The Orchestration of the respiratory rhythm: how to integrate multiple modulators and cellular properties

Abstract

Event Abstract Back to Event The Orchestration of the respiratory rhythm: how to integrate multiple modulators and cellular properties Jan M. Ramirez1* 1 University of Chicago, Department of Organismal Biology and Anatomy, United States It is well established that the pre-Bötzinger Complex plays a critical role in mammalian respiratory rhythm generation. This relatively small network is located within the ventrolateral medulla and it gives rise to different types of inspiratory activities that contribute to the generation of eupnea, sighs and gasps. The respiratory rhythm emerges through the interaction between various synaptic and intrinsic membrane properties. Non-NMDA, NMDA and metabotropic glutamatergic mechanisms provide an important excitatory synaptic drive, which is counterbalanced by prominent glycinergic and GABAergic inhibitory mechanisms. Synaptic inhibition plays equally important roles in establishing the different phases of respiration and in regulating the relative contribution of intrinsic membrane properties, of which bursting or pacemaker properties received considerable attention. In this study, we review the mechanisms of respiratory rhythm generation, but we will also emonstrate how multi-array recordings from slices containing the pre-Bötzinger Complex reveal important new insights into the dynamics of respiratory ensemble activity. Neurons exhibiting intrinsic bursting and pacemaker properties are characterized by a higher instantaneous discharge frequency during the burst and during baseline activity. On average, these neurons tend to lead an inspiratory cycle. But to our surprise, these neurons showed considerable cycle-bycycle variability. On some cycles, pacemaker neurons discharged before, on other cycles they discharged relatively late in the inspiratory phase. We therefore propose that the respiratory rhythm is assembled in a cycle-by-cycle manner. A given neuron can lead and potentially initiate an inspiration during a given cycle, while being a follower and amplifier of synaptic mechanisms in subsequent cycles. We speculate that the dynamic assembling of respiratory network activity imbues the respiratory network with an enormous flexibility, which is necessary to adjust to continuous changes in metabolic and behavioural conditions. Conference: 3rd Mediterranean Conference of Neuroscience , Alexandria, Egypt, 13 Dec - 16 Dec, 2009. Presentation Type: Oral Presentation Topic: Symposium 05 – Interactions of synaptic and intrinsic properties in rhythmic motor activities Citation: Ramirez JM (2009). The Orchestration of the respiratory rhythm: how to integrate multiple modulators and cellular properties. Front. Neurosci. Conference Abstract: 3rd Mediterranean Conference of Neuroscience . doi: 10.3389/conf.neuro.01.2009.16.030 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: 19 Nov 2009; Published Online: 19 Nov 2009. * Correspondence: Jan M Ramirez, University of Chicago, Department of Organismal Biology and Anatomy, Chicago, United States, jramire@midway.uchicago.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 Jan M Ramirez Google Jan M Ramirez Google Scholar Jan M Ramirez PubMed Jan M Ramirez 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.