Limits...
Temporal correlations in neuronal avalanche occurrence.

Lombardi F, Herrmann HJ, Plenz D, de Arcangelis L - Sci Rep (2016)

Bottom Line: Moreover we evidence that sizes of consecutive avalanches are correlated.In particular, we show that an avalanche tends to be larger or smaller than the following one for short or long time separation, respectively.Our analysis represents the first attempt to provide a quantitative estimate of correlations between activity and quiescence in the framework of neuronal avalanches and will help to enlighten the mechanisms underlying spontaneous activity.

View Article: PubMed Central - PubMed

Affiliation: Institute of Computational Physics for Engineering Materials, ETH, Zurich, Switzerland.

ABSTRACT
Ongoing cortical activity consists of sequences of synchronized bursts, named neuronal avalanches, whose size and duration are power law distributed. These features have been observed in a variety of systems and conditions, at all spatial scales, supporting scale invariance, universality and therefore criticality. However, the mechanisms leading to burst triggering, as well as the relationship between bursts and quiescence, are still unclear. The analysis of temporal correlations constitutes a major step towards a deeper understanding of burst dynamics. Here, we investigate the relation between avalanche sizes and quiet times, as well as between sizes of consecutive avalanches recorded in cortex slice cultures. We show that quiet times depend on the size of preceding avalanches and, at the same time, influence the size of the following one. Moreover we evidence that sizes of consecutive avalanches are correlated. In particular, we show that an avalanche tends to be larger or smaller than the following one for short or long time separation, respectively. Our analysis represents the first attempt to provide a quantitative estimate of correlations between activity and quiescence in the framework of neuronal avalanches and will help to enlighten the mechanisms underlying spontaneous activity.

No MeSH data available.


Related in: MedlinePlus

Significant correlations exist between the size si and the following quiet time Δti.The quantity δP(si < s0, Δti < t0) as a function of s0 for different values of t0 and different conditions, non-driven, driven and disinhibited (PTX). The bar on each data point is 2σ(si < s0, Δti < t0). Each curve represents an average over all experimental samples in a given condition. (a) Normal; (b) Driven; (c) Disinhibited. Insets: The ratio δP(si < s0, Δti < t0)/σ as a function of s0 for different values of t0; dashed lines delimit the interval (−2, 2). In most cases δP(si < s0, Δti < t0)/σ is much larger than 2. Therefore these results are significant at a level generally lower than 0.05 and give solid evidences of correlations between avalanches and following quiet times.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4837393&req=5

f3: Significant correlations exist between the size si and the following quiet time Δti.The quantity δP(si < s0, Δti < t0) as a function of s0 for different values of t0 and different conditions, non-driven, driven and disinhibited (PTX). The bar on each data point is 2σ(si < s0, Δti < t0). Each curve represents an average over all experimental samples in a given condition. (a) Normal; (b) Driven; (c) Disinhibited. Insets: The ratio δP(si < s0, Δti < t0)/σ as a function of s0 for different values of t0; dashed lines delimit the interval (−2, 2). In most cases δP(si < s0, Δti < t0)/σ is much larger than 2. Therefore these results are significant at a level generally lower than 0.05 and give solid evidences of correlations between avalanches and following quiet times.

Mentions: To investigate how the quiet time Δti depends on the size si of the previous avalanche, we evaluate the quantity δP(si < s0 / Δti < t0) for different values of s0 and t0 (see Methods). In Fig. 3 we show δP(si < s0 / Δti < t0) as a function of s0 for different values of t0. Both in the non-driven (Fig. 3a) and driven condition (Fig. 3b), for Δti < 200 ms, the quantity δP(si < s0, Δti < t0) takes always positive values beyond error bars, which implies that the probability of finding Δti < 200 ms after an avalanche of size si < 30s0 is larger in the real than in the reshuffled time series. Moreover, since δP(si < s0, Δti < t0) generally decreases by increasing t0, this probability gradually decreases if one considers avalanches separated by longer Δt.


Temporal correlations in neuronal avalanche occurrence.

Lombardi F, Herrmann HJ, Plenz D, de Arcangelis L - Sci Rep (2016)

Significant correlations exist between the size si and the following quiet time Δti.The quantity δP(si < s0, Δti < t0) as a function of s0 for different values of t0 and different conditions, non-driven, driven and disinhibited (PTX). The bar on each data point is 2σ(si < s0, Δti < t0). Each curve represents an average over all experimental samples in a given condition. (a) Normal; (b) Driven; (c) Disinhibited. Insets: The ratio δP(si < s0, Δti < t0)/σ as a function of s0 for different values of t0; dashed lines delimit the interval (−2, 2). In most cases δP(si < s0, Δti < t0)/σ is much larger than 2. Therefore these results are significant at a level generally lower than 0.05 and give solid evidences of correlations between avalanches and following quiet times.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4837393&req=5

f3: Significant correlations exist between the size si and the following quiet time Δti.The quantity δP(si < s0, Δti < t0) as a function of s0 for different values of t0 and different conditions, non-driven, driven and disinhibited (PTX). The bar on each data point is 2σ(si < s0, Δti < t0). Each curve represents an average over all experimental samples in a given condition. (a) Normal; (b) Driven; (c) Disinhibited. Insets: The ratio δP(si < s0, Δti < t0)/σ as a function of s0 for different values of t0; dashed lines delimit the interval (−2, 2). In most cases δP(si < s0, Δti < t0)/σ is much larger than 2. Therefore these results are significant at a level generally lower than 0.05 and give solid evidences of correlations between avalanches and following quiet times.
Mentions: To investigate how the quiet time Δti depends on the size si of the previous avalanche, we evaluate the quantity δP(si < s0 / Δti < t0) for different values of s0 and t0 (see Methods). In Fig. 3 we show δP(si < s0 / Δti < t0) as a function of s0 for different values of t0. Both in the non-driven (Fig. 3a) and driven condition (Fig. 3b), for Δti < 200 ms, the quantity δP(si < s0, Δti < t0) takes always positive values beyond error bars, which implies that the probability of finding Δti < 200 ms after an avalanche of size si < 30s0 is larger in the real than in the reshuffled time series. Moreover, since δP(si < s0, Δti < t0) generally decreases by increasing t0, this probability gradually decreases if one considers avalanches separated by longer Δt.

Bottom Line: Moreover we evidence that sizes of consecutive avalanches are correlated.In particular, we show that an avalanche tends to be larger or smaller than the following one for short or long time separation, respectively.Our analysis represents the first attempt to provide a quantitative estimate of correlations between activity and quiescence in the framework of neuronal avalanches and will help to enlighten the mechanisms underlying spontaneous activity.

View Article: PubMed Central - PubMed

Affiliation: Institute of Computational Physics for Engineering Materials, ETH, Zurich, Switzerland.

ABSTRACT
Ongoing cortical activity consists of sequences of synchronized bursts, named neuronal avalanches, whose size and duration are power law distributed. These features have been observed in a variety of systems and conditions, at all spatial scales, supporting scale invariance, universality and therefore criticality. However, the mechanisms leading to burst triggering, as well as the relationship between bursts and quiescence, are still unclear. The analysis of temporal correlations constitutes a major step towards a deeper understanding of burst dynamics. Here, we investigate the relation between avalanche sizes and quiet times, as well as between sizes of consecutive avalanches recorded in cortex slice cultures. We show that quiet times depend on the size of preceding avalanches and, at the same time, influence the size of the following one. Moreover we evidence that sizes of consecutive avalanches are correlated. In particular, we show that an avalanche tends to be larger or smaller than the following one for short or long time separation, respectively. Our analysis represents the first attempt to provide a quantitative estimate of correlations between activity and quiescence in the framework of neuronal avalanches and will help to enlighten the mechanisms underlying spontaneous activity.

No MeSH data available.


Related in: MedlinePlus