The goal of the proposed project is to understand whether and how neuronal control circuits exploit mechanical resonance during animal locomotion to achieve highly efficient rhythmic body movements. General principles will be uncovered through a specific case study of dynamical mechanisms underlying undulatory swimming of leeches. Diverse behaviors of leeches are generated by relatively simple neuronal circuits, providing a unique opportunity for preliminary understanding of how the brain works in the most primitive form. A simple integrated model of leech swimming, amenable to analytical studies, will be developed from detailed, experimentally validated, component models of the neuronal circuit, motoneuron activation, muscle biomechanics, and body-fluid interactions. Theoretical and computational studies of the model will then be performed to examine how the neural control circuits process sensory signals and achieve oscillations near a resonance under nominal and perturbed environmental conditions.
Once uncovered, resonance entrainment principles will contribute to understanding of general complex systems that achieve robustness, adaptability, and emergence. These new functionalities, when engineered, will have a broad range of applications, including robotic vehicles that maintain efficiency of transportation under varying environments. In the medical field, understanding of the neural control mechanisms is fundamental to determining the cause, rehabilitation, and cure for loss or reduction of locomotor ability due to neurological disorders or spinal cord injury. The research activities are integrated into educational activities at both K-12 and college levels. A graduate student will be trained for experimental data processing and model-based dynamical systems analyses. Through research experience activities, undergraduate students will develop educational software modules for simulation/animation of leech swimming to stimulate K-12 students' curiosity for science/engineering during such occasions as Engineering Open House. The results will be broadly disseminated to both biology and control engineering communities to enhance cross-cultural fertilization.
