Cochlear Fluid Space Dimensions for Six Species Derived From Reconstructions of Three‐Dimensional Magnetic Resonance Images

Thorne, Marc C.; Salt, Alec N.; DeMott, John E.; Henson, Miriam M.; Henson, O. W.; Gewalt, Sally L.

doi:10.1097/00005537-199910000-00021

Cited by 225 publications

(184 citation statements)

References 10 publications

Supporting

Mentioning

173

Contrasting

Unclassified

Order By: Relevance

“…In the mouse compared to other species, the endolymph volume is large relative to perilymph volume. From prior work by Thorne et al, endolymph to perilymph ratios in the cochlea were 1:7 in guinea pig and 1:3 in mouse (Thorne et al 1999). These measurements were performed using the cochlea only, not the vestibular organs, where an even larger percentage of the fluid consists of endolymph.…”

Section: The Fluid Sampled In These Experiments Is Perilymph Not Endmentioning

confidence: 86%

Systemic Lipopolysaccharide Compromises the Blood-Labyrinth Barrier and Increases Entry of Serum Fluorescein into the Perilymph

Hirose

Hartsock

Johnson

et al. 2014

JARO

Self Cite

View full text Add to dashboard Cite

The blood vessels that supply the inner ear form a barrier between the blood and the inner ear fluids to control the exchange of solutes, protein, and water. This barrier, called the blood-labyrinth barrier (BLB) is analogous to the blood-brain barrier (BBB), which plays a critical role in limiting the entry of inflammatory and infectious agents into the central nervous system. We have developed an in vivo method to assess the functional integrity of the BLB by injecting sodium fluorescein into the systemic circulation of mice and measuring the amount of fluorescein that enters perilymph in live animals. In these experiments, perilymph was collected from control and experimental mice in sequential samples taken from the posterior semicircular canal approximately 30 min after systemic fluorescein administration. Perilymph fluorescein concentrations in control mice were compared with perilymph fluorescein concentrations after lipopolysaccharide (LPS) treatment (1 mg/kg IP daily for 2 days). The concentration of perilymphatic fluorescein, normalized to serum fluorescein, was significantly higher in LPS-treated mice compared to controls. In order to assess the contributions of perilymph and endolymph in our inner ear fluid samples, sodium ion concentration of the inner ear fluid was measured using ion-selective electrodes. The sampled fluid from the posterior semicircular canal demonstrated an average sodium concentration of 145 mM, consistent with perilymph. These experiments establish a novel technique to assess the functional integrity of the BLB using quantitative methods and to provide a comparison of the BLB to the BBB.

show abstract

Section: The Fluid Sampled In These Experiments Is Perilymph Not Endmentioning

confidence: 86%

Systemic Lipopolysaccharide Compromises the Blood-Labyrinth Barrier and Increases Entry of Serum Fluorescein into the Perilymph

Hirose

Hartsock

Johnson

et al. 2014

JARO

Self Cite

View full text Add to dashboard Cite

show abstract

“…The geometry of the cochlear model was based on dimensions published in the literature (Thorne et al 1999) similar to the actual curved geometry of the cochlea, including the OW, RW, SV, ST, and BM. Figure 2 shows the structure of the cochlear model with detailed dimensions and boundary conditions.…”

Section: Model Geometry and Fe Meshmentioning

confidence: 99%

Inertial Bone Conduction: Symmetric and Anti-Symmetric Components

Kim

Homma²,

Puria

2011

JARO

View full text Add to dashboard Cite

Of the two pathways through which we hear, air conduction (AC) and bone conduction (BC), the fundamental mechanisms of the BC pathway remain poorly understood, despite their clinical significance. A finite element model of a human middle ear and cochlea was developed to gain insight into the mechanisms of BC hearing. The characteristics of various cochlear response quantities, including the basilar membrane (BM) vibration, oval-window (OW) and round-window (RW) volume velocities, and cochlear fluid pressures were examined for BC as well as AC excitations. These responses were tuned and validated against available experimental data from the literature. BC excitations were simulated in the form of rigid body vibrations of the surrounding bony structures in the x, y, and z orthogonal directions. The results show that the BM vibration characteristics are essentially invariant regardless of whether the excitation is via BC, independent of excitation direction, or via AC. This at first appeared surprising because the cochlear fluid pressures differ considerably depending on the excitation mode. Analysis reveals that the BM vibration responds only to the lower-magnitude anti-symmetric slow-wave cochlear fluid pressure component and not to the symmetric fast-wave pressure component, which dominates the magnitude of the total pressure field. This antisymmetric fluid pressure is produced by the antisymmetric component of the window volume velocities. As a result, the BM is effectively driven by the anti-symmetric component of the OW and RW volume velocities, irrespective of the type of excitation. Middle ear modifications that alter the anti-symmetric component of the OW and RW volume velocities corroborate this assertion. The current results provide further clarification of the mechanisms underlying Békésy's "paradoxical motion" concept.

show abstract

“…The material property values in Table 1 were taken from a number of sources [Smith 1968;Lim and Steele 2002;Miller 1985;Steele et al 1995;Karavitaki 2002] and the dimensions in Table 2 were from the anatomical measurements for gerbil cochlea [Sokolich et al 1976;Greenwood 1990;Dannhof et al 1991;Cohen et al 1992;Edge et al 1998;Thorne et al 1999].…”

Section: Resultsmentioning

confidence: 99%

Frequency and spatial response of basilar membrane vibration in a three-dimensional gerbil cochlear model

Yoon

Puria

Steele

2007

JOMMS

View full text Add to dashboard Cite

The cochlea of the inner ear presents severe difficulties for measurement and computation, and controversy exists on virtually every issue. However, the first in vivo measurement of the spatial distribution of elastic response for a fixed frequency is now available. This work compares experimental results and those from calculations with a three-dimensional model. This is a standard model that consists of a long, fluid-filled box with a partition, a portion of which is the elastic BM (basilar membrane). The BM velocity at a fixed point as a function of frequency and the spatial response for a fixed frequency are calculated. The model includes the three-dimensional viscous fluid and the pectinate zone of the elastic orthotropic BM with the gerbil dimensional and material property variation along its length. The radial BM thickness variation is, however, replaced by an equivalent constant thickness. The active process is represented by adding the motility of the OHCs (outer hair cells) to the passive model with a feed-forward approximation of the organ of Corti (OC). Asymptotic and numerical methods combined with Fourier series expansions are used to provide a fast and efficient iterative procedure that requires about one second on a desktop computer for obtaining the BM response for a given frequency. Our threedimensional model results show the following agreement with the experimental measurements in various situations: (i) for map of place of maximum response to frequency -excellent; (ii) for the response at a fixed point as a function of frequency -excellent for amplitude, poor for phase; (iii) for the spatial distribution for fixed frequency -fair for amplitude and excellent for phase. The discrepancies in (ii) and (iii) remain to be clarified.

show abstract

Cochlear Fluid Space Dimensions for Six Species Derived From Reconstructions of Three‐Dimensional Magnetic Resonance Images

Abstract: The quantification of cochlear fluid spaces provided by this study will enable the more accurate calculation of drug and other solute movements in fluids of the inner ear during experimental or clinical manipulations.

Cited by 225 publications

References 10 publications

Systemic Lipopolysaccharide Compromises the Blood-Labyrinth Barrier and Increases Entry of Serum Fluorescein into the Perilymph

Systemic Lipopolysaccharide Compromises the Blood-Labyrinth Barrier and Increases Entry of Serum Fluorescein into the Perilymph

Inertial Bone Conduction: Symmetric and Anti-Symmetric Components

Frequency and spatial response of basilar membrane vibration in a three-dimensional gerbil cochlear model

Contact Info

Product

Resources

About