Cortical Entropy, Mutual Information and Scale-Free Dynamics in Waking Mice

Cereb Cortex. 2016 Oct;26(10):3945-52. doi: 10.1093/cercor/bhw200. Epub 2016 Jul 6.


Some neural circuits operate with simple dynamics characterized by one or a few well-defined spatiotemporal scales (e.g. central pattern generators). In contrast, cortical neuronal networks often exhibit richer activity patterns in which all spatiotemporal scales are represented. Such "scale-free" cortical dynamics manifest as cascades of activity with cascade sizes that are distributed according to a power-law. Theory and in vitro experiments suggest that information transmission among cortical circuits is optimized by scale-free dynamics. In vivo tests of this hypothesis have been limited by experimental techniques with insufficient spatial coverage and resolution, i.e., restricted access to a wide range of scales. We overcame these limitations by using genetically encoded voltage imaging to track neural activity in layer 2/3 pyramidal cells across the cortex in mice. As mice recovered from anesthesia, we observed three changes: (a) cortical information capacity increased, (b) information transmission among cortical regions increased and (c) neural activity became scale-free. Our results demonstrate that both information capacity and information transmission are maximized in the awake state in cortical regions with scale-free network dynamics.

Keywords: anesthesia; information capacity; information transmission; scale-free dynamics; voltage imaging.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anesthesia
  • Animals
  • Cerebral Cortex / drug effects
  • Cerebral Cortex / physiology*
  • Cluster Analysis
  • Information Theory
  • Markov Chains
  • Mice, Transgenic
  • Neural Pathways / drug effects
  • Neural Pathways / physiology
  • Optical Imaging
  • Optogenetics
  • Pyramidal Cells / drug effects
  • Pyramidal Cells / physiology*
  • Rest
  • Signal Processing, Computer-Assisted
  • Wakefulness / drug effects
  • Wakefulness / physiology*