Chaotic Dynamics Enhance the Sensitivity of Inner Ear Hair Cells

Hair cells of the auditory and vestibular systems are capable of detecting sounds that induce sub-nanometer vibrations of the hair bundle, below the stochastic noise levels of the surrounding fluid. Furthermore, the auditory system exhibits a highly rapid response time, in the sub-millisecond regime...

Descripción completa

Detalles Bibliográficos
Autores principales: Faber, Justin, Bozovic, Dolores
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6895040/
https://www.ncbi.nlm.nih.gov/pubmed/31804578
http://dx.doi.org/10.1038/s41598-019-54952-y
_version_ 1783476507680702464
author Faber, Justin
Bozovic, Dolores
author_facet Faber, Justin
Bozovic, Dolores
author_sort Faber, Justin
collection PubMed
description Hair cells of the auditory and vestibular systems are capable of detecting sounds that induce sub-nanometer vibrations of the hair bundle, below the stochastic noise levels of the surrounding fluid. Furthermore, the auditory system exhibits a highly rapid response time, in the sub-millisecond regime. We propose that chaotic dynamics enhance the sensitivity and temporal resolution of the hair bundle response, and we provide experimental and theoretical evidence for this effect. We use the Kolmogorov entropy to measure the degree of chaos in the system and the transfer entropy to quantify the amount of stimulus information captured by the detector. By varying the viscosity and ionic composition of the surrounding fluid, we are able to experimentally modulate the degree of chaos observed in the hair bundle dynamics in vitro. We consistently find that the hair bundle is most sensitive to a stimulus of small amplitude when it is poised in the weakly chaotic regime. Further, we show that the response time to a force step decreases with increasing levels of chaos. These results agree well with our numerical simulations of a chaotic Hopf oscillator and suggest that chaos may be responsible for the high sensitivity and rapid temporal response of hair cells.
format Online
Article
Text
id pubmed-6895040
institution National Center for Biotechnology Information
language English
publishDate 2019
publisher Nature Publishing Group UK
record_format MEDLINE/PubMed
spelling pubmed-68950402019-12-11 Chaotic Dynamics Enhance the Sensitivity of Inner Ear Hair Cells Faber, Justin Bozovic, Dolores Sci Rep Article Hair cells of the auditory and vestibular systems are capable of detecting sounds that induce sub-nanometer vibrations of the hair bundle, below the stochastic noise levels of the surrounding fluid. Furthermore, the auditory system exhibits a highly rapid response time, in the sub-millisecond regime. We propose that chaotic dynamics enhance the sensitivity and temporal resolution of the hair bundle response, and we provide experimental and theoretical evidence for this effect. We use the Kolmogorov entropy to measure the degree of chaos in the system and the transfer entropy to quantify the amount of stimulus information captured by the detector. By varying the viscosity and ionic composition of the surrounding fluid, we are able to experimentally modulate the degree of chaos observed in the hair bundle dynamics in vitro. We consistently find that the hair bundle is most sensitive to a stimulus of small amplitude when it is poised in the weakly chaotic regime. Further, we show that the response time to a force step decreases with increasing levels of chaos. These results agree well with our numerical simulations of a chaotic Hopf oscillator and suggest that chaos may be responsible for the high sensitivity and rapid temporal response of hair cells. Nature Publishing Group UK 2019-12-05 /pmc/articles/PMC6895040/ /pubmed/31804578 http://dx.doi.org/10.1038/s41598-019-54952-y Text en © The Author(s) 2019 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
spellingShingle Article
Faber, Justin
Bozovic, Dolores
Chaotic Dynamics Enhance the Sensitivity of Inner Ear Hair Cells
title Chaotic Dynamics Enhance the Sensitivity of Inner Ear Hair Cells
title_full Chaotic Dynamics Enhance the Sensitivity of Inner Ear Hair Cells
title_fullStr Chaotic Dynamics Enhance the Sensitivity of Inner Ear Hair Cells
title_full_unstemmed Chaotic Dynamics Enhance the Sensitivity of Inner Ear Hair Cells
title_short Chaotic Dynamics Enhance the Sensitivity of Inner Ear Hair Cells
title_sort chaotic dynamics enhance the sensitivity of inner ear hair cells
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6895040/
https://www.ncbi.nlm.nih.gov/pubmed/31804578
http://dx.doi.org/10.1038/s41598-019-54952-y
work_keys_str_mv AT faberjustin chaoticdynamicsenhancethesensitivityofinnerearhaircells
AT bozovicdolores chaoticdynamicsenhancethesensitivityofinnerearhaircells