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Fernandez-Ruiz A, Sirota A, Lopes-Dos-Santos V, Dupret D. Over and above frequency: Gamma oscillations as units of neural circuit operations. Neuron 2023; 111:936-953. [PMID: 37023717 PMCID: PMC7614431 DOI: 10.1016/j.neuron.2023.02.026] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 11/30/2022] [Accepted: 02/16/2023] [Indexed: 04/08/2023]
Abstract
Gamma oscillations (∼30-150 Hz) are widespread correlates of neural circuit functions. These network activity patterns have been described across multiple animal species, brain structures, and behaviors, and are usually identified based on their spectral peak frequency. Yet, despite intensive investigation, whether gamma oscillations implement causal mechanisms of specific brain functions or represent a general dynamic mode of neural circuit operation remains unclear. In this perspective, we review recent advances in the study of gamma oscillations toward a deeper understanding of their cellular mechanisms, neural pathways, and functional roles. We discuss that a given gamma rhythm does not per se implement any specific cognitive function but rather constitutes an activity motif reporting the cellular substrates, communication channels, and computational operations underlying information processing in its generating brain circuit. Accordingly, we propose shifting the attention from a frequency-based to a circuit-level definition of gamma oscillations.
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Affiliation(s)
| | - Anton Sirota
- Bernstein Center for Computational Neuroscience, Faculty of Medicine, Ludwig-Maximilians Universität München, Planegg-Martinsried, Germany.
| | - Vítor Lopes-Dos-Santos
- Medical Research Council Brain Network Dynamics Unit, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK.
| | - David Dupret
- Medical Research Council Brain Network Dynamics Unit, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK.
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2
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Sánchez-Claros J, Pariz A, Valizadeh A, Canals S, Mirasso CR. Information Transmission in Delay-Coupled Neuronal Circuits in the Presence of a Relay Population. Front Syst Neurosci 2021; 15:705371. [PMID: 34393731 PMCID: PMC8357994 DOI: 10.3389/fnsys.2021.705371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 06/30/2021] [Indexed: 12/04/2022] Open
Abstract
Synchronization between neuronal populations is hypothesized to play a crucial role in the communication between brain networks. The binding of features, or the association of computations occurring in spatially segregated areas, is supposed to take place when a stable synchronization between cortical areas occurs. While a direct cortico-cortical connection typically fails to support this mechanism, the participation of a third area, a relay element, mediating in the communication was proposed to overcome this limitation. Among the different structures that could play the role of coordination during the binding process, the thalamus is the best placed region to carry out this task. In this paper we study how information flows in a canonical motif that mimics a cortico-thalamo-cortical circuit composed by three mutually coupled neuronal populations (also called the V-motif). Through extensive numerical simulations, we found that the amount of information transferred between the oscillating neuronal populations is determined by the delay in their connections and the mismatch in their oscillation frequencies (detuning). While the transmission from a cortical population is mostly restricted to positive detuning, transmission from the relay (thalamic) population to the cortical populations is robust for a broad range of detuning values, including negative values, while permitting feedback communication from the cortex at high frequencies, thus supporting robust bottom up and top down interaction. In this case, a strong feedback transmission between the cortex to thalamus supports the possibility of robust bottom-up and top-down interactions in this motif. Interestingly, adding a cortico-cortical bidirectional connection to the V-motif (C-motif) expands the dynamics of the system with distinct operation modes. While overall transmission efficiency is decreased, new communication channels establish cortico-thalamo-cortical association loops. Switching between operation modes depends on the synaptic strength of the cortico-cortical connections. Our results support a role of the transthalamic V-motif in the binding of spatially segregated cortical computations, and suggest an important regulatory role of the direct cortico-cortical connection.
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Affiliation(s)
- Jaime Sánchez-Claros
- Instituto de Física Interdisciplinar y Sistemas Complejos (IFISC, UIB-CSIC), Campus UIB, Palma de Mallorca, Spain
| | - Aref Pariz
- Institute for Advanced Studies in Basic Sciences, Zanjan, Iran.,Department of Biology, University of Ottawa, Ottawa, ON, Canada
| | | | - Santiago Canals
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas, Universidad Miguel Hernández, Sant Joan d'Alacant, Spain
| | - Claudio R Mirasso
- Instituto de Física Interdisciplinar y Sistemas Complejos (IFISC, UIB-CSIC), Campus UIB, Palma de Mallorca, Spain
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3
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Sawicki J, Koulen JM, Schöll E. Synchronization scenarios in three-layer networks with a hub. CHAOS (WOODBURY, N.Y.) 2021; 31:073131. [PMID: 34340334 DOI: 10.1063/5.0055835] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 06/22/2021] [Indexed: 06/13/2023]
Abstract
We study various relay synchronization scenarios in a three-layer network, where the middle (relay) layer is a single node, i.e., a hub. The two remote layers consist of non-locally coupled rings of FitzHugh-Nagumo oscillators modeling neuronal dynamics. All nodes of the remote layers are connected to the hub. The role of the hub and its importance for the existence of chimera states are investigated in dependence on the inter-layer coupling strength and inter-layer time delay. Tongue-like regions in the parameter plane exhibiting double chimeras, i.e., chimera states in the remote layers whose coherent cores are synchronized with each other, and salt-and-pepper states are found. At very low intra-layer coupling strength, when chimera states do not exist in single layers, these may be induced by the hub. Also, the influence of the dilution of links between the remote layers and the hub upon the dynamics is investigated. The greatest effect of dilution is observed when links to the coherent domain of the chimeras are removed.
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Affiliation(s)
- Jakub Sawicki
- Potsdam Institute for Climate Impact Research, Telegrafenberg A, 31, 14473 Potsdam, Germany
| | - Julia M Koulen
- Potsdam Institute for Climate Impact Research, Telegrafenberg A, 31, 14473 Potsdam, Germany
| | - Eckehard Schöll
- Potsdam Institute for Climate Impact Research, Telegrafenberg A, 31, 14473 Potsdam, Germany
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4
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Wason TD. A model integrating multiple processes of synchronization and coherence for information instantiation within a cortical area. Biosystems 2021; 205:104403. [PMID: 33746019 DOI: 10.1016/j.biosystems.2021.104403] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 03/05/2021] [Indexed: 12/14/2022]
Abstract
What is the form of dynamic, e.g., sensory, information in the mammalian cortex? Information in the cortex is modeled as a coherence map of a mixed chimera state of synchronous, phasic, and disordered minicolumns. The theoretical model is built on neurophysiological evidence. Complex spatiotemporal information is instantiated through a system of interacting biological processes that generate a synchronized cortical area, a coherent aperture. Minicolumn elements are grouped in macrocolumns in an array analogous to a phased-array radar, modeled as an aperture, a "hole through which radiant energy flows." Coherence maps in a cortical area transform inputs from multiple sources into outputs to multiple targets, while reducing complexity and entropy. Coherent apertures can assume extremely large numbers of different information states as coherence maps, which can be communicated among apertures with corresponding very large bandwidths. The coherent aperture model incorporates considerable reported research, integrating five conceptually and mathematically independent processes: 1) a damped Kuramoto network model, 2) a pumped area field potential, 3) the gating of nearly coincident spikes, 4) the coherence of activity across cortical lamina, and 5) complex information formed through functions in macrocolumns. Biological processes and their interactions are described in equations and a functional circuit such that the mathematical pieces can be assembled the same way the neurophysiological ones are. The model can be conceptually convolved over the specifics of local cortical areas within and across species. A coherent aperture becomes a node in a graph of cortical areas with a corresponding distribution of information.
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Affiliation(s)
- Thomas D Wason
- North Carolina State University, Department of Biological Sciences, Meitzen Laboratory, Campus Box 7617, 128 David Clark Labs, Raleigh, NC 27695-7617, USA.
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5
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Malagarriga D, Pons AJ, Villa AEP. Complex temporal patterns processing by a neural mass model of a cortical column. Cogn Neurodyn 2019; 13:379-392. [PMID: 31354883 PMCID: PMC6624230 DOI: 10.1007/s11571-019-09531-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 03/05/2019] [Accepted: 04/02/2019] [Indexed: 12/22/2022] Open
Abstract
It is well known that neuronal networks are capable of transmitting complex spatiotemporal information in the form of precise sequences of neuronal discharges characterized by recurrent patterns. At the same time, the synchronized activity of large ensembles produces local field potentials that propagate through highly dynamic oscillatory waves, such that, at the whole brain scale, complex spatiotemporal dynamics of electroencephalographic (EEG) signals may be associated to sensorimotor decision making processes. Despite these experimental evidences, the link between highly temporally organized input patterns and EEG waves has not been studied in detail. Here, we use a neural mass model to investigate to what extent precise temporal information, carried by deterministic nonlinear attractor mappings, is filtered and transformed into fluctuations in phase, frequency and amplitude of oscillatory brain activity. The phase shift that we observe, when we drive the neural mass model with specific chaotic inputs, shows that the local field potential amplitude peak appears in less than one full cycle, thus allowing traveling waves to encode temporal information. After converting phase and amplitude changes obtained into point processes, we quantify input-output similarity following a threshold-filtering algorithm onto the amplitude wave peaks. Our analysis shows that the neural mass model has the capacity for gating the input signal and propagate selected temporal features of that signal. Finally, we discuss the effect of local excitatory/inhibitory balance on these results and how excitability in cortical columns, controlled by neuromodulatory innervation of the cerebral cortex, may contribute to set a fine tuning and gating of the information fed to the cortex.
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Affiliation(s)
- Daniel Malagarriga
- Departament de Física, Universitat Politècnica de Catalunya, Edifici Gaia, Rambla Sant Nebridi 22, 08222 Terrassa, Spain
- Neuroheuristic Research Group, University of Lausanne, 1015 Lausanne, Switzerland
| | - Antonio J. Pons
- Departament de Física, Universitat Politècnica de Catalunya, Edifici Gaia, Rambla Sant Nebridi 22, 08222 Terrassa, Spain
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6
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John YJ, Zikopoulos B, Bullock D, Barbas H. Visual Attention Deficits in Schizophrenia Can Arise From Inhibitory Dysfunction in Thalamus or Cortex. COMPUTATIONAL PSYCHIATRY (CAMBRIDGE, MASS.) 2018; 2:223-257. [PMID: 30627672 PMCID: PMC6317791 DOI: 10.1162/cpsy_a_00023] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 10/17/2018] [Indexed: 01/13/2023]
Abstract
Schizophrenia is associated with diverse cognitive deficits, including disorders of attention-related oculomotor behavior. At the structural level, schizophrenia is associated with abnormal inhibitory control in the circuit linking cortex and thalamus. We developed a spiking neural network model that demonstrates how dysfunctional inhibition can degrade attentive gaze control. Our model revealed that perturbations of two functionally distinct classes of cortical inhibitory neurons, or of the inhibitory thalamic reticular nucleus, disrupted processing vital for sustained attention to a stimulus, leading to distractibility. Because perturbation at each circuit node led to comparable but qualitatively distinct disruptions in attentive tracking or fixation, our findings support the search for new eye movement metrics that may index distinct underlying neural defects. Moreover, because the cortico-thalamic circuit is a common motif across sensory, association, and motor systems, the model and extensions can be broadly applied to study normal function and the neural bases of other cognitive deficits in schizophrenia.
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Affiliation(s)
- Yohan J. John
- Neural Systems Laboratory, Department of Health Sciences, Boston University, Boston, Massachusetts, USA
| | - Basilis Zikopoulos
- Human Systems Neuroscience Laboratory, Department of Health Sciences, Boston University, Boston, Massachusetts, USA
- Graduate Program for Neuroscience, Boston University, and School of Medicine, Boston, Massachusetts, USA
| | - Daniel Bullock
- Graduate Program for Neuroscience, Boston University, and School of Medicine, Boston, Massachusetts, USA
- Department of Psychological and Brain Sciences, Boston University, Boston, Massachusetts, USA
| | - Helen Barbas
- Neural Systems Laboratory, Department of Health Sciences, Boston University, Boston, Massachusetts, USA
- Graduate Program for Neuroscience, Boston University, and School of Medicine, Boston, Massachusetts, USA
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7
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Pereda E, García-Torres M, Melián-Batista B, Mañas S, Méndez L, González JJ. The blessing of Dimensionality: Feature Selection outperforms functional connectivity-based feature transformation to classify ADHD subjects from EEG patterns of phase synchronisation. PLoS One 2018; 13:e0201660. [PMID: 30114248 PMCID: PMC6095525 DOI: 10.1371/journal.pone.0201660] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 07/19/2018] [Indexed: 11/19/2022] Open
Abstract
Functional connectivity (FC) characterizes brain activity from a multivariate set of N brain signals by means of an NxN matrix A, whose elements estimate the dependence within each possible pair of signals. Such matrix can be used as a feature vector for (un)supervised subject classification. Yet if N is large, A is highly dimensional. Little is known on the effect that different strategies to reduce its dimensionality may have on its classification ability. Here, we apply different machine learning algorithms to classify 33 children (age [6-14 years]) into two groups (healthy controls and Attention Deficit Hyperactivity Disorder patients) using EEG FC patterns obtained from two phase synchronisation indices. We found that the classification is highly successful (around 95%) if the whole matrix A is taken into account, and the relevant features are selected using machine learning methods. However, if FC algorithms are applied instead to transform A into a lower dimensionality matrix, the classification rate drops to less than 80%. We conclude that, for the purpose of pattern classification, the relevant features should be selected among the elements of A by using appropriate machine learning algorithms.
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Affiliation(s)
- Ernesto Pereda
- Electrical Engineering and Bioengineering Group, Department of Industrial Engineering & Instituto Universitario de Neurociencia (IUNE), Universidad de La Laguna, Santa Cruz de Tenerife, Spain
- Lab. of Cognitive and Computational Neuroscience, CTB, UPM, Madrid, Spain
- Dept. of Data Analysis, Faculty of Psychological and Educational Sciences, Ghent, Belgium
| | - Miguel García-Torres
- Division of Computer Science, Universidad Pablo de Olavide, ES-41013 Seville, Spain
| | - Belén Melián-Batista
- Department of Informatics and Systems Engineering, University of La Laguna, Santa Cruz de Tenerife, Spain
| | - Soledad Mañas
- Unit of Clinical Neurophysiology, Teaching Hospital Ntra. Sra. de La Candelaria, Santa Cruz de Tenerife, Spain
| | - Leopoldo Méndez
- Unit of Clinical Neurophysiology, Teaching Hospital Ntra. Sra. de La Candelaria, Santa Cruz de Tenerife, Spain
| | - Julián J. González
- Department of Basic Medical Sciences, University of La Laguna, Santa Cruz de Tenerife, Spain
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8
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The cortical focus in childhood absence epilepsy; evidence from nonlinear analysis of scalp EEG recordings. Clin Neurophysiol 2018; 129:602-617. [DOI: 10.1016/j.clinph.2017.11.029] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 11/05/2017] [Accepted: 11/29/2017] [Indexed: 11/19/2022]
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9
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Mirasso CR, Carelli PV, Pereira T, Matias FS, Copelli M. Anticipated and zero-lag synchronization in motifs of delay-coupled systems. CHAOS (WOODBURY, N.Y.) 2017; 27:114305. [PMID: 29195321 DOI: 10.1063/1.5006932] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Anticipated and zero-lag synchronization have been observed in different scientific fields. In the brain, they might play a fundamental role in information processing, temporal coding and spatial attention. Recent numerical work on anticipated and zero-lag synchronization studied the role of delays. However, an analytical understanding of the conditions for these phenomena remains elusive. In this paper, we study both phenomena in systems with small delays. By performing a phase reduction and studying phase locked solutions, we uncover the functional relation between the delay, excitation and inhibition for the onset of anticipated synchronization in a sender-receiver-interneuron motif. In the case of zero-lag synchronization in a chain motif, we determine the stability conditions. These analytical solutions provide an excellent prediction of the phase-locked regimes of Hodgkin-Huxley models and Roessler oscillators.
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Affiliation(s)
- Claudio R Mirasso
- Instituto de Física Interdisciplinar y Sistemas Complejos IFISC (CSIC-UIB), Universitat de les Illes Baleares, Campus UIB, E-07122 Palma de Mallorca, Spain
| | - Pedro V Carelli
- Departamento de Física, Universidade Federal de Pernambuco, Recife, Pernambuco, Brazil
| | - Tiago Pereira
- Instituto de Ciências Matemáticas e de Computação, Universidade de São Paulo, São Carlos, São Paulo, Brazil
| | - Fernanda S Matias
- Departamento de Física, Universidade Federal de Alagoas, Maceió, Alagoas, Brazil
| | - Mauro Copelli
- Departamento de Física, Universidade Federal de Pernambuco, Recife, Pernambuco, Brazil
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10
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Towards building a more complex view of the lateral geniculate nucleus: Recent advances in understanding its role. Prog Neurobiol 2017. [DOI: 10.1016/j.pneurobio.2017.06.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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11
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Esfahani ZG, Gollo LL, Valizadeh A. Stimulus-dependent synchronization in delayed-coupled neuronal networks. Sci Rep 2016; 6:23471. [PMID: 27001428 PMCID: PMC4802300 DOI: 10.1038/srep23471] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Accepted: 03/07/2016] [Indexed: 02/04/2023] Open
Abstract
Time delay is a general feature of all interactions. Although the effects of delayed interaction are often neglected when the intrinsic dynamics is much slower than the coupling delay, they can be crucial otherwise. We show that delayed coupled neuronal networks support transitions between synchronous and asynchronous states when the level of input to the network changes. The level of input determines the oscillation period of neurons and hence whether time-delayed connections are synchronizing or desynchronizing. We find that synchronizing connections lead to synchronous dynamics, whereas desynchronizing connections lead to out-of-phase oscillations in network motifs and to frustrated states with asynchronous dynamics in large networks. Since the impact of a neuronal network to downstream neurons increases when spikes are synchronous, networks with delayed connections can serve as gatekeeper layers mediating the firing transfer to other regions. This mechanism can regulate the opening and closing of communicating channels between cortical layers on demand.
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Affiliation(s)
- Zahra G Esfahani
- Department of physics, Institute for Advanced Studies in Basic Sciences, Zanjan, Iran
| | - Leonardo L Gollo
- Systems Neuroscience Group, QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Alireza Valizadeh
- Department of physics, Institute for Advanced Studies in Basic Sciences, Zanjan, Iran.,School of Cognitive Sciences, IPM, Niavaran, Tehran, Iran
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12
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Self-Organized Near-Zero-Lag Synchronization Induced by Spike-Timing Dependent Plasticity in Cortical Populations. PLoS One 2015; 10:e0140504. [PMID: 26474165 PMCID: PMC4608682 DOI: 10.1371/journal.pone.0140504] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 09/21/2015] [Indexed: 12/30/2022] Open
Abstract
Several cognitive tasks related to learning and memory exhibit synchronization of macroscopic cortical areas together with synaptic plasticity at neuronal level. Therefore, there is a growing effort among computational neuroscientists to understand the underlying mechanisms relating synchrony and plasticity in the brain. Here we numerically study the interplay between spike-timing dependent plasticity (STDP) and anticipated synchronization (AS). AS emerges when a dominant flux of information from one area to another is accompanied by a negative time lag (or phase). This means that the receiver region pulses before the sender does. In this paper we study the interplay between different synchronization regimes and STDP at the level of three-neuron microcircuits as well as cortical populations. We show that STDP can promote auto-organized zero-lag synchronization in unidirectionally coupled neuronal populations. We also find synchronization regimes with negative phase difference (AS) that are stable against plasticity. Finally, we show that the interplay between negative phase difference and STDP provides limited synaptic weight distribution without the need of imposing artificial boundaries.
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13
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Direct Functional Connectivity between the Thalamus (Vim) and the Contralateral Motor Cortex: Just a Single Case Observation or a Common Pathway in the Human Brain? Brain Stimul 2015; 8:1230-3. [PMID: 26386658 DOI: 10.1016/j.brs.2015.08.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 08/12/2015] [Indexed: 11/20/2022] Open
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14
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Ioannou CI, Pereda E, Lindsen JP, Bhattacharya J. Electrical Brain Responses to an Auditory Illusion and the Impact of Musical Expertise. PLoS One 2015; 10:e0129486. [PMID: 26065708 PMCID: PMC4466486 DOI: 10.1371/journal.pone.0129486] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Accepted: 05/08/2015] [Indexed: 12/30/2022] Open
Abstract
The presentation of two sinusoidal tones, one to each ear, with a slight frequency mismatch yields an auditory illusion of a beating frequency equal to the frequency difference between the two tones; this is known as binaural beat (BB). The effect of brief BB stimulation on scalp EEG is not conclusively demonstrated. Further, no studies have examined the impact of musical training associated with BB stimulation, yet musicians' brains are often associated with enhanced auditory processing. In this study, we analysed EEG brain responses from two groups, musicians and non-musicians, when stimulated by short presentation (1 min) of binaural beats with beat frequency varying from 1 Hz to 48 Hz. We focused our analysis on alpha and gamma band EEG signals, and they were analysed in terms of spectral power, and functional connectivity as measured by two phase synchrony based measures, phase locking value and phase lag index. Finally, these measures were used to characterize the degree of centrality, segregation and integration of the functional brain network. We found that beat frequencies belonging to alpha band produced the most significant steady-state responses across groups. Further, processing of low frequency (delta, theta, alpha) binaural beats had significant impact on cortical network patterns in the alpha band oscillations. Altogether these results provide a neurophysiological account of cortical responses to BB stimulation at varying frequencies, and demonstrate a modulation of cortico-cortical connectivity in musicians' brains, and further suggest a kind of neuronal entrainment of a linear and nonlinear relationship to the beating frequencies.
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Affiliation(s)
- Christos I Ioannou
- Department of Psychology, Goldsmiths, University of London, London, United Kingdom; Institute of Music Physiology and Musicians' Medicine, Hannover University of Music, Drama and Media, Hanover, Germany
| | - Ernesto Pereda
- Electrical Engineering and Bioengineering Group, Department of Industrial Engineering, University of La Laguna, Tenerife, Spain; Institute of Biomedical Technology (CIBICAN), University of La Laguna, Tenerife, Spain
| | - Job P Lindsen
- Department of Psychology, Goldsmiths, University of London, London, United Kingdom
| | - Joydeep Bhattacharya
- Department of Psychology, Goldsmiths, University of London, London, United Kingdom
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15
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Barardi A, Malagarriga D, Sancristobal B, Garcia-Ojalvo J, Pons AJ. Probing scale interaction in brain dynamics through synchronization. Philos Trans R Soc Lond B Biol Sci 2015; 369:rstb.2013.0533. [PMID: 25180311 DOI: 10.1098/rstb.2013.0533] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The mammalian brain operates in multiple spatial scales simultaneously, ranging from the microscopic scale of single neurons through the mesoscopic scale of cortical columns, to the macroscopic scale of brain areas. These levels of description are associated with distinct temporal scales, ranging from milliseconds in the case of neurons to tens of seconds in the case of brain areas. Here, we examine theoretically how these spatial and temporal scales interact in the functioning brain, by considering the coupled behaviour of two mesoscopic neural masses (NMs) that communicate with each other through a microscopic neuronal network (NN). We use the synchronization between the two NM models as a tool to probe the interaction between the mesoscopic scales of those neural populations and the microscopic scale of the mediating NN. The two NM oscillators are taken to operate in a low-frequency regime with different peak frequencies (and distinct dynamical behaviour). The microscopic neuronal population, in turn, is described by a network of several thousand excitatory and inhibitory spiking neurons operating in a synchronous irregular regime, in which the individual neurons fire very sparsely but collectively give rise to a well-defined rhythm in the gamma range. Our results show that this NN, which operates at a fast temporal scale, is indeed sufficient to mediate coupling between the two mesoscopic oscillators, which evolve dynamically at a slower scale. We also establish how this synchronization depends on the topological properties of the microscopic NN, on its size and on its oscillation frequency.
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Affiliation(s)
- Alessandro Barardi
- Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona Biomedical Research Park (PRBB), Dr. Aiguader 88, 08003 Barcelona, Spain Departament de Fìsica i Enginyeria Nuclear, Universitat Politécnica de Catalunya, Edifici Gaia, Rambla Sant Nebridi 22, 08222 Terrassa, Spain
| | - Daniel Malagarriga
- Departament de Fìsica i Enginyeria Nuclear, Universitat Politécnica de Catalunya, Edifici Gaia, Rambla Sant Nebridi 22, 08222 Terrassa, Spain Neuroheuristic Research Group, Faculty of Business and Economics, University of Lausanne, 1015 Lausanne, Switzerland
| | - Belén Sancristobal
- Center for Genomic Regulation, Barcelona Biomedical Research Park (PRBB), Dr. Aiguader 88, 08003 Barcelona, Spain
| | - Jordi Garcia-Ojalvo
- Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona Biomedical Research Park (PRBB), Dr. Aiguader 88, 08003 Barcelona, Spain
| | - Antonio J Pons
- Departament de Fìsica i Enginyeria Nuclear, Universitat Politécnica de Catalunya, Edifici Gaia, Rambla Sant Nebridi 22, 08222 Terrassa, Spain
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16
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Gollo LL, Breakspear M. The frustrated brain: from dynamics on motifs to communities and networks. Philos Trans R Soc Lond B Biol Sci 2015; 369:rstb.2013.0532. [PMID: 25180310 DOI: 10.1098/rstb.2013.0532] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Cognitive function depends on an adaptive balance between flexible dynamics and integrative processes in distributed cortical networks. Patterns of zero-lag synchrony likely underpin numerous perceptual and cognitive functions. Synchronization fulfils integration by reducing entropy, while adaptive function mandates that a broad variety of stable states be readily accessible. Here, we elucidate two complementary influences on patterns of zero-lag synchrony that derive from basic properties of brain networks. First, mutually coupled pairs of neuronal subsystems-resonance pairs-promote stable zero-lag synchrony among the small motifs in which they are embedded, and whose effects can propagate along connected chains. Second, frustrated closed-loop motifs disrupt synchronous dynamics, enabling metastable configurations of zero-lag synchrony to coexist. We document these two complementary influences in small motifs and illustrate how these effects underpin stable versus metastable phase-synchronization patterns in prototypical modular networks and in large-scale cortical networks of the macaque (CoCoMac). We find that the variability of synchronization patterns depends on the inter-node time delay, increases with the network size and is maximized for intermediate coupling strengths. We hypothesize that the dialectic influences of resonance versus frustration may form a dynamic substrate for flexible neuronal integration, an essential platform across diverse cognitive processes.
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Affiliation(s)
- Leonardo L Gollo
- Systems Neuroscience Group, QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Michael Breakspear
- Systems Neuroscience Group, QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia School of Psychiatry, University of New South Wales and The Black Dog Institute, Sydney, New South Wales, Australia The Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia
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Malagarriga D, Villa AEP, Garcia-Ojalvo J, Pons AJ. Mesoscopic segregation of excitation and inhibition in a brain network model. PLoS Comput Biol 2015; 11:e1004007. [PMID: 25671573 PMCID: PMC4324935 DOI: 10.1371/journal.pcbi.1004007] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Accepted: 10/28/2014] [Indexed: 02/02/2023] Open
Abstract
Neurons in the brain are known to operate under a careful balance of excitation and inhibition, which maintains neural microcircuits within the proper operational range. How this balance is played out at the mesoscopic level of neuronal populations is, however, less clear. In order to address this issue, here we use a coupled neural mass model to study computationally the dynamics of a network of cortical macrocolumns operating in a partially synchronized, irregular regime. The topology of the network is heterogeneous, with a few of the nodes acting as connector hubs while the rest are relatively poorly connected. Our results show that in this type of mesoscopic network excitation and inhibition spontaneously segregate, with some columns acting mainly in an excitatory manner while some others have predominantly an inhibitory effect on their neighbors. We characterize the conditions under which this segregation arises, and relate the character of the different columns with their topological role within the network. In particular, we show that the connector hubs are preferentially inhibitory, the more so the larger the node's connectivity. These results suggest a potential mesoscale organization of the excitation-inhibition balance in brain networks.
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Affiliation(s)
- Daniel Malagarriga
- Departament de Física i Enginyeria Nuclear, Universitat Politècnica de Catalunya, Terrassa, Spain
- Neuroheuristic Research Group, Faculty of Business and Economics, University of Lausanne, Lausanne, Switzerland
| | - Alessandro E. P. Villa
- Neuroheuristic Research Group, Faculty of Business and Economics, University of Lausanne, Lausanne, Switzerland
| | - Jordi Garcia-Ojalvo
- Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona, Spain
| | - Antonio J. Pons
- Departament de Física i Enginyeria Nuclear, Universitat Politècnica de Catalunya, Terrassa, Spain
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18
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Ghasemi Esfahani Z, Valizadeh A. Zero-lag synchronization despite inhomogeneities in a relay system. PLoS One 2014; 9:e112688. [PMID: 25486522 PMCID: PMC4259331 DOI: 10.1371/journal.pone.0112688] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 10/10/2014] [Indexed: 11/18/2022] Open
Abstract
A novel proposal for the zero-lag synchronization of the delayed coupled neurons, is to connect them indirectly via a third relay neuron. In this study, we develop a Poincaré map to investigate the robustness of the synchrony in such a relay system against inhomogeneity in the neurons and synaptic parameters. We show that when the inhomogeneity does not violate the symmetry of the system, synchrony is maintained and in some cases inhomogeneity enhances synchrony. On the other hand if the inhomogeneity breaks the symmetry of the system, zero lag synchrony can not be preserved. In this case we give analytical results for the phase lag of the spiking of the neurons in the stable state.
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19
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Barardi A, Sancristóbal B, Garcia-Ojalvo J. Phase-coherence transitions and communication in the gamma range between delay-coupled neuronal populations. PLoS Comput Biol 2014; 10:e1003723. [PMID: 25058021 PMCID: PMC4110076 DOI: 10.1371/journal.pcbi.1003723] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Accepted: 06/01/2014] [Indexed: 11/28/2022] Open
Abstract
Synchronization between neuronal populations plays an important role in information transmission between brain areas. In particular, collective oscillations emerging from the synchronized activity of thousands of neurons can increase the functional connectivity between neural assemblies by coherently coordinating their phases. This synchrony of neuronal activity can take place within a cortical patch or between different cortical regions. While short-range interactions between neurons involve just a few milliseconds, communication through long-range projections between different regions could take up to tens of milliseconds. How these heterogeneous transmission delays affect communication between neuronal populations is not well known. To address this question, we have studied the dynamics of two bidirectionally delayed-coupled neuronal populations using conductance-based spiking models, examining how different synaptic delays give rise to in-phase/anti-phase transitions at particular frequencies within the gamma range, and how this behavior is related to the phase coherence between the two populations at different frequencies. We have used spectral analysis and information theory to quantify the information exchanged between the two networks. For different transmission delays between the two coupled populations, we analyze how the local field potential and multi-unit activity calculated from one population convey information in response to a set of external inputs applied to the other population. The results confirm that zero-lag synchronization maximizes information transmission, although out-of-phase synchronization allows for efficient communication provided the coupling delay, the phase lag between the populations, and the frequency of the oscillations are properly matched.
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Affiliation(s)
- Alessandro Barardi
- Departament of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona Biomedical Research Park, Barcelona, Spain
- Departament de Física i Enginyeria Nuclear, Universitat Politècnica de Catalunya, Terrassa, Spain
| | - Belen Sancristóbal
- Center for Genomic Regulation, Barcelona Biomedical Research Park, Barcelona, Spain
| | - Jordi Garcia-Ojalvo
- Departament of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona Biomedical Research Park, Barcelona, Spain
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20
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Mechanisms of zero-lag synchronization in cortical motifs. PLoS Comput Biol 2014; 10:e1003548. [PMID: 24763382 PMCID: PMC3998884 DOI: 10.1371/journal.pcbi.1003548] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Accepted: 02/20/2014] [Indexed: 12/04/2022] Open
Abstract
Zero-lag synchronization between distant cortical areas has been observed in a diversity of experimental data sets and between many different regions of the brain. Several computational mechanisms have been proposed to account for such isochronous synchronization in the presence of long conduction delays: Of these, the phenomenon of “dynamical relaying” – a mechanism that relies on a specific network motif – has proven to be the most robust with respect to parameter mismatch and system noise. Surprisingly, despite a contrary belief in the community, the common driving motif is an unreliable means of establishing zero-lag synchrony. Although dynamical relaying has been validated in empirical and computational studies, the deeper dynamical mechanisms and comparison to dynamics on other motifs is lacking. By systematically comparing synchronization on a variety of small motifs, we establish that the presence of a single reciprocally connected pair – a “resonance pair” – plays a crucial role in disambiguating those motifs that foster zero-lag synchrony in the presence of conduction delays (such as dynamical relaying) from those that do not (such as the common driving triad). Remarkably, minor structural changes to the common driving motif that incorporate a reciprocal pair recover robust zero-lag synchrony. The findings are observed in computational models of spiking neurons, populations of spiking neurons and neural mass models, and arise whether the oscillatory systems are periodic, chaotic, noise-free or driven by stochastic inputs. The influence of the resonance pair is also robust to parameter mismatch and asymmetrical time delays amongst the elements of the motif. We call this manner of facilitating zero-lag synchrony resonance-induced synchronization, outline the conditions for its occurrence, and propose that it may be a general mechanism to promote zero-lag synchrony in the brain. Understanding large-scale neuronal dynamics – and how they relate to the cortical anatomy – is one of the key areas of neuroscience research. Despite a wealth of recent research, the key principles of this relationship have yet to be established. Here we employ computational modeling to study neuronal dynamics on small subgraphs – or motifs – across a hierarchy of spatial scales. We establish a novel organizing principle that we term a “resonance pair” (two mutually coupled nodes), which promotes stable, zero-lag synchrony amongst motif nodes. The bidirectional coupling between a resonance pair acts to mutually adjust their dynamics onto a common and relatively stable synchronized regime, which then propagates and stabilizes the synchronization of other nodes within the motif. Remarkably, we find that this effect can propagate along chains of coupled nodes and hence holds the potential to promote stable zero-lag synchrony in larger sub-networks of cortical systems. Our findings hence suggest a potential unifying account of the existence of zero-lag synchrony, an important phenomenon that may underlie crucial cognitive processes in the brain. Moreover, such pairs of mutually coupled oscillators are found in a wide variety of physical and biological systems suggesting a new, broadly relevant and unifying principle.
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21
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Sirovich R, Sacerdote L, Villa AEP. Cooperative behavior in a jump diffusion model for a simple network of spiking neurons. MATHEMATICAL BIOSCIENCES AND ENGINEERING : MBE 2014; 11:385-401. [PMID: 24245723 DOI: 10.3934/mbe.2014.11.385] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The distribution of time intervals between successive spikes generated by a neuronal cell --the interspike intervals (ISI)-- may reveal interesting features of the underlying dynamics. In this study we analyze the ISI sequence --the spike train-- generated by a simple network of neurons whose output activity is modeled by a jump-diffusion process. We prove that, when specific ranges of the involved parameters are chosen, it is possible to observe multimodal ISI distributions which reveal that the modeled network fires with more than one single preferred time interval. Furthermore, the system exhibits resonance behavior, with modulation of the spike timings by the noise intensity. We also show that inhibition helps the signal transmission between the units of the simple network.
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Affiliation(s)
- Roberta Sirovich
- Department of Mathematics "G. Peano", University of Torino, Via Carlo Alberto 10, 10123 Torino, Italy.
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22
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Perception of successive brief objects as a function of stimulus onset asynchrony: model experiments based on two-stage synchronization of neuronal oscillators. Cogn Neurodyn 2014; 7:465-75. [PMID: 24427220 DOI: 10.1007/s11571-013-9250-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2012] [Revised: 03/05/2013] [Accepted: 03/14/2013] [Indexed: 10/27/2022] Open
Abstract
Recently we introduced a new version of the perceptual retouch model incorporating two interactive binding operations-binding features for objects and binding the bound feature-objects with a large scale oscillatory system that acts as a mediary for the perceptual information to reach consciousness-level representation. The relative level of synchronized firing of the neurons representing the features of an object obtained after the second-stage synchronizing modulation is used as the equivalent of conscious perception of the corresponding object. Here, this model is used for simulating interaction of two successive featured objects as a function of stimulus onset asynchrony (SOA). Model output reproduces typical results of mutual masking-with shortest and longest SOAs first and second object correct perception rate is comparable while with intermediate SOAs second object dominates over the first one. Additionally, with shortest SOAs misbinding of features to form illusory objects is simulated by the model.
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23
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Kato H, Cuellar CA, Delgado-Lezama R, Rudomin P, Jimenez-Estrada I, Manjarrez E, Mirasso CR. Modeling zero-lag synchronization of dorsal horn neurons during the traveling of electrical waves in the cat spinal cord. Physiol Rep 2013; 1:e00021. [PMID: 24303110 PMCID: PMC3831917 DOI: 10.1002/phy2.21] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Accepted: 06/04/2013] [Indexed: 11/18/2022] Open
Abstract
The first electrophysiological evidence of the phenomenon of traveling electrical waves produced by populations of interneurons within the spinal cord was reported by our interdisciplinary research group. Two interesting observations derive from this study: first, the negative spontaneous cord dorsum potentials (CDPs) that are superimposed on the propagating sinusoidal electrical waves are not correlated with any scratching phase; second, these CDPs do not propagate along the lumbosacral spinal segments, but they appear almost simultaneously at different spinal segments. The aim of this study was to provide experimental data and a mathematical model to explain the simultaneous occurrence of traveling waves and the zero-lag synchronization of some CDPs.
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Affiliation(s)
- Hideyuki Kato
- Instituto de Física Interdisciplinar y Sistemas Complejos (IFISC, UIB-CSIC), Campus Universitat de les Illes Balears E-07122, Palma de Mallorca, Spain
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24
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Edelman GM, Gally JA. Reentry: a key mechanism for integration of brain function. Front Integr Neurosci 2013; 7:63. [PMID: 23986665 PMCID: PMC3753453 DOI: 10.3389/fnint.2013.00063] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Accepted: 08/06/2013] [Indexed: 11/26/2022] Open
Abstract
Reentry in nervous systems is the ongoing bidirectional exchange of signals along reciprocal axonal fibers linking two or more brain areas. The hypothesis that reentrant signaling serves as a general mechanism to couple the functioning of multiple areas of the cerebral cortex and thalamus was first proposed in 1977 and 1978 (Edelman, 1978). A review of the amount and diversity of supporting experimental evidence accumulated since then suggests that reentry is among the most important integrative mechanisms in vertebrate brains (Edelman, 1993). Moreover, these data prompt testable hypotheses regarding mechanisms that favor the development and evolution of reentrant neural architectures.
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25
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26
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Hart J, Maguire MJ, Motes M, Mudar RA, Chiang HS, Womack KB, Kraut MA. Semantic memory retrieval circuit: role of pre-SMA, caudate, and thalamus. BRAIN AND LANGUAGE 2013; 126:89-98. [PMID: 22964132 DOI: 10.1016/j.bandl.2012.08.002] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2011] [Revised: 07/06/2012] [Accepted: 08/13/2012] [Indexed: 06/01/2023]
Abstract
We propose that pre-supplementary motor area (pre-SMA)-thalamic interactions govern processes fundamental to semantic retrieval of an integrated object memory. At the onset of semantic retrieval, pre-SMA initiates electrical interactions between multiple cortical regions associated with semantic memory subsystems encodings as indexed by an increase in theta-band EEG power. This starts between 100-150 ms after stimulus presentation and is sustained throughout the task. We posit that this activity represents initiation of the object memory search, which continues in searching for an object memory. When the correct memory is retrieved, there is a high beta-band EEG power increase, which reflects communication between pre-SMA and thalamus, designates the end of the search process and resultant in object retrieval from multiple semantic memory subsystems. This high beta signal is also detected in cortical regions. This circuit is modulated by the caudate nuclei to facilitate correct and suppress incorrect target memories.
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Affiliation(s)
- John Hart
- Berman Laboratory for Learning and Memory, Center for BrainHealth, Dallas, TX 75235, USA.
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27
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Albéri L, Lintas A, Kretz R, Schwaller B, Villa AEP. The calcium-binding protein parvalbumin modulates the firing 1 properties of the reticular thalamic nucleus bursting neurons. J Neurophysiol 2013; 109:2827-41. [PMID: 23486206 DOI: 10.1152/jn.00375.2012] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The reticular thalamic nucleus (RTN) of the mouse is characterized by an overwhelming majority of GABAergic neurons receiving afferences from both the thalamus and the cerebral cortex and sending projections mainly on thalamocortical neurons. The RTN neurons express high levels of the "slow Ca(2+) buffer" parvalbumin (PV) and are characterized by low-threshold Ca(2+) currents, I(T). We performed extracellular recordings in ketamine/xylazine anesthetized mice in the rostromedial portion of the RTN. In the RTN of wild-type and PV knockout (PVKO) mice we distinguished four types of neurons characterized on the basis of their firing pattern: irregular firing (type I), medium bursting (type II), long bursting (type III), and tonically firing (type IV). Compared with wild-type mice, we observed in the PVKOs the medium bursting (type II) more frequently than the long bursting type and longer interspike intervals within the burst without affecting the number of spikes. This suggests that PV may affect the firing properties of RTN neurons via a mechanism associated with the kinetics of burst discharges. Ca(v)3.2 channels, which mediate the I(T) currents, were more localized to the somatic plasma membrane of RTN neurons in PVKO mice, whereas Ca(v)3.3 expression was similar in both genotypes. The immunoelectron microscopy analysis showed that Ca(v)3.2 channels were localized at active axosomatic synapses, thus suggesting that the differential localization of Ca(v)3.2 in the PVKOs may affect bursting dynamics. Cross-correlation analysis of simultaneously recorded neurons from the same electrode tip showed that about one-third of the cell pairs tended to fire synchronously in both genotypes, independent of PV expression. In summary, PV deficiency does not affect the functional connectivity between RTN neurons but affects the distribution of Ca(v)3.2 channels and the dynamics of burst discharges of RTN cells, which in turn regulate the activity in the thalamocortical circuit.
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Affiliation(s)
- Lavinia Albéri
- Unit of Anatomy, Department of Medicine, University of Fribourg, Fribourg, Switzerland
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28
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Bonath B, Tyll S, Budinger E, Krauel K, Hopf JM, Noesselt T. Task-demands and audio-visual stimulus configurations modulate neural activity in the human thalamus. Neuroimage 2013; 66:110-8. [DOI: 10.1016/j.neuroimage.2012.10.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Revised: 10/02/2012] [Accepted: 10/12/2012] [Indexed: 11/28/2022] Open
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29
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Brown SR. Emergence in the central nervous system. Cogn Neurodyn 2012; 7:173-95. [PMID: 24427200 DOI: 10.1007/s11571-012-9229-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2012] [Revised: 10/04/2012] [Accepted: 11/20/2012] [Indexed: 11/30/2022] Open
Abstract
"Emergence" is an idea that has received much attention in consciousness literature, but it is difficult to find characterizations of that concept which are both specific and useful. I will precisely define and characterize a type of epistemic ("weak") emergence and show that it is a property of some neural circuits throughout the CNS, on micro-, meso- and macroscopic levels. I will argue that possession of this property can result in profoundly altered neural dynamics on multiple levels in cortex and other systems. I will first describe emergent neural entities (ENEs) abstractly. I will then show how ENEs function specifically and concretely, and demonstrate some implications of this type of emergence for the CNS.
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Affiliation(s)
- Steven Ravett Brown
- Department of Neuroscience, Mt. Sinai School of Medicine, Icahn Medical Institute, 1425 Madison Ave, Rm 10-70E, New York, NY 10029 USA ; 158 W 23rd St, Fl 3, New York, NY 10011 USA
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30
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Rogala J, Waleszczyk WJ, Łęski S, Wróbel A, Wójcik DK. Reciprocal inhibition and slow calcium decay in perigeniculate interneurons explain changes of spontaneous firing of thalamic cells caused by cortical inactivation. J Comput Neurosci 2012; 34:461-76. [PMID: 23150147 PMCID: PMC3650241 DOI: 10.1007/s10827-012-0430-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2012] [Revised: 10/05/2012] [Accepted: 10/09/2012] [Indexed: 11/27/2022]
Abstract
The role of cortical feedback in the thalamocortical processing loop has been extensively investigated over the last decades. With an exception of several cases, these searches focused on the cortical feedback exerted onto thalamo-cortical relay (TC) cells of the dorsal lateral geniculate nucleus (LGN). In a previous, physiological study, we showed in the cat visual system that cessation of cortical input, despite decrease of spontaneous activity of TC cells, increased spontaneous firing of their recurrent inhibitory interneurons located in the perigeniculate nucleus (PGN). To identify mechanisms underlying such functional changes we conducted a modeling study in NEURON on several networks of point neurons with varied model parameters, such as membrane properties, synaptic weights and axonal delays. We considered six network topologies of the retino-geniculo-cortical system. All models were robust against changes of axonal delays except for the delay between the LGN feed-forward interneuron and the TC cell. The best representation of physiological results was obtained with models containing reciprocally connected PGN cells driven by the cortex and with relatively slow decay of intracellular calcium. This strongly indicates that the thalamic reticular nucleus plays an essential role in the cortical influence over thalamo-cortical relay cells while the thalamic feed-forward interneurons are not essential in this process. Further, we suggest that the dependence of the activity of PGN cells on the rate of calcium removal can be one of the key factors determining individual cell response to elimination of cortical input.
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Affiliation(s)
- Jacek Rogala
- Department of Neurophysiology, Nencki Institute of Experimental Biology, 3 Pasteur St, 02-093 Warsaw, Poland
| | - Wioletta J. Waleszczyk
- Department of Neurophysiology, Nencki Institute of Experimental Biology, 3 Pasteur St, 02-093 Warsaw, Poland
| | - Szymon Łęski
- Department of Neurophysiology, Nencki Institute of Experimental Biology, 3 Pasteur St, 02-093 Warsaw, Poland
| | - Andrzej Wróbel
- Department of Neurophysiology, Nencki Institute of Experimental Biology, 3 Pasteur St, 02-093 Warsaw, Poland
| | - Daniel K. Wójcik
- Department of Neurophysiology, Nencki Institute of Experimental Biology, 3 Pasteur St, 02-093 Warsaw, Poland
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31
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Kirt T, Bachmann T. Perceptual retouch theory derived modeling of interactions in the processing of successive visual objects for consciousness: two-stage synchronization of neuronal oscillators. Conscious Cogn 2012; 22:330-47. [PMID: 22892586 DOI: 10.1016/j.concog.2012.07.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2012] [Revised: 07/05/2012] [Accepted: 07/12/2012] [Indexed: 10/28/2022]
Abstract
We introduce a new version of the perceptual retouch model. This model was used for explaining properties of temporal interaction of successive objects in reaching conscious representation. The new model incorporates two interactive binding operations - binding features for objects and binding the bound feature-objects with a large scale oscillatory system that corresponds to perceptual consciousness. Here, the typical result of masking experiments - second object advantage in conscious perception - is achieved by applying the effects of a common synchronizing oscillator with a delay. This delayed modulation of each of the feature-binding first-order oscillators that represent emerging and decaying neural activities of each of the objects guarantees that the oscillating synchrony of the feature-neurons of the following object is higher than the synchrony of the feature-neurons of the first presented object. Thus we model the fact that the following object dominates the preceding object in conscious perception. We also show the capacity of the model to simulate illusory misbinding of features from different objects. The third qualitative effect, the relative release of the first object from backward masking is achieved by priming the non-specific oscillatory modulation ahead in time.
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Affiliation(s)
- Toomas Kirt
- Laboratory of Cognitive Neuroscience, Institute of Public Law, University of Tartu (Tallinn branch), Kaarli puiestee 3, Tallinn 10119, Estonia
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32
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Viriyopase A, Bojak I, Zeitler M, Gielen S. When Long-Range Zero-Lag Synchronization is Feasible in Cortical Networks. Front Comput Neurosci 2012; 6:49. [PMID: 22866034 PMCID: PMC3406310 DOI: 10.3389/fncom.2012.00049] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2012] [Accepted: 06/27/2012] [Indexed: 11/13/2022] Open
Abstract
Many studies have reported long-range synchronization of neuronal activity between brain areas, in particular in the beta and gamma bands with frequencies in the range of 14–30 and 40–80 Hz, respectively. Several studies have reported synchrony with zero phase lag, which is remarkable considering the synaptic and conduction delays inherent in the connections between distant brain areas. This result has led to many speculations about the possible functional role of zero-lag synchrony, such as for neuronal communication, attention, memory, and feature binding. However, recent studies using recordings of single-unit activity and local field potentials report that neuronal synchronization may occur with non-zero phase lags. This raises the questions whether zero-lag synchrony can occur in the brain and, if so, under which conditions. We used analytical methods and computer simulations to investigate which connectivity between neuronal populations allows or prohibits zero-lag synchrony. We did so for a model where two oscillators interact via a relay oscillator. Analytical results and computer simulations were obtained for both type I Mirollo–Strogatz neurons and type II Hodgkin–Huxley neurons. We have investigated the dynamics of the model for various types of synaptic coupling and importantly considered the potential impact of Spike-Timing Dependent Plasticity (STDP) and its learning window. We confirm previous results that zero-lag synchrony can be achieved in this configuration. This is much easier to achieve with Hodgkin–Huxley neurons, which have a biphasic phase response curve, than for type I neurons. STDP facilitates zero-lag synchrony as it adjusts the synaptic strengths such that zero-lag synchrony is feasible for a much larger range of parameters than without STDP.
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Affiliation(s)
- Atthaphon Viriyopase
- Donders Institute for Brain, Cognition and Behavior, Radboud University Nijmegen (Medical Centre) Nijmegen, Netherlands
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33
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Michels L, Lüchinger R, Koenig T, Martin E, Brandeis D. Developmental changes of BOLD signal correlations with global human EEG power and synchronization during working memory. PLoS One 2012; 7:e39447. [PMID: 22792176 PMCID: PMC3391196 DOI: 10.1371/journal.pone.0039447] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2011] [Accepted: 05/21/2012] [Indexed: 12/26/2022] Open
Abstract
In humans, theta band (5–7 Hz) power typically increases when performing cognitively demanding working memory (WM) tasks, and simultaneous EEG-fMRI recordings have revealed an inverse relationship between theta power and the BOLD (blood oxygen level dependent) signal in the default mode network during WM. However, synchronization also plays a fundamental role in cognitive processing, and the level of theta and higher frequency band synchronization is modulated during WM. Yet, little is known about the link between BOLD, EEG power, and EEG synchronization during WM, and how these measures develop with human brain maturation or relate to behavioral changes. We examined EEG-BOLD signal correlations from 18 young adults and 15 school-aged children for age-dependent effects during a load-modulated Sternberg WM task. Frontal load (in-)dependent EEG theta power was significantly enhanced in children compared to adults, while adults showed stronger fMRI load effects. Children demonstrated a stronger negative correlation between global theta power and the BOLD signal in the default mode network relative to adults. Therefore, we conclude that theta power mediates the suppression of a task-irrelevant network. We further conclude that children suppress this network even more than adults, probably from an increased level of task-preparedness to compensate for not fully mature cognitive functions, reflected in lower response accuracy and increased reaction time. In contrast to power, correlations between instantaneous theta global field synchronization and the BOLD signal were exclusively positive in both age groups but only significant in adults in the frontal-parietal and posterior cingulate cortices. Furthermore, theta synchronization was weaker in children and was –in contrast to EEG power– positively correlated with response accuracy in both age groups. In summary we conclude that theta EEG-BOLD signal correlations differ between spectral power and synchronization and that these opposite correlations with different distributions undergo similar and significant neuronal developments with brain maturation.
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Affiliation(s)
- Lars Michels
- Center for MR-Research, University Children's Hospital, Zurich, Switzerland.
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34
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Gollo LL, Kinouchi O, Copelli M. Statistical physics approach to dendritic computation: the excitable-wave mean-field approximation. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2012; 85:011911. [PMID: 22400595 DOI: 10.1103/physreve.85.011911] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2011] [Revised: 11/23/2011] [Indexed: 05/31/2023]
Abstract
We analytically study the input-output properties of a neuron whose active dendritic tree, modeled as a Cayley tree of excitable elements, is subjected to Poisson stimulus. Both single-site and two-site mean-field approximations incorrectly predict a nonequilibrium phase transition which is not allowed in the model. We propose an excitable-wave mean-field approximation which shows good agreement with previously published simulation results [Gollo et al., PLoS Comput. Biol. 5, e1000402 (2009)] and accounts for finite-size effects. We also discuss the relevance of our results to experiments in neuroscience, emphasizing the role of active dendrites in the enhancement of dynamic range and in gain control modulation.
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Affiliation(s)
- Leonardo L Gollo
- IFISC (CSIC - UIB), Instituto de Física Interdisciplinar y Sistemas Complejos, Campus Universitat Illes Balears, E-07122 Palma de Mallorca, Spain.
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Insular lateralization in tinnitus distress. Auton Neurosci 2011; 165:191-4. [PMID: 21889914 DOI: 10.1016/j.autneu.2011.06.007] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2010] [Revised: 06/28/2011] [Accepted: 06/29/2011] [Indexed: 11/23/2022]
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Shaposhnyk V, Villa AEP. Reciprocal projections in hierarchically organized evolvable neural circuits affect EEG-like signals. Brain Res 2011; 1434:266-76. [PMID: 21890119 DOI: 10.1016/j.brainres.2011.08.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2011] [Revised: 07/20/2011] [Accepted: 08/08/2011] [Indexed: 11/26/2022]
Abstract
Modular architecture is a hallmark of many brain circuits. In the cerebral cortex, in particular, it has been observed that reciprocal connections are often present between functionally interconnected areas that are hierarchically organized. We investigate the effect of reciprocal connections in a network of modules of simulated spiking neurons. The neural activity is recorded by means of virtual electrodes and EEG-like signals, called electrochipograms (EChG), analyzed by time- and frequency-domain methods. A major feature of our approach is the implementation of important bio-inspired processes that affect the connectivity within a neural module: synaptogenesis, cell death, spike-timing-dependent plasticity and synaptic pruning. These bio-inspired processes drive the build-up of auto-associative links within each module, which generate an areal activity, recorded by EChG, that reflect the changes in the corresponding functional connectivity within and between neuronal modules. We found that circuits with intra-layer reciprocal projections exhibited enhanced stimulus-locked response. We show evidence that all networks of modules are able to process and maintain patterns of activity associated with the stimulus after its offset. The presence of feedback and horizontal projections was necessary to evoke cross-layer coherence in bursts of -frequency at regular intervals. These findings bring new insights to the understanding of the relation between the functional organization of neural circuits and the electrophysiological signals generated by large cell assemblies. This article is part of a Special Issue entitled "Neural Coding".
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Affiliation(s)
- Vladyslav Shaposhnyk
- Neuroheuristic Research Group, Information Science Inst., Univ. of Lausanne, Switzerland
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Gollo LL, Mirasso CR, Atienza M, Crespo-Garcia M, Cantero JL. Theta band zero-lag long-range cortical synchronization via hippocampal dynamical relaying. PLoS One 2011; 6:e17756. [PMID: 21408082 PMCID: PMC3050931 DOI: 10.1371/journal.pone.0017756] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2010] [Accepted: 02/09/2011] [Indexed: 11/19/2022] Open
Abstract
Growing evidence suggests that synchronization among distributed neuronal networks underlie functional integration in the brain. Neural synchronization is typically revealed by a consistent phase delay between neural responses generated in two separated sources. But the influence of a third neuronal assembly in that synchrony pattern remains largely unexplored. We investigate here the potential role of the hippocampus in determining cortico-cortical theta synchronization in different behavioral states during motor quiescent and while animals actively explore the environment. To achieve this goal, the two states were modeled with a recurrent network involving the hippocampus, as a relay element, and two distant neocortical sites. We found that cortico-cortical neural coupling accompanied higher hippocampal theta oscillations in both behavioral states, although the highest level of synchronization between cortical regions emerged during motor exploration. Local field potentials recorded from the same brain regions qualitatively confirm these findings in the two behavioral states. These results suggest that zero-lag long-range cortico-cortical synchronization is likely mediated by hippocampal theta oscillations in lower mammals as a function of cognitive demands and motor acts.
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Affiliation(s)
- Leonardo L. Gollo
- IFISC, Instituto de Física Interdisciplinar y Sistemas Complejos (CSIC-UIB), Campus Universitat de les Illes Balears, Palma de Mallorca, Spain
| | - Claudio R. Mirasso
- IFISC, Instituto de Física Interdisciplinar y Sistemas Complejos (CSIC-UIB), Campus Universitat de les Illes Balears, Palma de Mallorca, Spain
| | - Mercedes Atienza
- Laboratory of Functional Neuroscience, Spanish Network of Excellence for Research on Neurodegenerative Diseases (CIBERNED), University Pablo de Olavide, Sevilla, Spain
| | - Maite Crespo-Garcia
- Laboratory of Functional Neuroscience, Spanish Network of Excellence for Research on Neurodegenerative Diseases (CIBERNED), University Pablo de Olavide, Sevilla, Spain
| | - Jose L. Cantero
- Laboratory of Functional Neuroscience, Spanish Network of Excellence for Research on Neurodegenerative Diseases (CIBERNED), University Pablo de Olavide, Sevilla, Spain
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Briggs F, Usrey WM. Patterned Activity within the Local Cortical Architecture. Front Neurosci 2010; 4:18. [PMID: 21103018 PMCID: PMC2987657 DOI: 10.3389/fnins.2010.00018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2010] [Accepted: 03/16/2010] [Indexed: 12/03/2022] Open
Abstract
The cerebral cortex is a vastly complex structure consisting of multiple distinct populations of neurons residing in functionally specialized cortical compartments. A fundamental goal in systems neuroscience is to understand the interactions among cortical neurons and their relationship to behavior. It is hypothesized that dynamic activity patterns, such as oscillations in global neuronal activity, could span large, heterogeneous populations of cortical neurons in such a manner as to bind together the activity of otherwise disparate cortical networks. Little is known about the mechanisms by which such global oscillatory patterns entrain cortical networks, or the contribution of such activity patterns to cortical function. An important step toward elucidating the role of such patterned activity in cortical information processing is understanding these interactions at the local circuit level. Here, we highlight recent findings that provide insight into how dynamic activity patterns affect specific neuronal populations and circuits.
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Affiliation(s)
- Farran Briggs
- Center for Neuroscience, University of California Davis, CA, USA
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