Locomotion is the product of neural output acting on muscles driving a mechanically complex body in an unpredictable environment. The lamprey is a simple, well-studied and relatively tractable vertebrate model with which to probe this neuromechanical system. We hypothesize that steady locomotion in a predictable environment requires only the central pattern generator (CPG) without the necessity of other input. We also hypothesize that in an unpredictable environment sensory feedback combined with strong intersegmental coupling is necessary. To investigate these hypotheses we will develop an integrated model, of lamprey swimming LAMPREYCOMP with Thelma Williams, from London, and researchers Philip Holmes and Alexander Smits from Princeton University. The model spans CPG, sensory feedback, muscle mechanics, body mechanics, and fluid mechanics, and is a full model of a complex behavior in a vertebrate, albeit a simple one. Cohen and colleagues will perform experimental studies of the CPG and its response to sensory feedback from spinal mechanoreceptors, skin and lateral line and will develop the component of LAMPREYCOMP that maps sensory input to motor nerve output. Work on muscle and body mechanics will be done by Holmes and Williams. Smits and Holmes will study the fluid mechanics of the swimming animals both experimentally and theoretically. The experimental work will include developing a mechanical analog, P-RAY, whose motion will be adjusted to reproduce that of live animals, allowing measurements of fluid motion and pressure variations along the body. The theoretical work will include developing the fluid dynamical component of LAMPREYCOMP, in consultation with C. Peskin, L. Fauci and colleagues. LAMPREYCOMP will be tested to insure that it reproduces the behavior of whole animal swimming, various reduced preparations and P-RAY. It will then be used to investigate the effect of manipulations, such as removing sensory feedback from spinal mechanoreceptors that are not experimentally possible. We also show that all components of the protocol are possible. Because the lamprey is a model system for all of vertebrate locomotion, our hypotheses and models will have broad implications for more advanced organisms in which such a complete approach is not presently feasible. ? ?

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
1R01NS054271-01
Application #
7046429
Study Section
Special Emphasis Panel (ZRG1-IFCN-B (50))
Program Officer
Liu, Yuan
Project Start
2005-09-15
Project End
2010-05-31
Budget Start
2005-09-15
Budget End
2006-05-31
Support Year
1
Fiscal Year
2005
Total Cost
$322,527
Indirect Cost
Name
University of Maryland College Park
Department
Biology
Type
Schools of Earth Sciences/Natur
DUNS #
790934285
City
College Park
State
MD
Country
United States
Zip Code
20742
Tytell, Eric D; Hsu, Chia-Yu; Fauci, Lisa J (2014) The role of mechanical resonance in the neural control of swimming in fishes. Zoology (Jena) 117:48-56
Leftwich, Megan C; Tytell, Eric D; Cohen, Avis H et al. (2012) Wake structures behind a swimming robotic lamprey with a passively flexible tail. J Exp Biol 215:416-25
Tytell, E D; Holmes, P; Cohen, A H (2011) Spikes alone do not behavior make: why neuroscience needs biomechanics. Curr Opin Neurobiol 21:816-22
Previte, Joseph P; Sheils, Natalie; Hoffman, Kathleen A et al. (2011) Entrainment ranges of forced phase oscillators. J Math Biol 62:589-603
Williams, Thelma L (2010) A new model for force generation by skeletal muscle, incorporating work-dependent deactivation. J Exp Biol 213:643-50
Green, Melissa A; Rowley, Clarence W; Smits, Alexander J (2010) Using hyperbolic Lagrangian coherent structures to investigate vortices in bioinspired fluid flows. Chaos 20:017510
Oliphint, Paul A; Alieva, Naila; Foldes, Andrea E et al. (2010) Regenerated synapses in lamprey spinal cord are sparse and small even after functional recovery from injury. J Comp Neurol 518:2854-72
Tytell, Eric D; Hsu, Chia-Yu; Williams, Thelma L et al. (2010) Interactions between internal forces, body stiffness, and fluid environment in a neuromechanical model of lamprey swimming. Proc Natl Acad Sci U S A 107:19832-7
Gelman, S; Cohen, A H; Sanovich, E (2009) Developmental changes in the ultrastructure of the lamprey lateral line nerve during metamorphosis. J Morphol 270:815-24
Buchholz, James H J; Clark, Richard P; Smits, Alexander J (2008) Thrust performance of unsteady propulsors using a novel measurement system, and corresponding wake patterns. Exp Fluids 45:461-472

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