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Evidence of Hyperacusis in Adult Rats Following Non-traumatic Sound Exposure

Manipulations that enhance neuroplasticity may inadvertently create opportunities for maladaptation. We have previously used passive exposures to non-traumatic white noise to open windows of plasticity in the adult rat auditory cortex and induce frequency-specific functional reorganizations of the t...

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Autores principales: Thomas, Maryse E., Guercio, Gerson D., Drudik, Kristina M., de Villers-Sidani, Étienne
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6819503/
https://www.ncbi.nlm.nih.gov/pubmed/31708754
http://dx.doi.org/10.3389/fnsys.2019.00055
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author Thomas, Maryse E.
Guercio, Gerson D.
Drudik, Kristina M.
de Villers-Sidani, Étienne
author_facet Thomas, Maryse E.
Guercio, Gerson D.
Drudik, Kristina M.
de Villers-Sidani, Étienne
author_sort Thomas, Maryse E.
collection PubMed
description Manipulations that enhance neuroplasticity may inadvertently create opportunities for maladaptation. We have previously used passive exposures to non-traumatic white noise to open windows of plasticity in the adult rat auditory cortex and induce frequency-specific functional reorganizations of the tonotopic map. However, similar reorganizations in the central auditory pathway are thought to contribute to the generation of hearing disorders such as tinnitus and hyperacusis. Here, we investigate whether noise-induced reorganizations are accompanied by electrophysiological or behavioral evidence of tinnitus or hyperacusis in adult Long-Evans rats. We used a 2-week passive exposure to moderate-intensity (70 dB SPL) broadband white noise to reopen a critical period for spectral tuning such that a second 1-week exposure to 7 kHz tone pips produced an expansion of the 7 kHz frequency region in the primary auditory cortex (A1). We demonstrate for the first time that this expansion also takes place in the ventral auditory field (VAF). Sound exposure also led to spontaneous and sound-evoked hyperactivity in the anterior auditory field (AAF). Rats were assessed for behavioral evidence of tinnitus or hyperacusis using gap and tone prepulse inhibition of the acoustic startle response. We found that sound exposure did not affect gap-prepulse inhibition. However, sound exposure led to an improvement in prepulse inhibition when the prepulse was a 7 kHz tone, showing that exposed rats had enhanced sensorimotor gating for the exposure frequency. Together, our electrophysiological and behavioral results provide evidence of hyperacusis but not tinnitus in sound-exposed animals. Our findings demonstrate that periods of prolonged noise exposure may open windows of plasticity that can also be understood as windows of vulnerability, potentially increasing the likelihood for maladaptive plasticity to take place.
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spelling pubmed-68195032019-11-08 Evidence of Hyperacusis in Adult Rats Following Non-traumatic Sound Exposure Thomas, Maryse E. Guercio, Gerson D. Drudik, Kristina M. de Villers-Sidani, Étienne Front Syst Neurosci Neuroscience Manipulations that enhance neuroplasticity may inadvertently create opportunities for maladaptation. We have previously used passive exposures to non-traumatic white noise to open windows of plasticity in the adult rat auditory cortex and induce frequency-specific functional reorganizations of the tonotopic map. However, similar reorganizations in the central auditory pathway are thought to contribute to the generation of hearing disorders such as tinnitus and hyperacusis. Here, we investigate whether noise-induced reorganizations are accompanied by electrophysiological or behavioral evidence of tinnitus or hyperacusis in adult Long-Evans rats. We used a 2-week passive exposure to moderate-intensity (70 dB SPL) broadband white noise to reopen a critical period for spectral tuning such that a second 1-week exposure to 7 kHz tone pips produced an expansion of the 7 kHz frequency region in the primary auditory cortex (A1). We demonstrate for the first time that this expansion also takes place in the ventral auditory field (VAF). Sound exposure also led to spontaneous and sound-evoked hyperactivity in the anterior auditory field (AAF). Rats were assessed for behavioral evidence of tinnitus or hyperacusis using gap and tone prepulse inhibition of the acoustic startle response. We found that sound exposure did not affect gap-prepulse inhibition. However, sound exposure led to an improvement in prepulse inhibition when the prepulse was a 7 kHz tone, showing that exposed rats had enhanced sensorimotor gating for the exposure frequency. Together, our electrophysiological and behavioral results provide evidence of hyperacusis but not tinnitus in sound-exposed animals. Our findings demonstrate that periods of prolonged noise exposure may open windows of plasticity that can also be understood as windows of vulnerability, potentially increasing the likelihood for maladaptive plasticity to take place. Frontiers Media S.A. 2019-10-23 /pmc/articles/PMC6819503/ /pubmed/31708754 http://dx.doi.org/10.3389/fnsys.2019.00055 Text en Copyright © 2019 Thomas, Guercio, Drudik and de Villers-Sidani. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Neuroscience
Thomas, Maryse E.
Guercio, Gerson D.
Drudik, Kristina M.
de Villers-Sidani, Étienne
Evidence of Hyperacusis in Adult Rats Following Non-traumatic Sound Exposure
title Evidence of Hyperacusis in Adult Rats Following Non-traumatic Sound Exposure
title_full Evidence of Hyperacusis in Adult Rats Following Non-traumatic Sound Exposure
title_fullStr Evidence of Hyperacusis in Adult Rats Following Non-traumatic Sound Exposure
title_full_unstemmed Evidence of Hyperacusis in Adult Rats Following Non-traumatic Sound Exposure
title_short Evidence of Hyperacusis in Adult Rats Following Non-traumatic Sound Exposure
title_sort evidence of hyperacusis in adult rats following non-traumatic sound exposure
topic Neuroscience
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6819503/
https://www.ncbi.nlm.nih.gov/pubmed/31708754
http://dx.doi.org/10.3389/fnsys.2019.00055
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