependent gamma oscillations in the lateral intraparietal area

2012 ◽  
Vol 108 (5) ◽  
pp. 1392-1402 ◽  
Author(s):  
Elsie Premereur ◽  
Wim Vanduffel ◽  
Pieter R. Roelfsema ◽  
Peter Janssen
Keyword(s):  
Spatial Attention ◽  
Field Potential ◽  
Gamma Oscillations ◽  
Oculomotor Control ◽  
Saccade Target ◽  
Frontal Eye Field ◽  
Alpha Power ◽  
Lateral Intraparietal Area ◽  
Electrical Microstimulation ◽  
Gamma Power

Macaque frontal eye fields (FEF) and the lateral intraparietal area (LIP) are high-level oculomotor control centers that have been implicated in the allocation of spatial attention. Electrical microstimulation of macaque FEF elicits functional magnetic resonance imaging (fMRI) activations in area LIP, but no study has yet investigated the effect of FEF microstimulation on LIP at the single-cell or local field potential (LFP) level. We recorded spiking and LFP activity in area LIP during weak, subthreshold microstimulation of the FEF in a delayed-saccade task. FEF microstimulation caused a highly time- and frequency-specific, task-dependent increase in gamma power in retinotopically corresponding sites in LIP: FEF microstimulation produced a significant increase in LIP gamma power when a saccade target appeared and remained present in the LIP receptive field (RF), whereas less specific increases in alpha power were evoked by FEF microstimulation for saccades directed away from the RF. Stimulating FEF with weak currents had no effect on LIP spike rates or on the gamma power during memory saccades or passive fixation. These results provide the first evidence for task-dependent modulations of LFPs in LIP caused by top-down stimulation of FEF. Since the allocation and disengagement of spatial attention in visual cortex have been associated with increases in gamma and alpha power, respectively, the effects of FEF microstimulation on LIP are consistent with the known effects of spatial attention.

Inter- and intra-hemispheric spatiotemporal organization of spontaneous electrocortical oscillations

1996 ◽  
Vol 76 (1) ◽  
pp. 423-437 ◽  
Author(s):  
K. D. MacDonald ◽  
B. Brett ◽  
D. S. Barth
Keyword(s):  
Time Series ◽  
Somatosensory Cortex ◽  
Phase Locking ◽  
Sensory Information ◽  
Gamma Oscillations ◽  
Sensory Cortex ◽  
Electrode Arrays ◽  
Sharp Wave ◽  
Lower Amplitude ◽  
The Right

1. Two 64-channel epipial electrode arrays were positioned on homologous locations of the right and left hemisphere, covering most of primary and secondary auditory and somatosensory cortex in eight lightly anesthetized rats. Array placement was verified with the use of cytochrome oxidase histochemistry. 2. Middle-latency auditory and somatosensory evoked potentials (MAEPs and MSEPs, respectively) and spontaneous oscillations in the frequency range of 20-40 Hz (gamma oscillations) were recorded and found to be spatially constrained to regions of granular cortex, suggesting that both phenomena are closely associated with sensory information processing. 3. The MAEP and MSEP consisted of an initial biphasic sharp wave in primary auditory and somatosensory cortex, respectively, and a similar biphasic sharp wave occurred approximately 4-8 ms later in secondary sensory cortex of the given modality. Averaged gamma oscillations also revealed asynchronous activation of sensory cortex, but with a shorter 2-ms delay between oscillations in primary and secondary regions. Although the long latency shift of the MAEP and MSEP may be due in part to asynchronous activation of parallel thalamocortical projections to primary and secondary sensory cortex, the much shorter shift of gamma oscillations in a given modality is consistent with intracortical coupling of these regions. 4. Gamma oscillations occurred independently in auditory and somatosensory cortex within a given hemisphere. Furthermore, time series averaging revealed that there was no phase-locking of oscillations between the sensory modalities. 5. Gamma oscillations were loosely coupled between hemispheres; oscillations occurring in auditory or somatosensory cortex of one hemisphere were often associated with lower-amplitude oscillations in homologous contralateral sensory cortex. Yet, the fact that time series averaging revealed no interhemispheric phase-locking suggests that the corpus callosum may not coordinate the bilateral gamma oscillations, and that a thalamic modulatory influence may be involved.

scholarly journals Distinct Processing of Selection and Execution Errors in Neural Signatures of Outcome Monitoring

2019 ◽  
Author(s):  
Faisal Mushtaq ◽  
Samuel D. McDougle ◽  
Matt P. Craddock ◽  
Darius E. Parvin ◽  
Jack Brookes ◽  
...  
Keyword(s):  
Behavioral Adjustment ◽  
Behavioral Changes ◽  
Behavioral Correlates ◽  
Feedback Information ◽  
Future Action ◽  
Outcome Monitoring ◽  
Frontal Negativity ◽  
Neural Signature ◽  
The Brain ◽  
Insight Into

AbstractLosing a point playing tennis may result from poor shot selection or poor stroke execution. To explore how the brain responds to these different types of errors, we examined EEG signatures of feedback-related processing while participants performed a simple decision-making task. In Experiment 1, we used a task in which unrewarded outcomes were framed as selection errors, similar to how feedback information is treated in most studies. Consistent with previous work, EEG differences between rewarded and unrewarded trials in the medial frontal negativity (MFN) correlated with behavioral adjustment. In Experiment 2, the task was modified such that unrewarded outcomes could arise from either poor execution or selection. For selection errors, the results replicated that observed in Experiment 1. However, unrewarded outcomes attributed to poor execution produced larger amplitude MFN, alongside an attenuation in activity preceding this component and a subsequent enhanced error positivity (Pe) response in posterior sites. In terms of behavioral correlates, only the degree of the early attenuation and amplitude of the Pe correlated with behavioral adjustment following execution errors relative to reward; the amplitude of the MFN did not correlate with behavioral changes related to execution errors. These results indicate the existence of distinct neural correlates of selection and execution error processing and are consistent with the hypothesis that execution errors can modulate action selection evaluation. More generally, they provide insight into how the brain responds to different classes of error that determine future action.Significance StatementTo learn from mistakes, we must resolve whether decisions that fail to produce rewards are due to poorly selected action plans or badly executed movements. EEG data were obtained to identify and compare the physiological correlates of selection and execution errors, and how these are related to behavioral changes. A neural signature associated with reinforcement learning, a medial frontal negative (MFN) ERP deflection, correlated with behavioral adjustment after selection errors relative to reward outcomes, but not motor execution errors. In contrast, activity preceding and following the MFN response correlated with behavioral adjustment after execution errors relative to reward. These results provide novel insight into how the brain responds to different classes of error that determine future action.

scholarly journals Coherent and intermittent ensemble oscillations emerge from networks of irregular spiking neurons

2016 ◽  
Vol 115 (1) ◽  
pp. 457-469 ◽  
Author(s):  
Mahmood S. Hoseini ◽  
Ralf Wessel
Keyword(s):  
Single Neuron ◽  
Experimental Studies ◽  
Field Potential ◽  
Gamma Oscillations ◽  
Peak Frequency ◽  
Spiking Neurons ◽  
Network Activity ◽  
Cortical Circuits ◽  
Model Network ◽  
Low Rate

Local field potential (LFP) recordings from spatially distant cortical circuits reveal episodes of coherent gamma oscillations that are intermittent, and of variable peak frequency and duration. Concurrently, single neuron spiking remains largely irregular and of low rate. The underlying potential mechanisms of this emergent network activity have long been debated. Here we reproduce such intermittent ensemble oscillations in a model network, consisting of excitatory and inhibitory model neurons with the characteristics of regular-spiking (RS) pyramidal neurons, and fast-spiking (FS) and low-threshold spiking (LTS) interneurons. We find that fluctuations in the external inputs trigger reciprocally connected and irregularly spiking RS and FS neurons in episodes of ensemble oscillations, which are terminated by the recruitment of the LTS population with concurrent accumulation of inhibitory conductance in both RS and FS neurons. The model qualitatively reproduces experimentally observed phase drift, oscillation episode duration distributions, variation in the peak frequency, and the concurrent irregular single-neuron spiking at low rate. Furthermore, consistent with previous experimental studies using optogenetic manipulation, periodic activation of FS, but not RS, model neurons causes enhancement of gamma oscillations. In addition, increasing the coupling between two model networks from low to high reveals a transition from independent intermittent oscillations to coherent intermittent oscillations. In conclusion, the model network suggests biologically plausible mechanisms for the generation of episodes of coherent intermittent ensemble oscillations with irregular spiking neurons in cortical circuits.

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