The Role of Integral Gain and its Neuromuscular Implementation in the Flight Control System of Drosophila

Citation

Ponce, Francesca V. (2024) The Role of Integral Gain and its Neuromuscular Implementation in the Flight Control System of Drosophila. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/j2mb-ka39. https://resolver.caltech.edu/CaltechTHESIS:06112024-013230923

Abstract

Small flying insects, such as the fruit fly Drosophila melanogaster, can navigate along a relatively straight path for long distances. During these journeys, they need a long-range navigational strategy to maintain a constant heading over time, as well as stabilizing behaviors to deal with perturbations, such as a sudden gust of wind or a broken wing. In this work, I characterize a behavioral strategy flies use to maintain stable flight using a combination of experimental and control theoretic approaches. I then investigate how this control strategy is implemented in the flight motor system. In Chapter 1, I describe release-and-recapture experiments performed in the Mojave Desert to investigate how flies interact with the wind to travel long distances. These experiments provide key insight into the dispersal behavior of small insects and suggest that these animals employ a single algorithm that is functionally robust in both still air and under windy conditions. In Chapter 2, I present an extensive set of behavioral experiments showing that the optomotor response, a well-described stabilizing flight reflex, can be accurately modelled by a proportional-integral controller. I also show simulations that exemplify the potential functional advantage of this controller model in natural flight conditions. In Chapter 3, I show the results from muscle imaging experiments designed to investigate how the integral gain of a proportional integral controller might be implemented within the flight motor system. Finally, in Chapter 4, I summarize the main findings, and discuss the limitations of this work and future directions.

Thesis Files