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Science Update

Sensory-driven and spontaneous gamma oscillations engage distinct cortical circuitry

Publication Details

Featured Authors

Cristin G. Welle

Diego Contreras

Journal Name
J Neurophysiology
Experiment Type
Acute
Animal Model
Mouse
Brain Region
Cortex Visual
Brain Signal
LFP
Product Category
  • Penetrating Electrode
Product
  • A1x16-3mm-50-177
Abstract
Gamma oscillations are a robust component of sensory responses but are also part of the background spontaneous activity of the brain. To determine whether the properties of gamma oscillations in cortex are specific to their mechanism of generation, we compared in mouse visual cortex in vivo the laminar geometry and single-neuron rhythmicity of oscillations produced during sensory representation with those occurring spontaneously in the absence of stimulation. In mouse visual cortex under anesthesia (isoflurane and xylazine), visual stimulation triggeredoscillations mainly between 20 and 50 Hz, which, because of their similar functional significance to gamma oscillations in higher mammals, we define here as gamma range. Sensory representation in visual cortex specifically increased gamma oscillation amplitude in the supragranular (L2/3) and granular (L4) layers and strongly entrained putative excitatory and inhibitory neurons in infragranular layers, while spontaneous gammaoscillations were distributed evenly through the cortical depth and primarily entrained putative inhibitory neurons in the infragranular (L5/6) corticallayers. The difference in laminar distribution of gamma oscillations during the two different conditions may result from differences in the source of excitatory input to the cortex. In addition, modulation of superficial gamma oscillation amplitude did not result in a corresponding change in deep-layer oscillations, suggesting that superficial and deep layers of cortex may utilize independent but related networks for gamma generation. These results demonstrate that stimulus-driven gamma oscillations engage cortical circuitry in a manner distinct from spontaneous oscillations and suggest multiple networks for the generation of gamma oscillations in cortex.
Citation
J Neurophysiol. 2016 Apr;115(4):1821-35. doi: 10.1152/jn.00137.2015. Epub 2015 Dec 30.
Publication Date
04/ 1/2016
Country
United States
Institution
US Food and Drug Administration