Evidence of Piezoelectric Resonance in Isolated Outer Hair Cells

摘要: Our results demonstrate high-frequency electrical resonances in outer hair cells (OHCs) exhibiting features analogous to classical piezoelectric transducers. The fundamental (first) resonance frequency averaged fn ∼ 13 kHz (Q 1.7). Higher-order were also observed. To obtain these results, OHCs positioned a custom microchamber and subjected stimulating electric fields along the axis of cell (1–100 kHz, 4–16 mV/80 μm). Electrodes embedded side walls used voltage-divider configuration estimate admittance top portion cell-loaded chamber (containing electromotile lateral wall) relative lower basal plasma membrane). This ratio exhibited resonance-like tuning. Resonance was detected independently using secondary 1-MHz radio-frequency interrogation signal applied transversely across diameter. revealed changes transverse impedance modulated by axial stimulus. Modulation particularly pronounced near resonant frequencies. our study isolated from apical region guinea pig cochlea, that responds exclusively low-frequency acoustic stimuli. In this sense, we observed vitro at least an order magnitude higher (ultrasonic) than best physiological same under stimuli vivo. These data further support theory OHC function, implicate piezoelectricity broad-band electromechanical behavior underlying mammalian cochlear function.