Locomotor network performance controls future network output in Xenopus frog tadpoles

Abstract

Event Abstract Back to Event Locomotor network performance controls future network output in Xenopus frog tadpoles HongYan Zhang1, Stephen P. Currie1, Laurence Picton1 and Keith T. Sillar1* 1 University of St Andrews, School of Biology, United Kingdom Most rhythm generating neural networks, often called CPGs, produce an output that can vary between two extremes; from fast intense to slow weak activity. How does the relative intensity of network activity influence network performance? We recently described a correlation between the duration of fictive swimming episodes in post-hatchling Xenopus frog tadpoles and the interval from the preceding episode. We reported an underlying minute-long post swim hyperpolarization that involves up-regulation of Na+/K+ pumps. This usAHP acts as a short term memory of CPG performance (Zhang & Sillar, 2012). Here we address in more detail: i) the effect of preceding activity on the basic parameters of swimming; ii) the impact of the usAHP on the firing properties of spinal neurons; and iii) whether the usAHP persists into later stages of development. i) We find that post swim-interval determines the duration of subsequent swim episodes and that short intervals lead to short episodes. During these shortened second episodes swimming occurs at a significantly lower initial frequency and both burst durations and duty cycles are reduced compared to episode 1. ii) Whole cell patch clamp recordings were made from spinal CPG neurons to explore the impact of the usAHP following either swimming or high frequency firing induced by depolarizing current steps. No change in conductance was detected during the usAHP. However, both the amplitude of the action potentials and spike accommodation properties were affected. For example, the delay to the first spike of a train was longer during a usAHP suggesting that SHAL-type voltage-dependent K+ conductances are de-inactivated. iii) Finally we report that the usAHP is present in later free swimming stages; the properties of the usAHP are similar at these stages but it is recorded in a higher proportion of neurons than at earlier stages of development. Acknowledgements Supported by a BBSRC grant (to KTS) and a BBSRC studentship (to SPC). References Zhang, H-Y. & Sillar (2012) Current Biology 22, 526-531. Keywords: Locomotion, modulation, network plasticity, short term memory, sodium pump, Swimming 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) Topic: Motor Systems Citation: Zhang H, Currie SP, Picton L and Sillar KT (2012). Locomotor network performance controls future network output in Xenopus frog tadpoles. Conference Abstract: Tenth International Congress of Neuroethology. doi: 10.3389/conf.fnbeh.2012.27.00114 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: 25 Apr 2012; Published Online: 07 Jul 2012. * Correspondence: Prof. Keith T Sillar, University of St Andrews, School of Biology, Scotland, United Kingdom, kts1@st-andrews.ac.uk 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 HongYan Zhang Stephen P Currie Laurence Picton Keith T Sillar Google HongYan Zhang Stephen P Currie Laurence Picton Keith T Sillar Google Scholar HongYan Zhang Stephen P Currie Laurence Picton Keith T Sillar PubMed HongYan Zhang Stephen P Currie Laurence Picton Keith T Sillar 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.