The Swartz Program in Theoretical Neuroscience, Harvard University, Cambridge, United States; Simons Center for Data Analysis, Simons Foundation, New York, United States
John A Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, United States; Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, United States; Wyss Institute for Bioinspired Engineering, Harvard University, Cambridge, United States; Kavli Institute for BioNano Science and Technology, Harvard University, Cambridge, United States; Department of Physics, Harvard University, Cambridge, United States
Locomotion in an organism is a consequence of the coupled interaction between brain, body and environment. Motivated by qualitative observations and quantitative perturbations of crawling in Drosophila melanogaster larvae, we construct a minimal integrative mathematical model for its locomotion. Our model couples the excitation-inhibition circuits in the nervous system to force production in the muscles and body movement in a frictional environment, thence linking neural dynamics to body mechanics via sensory feedback in a heterogeneous environment. Our results explain the basic observed phenomenology of crawling with and without proprioception, and elucidate the stabilizing role that proprioception plays in producing a robust crawling phenotype in the presence of biological perturbations. More generally, our approach allows us to make testable predictions on the effect of changing body-environment interactions on crawling, and serves as a step in the development of hierarchical models linking cellular processes to behavior.
