Data and code from: Viscoelasticity explains fast adaptation in the auditory amplifiers of mammals

When we hear, sound-induced deflections of our sensory outer-hair-cell
bundles are transduced into receptor currents. These receptor currents
drive the cochlear amplifier, which is required for our ear's high
sensitivity, broad dynamic range, and sharp frequency selectivity.
Adaptation maintains the sensitivity of receptor currents to bundle
deflections, but the mechanisms underlying adaptation in outer-hair-cell
bundles remain under debate, and how adaptation works at physiologically
relevant frequencies is unclear. We propose a mechanism for the fastest
components of adaptation, based on viscoelastic adaptation elements. To
evaluate this proposal, we fit a mathematical model of an outer-hair-cell
bundle with viscoelastic adaptation elements to twelve independent
experimental observations. We validate the model by successfully
predicting an observation not used for fitting --- how much
receptor-current sensitivity is maintained by fast adaptation. The
experimentally constrained model predicts the effects of fast adaptation
for physiologically relevant frequencies. We show that there is
considerable deflection-current hysteresis, the receptor current can lead
the bundle deflection to a large extent (up to 61° phase lead), and that
fast adaptation greatly high-pass filters the receptor current. Owing to
viscoelastic fast adaptation, the dynamic range of the outer-hair-cell
bundle depends on the stimulus frequency. These predictions and others are
experimentally testable. Because viscoelastic fast adaptation
substantially affects receptor-current sensitivity, hysteresis, phase
leads, high-pass filtering, and dynamic range, we expect viscoelastic fast
adaptation to greatly impact the cochlear amplifier and hearing. Here, we
provide the experimental data used to constrain the mathematical models
and the modeling code.