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A Brain without Brakes: Reduced Inhibition Is Associated with Enhanced but Dysregulated Plasticity in the Aged Rat Auditory Cortex

During early developmental windows known as critical periods (CPs) of plasticity, passive alterations in the quality and quantity of sensory inputs are sufficient to induce profound and long-lasting distortions in cortical sensory representations. With CP closure, those representations are stabilize...

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Autores principales: Cisneros-Franco, J. Miguel, Ouellet, Lydia, Kamal, Brishna, de Villers-Sidani, Etienne
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Society for Neuroscience 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6140119/
https://www.ncbi.nlm.nih.gov/pubmed/30225357
http://dx.doi.org/10.1523/ENEURO.0051-18.2018
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author Cisneros-Franco, J. Miguel
Ouellet, Lydia
Kamal, Brishna
de Villers-Sidani, Etienne
author_facet Cisneros-Franco, J. Miguel
Ouellet, Lydia
Kamal, Brishna
de Villers-Sidani, Etienne
author_sort Cisneros-Franco, J. Miguel
collection PubMed
description During early developmental windows known as critical periods (CPs) of plasticity, passive alterations in the quality and quantity of sensory inputs are sufficient to induce profound and long-lasting distortions in cortical sensory representations. With CP closure, those representations are stabilized, a process requiring the maturation of inhibitory networks and the maintenance of sufficient GABAergic tone in the cortex. In humans and rodents, however, cortical inhibition progressively decreases with advancing age, raising the possibility that the regulation of plasticity could be altered in older individuals. Here we tested the hypothesis that aging results in a destabilization of sensory representations and maladaptive dysregulated plasticity in the rat primary auditory cortex (A1). Consistent with this idea, we found that passive tone exposure is sufficient to distort frequency tuning in the A1 of older but not younger adult rats. However, we also found that these passive distortions decayed rapidly, indicating an ongoing instability of A1 tuning in the aging cortex. These changes were associated with a decrease in GABA neurotransmitter concentration and a reduction in parvalbumin and perineuronal net expression in the cortex. Finally, we show that artificially increasing GABA tone in the aging A1 is sufficient to restore representational stability and improve the retention of learning.
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spelling pubmed-61401192018-09-17 A Brain without Brakes: Reduced Inhibition Is Associated with Enhanced but Dysregulated Plasticity in the Aged Rat Auditory Cortex Cisneros-Franco, J. Miguel Ouellet, Lydia Kamal, Brishna de Villers-Sidani, Etienne eNeuro New Research During early developmental windows known as critical periods (CPs) of plasticity, passive alterations in the quality and quantity of sensory inputs are sufficient to induce profound and long-lasting distortions in cortical sensory representations. With CP closure, those representations are stabilized, a process requiring the maturation of inhibitory networks and the maintenance of sufficient GABAergic tone in the cortex. In humans and rodents, however, cortical inhibition progressively decreases with advancing age, raising the possibility that the regulation of plasticity could be altered in older individuals. Here we tested the hypothesis that aging results in a destabilization of sensory representations and maladaptive dysregulated plasticity in the rat primary auditory cortex (A1). Consistent with this idea, we found that passive tone exposure is sufficient to distort frequency tuning in the A1 of older but not younger adult rats. However, we also found that these passive distortions decayed rapidly, indicating an ongoing instability of A1 tuning in the aging cortex. These changes were associated with a decrease in GABA neurotransmitter concentration and a reduction in parvalbumin and perineuronal net expression in the cortex. Finally, we show that artificially increasing GABA tone in the aging A1 is sufficient to restore representational stability and improve the retention of learning. Society for Neuroscience 2018-09-05 /pmc/articles/PMC6140119/ /pubmed/30225357 http://dx.doi.org/10.1523/ENEURO.0051-18.2018 Text en Copyright © 2018 Cisneros-Franco et al. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International license (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution and reproduction in any medium provided that the original work is properly attributed.
spellingShingle New Research
Cisneros-Franco, J. Miguel
Ouellet, Lydia
Kamal, Brishna
de Villers-Sidani, Etienne
A Brain without Brakes: Reduced Inhibition Is Associated with Enhanced but Dysregulated Plasticity in the Aged Rat Auditory Cortex
title A Brain without Brakes: Reduced Inhibition Is Associated with Enhanced but Dysregulated Plasticity in the Aged Rat Auditory Cortex
title_full A Brain without Brakes: Reduced Inhibition Is Associated with Enhanced but Dysregulated Plasticity in the Aged Rat Auditory Cortex
title_fullStr A Brain without Brakes: Reduced Inhibition Is Associated with Enhanced but Dysregulated Plasticity in the Aged Rat Auditory Cortex
title_full_unstemmed A Brain without Brakes: Reduced Inhibition Is Associated with Enhanced but Dysregulated Plasticity in the Aged Rat Auditory Cortex
title_short A Brain without Brakes: Reduced Inhibition Is Associated with Enhanced but Dysregulated Plasticity in the Aged Rat Auditory Cortex
title_sort brain without brakes: reduced inhibition is associated with enhanced but dysregulated plasticity in the aged rat auditory cortex
topic New Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6140119/
https://www.ncbi.nlm.nih.gov/pubmed/30225357
http://dx.doi.org/10.1523/ENEURO.0051-18.2018
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