Adaptive control of six-legged locomotion

Abstract

Event Abstract Back to Event Adaptive control of six-legged locomotion Einat Fuchs1*, Amir Ayali2, 3, Philip Holmes1, 4, Tim Kiemel5 and Izhak David2 1 Princeton University, Dept. of Mechanical & Aerospace Engineering, United States 2 Tel Aviv Univresity, Dept. of Zoology, Israel 3 Tel Aviv University, Sagol school of Neuroscience, Israel 4 Princeton University, Program in Applied and Computational Mathematics, United States 5 University of Maryland, Department of Kinesiology, United States There is major interest in understanding how neurophysiology and body mechanics interact, both internally and with the external environment, to allow adaptive control of animal locomotion. Theoretical predictions suggest that the degree to which sensory feedback is used for coordinating movement depends on the specific properties of the movement, primarily speed, and the complexity and predictability of the environment. We study interactions between the motor and sensory systems that account for the generation of coordinated locomotion in the American cockroach (Periplaneta americana), an animal that is renowned for its rapid and stable running. In order to do so, we combine neurophysiological experiments with simulations of stochastic models of coupled oscillators to analyze the recorded data and estimate underlying physiological parameters. We record activity from leg motor-neurons in fully- and semi- deafferented preparations, and study the integration of sensory information to the centrally-generated motor patterns. Recorded data are compared with behavioral experiments in free-walking preparations as well as with computer simulation-generated activity. Our findings suggest that, in the absence of sensory feedback, a coordinated pattern can be elicited from the deafferented motor centers driving the different legs, indicating a primarily feed-forward control scheme. However, when we gradually allow the addition of limited and controlled proprioceptive information, from single moving legs, we note a speed-dependent stabilization of the centrally-generated pattern. This is manifested in stabilization of phase differences between activities recorded from different motor nerves, following individual steps of a single intact leg. In addition, we study the shape and strength of the coupling among the segmental circuits and suggest an asymmetric coupling map: we find that descending ipsilateral coupling is stronger than ascending coupling, while contra-lateral coupling in both the meso- and meta-thoracic ganglia appears to be symmetrical. Movement-related information from the front legs passes more slowly but in a more phasic-precise manner than that from the hind legs, selectively strengthening the inherent rhythmic pattern and modulating local perturbations in order to achieve a stable walking gait. Keywords: central pattern generator, Insects, intersegmental coordination, Locomotion, proprioceptive feedback Conference: Tenth International Congress of Neuroethology, College Park. Maryland USA, United States, 5 Aug - 10 Aug, 2012. Presentation Type: Invited Symposium (only for people who have been invited to a particular symposium) Topic: Motor Systems Citation: Fuchs E, Ayali A, Holmes P, Kiemel T and David I (2012). Adaptive control of six-legged locomotion. Conference Abstract: Tenth International Congress of Neuroethology. doi: 10.3389/conf.fnbeh.2012.27.00036 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 29 Apr 2012; Published Online: 07 Jul 2012. * Correspondence: Dr. Einat Fuchs, Princeton University, Dept. of Mechanical & Aerospace Engineering, Princeton, NJ, 08544, United States, einat@princeton.edu Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Einat Fuchs Amir Ayali Philip Holmes Tim Kiemel Izhak David Google Einat Fuchs Amir Ayali Philip Holmes Tim Kiemel Izhak David Google Scholar Einat Fuchs Amir Ayali Philip Holmes Tim Kiemel Izhak David PubMed Einat Fuchs Amir Ayali Philip Holmes Tim Kiemel Izhak David Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.