Up-states are rare in awake auditory cortex

Abstract

Event Abstract Back to Event Up-states are rare in awake auditory cortex Tomas Hromadka1*, Michael DeWeese2 and Anthony M. Zador1 1 Cold Spring Harbor Laboratory, United States 2 University of California at Berkeley, United States Up and down states—depolarized and hyperpolarized plateaus of membrane potential—have attracted a considerable attention, as they have been suggested to underlie persistent activity in cortical networks. The persistent activity, in turn, has been hypothesized to play a role in such interesting processes as short-term (working) memory, or attention. Large, persistent changes in membrane potential can also occur in a response to behavioral state changes, or sensory stimulation. Up and down states have been described in frontal cortical areas, somatosensory, visual, olfactory areas, striatum, etc. However, the nature and prevalence of up states have not been well studied in the auditory cortex. We have previously found that membrane potential in the auditory cortex consists of bumps, i.e. brief, stereotyped excursions of membrane potential. By contrast, ’canonical’ up-states are usually thought of as stereotyped plateaus at which the membrane potential remains for a prolonged period (hundreds of milliseconds to seconds). Answering the question of prevalence of up-states is complicated by the fact that there is no universally agreed upon definition of what constitutes up and down states. To characterize the nature and prevalence of up-states in the awake auditory cortex, we used whole-cell patch-clamp recording techniques to record intracellular activity of neurons (n=20) in auditory cortex of awake head-fixed rats (Sprague-Dawley, postnatal day 24-30). We have generalized the definition of up-states, and defined several membrane potential thresholds. We found that long up-states were rare in awake auditory cortex, with only 4 %of up-states longer than 200 ms. Most neurons displayed only brief up-states (bumps) and spent most of the time near their resting potential, typically spending less than 4 %of recording time in up-states longer than 200 ms. It is unclear why auditory cortex would differ from other sensory areas in terms of subthreshold dynamics. Whether the apparent lack of up-states in the auditory cortex reflects an inherent difference in cortical networks between auditory and other sensory areas, or is simply caused by difference in nomenclature (and bumps are simply brief up-states) remains an open question. Conference: Computational and Systems Neuroscience 2010, Salt Lake City, UT, United States, 25 Feb - 2 Mar, 2010. Presentation Type: Poster Presentation Topic: Poster session III Citation: Hromadka T, DeWeese M and Zador AM (2010). Up-states are rare in awake auditory cortex. Front. Neurosci. Conference Abstract: Computational and Systems Neuroscience 2010. doi: 10.3389/conf.fnins.2010.03.00270 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: 05 Mar 2010; Published Online: 05 Mar 2010. * Correspondence: Tomas Hromadka, Cold Spring Harbor Laboratory, New York, United States, hromadka@cshl.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 Tomas Hromadka Michael DeWeese Anthony M Zador Google Tomas Hromadka Michael DeWeese Anthony M Zador Google Scholar Tomas Hromadka Michael DeWeese Anthony M Zador PubMed Tomas Hromadka Michael DeWeese Anthony M Zador 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.