Quantitative Biosciences Thesis Proposal

Benjamin Doshna 

School of Biological Sciences

Flexible Coordination Patterns In a Complete, Spike Resolved Motor Program

Wednesday, April 30, 2025, at 10:00 am

In Person Location: Howey N201/202

Meeting Link:https://gatech.zoom.us/j/91417272302

Open to the Community

Advisor:

Dr. Simon Sponberg (School of Physics, School of Biological Sciences)

Committee Members:

Dr. Flavio Fenton (School of Physics)

Dr. Audrey Sederberg (School of Physics, School of Psychology)

Dr. Jeffrey Markowitz (Department of Biomedical Engineering)

Abstract:

Motor control depends on the nervous system's ability to generate sets of coordinated patterns of muscle activity. In the hawkmoth Manduca sexta, the activity of just 10 muscles controls the majority of wing motion, enabling complete recordings of the motor program during behavior. While previous work has shown that spike timing in individual muscles affects force production, how coordination across muscles supports both stability and flexibility in behavior remains unresolved.

My research uses Manduca sexta to investigate how coordination patterns in a complete motor program adapt to changing physiological, behavioral, and evolutionary contexts. First, I examine how moths maintain accurate flight control while rapidly increasing body mass during feeding. I explore if the moths actively change their control strategies or if their initial strategies are robust to this mass increase, with potential changes manifesting as coordinated changes in muscle activation timings in the motor program. Second, I compare coordination patterns across species in the Bombycoidea superfamily. Despite shared musculature, variation in flight kinematics and muscle physiology suggests constraints on coordination emerge along phylogenetic lines.

Third, I explore how coordination patterns are reorganized during motor learning using a closed-loop virtual reality task that requires moths to control novel visuomotor behaviors. Finally, I investigate the neural mechanisms underlying this flexibility by recording from ascending neurons in the neck connective to determine whether the moths store efference copies of these coordination patterns to help modulate their flight control strategies.

Together, this work leverages the spike-resolved completeness of the Manduca sexta motor program to uncover how precise, flexible coordination is structured, adapted, and controlled during agile behavior.