scholarly journals Maintained avalanche dynamics during task-induced changes of neuronal activity in nonhuman primates

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Shan Yu ◽  
Tiago L Ribeiro ◽  
Christian Meisel ◽  
Samantha Chou ◽  
Andrew Mitz ◽  
...  
Keyword(s):  
Cognitive Processing ◽  
Neuronal Activity ◽  
Unit Activity ◽  
Scale Invariance ◽  
Nonhuman Primates ◽  
Field Potential ◽  
Scale Invariant ◽  
Ongoing Activity ◽  
Statistical Regularities ◽  
Induced Changes

Sensory events, cognitive processing and motor actions correlate with transient changes in neuronal activity. In cortex, these transients form widespread spatiotemporal patterns with largely unknown statistical regularities. Here, we show that activity associated with behavioral events carry the signature of scale-invariant spatiotemporal clusters, neuronal avalanches. Using high-density microelectrode arrays in nonhuman primates, we recorded extracellular unit activity and the local field potential (LFP) in premotor and prefrontal cortex during motor and cognitive tasks. Unit activity and negative LFP deflections (nLFP) consistently changed in rate at single electrodes during tasks. Accordingly, nLFP clusters on the array deviated from scale-invariance compared to ongoing activity. Scale-invariance was recovered using ‘adaptive binning’, that is identifying clusters at temporal resolution given by task-induced changes in nLFP rate. Measures of LFP synchronization confirmed and computer simulations detailed our findings. We suggest optimization principles identified for avalanches during ongoing activity to apply to cortical information processing during behavior.

scholarly journals SSB OF SCALE SYMMETRY, FERMION FAMILIES AND QUINTESSENCE WITHOUT THE LONG-RANGE FORCE PROBLEM

2002 ◽  
Vol 17 (03) ◽  
pp. 417-433 ◽  
Author(s):  
E. I. GUENDELMAN ◽  
A. B. KAGANOVICH
Keyword(s):  
Particle Physics ◽  
Scale Invariance ◽  
Field Potential ◽  
Momentum Tensor ◽  
Kinetic Term ◽  
Exponential Potential ◽  
Scale Invariant ◽  
Fermion Masses ◽  
First Choice ◽  
Scaling Solution

We study a scale-invariant two measures theory where a dilaton field ϕ has no explicit potentials. The scale transformations include the translation of a dilaton ϕ→ϕ+ const . The theory demonstrates a new mechanism for generation of the exponential potential: in the conformal Einstein frame (CEF), after SSB of scale invariance, the theory develops the exponential potential and, in general, the nonlinear kinetic term is generated as well. The scale symmetry does not allow the appearance of terms breaking the exponential shape of the potential that solves the problem of the flatness of the scalar field potential in the context of quintessential scenarios. As examples, two different possibilities for the choice of the dimensionless parameters are presented where the theory permits to get interesting cosmological results. For the first choice, the theory has standard scaling solutions for ϕ usually used in the context of the quintessential scenario. For the second choice, the theory allows three different solutions, one of which is a scaling solution with equation of state pϕ=wρϕ where w is predicted to be restricted by -1<w<-0.82. The regime where the fermionic matter dominates (as compared to the dilatonic contribution) is analyzed. There it is found that starting from a single fermionic field we obtain exactly three different types of spin 1/2 particles in CEF that appears to suggest a new approach to the family problem of particle physics. It is automatically achieved that for two of them, fermion masses are constants, the energy–momentum tensor is canonical and the "fifth force" is absent. For the third type of particles, a fermionic self-interaction appears as a result of SSB of scale invariance.

scholarly journals Quasi-universal scaling in mouse-brain neuronal activity stems from edge-of-instability critical dynamics

2021 ◽  
Author(s):  
Guillermo B. Morales ◽  
Serena Di Santo ◽  
Miguel A Muñoz
Keyword(s):  
Mouse Brain ◽  
Neuronal Activity ◽  
Scale Invariance ◽  
Brain Networks ◽  
Brain Regions ◽  
Statistical Characteristics ◽  
Neural Population ◽  
Dynamical Regime ◽  
Scale Invariant ◽  
The Brain

The brain is in a state of perpetual reverberant neural activity, even in the absence of specific tasks or stimuli. Shedding light on the origin and functional significance of such activity is essential to understanding how the brain transmits, processes, and stores information. An inspiring, albeit controversial, conjecture proposes that some statistical characteristics of empirically observed neuronal activity can be understood by assuming that brain networks operate in a dynamical regime near the edge of a phase transition. Moreover, the resulting critical behavior, with its concomitant scale invariance, is assumed to carry crucial functional advantages. Here, we present a data-driven analysis based on simultaneous high-throughput recordings of the activity of thousands of individual neurons in various regions of the mouse brain. To analyze these data, we construct a unified theoretical framework that synergistically combines cutting-edge methods for the study of brain activity (such as a phenomenological renormalization group approach and techniques that infer the general dynamical state of a neural population), while designing complementary tools. This unified approach allows us to uncover strong signatures of scale invariance that is "quasi-universal" across brain regions and reveal that these areas operate, to a greater or lesser extent, at the edge of instability. Furthermore, this framework allows us to distinguish between quasi-universal background activity and non-universal input-related activity. Taken together, the following study provides strong evidence that brain networks actually operate in a critical regime which, among other functional advantages, provides them with a scale-invariant substrate of activity in which optimal input representations can be sustained.

scholarly journals Author response: Maintained avalanche dynamics during task-induced changes of neuronal activity in nonhuman primates

2017 ◽  
Author(s):  
Shan Yu ◽  
Tiago L Ribeiro ◽  
Christian Meisel ◽  
Samantha Chou ◽  
Andrew Mitz ◽  
...  
Keyword(s):  
Neuronal Activity ◽  
Nonhuman Primates ◽  
Author Response ◽  
Avalanche Dynamics ◽  
Induced Changes

Amacrine and ganglion cell contributions to the electroretinogram in amphibian retina

2001 ◽  
Vol 18 (1) ◽  
pp. 147-156 ◽  
Author(s):  
GAUTAM AWATRAMANI ◽  
JUE WANG ◽  
MALCOLM M. SLAUGHTER
Keyword(s):  
Contrast Agents ◽  
Ganglion Cell ◽  
Neuronal Activity ◽  
Opposite Effect ◽  
Cell Function ◽  
Ganglion Cells ◽  
Field Potential ◽  
Tiger Salamander ◽  
Third Order ◽  
Light Responses

The neuronal generators of the b- and d-waves of the electroretinogram (ERG) were investigated in the tiger salamander retina to determine if amacrine and ganglion cells contribute to this field potential. Several agents were used that affect third-order neurons, such as tetrodotoxin, baclofen, and NMDA agonists and antagonists. Baclofen, an agent that enhances light responses in third-order neurons, increased the d-wave and reduced the b-wave. In contrast, agents that decrease light responses in third-order neurons had the opposite effect of enhancing the b-wave and depressing the d-wave. The effect on the d-wave was particularly pronounced. The results indicate that third-order neuronal activity influences b- and d-waves of the ERG. The opposing actions suggest that the b-wave to d-wave ratio might serve as an measure of ganglion cell function.

scholarly journals Scale Invariance, Horizons, and Inflation

2021 ◽  
Author(s):  
Andre Maeder ◽  
Vesselin G Gueorguiev
Keyword(s):  
Scalar Field ◽  
Scale Invariance ◽  
Maxwell Equations ◽  
High Redshift ◽  
Empty Space ◽  
Causal Connection ◽  
Cosmological Constant Problem ◽  
Scale Invariant ◽  
Starting Point ◽  
Final Answer

Abstract Maxwell equations and the equations of General Relativity are scale invariant in empty space. The presence of charge or currents in electromagnetism or the presence of matter in cosmology are preventing scale invariance. The question arises on how much matter within the horizon is necessary to kill scale invariance. The scale invariant field equation, first written by Dirac in 1973 and then revisited by Canuto et al. in 1977, provides the starting point to address this question. The resulting cosmological models show that, as soon as matter is present, the effects of scale invariance rapidly decline from ϱ = 0 to ϱc, and are forbidden for densities above ϱc. The absence of scale invariance in this case is consistent with considerations about causal connection. Below ϱc, scale invariance appears as an open possibility, which also depends on the occurrence of in the scale invariant context. In the present approach, we identify the scalar field of the empty space in the Scale Invariant Vacuum (SIV) context to the scalar field ϕ in the energy density $\varrho = \frac{1}{2} \dot{\varphi }^2 + V(\varphi )$ of the vacuum at inflation. This leads to some constraints on the potential. This identification also solves the so-called “cosmological constant problem”. In the framework of scale invariance, an inflation with a large number of e-foldings is also predicted. We conclude that scale invariance for models with densities below ϱc is an open possibility; the final answer may come from high redshift observations, where differences from the ΛCDM models appear.

Cortical and Dopaminergic Regulation of Amphetamine-Induced Changes In Striatal Single-Unit Activity in Awake, Behaving Rats

1994 ◽  
pp. 457-463 ◽  
Author(s):  
George V. Rebec ◽  
Ariane Rosa-Kenig ◽  
John L. Haracz ◽  
JoAnn T. Tschanz ◽  
Karen E. Griffith ◽  
...  
Keyword(s):  
Unit Activity ◽  
Single Unit ◽  
Single Unit Activity ◽  
Dopaminergic Regulation ◽  
Induced Changes

scholarly journals Scale-invariance, dynamically induced Planck scale and inflation in the Palatini formulation

2021 ◽  
Vol 2105 (1) ◽  
pp. 012005
Author(s):  
Ioannis D. Gialamas ◽  
Alexandros Karam ◽  
Thomas D. Pappas ◽  
Antonio Racioppi ◽  
Vassilis C. Spanos
Keyword(s):  
Scale Invariance ◽  
Planck Scale ◽  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
Scalar Fields ◽  
Scale Invariant ◽  
Expectation Value ◽  
Hilbert Action

Abstract We present two scale invariant models of inflation in which the addition of quadratic in curvature terms in the usual Einstein-Hilbert action, in the context of Palatini formulation of gravity, manages to reduce the value of the tensor-to-scalar ratio. In both models the Planck scale is dynamically generated via the vacuum expectation value of the scalar fields.

Acute mitragynine administration suppresses cortical oscillatory power and systems theta coherence in rats

2020 ◽  
Vol 34 (7) ◽  
pp. 759-770
Author(s):  
Rachel-Karson Thériault ◽  
Joshua D Manduca ◽  
Colin R Blight ◽  
Jibran Y Khokhar ◽  
Tariq A Akhtar ◽  
...  
Keyword(s):  
Basolateral Amygdala ◽  
Spectral Power ◽  
Opioid Analgesic ◽  
Field Potential ◽  
Drug Effects ◽  
Underlying Mechanism ◽  
Oscillatory Activity ◽  
Drug Induced ◽  
Fos Expression ◽  
Induced Changes

Background: Mitragynine is the major alkaloid of Mitragyna speciosa (kratom) with potential as a therapeutic in pain management and in depression. There has been debate over the potential side effects of the drug including addiction risk and cognitive decline. Aims: To evaluate the effects of mitragynine on neurophysiological systems function in the prefrontal cortex (PFC), cingulate cortex (Cg), orbitofrontal cortex, nucleus accumbens (NAc), hippocampus (HIP), thalamus (THAL), basolateral amygdala (BLA) and ventral tegmental area of rats. Methods: Local field potential recordings were taken from animals at baseline and for 45 min following mitragynine administration (10 mg/kg, intraperitoneally). Drug-induced changes in spectral power and coherence between regions at specific frequencies were evaluated. Mitragynine-induced changes in c-fos expression were also analyzed. Results: Mitragynine increased delta power and reduced theta power in all three cortical regions that were accompanied by increased c-fos expression. A transient suppression of gamma power in PFC and Cg was also evident. There were no effects of mitragynine on spectral power in any of the other regions. Mitragynine induced a widespread reduction in theta coherence (7–9 Hz) that involved disruptions in cortical and NAc connectivity with the BLA, HIP and THAL. Conclusions: These findings show that mitragynine induces frequency-specific changes in cortical neural oscillatory activity that could potentially impact cognitive functioning. However, the absence of drug effects within regions of the mesolimbic pathway may suggest either a lack of addiction potential, or an underlying mechanism of addiction that is distinct from other opioid analgesic agents.

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