title: The phase of thalamic alpha activity modulates cortical gamma-band activity: evidence from resting-state MEG recordings.
abstract: Recent findings have implicated thalamic alpha oscillations in the phasic modulation of cortical activity. However, the precise relationship between thalamic alpha oscillations and neocortical activity remains unclear. Here we show in a large sample of healthy human participants (n = 45) using spatial filtering techniques and measures of phase amplitude coupling that the amplitude of gamma-band activity in posterior medial parietal cortex is modulated by the phase of thalamic alpha oscillations during eyes-closed resting-state recordings. In addition, our findings show that gamma-band activity in visual cortex was not modulated by thalamic alpha oscillations but coupled to the phase of strong cortical alpha activity. To overcome the limitations of electromagnetic source localization we estimated conduction delays using transfer entropy and found nonspurious information transfer from thalamus to cortex. The present findings provide novel evidence for magneto-encephalography-measured phase coupling between cortical gamma-band activity and thalamic alpha oscillations, which highlight the role of phasic inhibition in the coordination of cortical activity.
authors.affiliation: Basque Center on Cognition, Brain, and Language (BCBL), 2009 Donostia/San Sebastian, Spain, MEG Unit, Brain Imaging Center, Goethe University, 60528 Frankfurt am Main, Germany, Max-Planck Institute for Brain Research, Department of Neurophysiology, 60438 Frankfurt am Main, Germany, Ernst Strüngmann Institute, 60528 Frankfurt am Main, Germany, Frankfurt Institute for Advanced Sciences, 60438 Frankfurt am Main, Germany, and Institute of Neuroscience and Psychology, Glasgow University, Glasgow, G12 8QB Scotland.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Roux
authors.forename: Michael
authors.initials: M
authors.lastname: Wibral
authors.forename: Wolf
authors.initials: W
authors.lastname: Singer
authors.forename: Jaan
authors.initials: J
authors.lastname: Aru
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Uhlhaas
mesh_terms: D000293:Adolescent; D000328:Adult; D000513:Alpha Rhythm / Q000502:physiology*; D001931:Brain Mapping; D058256:Brain Waves / Q000502:physiology*; D005260:Female; D006801:Humans; D015225:Magnetoencephalography; D008297:Male; D010296:Parietal Lobe / Q000502:physiology*; D013788:Thalamus / Q000502:physiology*