Filtering Due to the Inner Hair-Cell Membrane Properties and its Relation to the Phase-Locking Limit in Cochlear Nerve Fibres

1986 ◽  
pp. 199-207 ◽  
Author(s):  
Ian Russell ◽  
Alan Palmer
Keyword(s):  
Cell Membrane ◽  
Hair Cell ◽  
Phase Locking ◽  
Cochlear Nerve ◽  
Membrane Properties ◽  
Inner Hair Cell ◽  
Nerve Fibres

Modeling the Mechanics of Tethers Pulled From the Cochlear Outer Hair Cell Membrane

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
Kristopher R. Schumacher ◽  
Aleksander S. Popel ◽  
Bahman Anvari ◽  
William E. Brownell ◽  
Alexander A. Spector
Keyword(s):  
Cell Membrane ◽  
Hair Cell ◽  
Outer Hair Cell ◽  
Lateral Wall ◽  
Outer Hair Cells ◽  
The Body ◽  
Computational Method ◽  
Membrane Properties ◽  
Bending Modulus ◽  
Sound Amplification

Cell membrane tethers are formed naturally (e.g., in leukocyte rolling) and experimentally to probe membrane properties. In cochlear outer hair cells, the plasma membrane is part of the trilayer lateral wall, where the membrane is attached to the cytoskeleton by a system of radial pillars. The mechanics of these cells is important to the sound amplification and frequency selectivity of the ear. We present a modeling study to simulate the membrane deflection, bending, and interaction with the cytoskeleton in the outer hair cell tether pulling experiment. In our analysis, three regions of the membrane are considered: the body of a cylindrical tether, the area where the membrane is attached and interacts with the cytoskeleton, and the transition region between the two. By using a computational method, we found the shape of the membrane in all three regions over a range of tether lengths and forces observed in experiments. We also analyze the effects of biophysical properties of the membrane, including the bending modulus and the forces of the membrane adhesion to the cytoskeleton. The model’s results provide a better understanding of the mechanics of tethers pulled from cell membranes.

scholarly journals Cell membrane organization is important for inner hair cell MET-channel gating

2018 ◽  
Author(s):  
Thomas Effertz ◽  
Alexandra L. Scharr ◽  
Anthony J. Ricci
Keyword(s):  
Cell Membrane ◽  
Hair Cell ◽  
Channel Gating ◽  
Membrane Organization ◽  
Inner Hair Cell

scholarly journals Quantitative Analysis of the Membrane Affinity of Local Anesthetics Using a Model Cell Membrane

Membranes ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 579
Author(s):  
Wanjae Choi ◽  
Hyunil Ryu ◽  
Ahmed Fuwad ◽  
Seulmini Goh ◽  
Chaoge Zhou ◽  
...  
Keyword(s):  
Cell Membrane ◽  
Local Anesthetics ◽  
Electrophysiological Study ◽  
Local Area ◽  
Membrane Properties ◽  
Dominant Factor ◽  
Free Standing ◽  
Membrane Affinity ◽  
Conformational Effects ◽  
Model Protein

Local anesthesia is a drug that penetrates the nerve cell membrane and binds to the voltage gate sodium channel, inhibiting the membrane potential and neurotransmission. It is mainly used in clinical uses to address the pain of surgical procedures in the local area. Local anesthetics (LAs), however, can be incorporated into the membrane, reducing the thermal stability of the membrane as well as altering membrane properties such as fluidity, permeability, and lipid packing order. The effects of LAs on the membrane are not yet fully understood, despite a number of previous studies. In particular, it is necessary to analyze which is the more dominant factor, the membrane affinity or the structural perturbation of the membrane. To analyze the effects of LAs on the cell membrane and compare the results with those from model membranes, morphological analysis and 50% inhibitory concentration (IC50) measurement of CCD-1064sk (fibroblast, human skin) membranes were carried out for lidocaine (LDC) and tetracaine (TTC), the most popular LAs in clinical use. Furthermore, the membrane affinity of the LAs was quantitatively analyzed using a colorimetric polydiacetylene assay, where the color shift represents their distribution in the membrane. Further, to confirm the membrane affinity and structural effects of the membranes, we performed an electrophysiological study using a model protein (gramicidin A, gA) and measured the channel lifetime of the model protein on the free-standing lipid bilayer according to the concentration of each LA. Our results show that when LAs interact with cell membranes, membrane affinity is a more dominant factor than steric or conformational effects of the membrane.

scholarly journals Inner hair cell stereocilia are embedded in the tectorial membrane

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Pierre Hakizimana ◽  
Anders Fridberger
Keyword(s):  
Electron Microscopy ◽  
Hair Cell ◽  
Mechanical Stimulation ◽  
Hair Cells ◽  
Viscous Drag ◽  
Tectorial Membrane ◽  
Inner Hair Cell ◽  
Inner Hair Cells ◽  
Inward Currents

AbstractMammalian hearing depends on sound-evoked displacements of the stereocilia of inner hair cells (IHCs), which cause the endogenous mechanoelectrical transducer channels to conduct inward currents of cations including Ca2+. Due to their presumed lack of contacts with the overlaying tectorial membrane (TM), the putative stimulation mechanism for these stereocilia is by means of the viscous drag of the surrounding endolymph. However, despite numerous efforts to characterize the TM by electron microscopy and other techniques, the exact IHC stereocilia-TM relationship remains elusive. Here we show that Ca2+-rich filamentous structures, that we call Ca2+ ducts, connect the TM to the IHC stereocilia to enable mechanical stimulation by the TM while also ensuring the stereocilia access to TM Ca2+. Our results call for a reassessment of the stimulation mechanism for the IHC stereocilia and the TM role in hearing.

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