Analyzing the Interplay Between Local CPG Activity and Sensory Signals for Inter-leg Coordination in Drosophila

Abstract

Leg coordination is important for walking robots. Insects are able to effectively walk despite having small metabolisms and size, and understanding the neural mechanisms which govern their walking could prove useful for improving legged robots. In order to explore the possible neural systems responsible for inter-leg coordination, leg positional data for walking fruit flies of the species Drosophila melanogaster was recorded, where one individual leg was amputated at the base of the tibia. These experiments have shown that when amputated, the remaining stump oscillates in a speed-dependent manner. At low walking speeds there is a wide range of possible stump periods, and this variance collapses down to a minimum as walking speed increases. We believe this behavior can be explained by noisy pattern generation networks (CPGs) within the legs, with intra-leg load feedback and inter-leg global signals stabilizing the network. In this paper, this biological data will be analyzed so that a simplified neuromechanical model can be designed in order to explain this behavior.