title: Gating of Acoustic Transducer Channels Is Shaped by Biomechanical Filter Processes.
abstract: Mechanoelectrical transduction of acoustic signals is the fundamental process for hearing in all ears across the animal kingdom. Here, we performed in vivo laser-vibrometric and electrophysiological measurements at the transduction site in an insect ear (Mecopoda elongata) to relate the biomechanical tonotopy along the hearing organ to the frequency tuning of the corresponding sensory cells. Our mechanical and electrophysiological map revealed a biomechanical filter process that considerably sharpens the neuronal response. We demonstrate that the channel gating, which acts on chordotonal stretch receptor neurons, is based on a mechanical directionality of the sound-induced motion. Further, anatomical studies of the transduction site support our finding of a stimulus-relevant tilt. In conclusion, we were able to show, in an insect ear, that directionality of channel gating considerably sharpens the neuronal frequency selectivity at the peripheral level and have identified a mechanism that enhances frequency discrimination in tonotopically organized ears.
authors.affiliation: Institute of Cell Biology and Neuroscience, Goethe University, 60438 Frankfurt am Main, Germany.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Hummel
authors.affiliation: Department of Zoology, University of Cambridge, CB2 3EJ Cambridge, United Kingdom, and.
authors.forename: Stefan
authors.initials: S
authors.lastname: Schöneich
authors.affiliation: Institute of Cell Biology and Neuroscience, Goethe University, 60438 Frankfurt am Main, Germany.
authors.forename: Manfred
authors.initials: M
authors.lastname: Kössl
authors.affiliation: Institute of Cell Biology and Neuroscience, Goethe University, 60438 Frankfurt am Main, Germany.
authors.forename: Jan
authors.initials: J
authors.lastname: Scherberich
authors.affiliation: Department of Zoology, University of Cambridge, CB2 3EJ Cambridge, United Kingdom, and.
authors.forename: Berthold
authors.initials: B
authors.lastname: Hedwig
authors.affiliation: Max-Planck-Institute for Biophysics, 60438 Frankfurt am Main, Germany.
authors.forename: Simone
authors.initials: S
authors.lastname: Prinz
authors.affiliation: Institute of Cell Biology and Neuroscience, Goethe University, 60438 Frankfurt am Main, Germany, nowotny@bio.uni-frankfurt.de.
authors.forename: Manuela
authors.initials: M
authors.lastname: Nowotny
mesh_terms: D000161:Acoustic Stimulation / Q000379:methods*; D000818:Animals; D001696:Biomechanical Phenomena / Q000502:physiology; D005260:Female; D006135:Gryllidae; D006198:Hair Cells, Auditory / Q000502:physiology*; D015640:Ion Channel Gating / Q000502:physiology*; D008297:Male; D008465:Mechanoreceptors / Q000502:physiology*
keywords: acoustic signal transduction; frequency tuning; insects; transduction channel