Neural mechanisms underlying the collision avoidance behavior in the African Clawed frog tadpole

Abstract

Event Abstract Back to Event Neural mechanisms underlying the collision avoidance behavior in the African Clawed frog tadpole Arseny S. Khakhalin1, David Koren1 and Carlos D. Aizenman1* 1 Brown University, Department of Neuroscience, United States The tadpole of the African Clawed frog Xenopus laevis is a broadly used experimental preparation in developmental and cellular neuroscience research. Premetamorphic Xenopus tadpoles are known to be suction feeders and do not track prey, however they do exhibit a range of orienting behaviors such as schooling, collision avoidance, and escape responses. It is assumed that in the tadpole most of these behaviors are mediated by the optic tectum, which is a structure that serves as a higher multisensory integrative center in these animals, and which is homologous to the mammalian superior colliculus. While a lot is known about the development and cellular organization of the optic tectal circuitry, it is still unclear how the information coming from the environment is encoded in the activity of the tectal cells, and how the necessary computations are performed in this structure. Here we describe a collision avoidance behavior in Xenopus laevis tadpoles, and through a series of sequentially reduced preparations we illustrate the mechanisms underlying this behavior. In the first set of experiments we presented freely swimming animals with computer-generated two-dimensional objects, approaching them at either collision or non-collision trajectories. By tracking the animals, and by reconstructing the geometry of approaches, and the projections computer-generated objects would have on the retinas, we identified temporal and spatial properties of those stimuli that successfully triggered the collision avoidance response. Then, in the second set of experiments, we presented partially immobilized animals with computer generated stimuli that were projected on a microfiber screen placed near one of the eyes. The stimuli were specifically designed so that their retinal projections mimicked our reconstructions from the first set of experiments. A high speed camera was used to track the movements of the tail, and we show that different stimuli induced different sub-variants of the avoidance motor program, with different latencies, and probabilities. Finally, we presented the same set of stimuli to fully immobilized animals, recording either the spiking activity, or the inhibitory and excitatory postsynaptic currents from individual cells in the optic tectum. We show that the spatial and temporal computations that are required for the identification of behaviorally relevant stimuli start at the level of the ganglion cells in the retina, and continue in the optic tectum, where they rely on the temporal interaction between excitatory and inhibitory drive to the tectal cells. Keywords: collision avoidance, Frog, navigation, optic tectum, superior colliculus, Vision, Xenopus Conference: Tenth International Congress of Neuroethology, College Park. Maryland USA, United States, 5 Aug - 10 Aug, 2012. Presentation Type: Poster (but consider for participant symposium and student poster award) Topic: Orientation and Navigation Citation: Khakhalin AS, Koren D and Aizenman CD (2012). Neural mechanisms underlying the collision avoidance behavior in the African Clawed frog tadpole. Conference Abstract: Tenth International Congress of Neuroethology. doi: 10.3389/conf.fnbeh.2012.27.00168 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: 27 Apr 2012; Published Online: 07 Jul 2012. * Correspondence: Dr. Carlos D Aizenman, Brown University, Department of Neuroscience, Providence, RI, 02912, United States, Carlos_Aizenman@brown.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 Arseny S Khakhalin David Koren Carlos D Aizenman Google Arseny S Khakhalin David Koren Carlos D Aizenman Google Scholar Arseny S Khakhalin David Koren Carlos D Aizenman PubMed Arseny S Khakhalin David Koren Carlos D Aizenman 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.