Local cortical circuit model inferred from power-law distributed neuronal avalanches

Teramae, Jun-nosuke; Fukai, Tomoki

doi:10.1007/s10827-006-0014-6

Cited by 59 publications

(47 citation statements)

References 48 publications

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“…Indeed, the finding of scale invariance does not exclude long-range or short-range heterogeneous corticocortical projections. Numerical simulations have shown that neuronal avalanches can arise at the critical state in models with scale-free (26), fully connected (27), random (28), and nearest-neighbor (18,26) topologies, although in each case the conditions to reach criticality can be different. In cortical cultures, the neuronal avalanches establish a functional small-world architecture with specific and highly diverse point-topoint connectivity between cortical sites that is, the network representing these site activations is densely interconnected, globally as well as locally (29).…”

Section: Scale Invariance In Time Nlfp Amplitude and Finite-size Scmentioning

confidence: 99%

Spontaneous cortical activity in awake monkeys composed of neuronal avalanches

Petermann

Thiagarajan

Lebedev

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

530

541

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Spontaneous neuronal activity is an important property of the cerebral cortex but its spatiotemporal organization and dynamical framework remain poorly understood. Studies in reduced systems-tissue cultures, acute slices, and anesthetized ratsshow that spontaneous activity forms characteristic clusters in space and time, called neuronal avalanches. Modeling studies suggest that networks with this property are poised at a critical state that optimizes input processing, information storage, and transfer, but the relevance of avalanches for fully functional cerebral systems has been controversial. Here we show that ongoing cortical synchronization in awake rhesus monkeys carries the signature of neuronal avalanches. Negative LFP deflections (nLFPs) correlate with neuronal spiking and increase in amplitude with increases in local population spike rate and synchrony. These nLFPs form neuronal avalanches that are scale-invariant in space and time and with respect to the threshold of nLFP detection. This dimension, threshold invariance, describes a fractal organization: smaller nLFPs are embedded in clusters of larger ones without destroying the spatial and temporal scale-invariance of the dynamics. These findings suggest an organization of ongoing cortical synchronization that is scale-invariant in its three fundamental dimensions-time, space, and local neuronal group size. Such scale-invariance has ontogenetic and phylogenetic implications because it allows large increases in network capacity without a fundamental reorganization of the system. neuronal synchronization ͉ resting state ͉ rhesus monkey ͉ spontaneous activity ͉ ongoing activity T he cerebral cortex displays spontaneous activity, also known as 'ongoing' or 'resting state' activity, which persists in the absence of sensory stimuli or motor outputs. The ongoing activity is a robust feature of cortical dynamics as it is only modulated to a small extent by stimulus presentation (1), but contributes significantly to the large variability observed in stimulus responses (2-5). In fact, ongoing activity has been found to reflect multiple aspects of neuronal processing. The activity is similar to that observed during stimulus presentation (1, 6-8), incorporates previously acquired information (9), and carries information about the underlying neuronal network [for review see (10)]. Indeed, correlations during resting state activity are altered in disease states such as schizophrenia or chronic pain (11, 12), which raises the question whether there is a general framework that describes the statistics in the spatiotemporal organization of this dynamics.Recently, we found that spontaneous cortical activity in slice cultures, acute slices, and in the anesthetized rat in vivo has a scale-invariant dynamics called neuronal avalanches (13)(14)(15). These spontaneous bursts of synchronized activity occur in clusters of sizes s (where s is the number of active sites in an electrode array) that distribute according to a power law with exponent ␣:where ␣ usually lies between ...

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Section: Scale Invariance In Time Nlfp Amplitude and Finite-size Scmentioning

confidence: 99%

Spontaneous cortical activity in awake monkeys composed of neuronal avalanches

Petermann

Thiagarajan

Lebedev

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

530

541

View full text Add to dashboard Cite

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“…Although not identical to the critical point of phase transitions, because it lacks the property of universality, the critical point of neural systems has attracted increasing theoretical and computational interest because of its importance to neural systems function [21,[30][31][32][33][34][35][36][37][38][39][40]. A critical neural system is balanced between a phase where activity is damped and a phase where activity is expanding.…”

Section: The Critical Pointmentioning

confidence: 99%

An open hypothesis: Is epilepsy learned, and can it be unlearned?

Hsu

Chen²,

M³

et al. 2008

Epilepsy & Behavior

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Plasticity is central to the ability of a neural system to learn and also to its ability to develop spontaneous seizures. What is the connection between the two? Learning itself is known to be a destabilizing process at the algorithmic level. We have investigated necessary constraints on a spontaneously active Hebbian learning system and find that the ability to learn appears to confer an intrinsic vulnerability to epileptogenesis on that system. We hypothesize that epilepsy arises as an abnormal learned response of such a system to certain repeated provocations. This response is a network level effect. If epilepsy really is a learned response, then it should be possible to reverse it, i.e., to unlearn epilepsy. Unlearning epilepsy may then provide a new approach to its treatment.

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“…Avalanche-like behavior occurs in wide-ranging examples in nature, from sand piles (13) and magnetic turbulence in plasmas (14) to solar flares (15), earthquakes (16), and neuronal activity (17), and has even been described in microtubule dynamics (18) and neuronal growth cone motility (19). Avalanching systems share the common feature that they are driven toward an unstable state by an input of energy or material that accumulates until an avalanche returns the system to a more stable state.…”

mentioning

confidence: 99%

Avalanche-like behavior in ciliary import

Ludington

Wemmer

Lechtreck

et al. 2013

Proc. Natl. Acad. Sci. U.S.A.

115

201

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Cilia and flagella are microtubule-based organelles that protrude from the cell body. Ciliary assembly requires intraflagellar transport (IFT), a motile system that delivers cargo from the cell body to the flagellar tip for assembly. The process controlling injections of IFT proteins into the flagellar compartment is, therefore, crucial to ciliogenesis. Extensive biochemical and genetic analyses have determined the molecular machinery of IFT, but these studies do not explain what regulates IFT injection rate. Here, we provide evidence that IFT injections result from avalanche-like releases of accumulated IFT material at the flagellar base and that the key regulated feature of length control is the recruitment of IFT material to the flagellar base. We used total internal reflection fluorescence microscopy of IFT proteins in live cells to quantify the size and frequency of injections over time. The injection dynamics reveal a power-law tailed distribution of injection event sizes and a negative correlation between injection size and frequency, as well as rich behaviors such as quasiperiodicity, bursting, and long-memory effects tied to the size of the localized load of IFT material awaiting injection at the flagellar base, collectively indicating that IFT injection dynamics result from avalanche-like behavior. Computational models based on avalanching recapitulate observed IFT dynamics, and we further show that the flagellar Ras-related nuclear protein (Ran) guanosine 5'-triphosphate (GTP) gradient can in theory act as a flagellar length sensor to regulate this localized accumulation of IFT. These results demonstrate that a self-organizing, physical mechanism can control a biochemically complex intracellular transport pathway.Chlamydomonas | self-organization | nuclear import | long flagella mutants | power spectrum C ilia and flagella generate fluid flows and mediate cell signaling (1), and ciliary length defects cause a wide range of congenital human diseases. Many of these defects arise from mutations in intraflagellar transport (IFT) proteins, which are required to build and maintain the length of cilia and flagella (2). The IFT proteins form complexes called IFT trains that haul cargo to the ciliary tip for assembly (3-7). IFT trains first localize to the basal body (8) and then enter the cilium as a group in an injection event. Understanding the IFT injection process is critical to understanding ciliary length control because the injection rate sets the overall amount of transport that in turn determines the rate of steadystate flagellar assembly (9).A previous report indicated that entry of new IFT trains is periodic (10), suggesting that a biochemical oscillator may regulate IFT injection. However, the biochemical components of this hypothetical oscillator are currently unknown. Components of the gate controlling entry into the cilium are being identified (4, 5), but identifying the oscillating components themselves could be an extremely difficult biochemical problem because it is not obvious how to determ...

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Local cortical circuit model inferred from power-law distributed neuronal avalanches

Cited by 59 publications

References 48 publications

Spontaneous cortical activity in awake monkeys composed of neuronal avalanches

Spontaneous cortical activity in awake monkeys composed of neuronal avalanches

An open hypothesis: Is epilepsy learned, and can it be unlearned?

Avalanche-like behavior in ciliary import

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