Spiking activity in the visual thalamus is coupled to pupil dynamics across temporal scales

Abstract

AU The:processing Pleaseconfirmthatallheadinglevelsarerepresentedcorrectly of sensory information, even at early stages, : is influenced by the internal state of the animal. Internal states, such as arousal, are often characterized by relating neural activity to a single “level” of arousal, defined by a behavioral indicator such as pupil size. In this study, we expand the understanding of arousal-related modulations in sensory systems by uncovering multiple timescales of pupil dynamics and their relationship to neural activity. Specifically, we observed a robust coupling between spiking activity in the mouse dorsolateral geniculate nucleus (dLGN) of the thalamus and pupil dynamics across timescales spanning a few seconds to several minutes. Throughout all these timescales, 2 distinct spiking modes—individual tonic spikes and tightly clustered bursts of spikes—preferred opposite phases of pupil dynamics. This multi-scale coupling reveals modulations distinct from those captured by pupil size per seAU , locomotion,: PerPLOSstyle and eye ; italicsshouldnotbeusedforemphasis movements. Furthermore, coupling persisted even during viewing of a naturalistic movie, where it contributed to differences in the encoding of visual information. We conclude that dLGN spiking activity is under the simultaneous influence of multiple arousal-related processes associated with pupil dynamics occurring over a broad range of timescales.