Rectifying and sluggish: Outer hair cells as regulators rather than amplifiers
| Autor: | Anna Vavakou, Marcel van der Heijden |
|---|---|
| Přispěvatelé: | Neurosciences |
| Rok vydání: | 2021 |
| Předmět: |
Physics
0303 health sciences Receptor potential 01 natural sciences Sensory Systems Basilar Membrane Cochlea 03 medical and health sciences Basilar membrane Hair Cells Auditory Outer Hair Cells Vestibular medicine.anatomical_structure Acoustic Stimulation Organ of Corti 0103 physical sciences medicine Biophysics sense organs Hair cell Tonotopy 010301 acoustics Transduction (physiology) 030304 developmental biology DC bias |
| Zdroj: | Hearing Research, 423:108367. Elsevier |
| ISSN: | 1878-5891 0378-5955 |
| Popis: | In the cochlea, mechano-electrical transduction is preceded by dynamic range compression. Outer hair cells (OHCs) and their voltage dependent length changes, known as electromotility, play a central role in this compression process, but the exact mechanisms are poorly understood. Here we review old and new experimental findings and show that (1) just audible high-frequency tones evoke an ∼1-microvolt AC receptor potential in basal OHCs; (2) any mechanical amplification of soft high-frequency tones by OHC motility would have an adverse effect on their audibility; (3) having a higher basolateral K+ conductance, while increasing the OHC corner frequency, does not boost the magnitude of the high-frequency AC receptor potential; (4) OHC receptor currents display a substantial rectified (DC) component; (5) mechanical DC responses (baseline shifts) to acoustic stimuli, while insignificant on the basilar membrane, can be comparable in magnitude to AC responses when recorded in the organ of Corti, both in the apex and the base. In the basal turn, the DC component may even exceed the AC component, lending support to Dallos’ suggestion that both apical and basal OHCs display a significant degree of rectification. We further show that (6) low-intensity cochlear traveling waves, by virtue of their abrupt transition from fast to slow propagation, are well suited to transport high-frequency energy with minimal losses (∼2-dB loss for 16-kHz tones in the gerbil); (7) a 90-dB, 16-kHz tone, if transmitted without loss to its tonotopic place, would evoke a destructive displacement amplitude of 564 nm. We interpret these findings in a framework in which local dissipation is regulated by OHC motility. This article is part of the Special Issue Outer hair cell Edited by Joseph Santos-Sacchi and Kumar Navaratnam. |
| Databáze: | OpenAIRE |
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