BottomUpFly · The Role of Ascending Proprioceptive Information in Decision-Making Processes in Walking Drosophila

Locomotion is one of the most relevant tasks of nervous systems, allowing animals to approach food, locate a mate, and escape predators. Most types of locomotion, like walking and flying, are based on rhythmic body movements generated by local premotor networks in the nerve cord, whereas the goal of where to move is generated in the brain e.g., a hungry fly visually locating a food source. For flexible, goal-directed locomotion, the communication between the brain and premotor networks in the nerve cord must be bidirectional. However, in contrast to descending commands from the brain, little is known about proprioceptive signals ascending from the nerve cord's premotor networks.We hypothesize that ascending information plays a vital role in decision-making and action selection processes. Before commanding the body to change direction, or to keep it from doing so to maintain a straight path, brain circuits need to consider the current stability of the body, its walking speed and direction. In this project we aim to characterize the ascending signals determining the direction of upcoming turns if the flys trajectory deviates from the intended one.We will identify the source of the ascending information, characterize functional differences of ascending information pathways, and determine their integration within brain circuits by harnessing the vast toolkit of Drosophila melanogaster and combining the expertise of the Chiappe group on sensorimotor integration in the brain of walking Drosophila with mine on networks controlling walking in the ventral nerve cord. This work will deepen our understanding of the function of proprioception in higher order brain functions, action selection, and decision-making.