by Lombardi F, Herrmann HJ, Plenz D, de Arcangelis L
Abstract:
Spontaneous activity of cortex in vitro and in vivo has been shown to organize as neuronal avalanches. Avalanches are cascades of neuronal activity that exhibit a power law in their size and duration distribution, typical features of balanced systems in a critical state. Recently it has been shown that the distribution of quiet times between consecutive avalanches in rat cortex slice cultures displays a non-monotonic behavior with a power law decay at short time scales. This behavior has been attributed to the slow alternation between up and down-states. Here we further characterize the avalanche process and investigate how the functional behavior of the quiet time distribution depends on the fine structure of avalanche sequences. By systematically removing smaller avalanches from the experimental time series we show that size and quiet times are correlated and highlight that avalanche occurrence exhibits the characteristic periodicity of θ and β/γ oscillations, which jointly emerge in most of the analyzed samples. Furthermore, our analysis indicates that smaller avalanches tend to be associated with faster β/γ oscillations, whereas larger ones are associated with slower θ and 1–2 Hz oscillations. In particular, large avalanches corresponding to θ cycles trigger cascades of smaller ones, which occur at β/γ frequency. This temporal structure follows closely the one of nested θ − β/γ oscillations. Finally we demonstrate that, because of the multiple time scales characterizing avalanche dynamics, the distributions of quiet times between avalanches larger than a certain size do not collapse onto a unique function when rescaled by the average occurrence rate. However, when considered separately in the up-state and in the down-state, these distributions are solely controlled by the respective average rate and two different unique function can be identified.
Reference:
On the temporal organization of neuronal avalanches (Lombardi F, Herrmann HJ, Plenz D, de Arcangelis L), In FRONTIERS IN SYSTEMS NEUROSCIENCE, volume 8, 2014. (Articolo in rivista)
Bibtex Entry:
@article{lom14,
author = {Lombardi F, and Herrmann HJ, and Plenz D, and de Arcangelis L,},
pages = {1-15},
title = {On the temporal organization of neuronal avalanches},
volume = {8},
note = {Articolo in rivista},
issn = {1662-5137},
journal = {FRONTIERS IN SYSTEMS NEUROSCIENCE},
year = {2014},
scopusId = {2-s2.0-84908365086},
abstract = {Spontaneous activity of cortex in vitro and in vivo has been shown to organize as neuronal
avalanches. Avalanches are cascades of neuronal activity that exhibit a power law in their
size and duration distribution, typical features of balanced systems in a critical state.
Recently it has been shown that the distribution of quiet times between consecutive
avalanches in rat cortex slice cultures displays a non-monotonic behavior with a power
law decay at short time scales. This behavior has been attributed to the slow alternation
between up and down-states. Here we further characterize the avalanche process and
investigate how the functional behavior of the quiet time distribution depends on the fine
structure of avalanche sequences. By systematically removing smaller avalanches from the
experimental time series we show that size and quiet times are correlated and highlight
that avalanche occurrence exhibits the characteristic periodicity of θ and β/γ oscillations,
which jointly emerge in most of the analyzed samples. Furthermore, our analysis indicates
that smaller avalanches tend to be associated with faster β/γ oscillations, whereas larger
ones are associated with slower θ and 1–2 Hz oscillations. In particular, large avalanches
corresponding to θ cycles trigger cascades of smaller ones, which occur at β/γ frequency.
This temporal structure follows closely the one of nested θ − β/γ oscillations. Finally we
demonstrate that, because of the multiple time scales characterizing avalanche dynamics,
the distributions of quiet times between avalanches larger than a certain size do not
collapse onto a unique function when rescaled by the average occurrence rate. However,
when considered separately in the up-state and in the down-state, these distributions are
solely controlled by the respective average rate and two different unique function can be identified.}
}