کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1957299 1057878 2005 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Evidence of Piezoelectric Resonance in Isolated Outer Hair Cells
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
Evidence of Piezoelectric Resonance in Isolated Outer Hair Cells
چکیده انگلیسی

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

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: - Volume 88, Issue 3, March 2005, Pages 2257–2265
نویسندگان
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