Visual Thalamocortical Mechanisms of Waking State Dependent Activity and Alpha Oscillations

Abstract

The brain exhibits distinct patterns of recurrent activity closely related to the behavioral state of the animal. The neural mechanisms that underlie state-dependent activity in the awake animal are incompletely understood. Here, we demonstrate that two types of state-dependent activity - rapid arousal/movement related signals and a 3-5 Hz alpha-like rhythm - in the primary visual cortex (V1) of mice strongly correlate with activity in the visual thalamus. Inactivation of V1 does not interrupt arousal/movement related signals in most visual thalamic neurons, but it abolishes the 3-5 Hz oscillation. Silencing of the visual thalamus similarly eradicates the alpha-like rhythm and perturbs arousal/movement-related activation in V1. Finally, we observed that whisker movement or locomotion is not required for rapid increases in cortical activation. Our results indicate that thalamocortical interactions together with cell-intrinsic properties of thalamocortical cells play a crucial role in shaping state-dependent activity in V1 of the awake animal. HighlightsO_LIWhisker movements correlate with rapid synaptic activation in V1 and visual thalamus C_LIO_LISilencing of V1 does not abolish movement related activation in most dLGN or LP cells C_LIO_LISilencing of visual thalamus strongly reduces movement related activation in V1 C_LIO_LIThalamocortical interactions generate state-dependent alpha frequency oscillation C_LIO_LIVisual thalamic cells exhibit LTS firing during alpha oscillation in the awake mouse C_LI