title: Cortical Entropy, Mutual Information and Scale-Free Dynamics in Waking Mice.
abstract: 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.
authors.affiliation: The Computational, Cognitive and Clinical Neuroimaging Laboratory, The Centre for Neuroscience, The Division of Brain Sciences, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London, W12 0NN, UK.
authors.forename: Erik D
authors.initials: ED
authors.lastname: Fagerholm
authors.affiliation: The Computational, Cognitive and Clinical Neuroimaging Laboratory, The Centre for Neuroscience, The Division of Brain Sciences, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London, W12 0NN, UK.
authors.forename: Gregory
authors.initials: G
authors.lastname: Scott
authors.affiliation: University of Arkansas, Department of Physics, Fayetteville, AR 72701, USA.
authors.forename: Woodrow L
authors.initials: WL
authors.lastname: Shew
authors.affiliation: Division of Brain Sciences, Department of Medicine, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London, W12 0NN, UK.
authors.forename: Chenchen
authors.initials: C
authors.lastname: Song
authors.affiliation: The Computational, Cognitive and Clinical Neuroimaging Laboratory, The Centre for Neuroscience, The Division of Brain Sciences, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London, W12 0NN, UK.
authors.forename: Robert
authors.initials: R
authors.lastname: Leech
authors.affiliation: Division of Brain Sciences, Department of Medicine, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London, W12 0NN, UK Centre for Neurotechnology, Institute of Biomedical Engineering, Imperial College London, South Kensington, London SW7 2AZ, UK.
authors.forename: Thomas
authors.initials: T
authors.lastname: Knöpfel
authors.affiliation: The Computational, Cognitive and Clinical Neuroimaging Laboratory, The Centre for Neuroscience, The Division of Brain Sciences, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London, W12 0NN, UK.
authors.forename: David J
authors.initials: DJ
authors.lastname: Sharp
mesh_terms: D000758:Anesthesia; D000818:Animals; D002540:Cerebral Cortex / Q000187:drug effects / Q000502:physiology*; D016000:Cluster Analysis; D007257:Information Theory; D008390:Markov Chains; D008822:Mice, Transgenic; D009434:Neural Pathways / Q000187:drug effects / Q000502:physiology; D061848:Optical Imaging; D062308:Optogenetics; D017966:Pyramidal Cells / Q000187:drug effects / Q000502:physiology*; D012146:Rest; D012815:Signal Processing, Computer-Assisted; D014851:Wakefulness / Q000187:drug effects / Q000502:physiology*
keywords: anesthesia; information capacity; information transmission; scale-free dynamics; voltage imaging