title: Subcortical Source and Modulation of the Narrowband Gamma Oscillation in Mouse Visual Cortex.
abstract: Primary visual cortex exhibits two types of gamma rhythm: broadband activity in the 30-90 Hz range and a narrowband oscillation seen in mice at frequencies close to 60 Hz. We investigated the sources of the narrowband gamma oscillation, the factors modulating its strength, and its relationship to broadband gamma activity. Narrowband and broadband gamma power were uncorrelated. Increasing visual contrast had opposite effects on the two rhythms: it increased broadband activity, but suppressed the narrowband oscillation. The narrowband oscillation was strongest in layer 4 and was mediated primarily by excitatory currents entrained by the synchronous, rhythmic firing of neurons in the lateral geniculate nucleus (LGN). The power and peak frequency of the narrowband gamma oscillation increased with light intensity. Silencing the cortex optogenetically did not abolish the narrowband oscillation in either LGN firing or cortical excitatory currents, suggesting that this oscillation reflects unidirectional flow of signals from thalamus to cortex.
authors.affiliation: UCL Institute of Ophthalmology, University College London, London WC1E 6BT, UK; UCL Institute of Neurology, University College London, London WC1E 6BT, UK; Department of Neuroscience, Physiology, and Pharmacology, University College London, London WC1E 6BT, UK. Electronic address: aman.saleem@ucl.ac.uk.
authors.forename: Aman B
authors.initials: AB
authors.lastname: Saleem
authors.affiliation: Division of Biological Sciences, University of San Diego, San Diego, CA 92110, USA.
authors.forename: Anthony D
authors.initials: AD
authors.lastname: Lien
authors.affiliation: UCL Institute of Ophthalmology, University College London, London WC1E 6BT, UK.
authors.forename: Michael
authors.initials: M
authors.lastname: Krumin
authors.affiliation: UCL Institute of Ophthalmology, University College London, London WC1E 6BT, UK.
authors.forename: Bilal
authors.initials: B
authors.lastname: Haider
authors.affiliation: Werner Reichardt Centre for Integrative Neuroscience, University of Tübingen, 72074 Tübingen, Germany; Graduate Training Centre of Neuroscience, University of Tübingen, 72074 Tübingen, Germany.
authors.forename: Miroslav Román
authors.initials: MR
authors.lastname: Rosón
authors.affiliation: UCL Institute of Ophthalmology, University College London, London WC1E 6BT, UK.
authors.forename: Asli
authors.initials: A
authors.lastname: Ayaz
authors.affiliation: Division of Biological Sciences, University of San Diego, San Diego, CA 92110, USA.
authors.forename: Kimberly
authors.initials: K
authors.lastname: Reinhold
authors.affiliation: Werner Reichardt Centre for Integrative Neuroscience, University of Tübingen, 72074 Tübingen, Germany.
authors.forename: Laura
authors.initials: L
authors.lastname: Busse
authors.affiliation: UCL Institute of Ophthalmology, University College London, London WC1E 6BT, UK. Electronic address: m.carandini@ucl.ac.uk.
authors.forename: Matteo
authors.initials: M
authors.lastname: Carandini
authors.affiliation: UCL Institute of Neurology, University College London, London WC1E 6BT, UK; Department of Neuroscience, Physiology, and Pharmacology, University College London, London WC1E 6BT, UK. Electronic address: kenneth.harris@ucl.ac.uk.
authors.forename: Kenneth D
authors.initials: KD
authors.lastname: Harris
mesh_terms: D000818:Animals; D019706:Excitatory Postsynaptic Potentials / Q000502:physiology*; D065818:Gamma Rhythm / Q000502:physiology*; D005829:Geniculate Bodies / Q000502:physiology*; D053444:Inhibitory Postsynaptic Potentials / Q000502:physiology*; D051379:Mice; D009474:Neurons / Q000502:physiology*; D010775:Photic Stimulation; D013569:Synapses / Q000502:physiology; D014793:Visual Cortex / Q000502:physiology*; D014795:Visual Pathways / Q000502:physiology*
keywords: gamma; lateral geniculate nucleus; mouse vision; neural circuits; primary visual cortex; thalamus