title: Phase-amplitude coupling and interlaminar synchrony are correlated in human neocortex.
abstract: One of the striking manifestations of neuronal population activity is that of rhythmic oscillations in the local field potential. It is thought that such oscillatory patterns, including phase-amplitude coupling (PAC) and inter-regional synchrony, may represent forms of local and long-range cortical computations, respectively. Although it has been speculated that these two oscillatory patterns are functionally related, and bind disparate cortical assemblies to one another at different timescales, there is little direct evidence to support this hypothesis. We have demonstrated recently that theta to high-gamma PAC and interlaminar phase coherence at theta frequencies can be generated in human cortical slices maintained in vitro. Here we show that not only do such oscillatory patterns exist within human temporal neocortex, but that the strength of one is related to the strength of the other. We demonstrate that at theta frequencies, metrics of temporal synchrony between superficial and deep cortical laminae (phase-dependent power correlations, and phase coherence) are correlated to the magnitude of intralaminar PAC between theta and high-gamma. Specifically, our results suggest that interlaminar communication within human temporal neocortex and local laminar excitability are linked to one another through a dependence mediated by theta oscillations. More generally, our results provide evidence for the hypothesis that theta oscillations may coordinate inter-areal excitability in the human brain.
authors.affiliation: Division of Fundamental Neurobiology, Toronto Western Hospital Research Institute, Toronto, Canada, M5T 2S8, Edward S. Rogers Department of Electrical and Computer Engineering, Faculty of Engineering and.
authors.forename: Ryan J
authors.initials: RJ
authors.lastname: McGinn
authors.affiliation: Division of Fundamental Neurobiology, Toronto Western Hospital Research Institute, Toronto, Canada, M5T 2S8, Krembil Neuroscience Center, Toronto, Canada, M5T 2S8, and Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto, Ontario, Canada, M5S 1A1 taufik.valiante@uhn.ca.
authors.forename: Taufik A
authors.identifier: http://orcid.org/0000-0002-3443-3790
authors.initials: TA
authors.lastname: Valiante
mesh_terms: D000200:Action Potentials / Q000502:physiology*; D003344:Cortical Synchronization / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D019579:Neocortex / Q000166:cytology / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D009924:Organ Culture Techniques; D013826:Theta Rhythm / Q000502:physiology*
keywords: cortical column; high-gamma; human cortex; phase-amplitude coupling; synchrony; theta