Spontaneous cortical activity in awake monkeys composed of neuronal avalanches.

Published

Journal Article

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 rats--show 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.

Full Text

Duke Authors

Cited Authors

  • Petermann, T; Thiagarajan, TC; Lebedev, MA; Nicolelis, MAL; Chialvo, DR; Plenz, D

Published Date

  • September 15, 2009

Published In

Volume / Issue

  • 106 / 37

Start / End Page

  • 15921 - 15926

PubMed ID

  • 19717463

Pubmed Central ID

  • 19717463

Electronic International Standard Serial Number (EISSN)

  • 1091-6490

Digital Object Identifier (DOI)

  • 10.1073/pnas.0904089106

Language

  • eng

Conference Location

  • United States