The role of tectorial membrane stiffness and viscosity on traveling waves and resonance

2015 ◽  
Author(s):  
Shirin Farrahi ◽  
Jonathan B. Sellon ◽  
Roozbeh Ghaffari ◽  
Dennis M. Freeman
Keyword(s):  
Traveling Waves ◽  
Tectorial Membrane ◽  
Membrane Stiffness

scholarly journals The Role of Prestin in the Generation of Electrically Evoked Otoacoustic Emissions in Mice

2008 ◽  
Vol 99 (4) ◽  
pp. 1607-1615 ◽  
Author(s):  
Markus Drexl ◽  
Marcia M. Mellado Lagarde ◽  
Jian Zuo ◽  
Andrei N. Lukashkin ◽  
Ian J. Russell
Keyword(s):  
Hair Cells ◽  
Otoacoustic Emissions ◽  
Temporal Structure ◽  
Organ Of Corti ◽  
Outer Hair Cells ◽  
Tectorial Membrane ◽  
Wild Type ◽  
Short Delay ◽  
Delay Component

Electrically evoked otoacoustic emissions are sounds emitted from the inner ear when alternating current is injected into the cochlea. Their temporal structure consists of short- and long-delay components and they have been attributed to the motile responses of the sensory-motor outer hair cells of the cochlea. The nature of these motile responses is unresolved and may depend on either somatic motility, hair bundle motility, or both. The short-delay component persists after almost complete elimination of outer hair cells. Outer hair cells are thus not the sole generators of electrically evoked otoacoustic emissions. We used prestin knockout mice, in which the motor protein prestin is absent from the lateral walls of outer hair cells, and Tecta ΔENT/ΔENT mice, in which the tectorial membrane, a structure with which the hair bundles of outer hair cells normally interact, is vestigial and completely detached from the organ of Corti. The amplitudes and delay spectra of electrically evoked otoacoustic emissions from Tecta ΔENT/ΔENT and Tecta +/+ mice are very similar. In comparison with prestin +/+ mice, however, the short-delay component of the emission in prestin −/− mice is dramatically reduced and the long-delay component is completely absent. Emissions are completely suppressed in wild-type and Tecta ΔENT/ΔENT mice at low stimulus levels, when prestin-based motility is blocked by salicylate. We conclude that near threshold, the emissions are generated by prestin-based somatic motility.

scholarly journals Learning poly-synaptic paths with traveling waves

2021 ◽  
Vol 17 (2) ◽  
pp. e1008700
Author(s):  
Yoshiki Ito ◽  
Taro Toyoizumi
Keyword(s):  
Synaptic Plasticity ◽  
Traveling Waves ◽  
Shortest Paths ◽  
Computational Approach ◽  
Input Output ◽  
Nonlinear Input ◽  
Output Mapping ◽  
Exclusive Or ◽  
The Brain

Traveling waves are commonly observed across the brain. While previous studies have suggested the role of traveling waves in learning, the mechanism remains unclear. We adopted a computational approach to investigate the effect of traveling waves on synaptic plasticity. Our results indicate that traveling waves facilitate the learning of poly-synaptic network paths when combined with a reward-dependent local synaptic plasticity rule. We also demonstrate that traveling waves expedite finding the shortest paths and learning nonlinear input/output mapping, such as exclusive or (XOR) function.

scholarly journals Persistence and propagation in periodic reaction-diffusion models

2014 ◽  
Vol 45 (3) ◽  
pp. 217-228 ◽  
Author(s):  
Francois Hamel ◽  
Lionel Roques
Keyword(s):  
Traveling Waves ◽  
Reaction Diffusion ◽  
Diffusion Models ◽  
Species Persistence ◽  
Periodic Reaction ◽  
Periodic Environments

In this paper, we consider Fisher-KPP reaction-diffusion models in periodic environments. We review some results on the questions of species persistence and propagation of pulsating traveling waves. We study the role of the heterogeneities and the fragmentation of the environment on the persistence and on the propagation speeds.

Role of the Tectorial Membrane Revealed by Otoacoustic Emissions Recorded From Wild-Type and Transgenic TectaΔENT/ΔENT Mice

2004 ◽  
Vol 91 (1) ◽  
pp. 163-171 ◽  
Author(s):  
Andrei N. Lukashkin ◽  
Victoria A. Lukashkina ◽  
P. Kevin Legan ◽  
Guy P. Richardson ◽  
Ian J. Russell
Keyword(s):  
Otoacoustic Emissions ◽  
Low Frequency ◽  
Tectorial Membrane ◽  
Local Minima ◽  
Wild Type ◽  
Distortion Product ◽  
Growth Functions ◽  
In The Wild ◽  
Surrounding Fluid

Distortion product otoacoustic emissions (DPOAE) were recorded from wild-type mice and mutant TectaΔ ENT/Δ ENT mice with detached tectorial membranes (TM) under combined ketamine/xylaxine anesthesia. In TectaΔ ENT/Δ ENT mice, DPOAEs could be detected above the noise floor only when the levels of the primary tones exceeded 65 dB SPL. DPOAE amplitude decreased with increasing frequency of the primaries in TectaΔ ENT/Δ ENT mice. This was attributed to hair cell excitation via viscous coupling to the surrounding fluid and not by interaction with the TM as in the wild-type mice. Local minima and corresponding phase transitions in the DPOAE growth functions occurred at higher DPOAE levels in wild-type than in TectaΔ ENT/Δ ENT mice. In less-sensitive TectaΔ ENT/Δ ENT mice, the position of the local minima varied nonsystematically with frequency or no minima were observed. A bell-like dependence of the DPOAE amplitude on the ratio of the primaries was recorded in both wild-type and TectaΔ ENT/Δ ENT mice. However, the pattern of this dependence was different in the wild-type and TectaΔ ENT/Δ ENT mice, an indication that the bell-like shape of the DPOAE was produced by a combination of different mechanisms. A nonlinear low-frequency resonance, revealed by nonmonotonicity of the phase behavior, was seen in the wild-type but not in TectaΔ ENT/Δ ENT mice.

scholarly journals The Unusual Midwinter Warming in the Southern Hemisphere Stratosphere 2002: A Comparison to Northern Hemisphere Phenomena

2005 ◽  
Vol 62 (3) ◽  
pp. 603-613 ◽  
Author(s):  
Kirstin Krüger ◽  
Barbara Naujokat ◽  
Karin Labitzke
Keyword(s):  
Detailed Analysis ◽  
Southern Hemisphere ◽  
Northern Hemisphere ◽  
Traveling Waves ◽  
Dominant Role ◽  
Polar Vortex ◽  
Planetary Waves ◽  
Wave Forcing ◽  
Northern Winter

Abstract A strong midwinter warming occurred in the Southern Hemisphere (SH) stratosphere in September 2002. Based on experiences from the Northern Hemisphere (NH), this event can be defined as a major warming with a breakdown of the polar vortex in midwinter, which has never been detected so far in the SH since observations began at the earliest in the 1940s. Minor midwinter warmings occasionally occurred in the SH, but a strong interannual variability, as is present in winter and spring in the NH, has been explicitly associated with the spring reversals. A detailed analysis of this winter reveals the dominant role of eastward-traveling waves and their interaction with quasi-stationary planetary waves forced in the troposphere. Such wave forcing, finally leading to the sudden breakdown of the vortex, is a familiar feature of the northern winter stratosphere. Therefore, the unusual development of this Antarctic winter is described in the context of more than 50 Arctic winters, concentrating on winters with similar wave perturbations. The relevance of preconditioning of major warmings by traveling and quasi-stationary planetary waves is discussed for both hemispheres.

scholarly journals The Role of Membrane Stiffness and Actin Turnover on the Force Exerted by DRG Lamellipodia

2012 ◽  
Vol 102 (11) ◽  
pp. 2451-2460 ◽  
Author(s):  
Ladan Amin ◽  
Erika Ercolini ◽  
Rajesh Shahapure ◽  
Elisa Migliorini ◽  
Vincent Torre
Keyword(s):  
Actin Turnover ◽  
Membrane Stiffness

scholarly journals The biomechanical role of extra-axonemal structures in shaping the flagellar beat of Euglena gracilis

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Giancarlo Cicconofri ◽  
Giovanni Noselli ◽  
Antonio DeSimone
Keyword(s):  
Traveling Waves ◽  
Euglena Gracilis ◽  
Coupled System ◽  
Flagellar Beat ◽  
Planar Shapes

We propose and discuss a model for flagellar mechanics inEuglena gracilis. We show that the peculiar non-planar shapes of its beating flagellum, dubbed 'spinning lasso', arise from the mechanical interactions between two of its inner components, namely, the axoneme and the paraflagellar rod. The spontaneous shape of the axoneme and the resting shape of the paraflagellar rod are incompatible. Thus, the complex non-planar configurations of the coupled system emerge as the energetically optimal compromise between the two antagonistic components. The model is able to reproduce the experimentally observed flagellar beats and the characteristic geometric signature of spinning lasso, namely, traveling waves of torsion with alternating sign along the length of the flagellum.

scholarly journals Tectorial Membrane Stiffness Gradients

2007 ◽  
Vol 93 (6) ◽  
pp. 2265-2276 ◽  
Author(s):  
Claus-Peter Richter ◽  
Gulam Emadi ◽  
Geoffrey Getnick ◽  
Alicia Quesnel ◽  
Peter Dallos
Keyword(s):  
Tectorial Membrane ◽  
Membrane Stiffness
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