Ren 2002 — Longitudinal pattern of basilar membrane vibration in the sensitive cochlea
CORRECTION FLAG: The STRC topic file cites this as “Ren T (2002) Nat Neurosci 5:169.” That citation is incorrect. The verified Ren T 2002 paper is in PNAS 99(26):17101–17106, not Nature Neuroscience. No Ren T 2002 Nat Neurosci paper with those details was found in PubMed. The “Nat Neurosci 5:169” citation may refer to a different paper or may be a phantom citation.
TL;DR. Using scanning laser interferometry in sensitive gerbil cochlea, Ren captured the first instantaneous waveform of BM vibration: 16 kHz tone shows up to 6π phase delay over <1000 µm; wave is spatially restricted (~600 µm detectable), compressively nonlinear, with shorter wavelength than predicted. Confirms traveling wave existence.
Key finding. The BM traveling wave is real, spatially restricted, and nonlinear. This paper is context for the TM displacement estimates — the traveling wave drives TM displacement, so BM mechanics set an upper bound on TM input. However, this paper does NOT provide TM displacement values in nm; it measures BM vibration phase and magnitude.
Numbers that matter
| Parameter | Value | Units | Source location | Conditions |
|---|---|---|---|---|
| Phase delay over BM length measured | up to 6π | radians | Abstract | 16 kHz tone, <1000 µm gerbil basal turn |
| Detectable BM response range (low level) | ~600 | µm | Abstract | Low-level 16 kHz tone |
| Peak BM sensitivity (sensitive cochlea vs postmortem) | >30 | dB | Fig 3 | Nonlinear amplification at CF |
| BM velocities | frequency-dependent | nm/s | Figs 1–4 | 10–90 dB SPL, 8–24 kHz |
| Absolute BM displacement in nm | Not directly reported | — | — | Phase and magnitude normalized; not in nm |
Not useful for TM displacement. This paper establishes that BM traveling wave exists in gerbil basal turn. It does not report TM displacement, does not report apical-turn measurements (apical was less well characterized in 2002), and does not address the 5–30 nm range for TM at 60 dB SPL.
Limitations
- Gerbil basal turn only; mouse apical data (where h02 is most relevant) not in this study.
- Normalized phase/magnitude; no absolute displacement in nm without cross-referencing stapes/ossicular input.
- 2002 technology; more recent OCT measurements (Gao 2014, Ren lab subsequent work) provide better spatial resolution.
Connections
[source]tectorial-membrane — corrects “Ren 2002 Nat Neurosci 5:169” → “Ren 2002 PNAS 99:17101”; not a TM displacement source[see-also]2026-04-25-gao-2014-organ-corti-oct-vibration — more recent OCT vibration measurements, same lab lineage[see-also]2026-04-25-ghaffari-2007-tm-traveling-wave-pnas — TM-specific wave propagation[applies]STRC Piezoelectric TM Bioelectronic Amplifier