Effects of locomotion on visual inter-areal processing - PROJECT SUMMARY/ABSTRACT A central question in systems neuroscience is how brain states modulate sensory processing. Because sensory processing is accomplished by a distributed network of areas, a major component of how brain states modulate sensory processing might involve dynamic and flexible relaying of sensory signals between brain areas. The visual system’s rich inter-connectivity makes it an excellent model for elucidating flexible inter-areal communication. Brain state changes with locomotion, in a manner that is intimately and intricately intertwined with visual processing. Locomotion has been shown to affect visual responses and may also be used to generate internal predictions of visual input. However, previous research has focused on within-area effects of locomotion in visual processing. To understand how locomotion influences visual processing, we must understand how locomotion alters visual inter-areal signaling. Our goal in this project is to understand how locomotion affects the flow of visual information between areas during contexts of passive viewing and visuomotor feedback. We hypothesize that locomotion will flexibly alter inter-areal visual processing by improving communication of visual information and generating feedback predictions of visual input. To this end, we will utilize high density laminar probes that will record population activity from multiple brain areas simultaneously during different locomotive contexts. We will evaluate communication between areas using modern multivariate analytic methods which have revealed the patterns of population activity that are relayed between brain areas, termed “communication subspaces”. In Aim 1, we will present mice with visual stimuli during locomotion whilst recording from visual areas dLGN, V1 and LM. We will use the resultant data to evaluate how locomotion affects the inter-areal signaling of visual information via communication subspaces. In Aim 2, we will manipulate the relationship between locomotion and concurrent visual input via virtual reality feedback, whilst recording from dLGN, V1, and frontal areas ACC/M2, to determine how locomotion-generated expectations of visual input are transmitted between areas and affect sensory representations. We will momentarily decouple locomotion and visual feedback and evaluate how discrepancies between visuomotor expectation are relayed between areas and alter sensory representations. We will also provide a causal test of ACC/M2’s role in affecting visual representations by providing visuomotor predictions. Our project seeks to uncover the nature of the interaction between locomotion and sensory information flow within the visual system. In doing so, we aim to elucidate basic principles of how brain states flexibly modulate communication between brain areas.
