Behavioral adaption to a changing environment is critical for an animal's survival. How well the brain can modify its functional properties based on experience essentially defines the limits of behavioral adaptation. In adult animals the extent to which experience shapes brain function has not been fully explored. Moreover, the perceptual consequences of experience-induced changes in the brains of adults remain unknown. Here we show that the tonotopic map in the primary auditory cortex of adult rats living with low-level ambient noise underwent a dramatic reorganization. Behaviorally, chronic noise-exposure impaired fine, but not coarse pitch discrimination. When tested in a noisy environment, the noise-exposed rats performed as well as in a quiet environment whereas the control rats performed poorly. This suggests that noise-exposed animals had adapted to living in a noisy environment. Behavioral pattern analyses revealed that stress or distraction engendered by the noisy background could not account for the poor performance of the control rats in a noisy environment. A reorganized auditory map may therefore have served as the neural substrate for the consistent performance of the noise-exposed rats in a noisy environment.
Keywords: experience-dependent plasticity, neural plasticity, tonotopic map, auditory operant task, auditory cortex, pitch discrimination, adaptation, rats
Citation: Zheng W (2012) Auditory map reorganization and pitch discrimination in adult rats chronically exposed to low-level ambient noise. Front. Syst. Neurosci. 6:65. doi: 10.3389/fnsys.2012.00065
Received: 06 April 2012; Accepted: 27 August 2012;
Published online: 11 September 2012.
Edited by:Raphael Pinaud, Northwestern University, USA
Reviewed by:Robert N. S. Sachdev, Yale School of Medicine, USA
Copyright © 2012 Zheng. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in other forums, provided the original authors and source are credited and subject to any copyright notices concerning any third-party graphics etc.
*Correspondence: Weimin Zheng, The Neurosciences Institute, 10640 John J. Hopkins Dr., San Diego, CA, USA. e-mail: email@example.com