Work

Tonotopic Relationships Reveal the Charge Density Varies along the Lateral Wall of Outer Hair Cells

Year: 2012

Type: article

Abstract: Outer hair cells amplify and improve the frequency selectivity of sound within the mammalian cochlea through a sound-evoked receptor potential that induces an electromechanical response in their lateral wall membrane. We experimentally show that the membrane area and linear membrane capacitance of outer hair cells increases exponentially with the electrically evoked voltage-dependent charge movement (Q(T)) and peak membrane capacitance (C(peak)). We determine the size of the different functional regions (e.g., lateral wall, synaptic basal pole) of the polarized cells from the tonotopic relationships. We then establish that Q(T) and C(peak) increase with the logarithm of the lateral wall area (A(LW)) and determine from the functions that the charge (σ(LW,) pC/μm(2)) and peak (ρ(LW,) pF/μm(2)) densities vary inversely with A(LW) (σ(LW) = 1.3/A(LW) and ρ(LW) = 9/A(LW)). This shows contrary to conventional wisdom that σ(LW) and ρ(LW) are not constant along the length of an individual outer hair cell.

Source: Biophysical Journal

DOI: 10.1016/j.bpj.2012.04.054

Authors: Christian Corbitt, Federica Farinelli, William E. Brownell, Brenda Farrell

Institution: Baylor College of Medicine

Language: English

Topic: Hearing, Cochlea, Tinnitus, Genetics

Subfield: Sensory Systems

Field: Neuroscience

Domain: Life Sciences

Open Access status: hybrid

Estimated APC paid: $3,000

Funder: National Institute on Deafness and Other Communication Disorders