title: Simultaneous recordings from the primary visual cortex and lateral geniculate nucleus reveal rhythmic interactions and a cortical source for γ-band oscillations.
abstract: Oscillatory synchronization of neuronal activity has been proposed as a mechanism to modulate effective connectivity between interacting neuronal populations. In the visual system, oscillations in the gamma-frequency range (30-100 Hz) are thought to subserve corticocortical communication. To test whether a similar mechanism might influence subcortical-cortical communication, we recorded local field potential activity from retinotopically aligned regions in the lateral geniculate nucleus (LGN) and primary visual cortex (V1) of alert macaque monkeys viewing stimuli known to produce strong cortical gamma-band oscillations. As predicted, we found robust gamma-band power in V1. In contrast, visual stimulation did not evoke gamma-band activity in the LGN. Interestingly, an analysis of oscillatory phase synchronization of LGN and V1 activity identified synchronization in the alpha (8-14 Hz) and beta (15-30 Hz) frequency bands. Further analysis of directed connectivity revealed that alpha-band interactions mediated corticogeniculate feedback processing, whereas beta-band interactions mediated geniculocortical feedforward processing. These results demonstrate that although the LGN and V1 display functional interactions in the lower frequency bands, gamma-band activity in the alert monkey is largely an emergent property of cortex.
authors.affiliation: Centers for Neuroscience, Mind and Brain, Ernst Strüngmann Institute for Neuroscience in Cooperation with Max Planck Society, 60528 Frankfurt, Germany.
authors.forename: Andre M
authors.initials: AM
authors.lastname: Bastos
authors.affiliation: Centers for Neuroscience, Department of Physiology and Neurobiology, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire 03756, and.
authors.forename: Farran
authors.initials: F
authors.lastname: Briggs
authors.affiliation: Centers for Neuroscience, Departments of Neurobiology, Physiology and Behavior, and.
authors.forename: Henry J
authors.initials: HJ
authors.lastname: Alitto
authors.affiliation: Mind and Brain, Psychology, University of California Davis, Davis, California 95616, Department of Neurology, University of California Davis, Sacramento, California 95817.
authors.forename: George R
authors.initials: GR
authors.lastname: Mangun
authors.affiliation: Centers for Neuroscience, Departments of Neurobiology, Physiology and Behavior, and Department of Neurology, University of California Davis, Sacramento, California 95817 wmusrey@ucdavis.edu.
authors.forename: W Martin
authors.initials: WM
authors.lastname: Usrey
mesh_terms: D000818:Animals; D058256:Brain Waves / Q000502:physiology*; D005074:Evoked Potentials, Visual / Q000502:physiology; D005260:Female; D005829:Geniculate Bodies / Q000502:physiology*; D008253:Macaca mulatta; D008297:Male; D010507:Periodicity; D010775:Photic Stimulation / Q000379:methods*; D014793:Visual Cortex / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*
keywords: LGN; V1; cortex; monkey; oscillations; vision