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Updated: Jul 14, 2026
06:16
Electrophysiological Measurements from a Moth Olfactory System
Published on: March 29, 2011
Otoacoustic emissions from insect ears having just one auditory neuron
Manfred Kössl1, Frank Coro, Ernst-August Seyfarth
1Institut für Zellbiologie und Neurowissenschaft, J.W. Goethe-Universität, Siesmayerstrasse 70, 60323 Frankfurt am Main, Germany. koessl@bio.uni-frankfurt.de
Summary
Researchers detected high-frequency distortion-product emissions from a moth's auditory organ. These emissions, similar to those in mammals, suggest a single nonlinear source may be responsible for complex sound processing in hearing.
Area of Science:
- Bioacoustics
- Auditory Neuroscience
- Insect Physiology
Background:
- Sensitive hearing organs utilize nonlinear mechanical sound processing, generating distortion-product otoacoustic emissions (DPOAEs).
- DPOAEs are also observed in insect tympanal organs, suggesting conserved mechanisms for sound detection.
Purpose of the Study:
- To investigate high-frequency DPOAEs in the tympanal organ of the notodontid moth, Ptilodon cucullina.
- To explore the nonlinear properties and potential sources of these emissions in an auditory system with a single receptor neuron.
Main Methods:
- Evoking and recording high-frequency DPOAEs (up to 95 kHz) from Ptilodon cucullina tympanal organs.
- Analyzing emission growth functions, including notch depth and phase shifts, across different stimulus levels.
- Assessing the effect of ethyl ether on DPOAEs to probe the vulnerability of the underlying nonlinear source.
Main Results:
- High-frequency DPOAEs (2f1-f2) were detected, reaching sound levels above 40 dB SPL.
- Emission growth functions exhibited a prominent notch (20 dB depth) and phase shift (119 degrees) around 60-70 dB SPL, separating low- and high-level components.
- Ethyl ether application shifted growth functions by ~20 dB, indicating physiological vulnerability of the emission source.
Conclusions:
- The findings suggest that a single nonlinear source, potentially the sole receptor cell, could account for the observed nonlinear amplification in the moth's auditory organ.
- This challenges the notion that multiple cellular interactions are necessary for complex nonlinear processing in hearing.
- Further research is needed to clarify the role of accessory cells in the nonlinear properties of the scolopidial hearing organ.
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