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Mechanical Amplification Exhibited by Quiescent Saccular Hair Bundles
Spontaneous oscillations exhibited by free-standing hair bundles from the Bullfrog sacculus suggest the existence of an active process that might underlie the exquisite sensitivity of the sacculus to mechanical stimulation. However, this spontaneous activity is suppressed by coupling to an overlying...
Autores principales: | , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
The Biophysical Society
2015
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4286608/ https://www.ncbi.nlm.nih.gov/pubmed/25564852 http://dx.doi.org/10.1016/j.bpj.2014.11.009 |
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author | Roongthumskul, Yuttana Bozovic, Dolores |
author_facet | Roongthumskul, Yuttana Bozovic, Dolores |
author_sort | Roongthumskul, Yuttana |
collection | PubMed |
description | Spontaneous oscillations exhibited by free-standing hair bundles from the Bullfrog sacculus suggest the existence of an active process that might underlie the exquisite sensitivity of the sacculus to mechanical stimulation. However, this spontaneous activity is suppressed by coupling to an overlying membrane, which applies a large mechanical load on the bundle. How a quiescent hair bundle utilizes its active process is still unknown. We studied the dynamics of motion of individual hair bundles under different offsets in the bundle position, and observed the occurrence of spikes in hair-bundle motion, associated with the generation of active work. These mechanical spikes can be evoked by a sinusoidal stimulus, leading to an amplified movement of the bundle with respect to the passive response. Amplitude gain reached as high as 100-fold at small stimulus amplitudes. Amplification of motion decreased with increasing amplitude of stimulation, ceasing at ∼6–12 pN stimuli. Results from numerical simulations suggest that the adaptation process, mediated by myosin 1c, is not required for the production of mechanical spikes. |
format | Online Article Text |
id | pubmed-4286608 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2015 |
publisher | The Biophysical Society |
record_format | MEDLINE/PubMed |
spelling | pubmed-42866082015-07-10 Mechanical Amplification Exhibited by Quiescent Saccular Hair Bundles Roongthumskul, Yuttana Bozovic, Dolores Biophys J Cell Biophysics Spontaneous oscillations exhibited by free-standing hair bundles from the Bullfrog sacculus suggest the existence of an active process that might underlie the exquisite sensitivity of the sacculus to mechanical stimulation. However, this spontaneous activity is suppressed by coupling to an overlying membrane, which applies a large mechanical load on the bundle. How a quiescent hair bundle utilizes its active process is still unknown. We studied the dynamics of motion of individual hair bundles under different offsets in the bundle position, and observed the occurrence of spikes in hair-bundle motion, associated with the generation of active work. These mechanical spikes can be evoked by a sinusoidal stimulus, leading to an amplified movement of the bundle with respect to the passive response. Amplitude gain reached as high as 100-fold at small stimulus amplitudes. Amplification of motion decreased with increasing amplitude of stimulation, ceasing at ∼6–12 pN stimuli. Results from numerical simulations suggest that the adaptation process, mediated by myosin 1c, is not required for the production of mechanical spikes. The Biophysical Society 2015-01-06 /pmc/articles/PMC4286608/ /pubmed/25564852 http://dx.doi.org/10.1016/j.bpj.2014.11.009 Text en © 2015 The Authors http://creativecommons.org/licenses/by-nc-nd/3.0/ This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/). |
spellingShingle | Cell Biophysics Roongthumskul, Yuttana Bozovic, Dolores Mechanical Amplification Exhibited by Quiescent Saccular Hair Bundles |
title | Mechanical Amplification Exhibited by Quiescent Saccular Hair Bundles |
title_full | Mechanical Amplification Exhibited by Quiescent Saccular Hair Bundles |
title_fullStr | Mechanical Amplification Exhibited by Quiescent Saccular Hair Bundles |
title_full_unstemmed | Mechanical Amplification Exhibited by Quiescent Saccular Hair Bundles |
title_short | Mechanical Amplification Exhibited by Quiescent Saccular Hair Bundles |
title_sort | mechanical amplification exhibited by quiescent saccular hair bundles |
topic | Cell Biophysics |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4286608/ https://www.ncbi.nlm.nih.gov/pubmed/25564852 http://dx.doi.org/10.1016/j.bpj.2014.11.009 |
work_keys_str_mv | AT roongthumskulyuttana mechanicalamplificationexhibitedbyquiescentsaccularhairbundles AT bozovicdolores mechanicalamplificationexhibitedbyquiescentsaccularhairbundles |