The mechanisms of neocortical activity patterns accompanying locomotion

Locomotion is the fundamental means by which animals interact with their environment, enabling the basic behaviors of survival including feeding, reproduction, and escape from predation. Thus, understanding the brain functions that regulate locomotion is an essential question in neuroscience. During locomotion, specific brain areas become active, and the landscape of brain activity during movement is fundamentally different than during rest. Although it is known that locomotion alters activity in cortical sensory systems, most studies have used subjects that are immobile, due to experimental constraints. Therefore, we lack a fundamental understanding of the cortical activity patterns in the brain during this basic, critical behavior. We require a more thorough comprehension of movement-dependent sensory processing in order to confront disease states in which locomotion goes awry, such as Parkinson's, which is characterized by both motor and sensory processing deficits. Recent advances in two-photon imaging have enabled the ability to monitor brain activity with single cell resolution in large populations of cells, and we can now carry out these experiments in locomoting animals. The advantage of these imaging techniques is that a large numbers of active and inactive cells can be studied across a large area of cortical space, whereas previous electrophysiological techniques were limited to small local groups of only active cells. My objective is to visualize the activity patterns in the cortex during locomotion, to determine the mechanisms of locomotor-cortex interactions, and to decipher the function of locomotion for sensory processing in the visual cortex. These experiments will provide novel and fundamental data regarding how groups of cortical neurons process sensory information during different motor states. With these data, I hope to elucidate the basic mechanisms of locomotion-dependent sensory processing.