Adaptation in phasic auditory units of the frog midbrain is sensitive to changes in stimulus frequency and ear of input

Abstract

Event Abstract Back to Event Adaptation in phasic auditory units of the frog midbrain is sensitive to changes in stimulus frequency and ear of input Abhilash Ponnath1, Kim Hoke2 and Hamilton Farris1* 1 Louisiana St. University Health Sciences Center, Neuroscience, United States 2 Colorado State University, Biology, United States Neural adaptation, a reduction in response to a constant or maintained stimulus, is an important mechanism for detecting stimulus change. Contributing to stimulus change detection is the fact that neural adaptation is often stimulus specific: adaptation to a particular stimulus reduces excitability to only a subset of stimuli, while the ability to respond to other stimuli is unaffected. Phasic cells (e.g., responding to stimulus onset), with their fast adaptation, are considered good candidates for detecting the most rapid changes in natural auditory scenes, as they adapt quickly to the initial presentation of a stimulus and do not require adaptation buildup from many repeated stimulus presentations. Our study uses in vivo, single unit recordings to show that the fast and complete adaptation of phasic auditory units in the frog torus semicircularis is specific to stimulus frequency and ear of input. In response to an instantaneous frequency step in a 200 ms tone, 28% of cells exhibit frequency specific adaptation (FSA) based on relative frequency change (delta-f = +/-16%). FSA is not limited to frequency steps, however, as adaptation is also overcome during continuous frequency modulated stimuli. When temporal gaps in tones produce frequency transients, FSA cells outperform non-FSA cells in gap detection. When gaps in noise produce only temporal cues, however, gap detection is identical in the two cell classes. The results suggest that adaptation is separated for peripheral (e.g., frequency) channels, which we tested directly using dichotic stimuli. In 45% of binaural phasic units, adaptation was ear specific: adaptation to stimulation of one ear does not affect responses to stimulation of the other ear. Thus, adaptation exhibits specificity during processing of frequency and lateralization at the level of the midbrain. This mechanism could be employed to detect stimulus change within and between acoustic sources in rapidly changing complex acoustic environments. Acknowledgements KLH and HEF were supported in part by a Grass Faculty Fellowship at the Marine Biological Laboratory, Woods Hole, MA (2009). AP and HEF were supported by NIH grant P20RR016816 (to N. Bazan). Keywords: adaptation, auditory scene, chorus, critical band Conference: Tenth International Congress of Neuroethology, College Park. Maryland USA, United States, 5 Aug - 10 Aug, 2012. Presentation Type: Poster Presentation (see alternatives below as well) Topic: Sensory: Audition Citation: Ponnath A, Hoke K and Farris H (2012). Adaptation in phasic auditory units of the frog midbrain is sensitive to changes in stimulus frequency and ear of input. Conference Abstract: Tenth International Congress of Neuroethology. doi: 10.3389/conf.fnbeh.2012.27.00157 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. Hamilton Farris, Louisiana St. University Health Sciences Center, Neuroscience, New Orleans, Louisiana, 70112, United States, hfarri@lsuhsc.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 Abhilash Ponnath Kim Hoke Hamilton Farris Google Abhilash Ponnath Kim Hoke Hamilton Farris Google Scholar Abhilash Ponnath Kim Hoke Hamilton Farris PubMed Abhilash Ponnath Kim Hoke Hamilton Farris 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.